Input: Properties like macro- and microstructure, mechanical properties like hardness and its course in the layers, high-cycle fatigue resistance in bending and fatigue damage mechanisms were investigated with the emphasis on fatigue crack initiation process evaluated using scanning electron microscopy.

Properties

microstructure

mechanical properties

process

hardness

fatigue

fatigue damage

fatigue

bending

scanning electron microscopy


Input: The results indicated that surface additive laser welded layers of a high quality can be reached.

surface

quality

additive

be

welded


Input: On the other hand, some drop of fatigue resistance and endurance limit was observed, affected by surface defects–small welding imperfections Ti-6Al-4V and AlSi5 wires were used for wire and arc additive manufacturing using the direct current cold metal transfer welding.

fatigue

endurance limit

surface defects

imperfections

welding

wire and arc additive manufacturing

cold metal transfer


Input: Ti alloy was deposited first, and then Al alloy was deposited on the Ti layer.

Ti alloy

Al alloy

Ti

layer


Input: A small amount of Ti alloy was melted when the first layer of Al alloy was deposited due to the low heat input.

Ti alloy

Al alloy

melted

heat

layer


Input: A component composed of Ti/Al dissimilar alloys can be produced.

component

dissimilar alloys

be


Input: The interface layer between the Ti and Al alloys included a continuous layer and a discontinuous layer.

interface

Ti

Al alloys

layer

layer


Input: The continuous layer was composed of Ti7Al5Si12, and the discontinuous layer consisted of Ti (Al1-xSix) 3.

layer

layer

Ti


Input: Element Si was rich in the continuous layer.

Element

layer


Input: The hardness and modulus of the interface layer were between those of Al and Ti alloys.

hardness

interface

Al

Ti alloys


Input: The average tensile strength of the component was 79 MPa.

average

MPa

strength

component


Input: The fracture located at the interface layer.

fracture

interface


Input: A finite element model is developed to calculate the heat propagation of a circular thin-walled component fabricated in gas metal arc welding based additive manufacturing.

finite element model

heat propagation

fabricated

thin-walled component

gas metal arc welding

additive manufacturing


Input: The heat evolution, thermal cycle feature, and temperature gradient in molten pool and deposited layers are revealed.

heat evolution

molten pool

thermal cycle

temperature gradient

feature

deposited layers


Input: The temperature simulations at some locations are in agreement with measured values from thermocouples.

temperature

simulations

thermocouples


Input: As the deposition process proceeds, the high-temperature regions of the substrate and molten pool increase.

As

substrate

deposition process

molten pool


Input: The temperature gradient in the molten pool decreases with the increasing deposition height.

temperature gradient

molten pool

deposition


Input: The heat dissipation condition in the molten pool of current layer tightly depends on the deposition direction of fore layer.

heat dissipation

molten pool

layer

deposition direction

layer


Input: At the deposition ending moment, the heat conduction in the axial direction is the predominant heat dissipation orientation, whereas the circumferential orientation becomes the main heat dissipation direction in the top layers.

deposition

heat conduction

heat dissipation

orientation

heat dissipation


Input: An automated arc-welding-based additive manufacturing system was reported.

arc-welding-based additive manufacturing


Input: Integrated additive and subtractive manufacturing methodology was developed.

additive

subtractive manufacturing

methodology


Input: Deposition paths and welding parameters were automatically generated.

Deposition paths

welding

parameters


Input: User interface using only CAD models as inputs was developed.

interface

CAD models

as


Input: Arc welding has been widely explored for additive manufacturing of large metal components over the last three decades due to its lower capital cost, an unlimited build envelope, and higher deposition rates.

Arc welding

additive manufacturing

metal

components

capital cost

build envelope

deposition rates


Input: Although significant improvements have been made, an arc welding process has yet to be incorporated in a commercially available additive manufacturing system.

arc welding

be

additive manufacturing system


Input: The next step in exploiting “true” arc-welding-based additive manufacturing is to develop the automation software required to produce CAD-to-part capability.

step

automation

CAD-to-part

arc-welding-based additive manufacturing


Input: This study focuses on developing a fully automated system using robotic gas metal arc welding to additively manufacture metal components.

gas metal arc welding

additively manufacture

components


Input: The system contains several modules, including bead modelling, slicing, deposition path planning, weld setting, and post-process machining.

bead modelling

slicing

deposition path planning

weld

post-process machining


Input: Among these modules, bead modelling provides the essential database for process control, and an innovative path planning strategy fulfils the requirements of the automated system.

bead modelling

process control

database

path planning


Input: Finally, a thin-walled aluminium structure has been fabricated automatically using only a CAD model as the informational input to the system.

thin-walled aluminium structure

fabricated

CAD model

as


Input: This exercise demonstrates that the developed system is a significant contribution towards the ultimate goal of producing a practical and highly automated arc-welding-based additive manufacturing system for industrial application.

arc-welding-based additive manufacturing

industrial


Input: Laser additive manufacturing titanium alloy 40 mm thick plate can obtain full penetration joint by EBW.

Laser additive manufacturing

mm

EBW

alloy

penetration joint


Input: In fusion zone, due to acicular α′ formation, the microhardness is higher than base metal and heat affected zone.

fusion zone

microhardness

heat affected zone

base metal


Input: All tensile samples fail in base metal.

tensile

samples

base metal


Input: The L-joint shows higher strength but lower ductility than T-joint.

L-joint

T-joint

strength

ductility


Input: Individually fabrication parts by laser additive manufacturing (LAM) and then jointing them together through electron beam welding (EBW) is a viable way for manufacturing large components with reduction of internal stress.

fabrication

laser additive manufacturing

LAM

electron beam welding

EBW

manufacturing

components

reduction

internal stress


Input: For investigating the microstructure and mechanical property of EBW joint along longitudinal and transverse direction in LAMed component, two LAMed Ti–6.5Al–3.5Mo–1.5Zr–0.3Si plates were successfully welded without defects.

microstructure

mechanical property

defects

EBW

welded

component


Input: Results show that the microstructure of base metal (BM) is a typical basket-weave morphology that exhibits lamellar α within β matrix.

microstructure

basket-weave morphology

lamellar

base metal

BM


Input: In heat affected zone (HAZ), the part of primary α transforms to β with the some very fine lamellar αs precipitates out.

heat affected zone

HAZ

lamellar

precipitates


Input: Due to the fast solidification rate, a large number of acicular α′ forms in fusion zone (FZ), leading to the highest microhardness.

solidification rate

fusion zone

FZ

microhardness


Input: All tensile samples fail in BM region with the fracture type of intergranular dimpled fracture.

tensile

samples

fracture

fracture

BM


Input: Compared with the T-joint, the L-joint shows higher ultimate tensile strength and yield strength, but lower elongation and reduction of area due to the morphology of columnar grains and the strong texture of β < 010 > parallel to the deposition direction.

T-joint

L-joint

texture

ultimate tensile strength

yield strength

elongation

columnar grains

reduction of area

morphology

deposition direction


Input: In Laser-based Manufacturing, the configuration of process parameters aims to maintain quality measures within specific boundaries and it is obtained through experimentation.

Laser-based Manufacturing

configuration

process parameters

quality

boundaries


Input: The idea developed and presented in this paper concerns the prediction of the performance of adaptive control policies, based on process modeling.

prediction

performance

adaptive control

process modeling


Input: Two examples of Laser-based Manufacturing are deployed in order to verify the response of adaptive control algorithms through empirical design, Laser welding and Laser-based Additive Manufacturing processes.

Laser-based Manufacturing

Laser welding

Laser-based Additive Manufacturing

adaptive control

empirical

design


Input: The penetration depth has been utilized as the quality criterion of the adaptive control loop for both processes.

penetration depth

as

quality

adaptive control

processes


Input: The solidification phase has also been examined.

solidification phase


Input: Dissolved oxygen in weld zone leads to distinct microstructures from base metal after annealing.

oxygen

microstructures

base metal

weld zone

annealing


Input: The repaired specimens have lower plasticity and slightly higher strength than base metal.

plasticity

strength

base metal


Input: Columnar grain boundary α phases in weld zone are the earliest microcracks nucleation sites.

Columnar grain boundary

weld zone

microcracks


Input: Gas tungsten arc welding was used to repair the laser additive manufactured Ti-5Al-5Mo-5V-1Cr-1Fe (Ti-55511) alloy with a subsequent triplex annealing treatment.

Gas tungsten arc welding

additive manufactured

annealing treatment

laser

alloy


Input: The tensile properties of heat treated specimens containing of different proportions of weld zone were designed to evaluate the influence of weld zone on tensile properties of the alloy.

tensile properties

tensile properties

heat

weld zone

weld zone

designed

alloy


Input: Microstructures, microhardness and tensile tests were performed to study the mechanical properties and fracture behaviors of the specimens.

Microstructures

microhardness

mechanical properties

fracture

tensile tests


Input: Results show that dissolved oxygen in the weld zone has a strong influence on increasing the number of α phase nucleation sites that can lead to different αp morphologies in the base metal and weld zone.

oxygen

lead

base metal

weld zone

phase nucleation sites

morphologies

weld zone


Input: These different αp can lead to distinct microstructures after triplex annealing treatment but with similar α volume fractions.

lead

microstructures

annealing treatment

volume fractions


Input: Besides, plasticity deterioration of the repaired tensile specimens is mainly attributed to the formation of columnar grain boundary α phases in the weld zone which are considered to be the earliest nucleation sites of microcracks and confirmed by in situ tensile test.

plasticity

tensile specimens

columnar grain boundary

weld zone

nucleation

microcracks

in situ

be


Input: With the increase of WZ proportions in the cross section of tensile specimens, the plasticity of the alloy gradually decreases.

WZ

cross section

tensile specimens

plasticity

alloy


Input: Ultrasonic additive manufacturing (UAM) is a solid-state additive manufacturing technique employing principles of ultrasonic welding coupled with mechanized tape layering to fabricate fully functional parts.

Ultrasonic additive manufacturing

UAM

additive manufacturing

ultrasonic welding

fabricate

solid-state


Input: However, parts fabricated using UAM often exhibit a reduction in strength levels when loaded normal to the welding interfaces (Z-direction).

fabricated

reduction

UAM

strength

welding interfaces

Z-direction


Input: In this work, the effect of post-weld heat treatments (PWHT) on Al-6061 builds fabricated using the UAM process was explored aiming to improve the mechanical strength of the UAM builds.

post-weld heat treatments

UAM

UAM

PWHT

fabricated

process

mechanical strength

builds


Input: Tensile testing with digital image correlation (DIC) coupled with metallography along with multi-scale structure characterization (SEM-EBSD) was used to investigate and rationalize the mechanical performance of the UAM builds.

Tensile testing

multi-scale structure characterization

builds

digital image correlation

DIC

metallography

SEM-EBSD

mechanical

UAM


Input: It was established that PWHTs may improve the Z-strength level by the factor of ~3÷3.5 (from ~46 to 177 MPa).

PWHTs

Z-strength

MPa


Input: The improvements in the strength level were primarily aided by material aging and grain growth across the bond interface.

strength

material aging

grain growth

bond interface


Input: Ultrasonic additive manufacturing (UAM) is a solid-state additive manufacturing process that uses fundamental principles of ultrasonic welding and sequential layering of tapes to fabricate complex three-dimensional (3-D) components.

Ultrasonic additive manufacturing

UAM

additive manufacturing process

ultrasonic welding

fabricate

solid-state

three-dimensional

components


Input: One of the factors limiting the use of this technology is the poor tensile strength along the z-axis.

technology

z-axis

tensile strength


Input: Recent work has demonstrated the improvement of the z-axis properties after post-processing treatments.

z-axis properties

post-processing treatments


Input: The abnormally high stability of the grains at the interface during post-weld heat treatments is, however, not yet well understood.

stability

grains

interface

post-weld heat treatments


Input: In this work we use multiscale characterization to understand the stability of the grains during post-weld heat treatments.

stability

grains

post-weld heat treatments


Input: Aluminum alloy (6061) builds, fabricated using ultrasonic additive manufacturing, were post-weld heat treated at 180, 330 and 580 °C.

Aluminum alloy

builds

fabricated

ultrasonic additive manufacturing

post-weld heat treated


Input: The grains close to the tape interfaces are stable during post-weld heat treatments at high temperatures (i.e., 580 °C).

grains

post-weld heat treatments

temperatures


Input: This is in contrast to rapid grain growth that takes place in the bulk.

rapid grain growth


Input: Transmission electron microscopy and atom-probe tomography display a significant enrichment of oxygen and magnesium near the stable interfaces.

Transmission electron microscopy

atom-probe tomography

oxygen

magnesium


Input: Based on the detailed characterization, two mechanisms are proposed and evaluated: nonequilibrium nano-dispersed oxides impeding the grain growth due to grain boundary pinning, or grain boundary segregation of magnesium and oxygen reducing the grain boundary energy.

nano-dispersed oxides

magnesium

oxygen

grain growth

grain boundary

grain boundary

grain boundary energy


Input: Additive manufacturing will be an option to develop prototypes or mechanical parts that will be made faster and cheaper than other techniques such as laser cladding or electron beam.

Additive manufacturing

cladding

be

be

as

prototypes

electron beam

mechanical parts


Input: The main objective of this research was to study the optimal initial conditions of the proposed additive manufacturing system in order to obtain metal prototypes.

research

additive manufacturing system

metal


Input: This optimal conditions have been presented taking into account the measurements of geometrical conditions and surface finishing.

surface finishing


Input: The proposed additive manufacturing system consist on an integration of a Fronius TPS 4000 CMT R welding machine with a BF30 Vario Optimun CNC milling machine.

additive manufacturing system

Fronius TPS 4000 CMT R

machine

CNC milling


Input: Once the material was selected, the optimal conditions to make the first layer have been obtained.

material

layer


Input: Previous simple geometries, such as prismatic and cylindrical parts have been manufactured.

simple

geometries

cylindrical

manufactured

as


Input: Efficient way of depositing thin-walled overhang features, without supports, based on inclined slicing and weld-deposition.

overhang features

supports

slicing

weld-deposition


Input: Uses higher order kinematics to the work piece for fabricating complex thin-walled fully dense functional metallic parts.

kinematics

work piece

metallic parts

fabricating

fully dense


Input: Geometrical modelling of the weld-bead to predict the layer thickness of a given layer for bead-on-bead deposition.

modelling

weld-bead

layer thickness

layer

bead-on-bead deposition


Input: In-house MATLAB code to slice the CAD model and generate the tool path for inclined deposition of a given layer.

MATLAB code

slice

tool path

deposition

CAD model

layer


Input: Fabrication of complex thin-walled parts using GMAW based weld-deposition for illustration of above mentioned concepts.

Fabrication

GMAW

thin-walled parts

weld-deposition


Input: Gas Metal Arc Welding (GMAW) based weld-deposition process is one of the deposition-based Additive Manufacturing (AM) processes with the ability to produce fully dense complex functional metallic objects.

Gas Metal Arc Welding

GMAW

Additive Manufacturing

AM

weld-deposition process

processes

fully dense

metallic


Input: Due to its high deposition rates, high material and power efficiency, lower investment costs, simpler setup and work environment requirements it is slowly becoming a viable metallic AM method.

high deposition rates

power efficiency

material

metallic AM


Input: Amongst various geometrical features that can be realized in weld-deposition based AM, the thin-walled features (i.e., features with one single deposition pass) are the toughest as the process has to overcome the bead-over-bead complexity.

geometrical features

be

as

weld-deposition based AM

deposition

process

bead-over-bead


Input: Based on geometric modelling and experimentation, this paper presents an efficient technique for producing the thin-walled metallic structures, including objects with undercut features.

geometric modelling

metallic structures

undercut


Input: This is possible by adding extra degrees of freedom or by using higher order kinematics to the work piece and/or to the deposition head by suitably aligning the overhanging feature in-line to the deposition direction.

degrees of freedom

kinematics

deposition

work piece

overhanging feature

deposition direction


Input: An in-house MATLAB code was developed to slice the CAD model and generate the tool path for inclined deposition of a given layer of a thin-walled model.

MATLAB code

slice

tool path

deposition

CAD model

layer

thin-walled model


Input: A geometrical model proposed to predict the layer thickness of a given layer during such bead-on-bead deposition showed good correlation with experimental data.

geometrical model

bead-on-bead deposition

experimental data

layer thickness

layer


Input: Some illustrative complex thin-walled components successfully fabricated using this model have also been presented.

thin-walled components

fabricated

model


Input: Additive layer manufacturing (ALM), using gas tungsten arc welding (GTAW) as heat source, is a promising technology in producing Inconel 625 components due to significant cost savings, high deposition rate and convenience of processing.

Additive layer manufacturing

ALM

gas tungsten arc welding

GTAW

as

Inconel 625

source

technology

components

high deposition rate


Input: With the purpose of revealing how microstructure and mechanical properties are affected by the location within the manufactured wall component, the present study has been carried out.

microstructure

mechanical properties

manufactured

component


Input: The manufactured Inconel 625 consists of cellular grains without secondary dendrites in the near-substrate region, columnar dendrites structure oriented upwards in the layer bands, followed by the transition from directional dendrites to equiaxed grain in the top region.

manufactured

cellular grains

transition

equiaxed grain

Inconel 625

secondary dendrites

columnar dendrites

directional dendrites

layer


Input: With the increase in deposited height, segregation behavior of alloying elements Nb and Mo constantly strengthens with maximal evolution in the top region.

segregation

evolution

alloying elements

Mo


Input: The primary dendrite arm spacing has a well coherence with the content of Laves phase.

dendrite

Laves phase


Input: The microhardness and tensile strength show obvious variation in different regions.

microhardness

variation

tensile strength


Input: The microhardness and tensile strength of near-substrate region are superior to that of layer bands and top region.

microhardness

tensile strength

layer


Input: The results are further explained in detail through the weld pool behavior and temperature field measurement.

weld pool

temperature

measurement


Input: This paper describes results of seam welding of relatively high temperature melting materials, AISI 304, C-Mn steels, Ni-based alloys, CP Cu, CP Ni, Ti6Al4V and relatively low temperature melting material, AA6061.

seam welding

temperature

temperature

melting materials

melting material

AISI 304

C-Mn steels

Ni-based alloys

Cu

Ni


Input: It describes the seam welding of multi-layered similar and dissimilar metallic sheets.

seam welding

metallic sheets


Input: The method described and involved advancing a rotating non-consumable rod (CP Mo or AISI 304) toward the upper sheet of a metallic stack clamped under pressure.

rod

Mo

AISI 304

sheet

metallic stack

pressure


Input: As soon as the distal end of the rod touched the top portion of the upper metallic sheet, an axial force was applied.

As

as

metallic sheet

rod

axial force


Input: After an initial dwell time, the metallic stack moved horizontally relative to the stationery non-consumable rod by a desired length, thereby forming a metallurgical bond between the metallic sheets.

dwell time

metallic stack

metallic sheets

rod

forming

metallurgical bond


Input: Multi-track and multi-metal seam welds of high temperature metallic sheets, AISI 304, C-Mn steel, Nickel-based alloys, Cp Cu, Ti6Al4V and low temperature metallic sheets, AA6061 were obtained.

seam welds

temperature

temperature

metallic sheets

AISI 304

C-Mn steel

Nickel-based alloys

Cu

metallic sheets


Input: Optical and scanning electron microscopy examination and 180 degree U-bend test indicated that defect free seam welds could be obtained with this method.

Optical

scanning electron microscopy

U-bend test

defect

seam welds

be


Input: Tensile- shear testing showed that the seam welds of AISI 304, C-Mn steel, Nickel-based alloy were stronger than the starting base metal counterparts while AA6061 was weaker due to softening.

Tensile- shear testing

seam welds

AISI 304

C-Mn steel

Nickel-based alloy

base metal


Input: The metallurgical bonding at the interface between the metallic sheets was attributed to localized stick and slip at the interface, dynamic recrystallization and diffusion.

metallurgical bonding

interface

interface

dynamic

diffusion

metallic sheets


Input: The method developed can be used as a means of welding, cladding and additive manufacturing.

be

as

welding

cladding

additive manufacturing


Input: In this paper the joinability of titanium Additive Manufactured (AM) parts is explored.

titanium

Additive Manufactured

AM


Input: Keyhole welding, using a pulsed laser beam, of conventionally produced parts is compared to AM parts.

Keyhole welding

pulsed laser beam

AM parts


Input: Metal AM parts are notorious for having remaining porosities and other non-isotropic properties due to the layered manufacturing process.

Metal AM

manufacturing process

porosities

non-isotropic


Input: This study shows that due to these deficiencies more energy per unit weld length is required to obtain a similar keyhole geometry for titanium AM parts.

weld length

geometry

titanium

AM parts


Input: It is also demonstrated that, with adjusted laser process parameters, good quality welds for aerospace applications in terms of pressure resistance and leak tightness are achievable.

laser

parameters

quality welds

aerospace

pressure resistance


Input: Part size in additive manufacturing is limited by the size of building area of AM equipment.

additive manufacturing

AM

area


Input: Occasionally, larger constructions that AM machines are able to produce, are needed, and this creates demand for welding AM parts together.

AM machines

AM parts

welding


Input: However there is very little information on welding of additive manufactured stainless steels.

welding

additive manufactured

steels


Input: The aim of this study was to investigate the weldability aspects of AM material.

weldability

AM material


Input: In this study, comparison of the bead on plate welds between AM parts and sheet metal parts is done.Used material was 316L stainless steel, AM and sheet metal, and parts were welded with laser welding.

bead

welds

AM parts

sheet metal

material

316L stainless steel

sheet metal

AM

welded

laser welding


Input: Weld quality was evaluated visually from macroscopic images.

Weld quality

macroscopic images


Input: Results show that there are certain differences in the welds in AM parts compared to the welds in sheet metal parts.

welds

welds

AM parts

sheet metal


Input: Differences were found in penetration depths and in type of welding defects.

penetration depths

welding defects


Input: Nevertheless, this study presents that laser welding is suitable process for welding AM parts.

laser welding

welding

process

AM parts


Input: Additive manufacturing (AM) of high γ′ strengthened Nickel-base superalloys, such as IN738LC, is of high interest for applications in hot section components for gas turbines.

Additive manufacturing

AM

Nickel-base superalloys

as

components

gas turbines


Input: The creep property acts as the critical indicator of component performance under load at elevated temperature.

creep

as

component

temperature


Input: In order to evaluate the short-term creep behavior, slow strain rate tensile (SSRT) tests were performed.

creep behavior

slow strain rate tensile

SSRT


Input: IN738LC bars were built by laser powder-bed-fusion (L-PBF) and then subjected to hot isostatic pressing (HIP) followed by the standard two-step heat treatment.

laser powder-bed-fusion

L-PBF

hot isostatic pressing

HIP

heat treatment

standard


Input: The samples were subjected to SSRT testing at 850 °C under strain rates of 1 × 10−5/s, 1 × 10−6/s, and 1 × 10−7/s.

samples

SSRT

strain rates


Input: In this research, the underlying creep deformation mechanism of AM processed IN738LC is investigated using the serial sectioning technique, electron backscatter diffraction (EBSD), transmission electron microscopy (TEM).

research

creep deformation mechanism

AM

serial sectioning

electron backscatter diffraction

EBSD

transmission electron microscopy

TEM


Input: On the creep mechanism of AM polycrystalline IN738LC, grain boundary sliding is predominant.

creep

AM polycrystalline IN738LC

grain boundary sliding


Input: However, due to the interlock feature of grain boundaries in AM processed IN738LC, the grain structure retains its integrity after deformation.

feature

grain boundaries

grain structure

integrity

deformation

AM


Input: The dislocation motion acts as the major accommodation process of grain boundary sliding.

dislocation motion

process

grain boundary sliding

as


Input: Dislocations bypass the γ′ precipitates by Orowan looping and wavy slip.

Dislocations

Orowan looping

precipitates


Input: The rearrangement of screw dislocations is responsible for the formation of subgrains within the grain interior.

screw dislocations

subgrains

grain


Input: This research elucidates the short-creep behavior of AM processed IN738LC.

research

short-creep

AM


Input: It also shed new light on the creep deformation mechanism of additive manufactured γ′ strengthened polycrystalline Nickel-base superalloys.

creep deformation mechanism

additive manufactured

Nickel-base superalloys


Input: Due to the cost advantage, weld-based Additive Manufacturing (AM) is suitable for directly fabricating large metallic parts.

weld-based Additive Manufacturing

AM

fabricating

metallic parts


Input: One of challenges for weld-based Additive M anufacturing is to build overhanging structure or tilt structure at a large slant angle, because liquid metal on the boundary would flow down by gravity due to lack of sufficient support.

Additive

liquid metal

build

slant angle

structure

tilt structure

boundary

support


Input: In the present work, electromagnetically confined weld-based Additive Manufacturing is develop ed to solve this problem.

electromagnetically

weld-based Additive Manufacturing

ed


Input: In the process, liquid metal is confined and semi-levitated by the Lorentz force exerted by magnetic field and thus the flow of liquid metal is restricted.

process

Lorentz force

magnetic field

liquid metal

liquid metal


Input: Experiments and numerical simulations are performed to investigate the effect mechanism of electromagnetic confinement.

numerical simulations

mechanism

electromagnetic confinement


Input: Experimental results verify that the flow-down or collapse of liquid metal is impeded by electromagnetic confinement.

Experimental

electromagnetic confinement

liquid metal


Input: With specific welding parameters, the maximum tilt angle of successful building increases from 50° to 60° when imposing electromagnetic confinement.

welding

parameters

electromagnetic confinement

tilt angle


Input: New technologies can be justified with the advent of the additive manufacturing, excels by its flexibility in manufacturing parts of various geometries, good accuracy and material waste reduction savings.

technologies

flexibility in manufacturing

geometries

reduction

be

material

additive manufacturing

accuracy


Input: This circumstance requires the application of techniques to determine the reliability of the results in the deposition of layers in order to have a good accuracy.

reliability

accuracy

deposition


Input: This work aims to present a new technology applied to additive manufacturing, focusing on accuracy in the deposition of layers, lower cost and user friendliness man-machine.

technology

deposition

additive manufacturing

accuracy


Input: New method was proposed in order to obtain advantages regarding the use of Plasma welding process.

Plasma welding


Input: An apparatus for generating plasma was used to obtain the arc.

plasma

arc


Input: Correlated magnitudes helped in determining Efficient Model of Deposition for use in offsetting the geometric and thermal errors.

Correlated

Model

Deposition

errors


Input: Computer simulations were applied to the new concept of deposition and the efficiency of the presented system was performed, but no experimental results are provided herein.

Computer simulations

deposition

experimental


Input: Ultrasonic additive manufacturing (UAM) is a solid-state hybrid manufacturing technique.

Ultrasonic additive manufacturing

UAM

solid-state

hybrid manufacturing


Input: In this work characterization using electron back scatter diffraction was performed on aluminum–titanium dissimilar metal welds made using a 9 kW ultrasonic additive manufacturing system.

electron back scatter diffraction

metal

ultrasonic additive manufacturing


Input: The results showed that the aluminum texture at the interface after ultrasonic additive manufacturing is similar to aluminum texture observed during accumulative roll bonding of aluminum alloys.

aluminum

aluminum

aluminum alloys

interface

ultrasonic additive manufacturing

roll bonding


Input: It is finally concluded that the underlying mechanism of bond formation in ultrasonic additive manufacturing primarily relies on severe shear deformation at the interface.

mechanism

deformation

interface

ultrasonic additive manufacturing


Input: The wire arc additive manufacturing (WAAM) 2Cr13 thin-wall part was deposited using robotic cold metal transfer (CMT) technology, and the location-related thermal history, densification, phase identification, microstructure, and mechanical properties of the part were explored.

wire arc additive manufacturing

WAAM

cold metal transfer

CMT

densification

technology

phase

microstructure

mechanical properties


Input: The results show that pre-heating effect from previously built layers can be effectively used to reduce residual stresses; cooling rate firstly decreased rapidly and then kept stable in the 15th–25th layers.

be

residual stresses

cooling rate


Input: The peaks of the α-Fe phase of the AM part drifted slightly toward a relatively smaller Bragg's angle as a result of solute atoms incorporation when compared with that of the base metal.

phase

AM part

as

solute atoms

base metal


Input: As-deposited microstructure consisted of martensite and ferrite, along with (Fe, Cr) 23C6 phase precipitated at α-Fe grain boundaries.

microstructure

phase

grain boundaries

martensite

ferrite

Fe

Cr


Input: Martensite content increased gradually from the 5th layer to the 25th layers, indicating that metastable martensite partly decomposed into stable ferrite due to the carbon atoms diffusion.

Martensite

martensite

ferrite

carbon atoms

layer

metastable


Input: The hardness and UTS changed slightly in the 05th–15th layers and then increased quickly from the 20th layer to the 25th layers at the expense of ductility; the fracture process transformed from ductile (01st–10th layers) to mixed-mode (15th–20th layers), and finally to brittle fracture (25th layer).

hardness

UTS

ductility

ductile

layer

layer

fracture

brittle fracture


Input: The findings above suggest that, despite the emergency of few pores and slightly inadequate ductility, this robotic CMT technology is a feasible method to obtain desired microstructures and enhanced mechanical properties for the WAAM 2Cr13 part in comparison with its as-solutioned counterpart.

pores

ductility

CMT

WAAM

microstructures

mechanical properties


Input: An innovative and low cost additive layer manufacturing (ALM) process is used to produce γ-TiAl based alloy wall components.

additive layer manufacturing

ALM

process

alloy

components


Input: Gas tungsten arc welding (GTAW) provides the heat source for this new approach, combined with in-situ alloying through separate feeding of commercially pure Ti and Al wires into the weld pool.

Gas tungsten arc welding

GTAW

heat source

in-situ

weld pool

alloying

Ti

Al


Input: This paper investigates the morphology, microstructure and mechanical properties of the additively manufactured TiAl material, and how these are affected by the location within the manufactured component.

investigates

morphology

microstructure

mechanical properties

manufactured

additively manufactured

material

component


Input: The typical additively layer manufactured morphology exhibits epitaxial growth of columnar grains and several layer bands.

layer

layer

morphology

epitaxial

columnar grains


Input: The fabricated γ-TiAl based alloy consists of comparatively large α2 grains in the near-substrate region, fully lamellar colonies with various sizes and interdendritic γ structure in the intermediate layer bands, followed by fine dendrites and interdendritic γ phases in the top region.

fabricated

grains

lamellar

structure

alloy

layer

dendrites


Input: Microhardness measurements and tensile testing results indicated relatively homogeneous mechanical characteristics throughout the deposited material.

Microhardness

homogeneous

tensile testing

material


Input: The exception to this homogeneity occurs in the near-substrate region immediately adjacent to the pure Ti substrate used in these experiments, where the alloying process is not as well controlled as in the higher regions.

Ti substrate

as

as

alloying


Input: The tensile properties are also different for the vertical (build) direction and horizontal (travel) direction because of the differing microstructure in each direction.

tensile properties

vertical

microstructure

build


Input: The microstructure variation and strengthening mechanisms resulting from the new manufacturing approach are analysed in detail.

microstructure

strengthening mechanisms

manufacturing approach


Input: The results demonstrate the potential to produce full density titanium aluminide components directly using the new additive layer manufacturing method.

density

components

additive layer manufacturing


Input: Amorphous polymer melt is extruded and deposited filament-by-filament.

polymer melt

extruded


Input: Non-isothermal inter-diffusion from an anisotropic configuration is modelled.

anisotropic


Input: Weld thickness (∼Rg) is sufficient to achieve bulk mechanical strength at weld.

Weld thickness

mechanical strength

weld


Input: Reduced weld strength is attributed to a partially entangled structure.

weld strength

structure


Input: Although 3D printing has the potential to transform manufacturing processes, the strength of printed parts often does not rival that of traditionally-manufactured parts.

3D printing

manufacturing processes

strength


Input: The fused-filament fabrication method involves melting a thermoplastic, followed by layer-by-layer extrusion of the molten viscoelastic material to fabricate a three-dimensional object.

fused-filament fabrication

melting

extrusion

fabricate

thermoplastic

material

layer-by-layer

three-dimensional

viscoelastic


Input: The strength of the welds between layers is controlled by interdiffusion and entanglement of the melt across the interface.

strength

welds

melt

interface


Input: However, diffusion slows down as the printed layer cools towards the glass transition temperature.

diffusion

glass transition temperature

as

layer


Input: Diffusion is also affected by high shear rates in the nozzle, which significantly deform and disentangle the polymer microstructure prior to welding.

Diffusion

microstructure

nozzle

polymer

welding


Input: In this paper, we model non-isothermal polymer relaxation, entanglement recovery, and diffusion processes that occur post-extrusion to investigate the effects that typical printing conditions and amorphous (non-crystalline) polymer rheology have on the ultimate weld structure.

model

diffusion

structure

polymer

polymer

weld


Input: Although we find the weld thickness to be of the order of the polymer size, the structure of the weld is anisotropic and relatively disentangled; reduced mechanical strength at the weld is attributed to this lower degree of entanglement.

weld thickness

be

polymer

structure

weld

weld

anisotropic

mechanical strength


Input: The microstructures of Al alloy 6061 subjected to very-high-power ultrasonic additive manufacturing were systematically examined to understand the underlying ultrasonic welding mechanism.

microstructures

Al alloy

ultrasonic additive manufacturing

ultrasonic welding

mechanism


Input: The microstructure of the weld interface between the metal tapes consisted of fine, equiaxed grains resulting from recrystallization, which is driven by simple shear deformation along the ultrasonically vibrating direction of the tape surface.

microstructure

interface

equiaxed grains

recrystallization

deformation

surface

weld

metal

simple


Input: Void formation at the weld interface is attributed to surface asperities resulting from pressure induced by the sonotrode at the initial tape deposition.

Void

interface

surface asperities

pressure

deposition

weld

sonotrode


Input: Transmission electron microscopy revealed that Al–Al metallic bonding without surface oxide layers was mainly achieved, although some oxide clusters were locally observed at the original interface.

Transmission electron microscopy

metallic bonding

surface

interface

oxide

oxide


Input: The results suggest that the oxide layers were broken up and then locally clustered on the interface by ultrasonic vibration.

oxide

interface

ultrasonic vibration


Input: A theoretical analysis of the metal transfer behaviour and bead shape formation using positional GMAW are provided.

theoretical

metal

bead

GMAW


Input: The effects of various process parameters on the stability of positional deposition are investigated.

process parameters

deposition

stability


Input: The effectiveness of the proposed strategy is verified by three complex samples using a positional GMAW-WAAM process.

effectiveness

samples

process


Input: Robotic wire arc additive manufacturing (WAAM) technology has been widely employed to fabricate medium to large scale metallic components.

wire arc additive manufacturing

WAAM

fabricate

technology

metallic

components


Input: It has the advantages of high deposition rates and low cost.

high deposition rates


Input: Ideally, the deposition process is carried out in a flat position.

deposition process


Input: The build direction is vertically upward and perpendicular to a horizontal worktable.

build direction


Input: However, it would be difficult to directly deposit complex parts with near horizontal ‘overhangs’, and temporary supports may be required.

be

be

overhangs

supports


Input: Thus, it is necessary to find an alternative approach for the deposition of ‘overhangs’ without extra support in order to simplify the deposition set-up.

deposition

deposition

overhangs

support


Input: This paper proposed a fabrication method of producing metallic parts with overhanging structures using the multi-directional wire arc additive manufacturing.

fabrication

wire arc additive manufacturing

metallic parts

overhanging structures


Input: Firstly, based on the metal droplet kinetics and weld bead geometry, two different Gas Metal Arc Welding (GMAW) metal transfer modes, namely short circuit transfer and free flight transfer, were evaluated for the multi-directional wire arc additive manufacturing.

metal

metal

droplet

weld bead geometry

Gas Metal Arc Welding

GMAW

wire arc additive manufacturing


Input: Subsequently, the effects of process parameters, including wire feed speed (WFS), torch travel speed (TS), nozzle to work distance (NTWD) and torch angle, on the stability of positional deposition were investigated.

process parameters

deposition

feed

nozzle

stability


Input: Finally, the effectiveness of the proposed strategy was verified by fabricating three complex samples with overhangs.

effectiveness

samples

fabricating

overhangs


Input: Wire Arc Additive Manufacturing underwent remarkable development in the past decade.

Wire Arc Additive Manufacturing


Input: In the present work effect of welding parameters on additively deposited layer width is investigated.

welding

parameters

deposited layer


Input: MIG welding is chosen for the present study and Inconel 825 having high industrial application is selected as wire spool.

MIG welding

Inconel

as

industrial

spool


Input: This paper is concentrating on the effect of weld parameters on additively deposited layer width using the Taguchi method.

weld

parameters

Taguchi method

deposited layer


Input: Waviness, weld cracks, porosity, and discontinuity of weld bead of a surface can be reduced by selection and optimising the parameters; otherwise, irregular shapes will come during the manufacturing of thin or thick wall construction by Wire Arc Additive Manufacturing.

Waviness

weld

porosity

weld bead

surface

parameters

be

manufacturing

Wire Arc Additive Manufacturing

construction


Input: L9 Orthogonal array is used in Taguchi for the experimentation to analyze input parameters, namely, Welding speed, Wire feed speed and Voltage.

parameters

Welding

feed


Input: Best parameter combination and significant parameters are obtained from the main effect plot and analysis of variance respectively.

parameter

parameters


Input: A mathematical model on the response variable is generated using a linear regression model.

mathematical

regression model


Input: At 0.55 m/min welding velocity, 4 m/min Wire feed speed and 18 V Voltage is having least bead Width of 3.07 mm length.

welding

mm

feed

V

bead Width


Input: 0.25 m/min welding velocity, 8 m/min Wire feed speed and 28 V Voltage is having highest bead Width of 15.83 mm length.

welding

mm

feed

V

bead Width


Input: Confirmation tests are carried out after obtaining optimized parameters and results are correlated with obtained results.

parameters

correlated


Input: Wire based Additive Manufacturing provides an attractive option to powder-based processes due to their high deposition rates.

Additive Manufacturing

processes

high deposition rates


Input: In the present work effect of welding parameters on pre-positioned wire Electron Beam additively deposited layer width is investigated.

welding

parameters

Electron Beam

deposited layer


Input: Electron Beam welding is chosen for the present study and Ti6Al4V having high aerospace application is selected as filler wire.

Electron Beam welding

as

aerospace


Input: This paper concentrates on the effect of weld parameters on additively deposited layer width using the Taguchi method.

weld

parameters

Taguchi method

deposited layer


Input: Unacceptable weld cracks, porosity, and discontinuity of weld bead of a surface can be reduced by selection and optimizing the parameters; otherwise, irregular shapes will come during the manufacturing of thin or thick wall construction by Wire Electron Beam Additive Manufacturing.

weld

porosity

weld bead

surface

parameters

be

manufacturing

Electron Beam Additive Manufacturing

construction


Input: L9 Orthogonal array is used in Taguchi for the experimentation to analyze input parameters, namely, Welding speed, Accelerating voltage and Beam current.

parameters

Welding

Beam


Input: Best parameter combination and significant parameters are obtained from the main effect plot and analysis of variance respectively.

parameter

parameters


Input: A mathematical model on the response variable is generated using a linear regression model.

mathematical

regression model


Input: At 700 mm/min welding speed, 138 kV accelerating voltage and 05 mA beam current is having least bead Width of 2.30222 mm length.

welding

mm

beam

bead Width


Input: 500 mm/min welding speed, 142 kV accelerating voltage and 09 mA beam current is having highest bead Width of 4.09 mm length.

welding

mm

beam

bead Width


Input: Confirmation tests are carried out after obtaining optimized parameters and results are correlated with obtained results.

parameters

correlated


Input: Comparison between laser welding and laser-based additive manufacturing parameters is established.

laser welding

laser-based additive manufacturing


Input: Major process parameters during laser-based additive manufacturing and their influence are discussed.

process parameters

laser-based additive manufacturing


Input: Remedies for avoid several problems found during additive manufacturing are proposed.

additive manufacturing


Input: As metallic additive manufacturing grew in sophistication, users have requested greater control over the systems, namely the ability to fully change the process parameters.

As

additive manufacturing

process parameters


Input: The goal of this manuscript is to review the effects of major process parameters on build quality (porosity, residual stress, and composition changes) and materials properties (microstructure and microsegregation), and to serve as a guide on how these parameters may be modified to achieve specific design goals for a given part.

manuscript

process parameters

composition

materials

microstructure

microsegregation

parameters

build

porosity

residual stress

as

be

design


Input: The focus of this paper is on laser powder bed fusion, but elements can be applied to electron beam powder bed fusion or direct energy deposition techniques.

laser powder bed fusion

bed fusion

direct energy deposition

elements

be

electron beam


Input: Stellite-6 FSW tools were developed on H13 steel by additive manufacturing (AM).

FSW

additive manufacturing

AM

H13 steel


Input: Tool performance was evaluated in friction stir welding/ processing of CuCrZr.

Tool

performance

friction


Input: No tool wear or plastic deformation was observed on Stellite-6 tool.

tool wear

plastic deformation

tool


Input: This performed better than H13 as-received, heat treated and laser remelted tools.

heat

laser

tools


Input: Tool wear and failure mechanism investigated in conventional and AM tools.

Tool wear

failure mechanism

AM


Input: In the recent time friction stir welding (FSW), a solid state welding process has rapidly gained attention for joining high melting point materials like Cu, Fe, Ti and their alloys apart from Al alloys due to its several advantages over fusion welding techniques.

friction stir welding

FSW

solid state welding

joining

fusion welding

process

materials

melting point

Cu

Fe

Ti

alloys

Al alloys


Input: AISI H13, a versatile chromium–molybdenum hot work hardened steel, has been the most commonly used as a tool material for aluminium alloys.

as

material

aluminium alloys

hardened

tool


Input: However, low tool life due to plastic deformation and wear at elevated temperatures is limiting its application in welding of high melting point materials.

tool life

wear

materials

plastic deformation

melting point

temperatures

welding


Input: In the present work the performances of as-received, heat treated, laser remelted and Stellite 6 hardfaced H13 steel tools in friction stir processing (FSP) of CuCrZr have been investigated.

heat

friction

laser

Stellite

H13 steel


Input: Stellite 6 hardfaced FSW tools are developed by additive manufacturing (AM) process on H13 steel as a base material.

Stellite

H13 steel

as

material

FSW

additive manufacturing

AM

process


Input: In all these cases except the Stellite 6 hardfaced tool, the shoulder and pin are found to deform plastically with significant wear of shoulder along with the diffusion of CuCrZr into tool from tool pin-shoulder interface.

Stellite

tool

tool

tool

wear

diffusion

interface


Input: However, tools developed by AM process are found to remain intact without any significant deformation or wear.

tools

AM process

deformation

wear


Input: GMAW (Gas Metal Arc Welding) of titanium is not currently used in industry due to the high levels of spatter generation, the wandering of the welding arc and the consequent waviness of the weld bead.

GMAW

Gas Metal Arc Welding

welding

titanium

industry

spatter

arc

weld bead

waviness


Input: This paper reports on the use of laser welding in conduction mode to stabilize the CMT (Cold Metal Transfer), a low heat input GMAW process.

laser welding

CMT

Cold Metal Transfer

GMAW

heat


Input: The stabilization and reshaping of Ti-6Al-4 V weld beads was verified for laser hybrid GMAW bead on plate deposition.

stabilization

deposition

Ti-6Al-4 V

beads

bead

laser

GMAW


Input: The laser beam was defocused, used in conduction mode, and was positioned concentric with the welding wire and the welding arc (CMT) .Finally, the results obtained for bead-on-plate welding were applied to an additively manufactured structure, in which a laser-hybrid stabilized sample was built and then evaluated against CMT-only sample.

laser beam

arc

sample

sample

welding

welding

CMT

welding

additively manufactured


Input: This work reveals that laser can be used to stabilize the welding process, improve the weld-bead shape of single and multiple layer depositions and increase the deposition rate of additive manufacture of Ti-6Al-4 V from1.7 kg/h to 2.0 kg/h.

laser

be

Ti-6Al-4 V

welding

additive manufacture

process

weld-bead

layer

deposition rate


Input: Additive Manufacturing is an established process group that includes various technologies.

Additive Manufacturing

process

technologies


Input: In contrast to subtractive methods, complex components can be produced by applying layers of construction materials.

subtractive

components

be

construction


Input: In accordance with the standard VDI Guideline 3405, additive manufacturing technologies can be differentiated into wire- and powder-based technologies.

standard

technologies

additive manufacturing

be


Input: The basis for these experimental investigations is a Wire Arc Additive Manufacturing (WAAM) process with a high build-up rate (Cold Metal Transfer-CMT) to produce a rectangular thin-walled component made of G4Si1 (1.5130).

experimental

process

Wire Arc Additive Manufacturing

WAAM

Cold Metal Transfer

CMT

thin-walled component


Input: In order to analyze the influence of a subsequent forming process on the microstructural properties and the forming behavior of the components, compression tests were carried out.

forming process

forming

microstructural

components

compression tests


Input: Therefore, cylindrical specimens were made out of the additively manufactured components by machining.

cylindrical

additively manufactured

machining


Input: To be able to take a possible anisotropy in the workpiece caused by the multi-layer welding into account, the samples were taken both along and across the welding direction.

be

anisotropy

workpiece

samples

welding

welding


Input: To evaluate the inhomogeneous component properties, cast specimens with a representative microstructure were produced by inductive melting of the filler material and subsequent a solidification with an appropriate cooling rate.

component

cast

melting

microstructure

solidification

material

cooling rate


Input: In addition to the cold forming of the additively manufactured components, the investigation also includes hot forming and the influence of a corresponding heat treatment.

cold forming

additively manufactured

hot forming

heat treatment


Input: The experimental examination was completed by the analysis of the microstructure of each material state.The aim of the research work was to prove the homogenization and optimization of the mechanical properties of additive manufactured components due to a subsequent forming process.

experimental

microstructure

research

optimization

mechanical properties

material

homogenization

additive manufactured

forming process


Input: Highlight An experimental work to investigate the formation of the humping phenomena in the positional deposition using WAAM.

experimental

deposition

WAAM


Input: Mechanism of humping formation is analysed to explain humping occurrence for positional deposition.

Mechanism

deposition


Input: The impacts of welding parameters and positions on humping formation are investigated through a series of tests.

welding

parameters


Input: A series of guidelines are summarised to assist the path planning and process parameter selection processes in multi-directional WAAM.

path planning

process parameter

processes

WAAM


Input: Wire Arc Additive Manufacturing (WAAM) is a promising technology for fabricating medium to large scale metallic parts with excellent productivity and flexibility.

Wire Arc Additive Manufacturing

WAAM

fabricating

technology

productivity

metallic parts

flexibility


Input: Due to the positional capability of some welding processes, WAAM is able to deposit parts with overhanging features in an arbitrary direction without additional support structures.

welding

WAAM

processes

overhanging features

support structures


Input: There has been significant research on the humping phenomenon in the downhand welding, but it is doubtful whether the existing theories of humping formation can be applied in the positional deposition during WAAM process.

research

deposition

process

welding

WAAM

be


Input: This study has therefore provided an experimental work to investigate the formation of the humping phenomena in the positional deposition during additive manufacturing with the gas metal arc welding.

experimental

deposition

additive manufacturing

gas metal arc welding


Input: Firstly, the mechanism of humping formation was analysed to explain humping occurrence for positional deposition.

mechanism

deposition


Input: Then, the mechanism was validated through experiments with different welding parameters and positions.

mechanism

parameters

welding


Input: Finally, a series of guidelines are summarised to assist the path planning and process parameter selection processes in multi-directional WAAM.

path planning

process parameter

processes

WAAM


Input: Automated weld deposition coupled with the real-time robotic NDT is discussed.

weld

deposition

NDT


Input: An intentionally embedded defect, a tungsten rod, is introduced for verification.

defect

verification

tungsten

rod


Input: A partially-filled groove sample is also manufactured and ultrasonically tested.

sample

manufactured


Input: For performance verification of the in-process inspection system, an intentionally embedded defect, a tungsten rod, is introduced into the multi-pass weld.

performance

defect

inspection

tungsten

rod

weld


Input: A partially-filled groove (staircase) sample is also manufactured and ultrasonically tested to calibrate the real-time inspection implemented on all seven layers of the weld which are deposited progressively.

sample

manufactured

inspection

weld


Input: The tungsten rod is successfully detected in the real-time NDE of the deposited position.

tungsten

rod


Input: Non-weldable Ni-based superalloy Alloy713ELC could be fabricated by electron beam melting.

be

electron beam melting


Input: Process condition could be efficiently optimized by using support vector machine.

Process

be

support

machine


Input: Additive manufactured Alloy713ELC showed columnar grain along building direction.

Additive manufactured

columnar grain

building direction


Input: Additive manufactured Alloy713ELC showed good ductility along building direction.

Additive manufactured

ductility

building direction


Input: Additive manufactured Alloy713ELC showed good creep properties along building direction.

Additive manufactured

creep

building direction


Input: An efficient optimization method based on a support vector machine (SVM) is used to optimize multiple process parameters of selective electron beam melting (SEBM) for a non-weldable nickel-base superalloy Alloy713ELC.

optimization

process parameters

support

machine

selective electron beam melting

SEBM

nickel-base superalloy


Input: The global optimum condition and the near optimum conditions are extracted to fabricate SEBM samples.

extracted

samples

fabricate


Input: All the SVM optimized conditions lead to near net shaped samples with even top surfaces.

lead

samples

surfaces


Input: The sample fabricated under the global optimum condition for sample dimension of 10 mm exhibits pore-less cross-sections, columnar grains with fine γ′ precipitates and fine substructure, a small amount of grain boundary crack and excellent room temperature tensile properties.

sample

fabricated

sample

cross-sections

properties

dimension

mm

columnar grains

grain boundary crack

precipitates

temperature


Input: The samples fabricated under the global optimum condition and a near optimum condition with increased beam current for sample dimension of 15 mm exhibit excellent creep properties under 980 °C.

samples fabricated

sample

beam

dimension

mm

creep


Input: In both the two situations for sample dimensions of 10 mm and 15 mm, SEBM samples with mechanical properties superior to conventional cast alloys can be achieved by testing only 1–3 SVM optimized conditions.

sample

samples

mechanical properties

dimensions

mm

mm

SEBM

cast

alloys

be

testing


Input: We demonstrate the current method is effective for optimizing SEBM process, especially when multiple parameters need to be considered simultaneously.

SEBM

process

parameters

be


Input: Besides, this method can rapidly provide not only a batch of conditions leading to samples with good top surfaces but also the optimum conditions leading to good building quality and superior mechanical properties.

samples

surfaces

quality

mechanical properties


Input: In gas tungsten arc welding (GTAW) based additive manufacturing (AM), omni-directional deposition with side feeding is common when depositing complex parts, which is different from the gas metal arc welding (GMAW).

gas tungsten arc welding

GTAW

additive manufacturing

AM

gas metal arc welding

GMAW

deposition


Input: While side feeding may lead to unstable deposition process and deposition deviation.

lead

deposition process

deposition


Input: In this paper, a wire melting simulation model was established to analyse the behaviour of the wire in the arc column.

melting

model

arc


Input: An index of weld bead offset tolerance capacity is proposed to quantitatively analyse the sensitivity of the weld bead offset to the wire feed speed.

weld bead offset

tolerance capacity

sensitivity

weld bead offset

feed

quantitatively


Input: Single-layer experiments were conducted to analyse the relationships between the deposition parameters and the weld melting/bead offset.

deposition

offset

weld


Input: A multi-layer sample with an actual usable area ratio of 95.11% was deposited by using the proposed model and the optimized deposition parameters.

sample

model

deposition

area


Input: The experimental results show that the control of the weld melting offset is the key factor in realizing the stability and accuracy of omni-directional GTAW-based AM.

experimental

weld

melting

AM

stability

accuracy


Input: Advancement in manufacturing technology, prototyping, machining etc.

manufacturing technology

machining

prototyping


Input: are concerned with material optimization, process optimization, financial optimization and sustainable development.

material

process optimization

optimization

sustainable


Input: The current review on characterization, applications and process study of various additive manufacturing (AM) processes deals with the systematic use of resources in product development.

process

processes

product development

additive manufacturing

AM


Input: The comprehensive description on additive manufacturing techniques, its applications and needs are illustrated.

additive manufacturing


Input: The attempt is to diagnose the research gap in the process study and to forecast the new methodology and applications in the all the field like automobile, aerospace, biomedical etc.

research

process

methodology

automobile

aerospace

biomedical


Input: through AM.

AM


Input: The tool making for friction stir welding purpose, complex geometries, etc.

tool

friction stir welding

complex geometries


Input: were fabricated without increasing the overall cost through AM techniques.

fabricated

AM techniques


Input: The applications of AM techniques in composite based materials are also characterized.

AM techniques

composite

materials


Input: The comparative analysis between subtractive and additive manufacturing are highlighted and future scope is tried to identify.

subtractive

additive manufacturing


Input: Internal defects in additive manufactured Mo are analyzed.

defects

additive manufactured


Input: 3D Computed Tomography is used to analyze the 3D information.


Input: Volume and sphericity distribution of defects are studied.

Volume

distribution

defects


Input: Formation mechanisms of different internal defects are proposed.

defects


Input: Relationship between defects and process parameters is disclosed.

defects

process parameters


Input: Molybdenum (Mo) is an important high-temperature structural material but has poor processability.

Molybdenum

Mo

material


Input: Additive manufacturing (AM) leads to a new possibility of fabricating Mo structural parts.

Additive manufacturing

AM

fabricating


Input: However, a large number of internal defects appear during welding and AM processes in Mo and its alloys, which is far from well understood and has greatly limited their application.

defects

welding

AM processes

Mo

alloys


Input: In this paper, the formation and evolution mechanisms of internal defects in Mo are systematically studied, based on the state-of-the-art high-resolution computed tomography.

evolution

defects

state-of-the-art

Mo

high-resolution

computed tomography


Input: This study demonstrates three main types of defects in Mo: (1) small spherical pores; (2) inverted pear-shaped pores; and (3) cavities.

defects

spherical

Mo

pores

pores


Input: The first type is similar to the observation in welded Mo, while the last two types are not reported before, which are associated with the heat cycling process during AM.

welded

AM

Mo

heat

process


Input: The formation mechanism of different types of internal defects is proposed based on the experimental observations.

mechanism

defects

experimental


Input: Material extrusion (MatEx) additive manufacturing ranges in size from the desktop scale fused filament fabrication (FFF) to the room scale big area additive manufacturing (BAAM).

Material extrusion

additive manufacturing

fused filament fabrication

FFF

additive manufacturing

area


Input: The principles of how FFF and BAAM operate are similar–polymer feedstocks are heated until molten and then extruded to form three-dimensional parts through layer-by-layer additive manufacturing.

FFF

extruded

additive manufacturing

polymer feedstocks

three-dimensional

layer-by-layer


Input: This study compares heat transfer in FFF and BAAM using finite element thermal modeling.

heat transfer

finite element

FFF

modeling


Input: Parameterization is performed across material properties, layer number, and print speed at the desktop and room scale for MatEx.

material properties

layer

print


Input: BAAM stays hotter than FFF for a longer period of time, which facilitates interlayer diffusion and weld formation, but can also lead to slumping or sagging.

FFF

diffusion

weld

lead


Input: Changes in thermal diffusivity affect FFF more than BAAM, with FFF exhibiting a local maximum in weld time at the thermal diffusivity of ABS.

thermal diffusivity

thermal diffusivity

FFF

FFF

weld

ABS


Input: For BAAM, the temperature and thermal history of the center of an extruded bead differs greatly from the surface of the bead, which has important implications for process monitoring, property prediction, and part performance.

temperature

extruded

bead

bead

surface

process monitoring

property

prediction

performance


Input: Wire arc additive manufacturing, WAAM, is a popular wire-feed additive manufacturing technology that creates components through the deposition of material layer-by-layer.

Wire arc additive manufacturing

WAAM

additive manufacturing

components

deposition

layer-by-layer

material


Input: WAAM has become a promising alternative to conventional machining due to its high deposition rate, environmental friendliness and cost competitiveness.

WAAM

conventional machining

high deposition rate


Input: In this research work, a comparison is made between two different WAAM technologies, GMAW (gas metal arc welding) and PAW (plasma arc welding).

research

technologies

WAAM

GMAW

gas metal arc welding

PAW

plasma arc welding


Input: Comparative between processes is centered in the main variations while manufacturing Mn4Ni2CrMo steel walls concerning geometry and process parameters maintaining the same deposition ratio as well as the mechanical and metallographic properties obtained in the walls with both processes, in which the applied energy is significantly different.

processes

variations

geometry

process parameters

deposition

properties

processes

manufacturing

steel

as

as

mechanical


Input: This study shows that acceptable mechanical characteristics are obtained in both processes compared to the corresponding forging standard for the tested material, values are 23% higher for UTS and 56% for elongation in vertical direction in the PAW process compared to GMAW (no differences in UTS and elongation results for horizontal direction and in Charpy for both directions) and without significant directional effects of the additive manufacturing technology used.

mechanical

processes

vertical

forging

PAW

GMAW

additive manufacturing

material

UTS

elongation

UTS

elongation


Input: Based on cold metal transfer welding, wire and arc additive manufacturing is used to manufacture 9Cr ferritic/martensitic nuclear grade steel component for the first time.

cold metal transfer

wire and arc additive manufacturing

manufacture

steel

component


Input: The microstructure mainly consists of untempered martensite laths showing columnar laths and equiaxed laths.

microstructure

martensite


Input: Positions at different heights along the deposition direction have no significant influence on micro hardness and tensile properties.

deposition direction

hardness

tensile properties


Input: Tensile properties in the horizontal and vertical directions show anisotropy.

Tensile properties

anisotropy

vertical


Input: Fracture surfaces mainly exhibit typical mixed mode fracture.

Fracture

fracture


Input: Wire and arc additive manufacturing (WAAM) technology was successfully applied to manufacture the 9Cr ferritic/martensitic nuclear grade steel for the first time.

Wire and arc additive manufacturing

WAAM

technology

manufacture

steel


Input: With the purpose of revealing how microstructure and mechanical properties are affected by the different locations within the manufactured wall, cold metal transfer (CMT) welding was used as heat source, the microstructure and mechanical properties of the additively manufactured 9Cr ferritic/martensitic wall in the different locations have been investigated.

microstructure

mechanical properties

manufactured

microstructure

mechanical properties

cold metal transfer

CMT

welding

additively manufactured

as

source


Input: The results show that the differences in the mechanical properties were related to the anisotropy in microstructure.

mechanical properties

microstructure

anisotropy


Input: The microstructure mainly consisted of untempered martensite laths showing columnar laths and equiaxed laths.

microstructure

martensite


Input: As the height of the deposited wall increased, the microstructures exhibited differences.

As

microstructures


Input: Positions at different heights had no significant influence on micro hardness and room-temperature tensile testing results.

hardness

tensile testing


Input: However, the tensile properties including the ultimate tensile strength, 0.2% offset yield strength and elongation exhibited anisotropy for the perpendicular to and parallel to the deposition direction.

tensile properties

ultimate tensile strength

strength

elongation

anisotropy

offset

deposition direction


Input: The defects and tensile fracture behavior were also analyzed carefully.

defects

fracture

tensile


Input: The findings suggest that, despite the emergency of a few shortcomings, the WAAM technology is a feasible method to obtain 9Cr ferritic/martensitic nuclear grade steel parts.

WAAM

technology

steel


Input: Wire arc additive manufacturing (WAAM) is a metal additive manufacturing process based on gas metal arc welding and it is known to be economically convenient for large metal parts with low complexity.

Wire arc additive manufacturing

WAAM

metal additive manufacturing

gas metal arc welding

be

metal

complexity


Input: The main issue WAAM is the sensibility to heat accumulation, i.e., a progressive increase in the internal energy of the workpiece due to the high heat input of the deposition process, that is responsible of excessive remelting of the lower layers and the related change in bead geometry.

WAAM

deposition process

heat accumulation

workpiece

heat

bead geometry


Input: A promising technique to mitigate such issue is to use an air jet impinging on the deposited material to increase the rate of convective heat transfer.

material

heat transfer


Input: Different samples are manufactured using AWS ER70S-6 as filler material, using as cooling approaches free convection and air jet impingement, with different interlayer idle times.

samples

manufactured

as

material

as


Input: The measurement of substrate temperatures has been used to validate the process simulation, used for obtaining the temperature field of the whole part.

measurement

substrate

process simulation

temperature


Input: The results indicate that air jet impingement has a significant impact on the process, limiting the progressive increase in the interlayer temperature as compared to free convection cooling.

impact

process

temperature

as

cooling


Input: From the results arise that the optimal idle time is 30 s, as a compromise between productivity and reduction of heat accumulation, independently from the cooling strategy.

s

as

productivity

reduction

heat accumulation

cooling


Input: Friction stir additive manufacturing (FSAM) was performed successfully using 2 mm thick sheets of 2195-T8 aluminum-lithium alloy.

Friction

additive manufacturing

mm

sheets

alloy


Input: The influence of the tool pin shape and process parameters on the interfacial bonding features among the additive manufactured layers was discussed, and the effects of interfacial defects on the performances of the additive build were analyzed based on microstructures, hardness profiles, and mechanical property evaluations.

tool

process parameters

interfacial bonding

defects

mechanical property

additive manufactured

additive

microstructures

hardness


Input: It is shown that the shape of the tool pin is one of the key factors in influencing the bonding interface between two manufactured layers.

tool

bonding

manufactured


Input: The cylindrical pin and the conical pin with three flats are not suitable for the FSAM process since very poor material mixing features are produced along the bonding interface.

cylindrical

process

bonding

material


Input: Although the material mixing degree of bonding interface is obviously improved at the advancing side (AS) interface of the nugget zone (NZ) by using the convex featured pin or the pin with three concave arc grooves, the material mixing degree at the retreating side (RS) interface of the NZ is always insufficient.

material

AS

material

bonding

interface

arc

interface


Input: Meanwhile, the weak-bonding defects along the bonding interfaces could be formed, which are originated from the hooking defects on the RS.

defects

bonding

defects

be


Input: The weak-bonding defects are related to the oxides and impurities existing at the original bonding interfaces as well as the insufficient stirring action of the tool pin.

defects

bonding

oxides

as

as

impurities

tool


Input: The welding rotation speeds of 800, 900 and 1000 rpm for giving welding speed of 100 mm/min were used in the additive manufacturing processes of 2195-T8 aluminum-lithium alloy, in which the optimum microstructure is obtained with the rotation speed of 800 rpm.

welding

welding

additive manufacturing processes

alloy

microstructure


Input: The soften degree for the multilayered build is obvious, and the hardness profiles across the different bonding interfaces are always uneven.

build

hardness

bonding


Input: Meanwhile, compared with the AS interface, the fluctuation of the hardness value at the RS interface is greater.

AS

hardness

interface


Input: The mechanical properties of the multilayered build are inhomogeneous, and the maximum tensile strength of the multilayered build is only reached the 56.6% of the base metal.

mechanical properties

build

build

tensile strength

base metal


Input: The mechanical properties are closely associated with the soften tendency of the material and the degree of the amelioration of weak-bonding defect along the bonding interface.

mechanical properties

defect

bonding

material


Input: The influence of the addition of filler powder on the microstructure and properties of laser-welded Ti2AlNb joints was comparatively investigated using scanning electron microscopy, transmission electron microscopy, electron back scattered diffraction, and tensile tests.

powder

microstructure

properties

scanning electron microscopy

transmission electron microscopy

diffraction

tensile tests


Input: The heat affected zone (HAZ) of laser-additive-welded joints was divided into B2, B2 + α2, and B2 + α2 + O—three regions with increasing distance from the fusion line.

heat affected zone

HAZ

fusion

O


Input: The HAZ of laser-welded joints could only be divided into two regions, viz., B2 + α2 and B2 + α2 + O.

HAZ

be

O


Input: The microstructure of the fusion zone was composed of a single B2 phase for both laser welding and laser-additive welding.

microstructure

fusion zone

phase

laser welding

welding


Input: Columnar grains were observed in the fusion zone of laser-welded joints, while the B2 grains in the fusion zone of laser-additive-welded joints were basically equiaxed.

Columnar grains

fusion zone

grains

fusion zone


Input: A misorientation angle distribution analysis showed that the fraction of high-angle grain boundaries of laser-additive-welded joints was higher than that of laser-welded joints.

distribution

fraction

grain boundaries


Input: The addition of filler powder promoted heterogeneous nucleation during solidification in laser-additive welding.

powder

heterogeneous nucleation

solidification

welding


Input: Following tensile tests at room temperature, failure tended to occur in the fusion zone of the laser-welded joints and in the HAZ of the laser-additive-welded joints.

tensile tests

temperature

failure

fusion zone

HAZ


Input: The laser-additive-welded joints exhibited better tensile properties because of the higher Mo content as well as the equiaxed microstructure of the fusion zone.

tensile properties

Mo

as

as

microstructure

fusion zone


Input: A flat specimen and a curved specimen with a thickness of 50 mm were excavated from a large circular wire+arc additive manufacturing (WAAM) mockup.

mm

wire+arc additive manufacturing

WAAM


Input: The biaxial internal residual stress distributions in the specimens were measured using the two-cut contour method.

internal residual stress

distributions

contour


Input: The stress distributions in the large circular WAAM mockup were deduced, and the effects of specimen shape and dimension on the remnant stress distributions in the specimens were discussed.

stress distributions

stress distributions

WAAM

dimension


Input: The investigated results show that the stress in the circular WAAM mockup has a similar distribution as that in thick multipass joints at the weld centerline, the stress in the curved specimen extracted from a large circular WAAM mockup can reflect the stress distribution trend in the mockup.

stress

stress

stress distribution

WAAM

WAAM

distribution

extracted

as

weld


Input: For specimens excavated from a large circular mockup, the specimen shape has no significant effect on the through-thickness axial stress distribution, while it has a significant effect on the hoop stress distribution.

stress distribution

stress distribution


Input: Carbon fiber reinforced plastic (CFRP) is an extremely beneficial composite material in the aerospace and automobile industries owing to its high-strength-to-weight ratio, high stiffness, lightweight, and corrosion resistance.

Carbon fiber

plastic

composite material

aerospace

automobile

stiffness

lightweight

corrosion resistance


Input: A thin layer material such as Titanium (Ti) is often used along with CFRP laminates to address these issues.

layer

as

Ti

laminates


Input: These techniques have several limitations including weight addition, stress cracking, delamination, and limited operating temperatures.

weight

temperatures

stress cracking

delamination


Input: These limitations can be readily addressed by the use of solid-state welding techniques based on ultrasonic energy.

be

solid-state welding


Input: One such technique is the Ultrasonic Additive Manufacturing (UAM) process, which is capable of fabricating 3D structures of CFRP/Ti laminar composites.

Ultrasonic Additive Manufacturing

UAM

fabricating

process

3D structures

composites


Input: Preliminary experimental studies proved the feasibility of using the UAM process to join CFRP/Ti stacks.

experimental

feasibility

process

UAM


Input: Further development of this process needs a detailed investigation of the process parameters.

process

process parameters


Input: This study aims to study the effect of critical process parameters including the ultrasonic energy and pre-surface roughness on the shear strength of the fabricated CFRP/Ti stacks using the UAM process.

process parameters

fabricated

process

roughness

shear strength

UAM


Input: The study found that both ultrasonic energy and surface roughness have a positive impact on the resulting shear strengths of the UAM fabricated structures.

surface roughness

shear strengths

impact

fabricated

UAM


Input: Magnetic Arc Oscillation was applied during the construction of single-pass multi-layer walls of low carbon steel and Ti6Al4V by the Gas Tungsten Arc Welding-based Wire and Arc Additive Manufacturing process, and the influence on the geometry and the process stability was evaluated.

Arc

Gas

Arc

process

geometry

process

construction

low carbon steel

Wire and Arc Additive Manufacturing


Input: The geometric features were assessed using transverse section macrographs and the effects of different patterns and frequencies of oscillation on the arc characteristics, metal transfer and weld pool behavior during the layer deposition were investigated using high speed and welding cameras.

arc

weld pool

deposition

metal

layer

welding


Input: Furthermore, the distribution of material along the wall length becomes more homogeneous.

distribution

homogeneous

material


Input: An explanation of the effects of Magnetic Arc Oscillation on the wall geometry based on forces that act on the molten metal during layer deposition was made.

Arc

geometry

forces

deposition

molten metal

layer


Input: Because of the swinging movement of the welding arc, the heat is distributed over a larger area, and the power density decreases.

welding

arc

heat

area

power

density


Input: Thus, fewer previous layers are remelted, and the volume and the weight of the weld pool reduce.

volume

weld pool

weight


Input: The weld pool temperature drops, and the surface tension force and the viscous friction increase.

weld pool

force

friction

temperature

surface tension


Input: The distribution of arc pressure also becomes less concentrated, and the arc force on the molten metal decreases.

distribution

arc

arc pressure

molten metal


Input: Additionally, a magnetic force appears on the molten metal, which contributes to a change in the direction of the resultant force on the weld pool.

force

weld pool

molten metal

resultant force


Input: The article presents new findings on arc stability in twin-wire robotic arc welding corresponding to the torch orientation and electrodes' position.

arc

orientation

arc welding

electrodes


Input: The two mutually influencing co-existing arcs affect the stability of counterpart arc, and thereby alter the weld bead properties.

stability

arc

weld bead

properties


Input: The investigation divulges that electrode positions and torch orientation significantly impact arc stability which in turn impacts the heat input and weld bead geometry.

electrode

orientation

impact arc

heat

weld bead geometry


Input: The arc penetration in tandem orientation is augmented by the secondary arc that operates in the same weld pool.

arc

orientation

arc

weld pool


Input: While the transverse orientation improves the arc stability and facilitates a wider weld bead with reasonable weld penetration suitable for applications such as wire additive manufacturing and cladding.

orientation

arc

weld bead

penetration

weld

as

additive manufacturing

cladding


Input: An approach for predicting arc stability as a function of process parameters is a significant contribution from this investigation.

arc

process parameters

as


Input: The insight into the arching phenomenon in twin-wire gas metal arc welding due to the investigation is expected to help the machine builders to design an appropriate controller that minimizes arc interference.

gas metal arc welding

machine

controller

design

arc


Input: This study presents investigations on the additive manufacturing of hot work steel with the energy-reduced gas metal arc welding (GMAW) process, which is a cold metal transfer (CMT) process.

additive manufacturing

gas metal arc welding

GMAW

cold metal transfer

CMT

hot work steel

process

process


Input: The paper analyses the influence of arc energy and the thermal field on the resulting mechanical properties and microstructure of the material.

arc

mechanical properties

microstructure

material


Input: The investigations were carried out with hot work tool steel X37CrMoV 5-1, which is used for the manufacturing of plastic moulds, hot extrusion dies, and forging dies.

tool

moulds

dies

dies

steel

plastic

manufacturing

hot extrusion

forging


Input: The results show that this steel can be used to generate 3D metal components or structures with high reproducibility, near-net-shaped geometry, absence of cracks, and a deposition rate of up to 3.6 kg/h.

steel

be

reproducibility

geometry

components

deposition rate


Input: The variation of the wire feed speed and the welding speed enables the production of weld beads of width up to 9.4 mm.

variation

weld beads

feed

welding

production

mm


Input: The mechanical properties of the generated structures can be adapted by the dominant thermal field, which in turn is influenced by the bypass temperature and the electric arc energy.

mechanical properties

be

temperature

electric arc


Input: If the bypass temperature is above the martensite start temperature (Ms), there is a homogeneous hardness level along the height of the additively manufactured structure height as long as the energy produced by the welding arc is enough to keep the temperature of all layers above Ms. Wire-arc additive manufacturing has become an alternative way to produce industrial parts.

temperature

temperature

temperature

martensite

as

as

homogeneous

arc

hardness

additively manufactured

welding

Wire-arc additive manufacturing

industrial


Input: In this work 15 kg walls are built with an effective building rate of 4.85 kg/h using an ER100 wire providing good tensile properties and toughness under welding conditions.

tensile properties

toughness

welding


Input: The thermal evolution of the walls during manufacturing is measured by thermocouples and an IR camera: it depends on process parameters, deposit strategy and the size of the part.

evolution

process parameters

manufacturing

thermocouples

camera

IR


Input: The walls are then characterised as deposit and after heat treatment through hardness, tensile and Charpy-V notch tests.

as

heat treatment

hardness

tensile

notch


Input: The results show a fine microstructure with unexpected retained austenite and coarse allotriomorphic ferrite in the as deposited walls.

microstructure

retained austenite

ferrite

as


Input: The final hardness values vary from about 220 to 280 HV2; the yield stress and tensile strength are 520 and 790 MPa, respectively, and a toughness of about 50 J is obtained at room temperature.

hardness

yield stress

tensile strength

toughness

MPa

temperature


Input: The heat treatment transforms the retained austenite, leading to an improvement of the yield stress to 600 MPa.

heat treatment

retained austenite

yield stress

MPa


Input: Ultrasonic additive manufacturing is a promising approach for making net-shaped multi-material laminates from material combinations difficult to process with fusion-based additive manufacturing techniques.

Ultrasonic additive manufacturing

additive manufacturing

multi-material laminates

process

material


Input: The properties of these multi-material laminates depend sensitively on the interface between the constituents, which can be decorated with pores as well as thin intermetallic layers.

properties

multi-material laminates

interface

be

as

as

intermetallic

pores


Input: Here, we develop process models for junction growth and interdiffusion during ultrasonic additive manufacturing of dissimilar metals.

process models

junction

ultrasonic additive manufacturing

metals


Input: These process models are validated against published experimental data, then used to generate process diagrams which reveal that high normal loads and high sonotrode velocities can reduce intermetallic growth while maintaining strong interlayer bonding.

process models

experimental data

process

bonding

sonotrode

intermetallic


Input: Ultrasonic additive manufacturing (UAM) is a solid-state manufacturing technology for producing near-net shape metallic parts combining additive ultrasonic metal welding and subtractive machining.

Ultrasonic additive manufacturing

UAM

manufacturing technology

subtractive machining

solid-state

metallic parts

additive

metal


Input: Even though UAM has been demonstrated to produce robust metal builds in Al–Al, Al–Ti, Al-steel, Cu–Cu, Al–Cu, and other material systems, UAM welding of high strength steels has proven challenging.

UAM

UAM

metal

material

steels

builds

strength


Input: This study investigates process and post-processing methods to improve UAM steel weld quality and demonstrates the UAM fabrication of stainless steel 410 (SS 410) builds which possess, after post-processing, mechanical properties comparable with bulk material.

investigates

post-processing

quality

post-processing

mechanical properties

UAM

UAM fabrication

steel

stainless steel

SS

material

builds


Input: Unlike UAM fabrication of softer metals, this study shows that increasing the baseplate temperature from 38∘C (100∘F) to 204∘C (400∘F) improves interfacial strength and structural homogeneity of the UAM steel samples.

UAM fabrication

UAM

metals

steel

temperature

strength

samples


Input: Further improvement in strength is achieved through post-processing.

strength

post-processing


Input: The hot isostatic pressing (HIP) post treatment improves the shear strength of UAM samples to 344 MPa from 154 MPa for as-welded samples.

hot isostatic pressing

HIP

UAM

shear strength

samples

MPa

MPa

samples


Input: Microstructural analyses with SEM and EBSD show no evidence of body centered cubic (BCC) ferrite to face centered cubic (FCC) austenite transformation taking place during UAM welding of SS 410.

Microstructural analyses

SEM

EBSD

body centered cubic

BCC

face centered cubic

FCC

ferrite

austenite

SS

UAM


Input: The weld quality improvement of UAM steel at higher baseplate temperatures is believed to be caused by the reduction of the yield strength of SS 410 at elevated temperature.

weld quality

temperatures

temperature

UAM

steel

be

SS

reduction

yield strength


Input: HIP treatment is shown to increase the overall hardness of UAM SS 410 from 204 ± 7 HV to 240 ± 16 HV due to the formation of local pockets of martensite.

HIP

UAM

hardness

SS

martensite


Input: Nanohardness tests show that the top of layer n is harder than the bottom of layer n+1 due to grain boundary strengthening.

layer

layer

grain boundary


Input: The locked in residual stresses in a monopile structure have a great impact on its fatigue life.

residual stresses

fatigue life

structure

impact


Input: The new emerged technology of additive manufacturing (AM), which is widely used in other industries such as aerospace and automotive, has the potential to significantly improve a lifespan of the structure by managing the residual stress fields and microstructure in the future monopiles, and moreover reduce the manufacturing cost.

technology

structure

microstructure

manufacturing cost

additive manufacturing

AM

industries

aerospace

automotive

as

residual stress


Input: In order to achieve this goal, new materials that are used for additive manufacturing parts fabrication and their behaviour in the harsh marine environment and under operational loading conditions need to be understood.

materials

additive manufacturing

fabrication

be


Input: Also purely welding fabrication technique employed during AM process is likely to significantly affect crack growth behaviour in air as well as in seawater.

welding fabrication

AM process

crack growth

as

as


Input: This paper presents a review of additive manufacturing technology and suitable techniques for offshore structures.

additive manufacturing


Input: Existing literature that reports current data on fracture toughness and fatigue crack growth tests conducted on AM parts is summarised and analysed, highlighting different steel grades and applications, with the view to illustrating the requirements for the new optimised functionally graded structures in offshore wind structures by means of AM technique.

data

fracture

fatigue crack growth

AM parts

steel

functionally graded structures

AM technique


Input: In this paper, the results of two different wire based additive-layer-manufacturing systems are compared: in one system Ti-6Al4V is deposited by a Nd: YAG laser beam, in the other by an arc beam (tungsten inert gas process).

Nd: YAG

laser beam

arc

process

tungsten inert gas


Input: Mechanical properties of the deposits and of plate material are presented and evaluated with respect to aerospace material specifications.

Mechanical properties

material

aerospace

specifications


Input: The mechanical tests including static tension and high cycle fatigue were performed in as-built, stress-relieved and annealed conditions.Generally, the mechanical properties of the components are competitive to cast and even wrought material properties and can attain properties suitable for space or aerospace applications.

mechanical tests

fatigue

mechanical properties

properties

properties

components

cast

wrought material

aerospace


Input: Realizing improved strength in composite metallic materials remains a challenge using conventional welding and joining systems due to the generation and development of brittle intermetallic compounds caused by complex thermal profiles during solidification.

strength

brittle

composite

materials

thermal profiles

solidification

conventional welding

joining


Input: Here, wire arc additive manufacturing (WAAM) process was used to fabricate a steel-nickel structural component, whose average tensile strength of 634 MPa significantly exceeded that of feedstock materials (steel, 537 MPa and nickel, 455 MPa), which has not been reported previously.

wire arc additive manufacturing

WAAM

fabricate

process

structural component

average

MPa

MPa

MPa

strength

feedstock materials

steel

nickel


Input: The as-fabricated sample exhibited hierarchically structural heterogeneity due to the interweaving deposition strategy.

sample

heterogeneity

deposition


Input: The improved mechanical response during tensile testing was due to the inter-locking microstructure forming a strong bond at the interface and solid solutions strengthening from the intermixing of the Fe and Ni increased the interface strength, beyond the sum of parts.

mechanical response

microstructure

interface

interface

tensile testing

forming

solid solutions

Fe

Ni


Input: The research offers a new route for producing high-quality steel-nickel dissimilar structures and widens the design opportunities of monolithic components, with site-specific properties, for specific structural or functional applications.

research

properties

design

monolithic

components


Input: Wire Arc Additive Manufacturing (WAAM) is a fusion- and wire-based additive manufacturing technology which has gained industrial interest for the production of medium-to-large components with high material deposition rates.

Wire Arc Additive Manufacturing

WAAM

wire-based additive manufacturing

production

technology

industrial

components

material

deposition rates


Input: However, in-depth studies on performance indicators that incorporate economic and environmental sustainability still have to be carried out.

performance

sustainability

be


Input: The first aim of the paper has been to quantify the performance metrics of WAAM-based manufacturing approaches, while varying the size and the deposited material of the component.

performance

manufacturing approaches

material

component


Input: Wire-arc additive manufacturing is an additive manufacturing technology which allows for high deposition rates and is well suited for manufacturing larger parts in a short time compared to other additive manufacturing technologies.

Wire-arc additive manufacturing

additive manufacturing

manufacturing

additive manufacturing

high deposition rates


Input: The technology has already received considerable industrial take-up for various materials and applications.

technology

industrial

various materials


Input: The aim of this work is to investigate the alloy EN AW 6016 as wire stock for WAAM.

alloy

as

WAAM


Input: To establish this, aluminum wire was produced by wire drawing.

aluminum

wire drawing


Input: Using this wire, specimens were produced on base plate material using a variety of process parameters.

material

process parameters


Input: These parts were then used to evaluate the mechanical properties.

mechanical properties


Input: Further properties such as porosity and hardness were investigated using light optical microscopy.

properties

as

hardness

optical microscopy


Input: Based on the results, the potential of the alloy for WAAM of lightweight parts is discussed.

alloy

WAAM

lightweight


Input: Cu-Al alloy was in-situ fabricated by twin wire arc additive manufacturing.

alloy

in-situ fabricated

wire arc additive manufacturing


Input: Addition of about 2% silicon to the copper-aluminum alloy helps to increase the hardness by 0.5–1 times.

silicon

alloy

hardness