Input: With the aluminum content increases, the yield strength increases 150 MPa.

aluminum

yield strength

MPa


Input: CuAl2 with the different crystal structures were synthetized.

crystal structures


Input: Present work investigated the use of Cold Metal Transfer (CMT) welding for additive manufacturing of copper‑aluminum alloys with addition of silicon in small amount.

Cold Metal Transfer

CMT

welding

additive manufacturing

alloys

silicon


Input: The additive manufacturing was successfully demonstrated through two samples with the 4.34% (sample-1) and 6.58% (sample-2) aluminum content, which is not much different with the content of the design.

additive manufacturing

samples

aluminum

design


Input: The analyses of performance of samples reveal that both samples have good strength and ductility.

performance

samples

samples

strength

ductility


Input: It is also found addition of silicon in small amount (2.1% –2.4%) effectively improves hardness, tensile strength and 0.2% offset Yield Strength in comparison to pure copper‑aluminum alloy.

silicon

alloy

hardness

tensile strength

Strength

offset


Input: The results of X-ray diffraction (XRD), showed that sample-2 possessed CuAl2 with different crystal structure whereas sample-1 did not.

X-ray diffraction

XRD

crystal structure


Input: It is found that an increase in aluminum caused both tensile strength and 0.2% offset Yield Strength to increase, however, increase in yield strength was very significant (155 MPa i.e.

aluminum

tensile strength

Strength

yield strength

offset

MPa


Input: In this study, the 0.2Pct offset Yield Strength of sample-1 is 150 MPa more than that of sample-2.

offset

MPa

Strength


Input: Embedding with additive manufacturing (AM) is a process of incorporating functional components, such as sensors and actuators, in the printed structure by inserting them into a specially designed cavity.

additive manufacturing

AM

process

functional components

structure

as

actuators

designed


Input: The print process has to be interrupted after the cavity is printed to insert the component.

print

be

insert

component


Input: This allows for multifunctional structures to be created directly from the build plate.

be

build plate


Input: However, previous research has shown that this process interruption causes failure at the paused layer due to the cooling between the layers.

research

process

failure

layer

cooling


Input: The presence of the designed cavity further impacts the strength of the part due to a reduction in the effective cross-section in contact between the paused and the resumed layers.

designed

strength

reduction

contact


Input: This research presents a methodology to predict the weld strength between the layers of an embedded material extrusion structure by obtaining the thermal history at the layer interface as a result of process interruption.

research

methodology

interface

process

weld strength

material extrusion

layer

as


Input: An infrared camera and an embedded thermocouple are used to obtain the thermal history of the depositing fresh layer and of the layer interface, respectively.

infrared

interface

camera

thermocouple

layer

layer


Input: The impact of toolpath design on the thermal history of the layer interface is considered by dividing the cross-section area into zones with similar thermal history.

impact

interface

toolpath

layer

area

design


Input: Polymer weld theory is utilized to predict the strength at these different zones, where material properties are obtained through rheology measurements.

Polymer

strength

rheology

material properties


Input: These strength values for the zones are then used to predict the load at failure for different specimens by treating them as composites.

strength

failure

as


Input: Findings confirm that this approach can be used to more accurately predict tensile loads at failure for embedded structures, with errors ranging from 1% to 20% depending on the toolpath geometry.

be

accurately

tensile loads

failure

errors

geometry

toolpath


Input: Additive manufacturing (AM) is the umbrella term that covers a variety of techniques that build up structures layer-by-layer as opposed to machining and other subtracting methods.

Additive manufacturing

AM

machining

build

layer-by-layer

as


Input: It keeps evolving as an important technology in prototyping and the development of new devices.

as

technology

prototyping


Input: However, using AM on a larger scale is still challenging, as traditional methods require the AM machines to be larger than the manufactured structure.

AM

as

be

AM machines

manufactured


Input: The focus in this paper is the feasibility of large-scale AM of metallic materials by arc welding.

feasibility

AM

arc welding

metallic materials


Input: A series of experiments with robotic arc welding using an ABB IRB2400/10 robot are presented and discussed.

arc welding

robot


Input: These experiment will help map some of the challenges that need to be addressed in future work.

experiment

be


Input: Hydrodynamic flow is used for surface finishing of additive manufactured channels.

surface finishing

additive manufactured


Input: The surface finish quality (Ra and Rz) of additive manufactured channels improves by > 90%.

surface finish

quality

additive manufactured


Input: The surface integrity of the channels also improves after surface finishing.

surface integrity

surface finishing


Input: A surface roughness ratio of ≈1.0 is achieved in the additive manufactured channel.

surface roughness

additive manufactured


Input: The surface finishing of internal channels for components built using additive manufacturing is a challenge.

surface finishing

additive manufacturing

components


Input: The resulting surface finish uniformity of additive manufactured internal channels (such as fuel transfer lines and cooling passages) is an issue.

surface finish

additive manufactured

cooling

as

transfer lines


Input: Therefore, we propose a novel surface finishing technique using controlled hydrodynamic multiphase flow with abrasion phenomenon to overcome the challenges in the surface finishing of additive manufactured internal channels.

surface finishing

surface finishing

additive manufactured


Input: In this study, we performed the internal surface finishing on AlSi10Mg components manufactured by direct metal laser sintering.

surface finishing

direct metal laser sintering

manufactured


Input: We investigated the surface finish potential of the proposed hydrodynamic cavitation abrasive finishing (HCAF) by varying the process parameters, namely, the hydrodynamic upstream and downstream fluid pressures, fluid temperature, abrasive concentration, and processing time.

surface finish

cavitation

process parameters

abrasive

fluid

fluid

abrasive


Input: The HCAF process resulted in greater than 90% (Ra and Rz) surface finish improvements with an acceptable thickness loss from the internal channels.

process

surface finish


Input: We precisely mapped the surface morphology transformation at the demarcated zones over the processing time and explained the material removal mechanism.

surface morphology

material

mechanism


Input: In addition, we analyzed and discussed the surface integrity of the channels in terms of the microstructure, surface hardness, and residual stress.

surface integrity

microstructure

surface

hardness

residual stress


Input: Furthermore, we performed large-area surface topography measurements.

surface topography


Input: Then, we analyzed the resulting areal surface texture parameters to determine the uniformity and flatness of the surface after internal surface finishing.

surface texture

parameters

surface

flatness

surface finishing


Input: Finally, we discussed the significance of using the proposed HCAF process for complex additive manufactured internal channels.

process

additive manufactured


Input: Additive manufacturing can produce very complex and highly integrated parts that can not be manufactured by traditional methods.

Additive manufacturing

be


Input: The aim of this study was to find out the laser weldability of the printed AlSi10Mg material without filler material.

laser

material


Input: The laser used in these welding experiments was Yb: YAG disk laser.

laser

laser

welding

Yb

YAG


Input: The laser wavelength was 1030 nm and the maximum output power on the workpiece surface was 4 kW.

laser

power

workpiece

surface


Input: AlSi10Mg is a widely used material in parts that are produced utilizing the SLM technique.

material

SLM


Input: The material has very good corrosion resistance properties, good electrical conductivity and excellent thermal conductivity.

material

corrosion resistance

electrical conductivity

thermal conductivity


Input: AlSi10Mg has proven to be much easier to print than steel materials, so it is a popular material also in prototype production.

be

steel materials

material

print

production

prototype


Input: Based on welding tests, laser welding without filler material is suitable for AlSi10Mg material and the static strength of the weld is reasonably good compared to the base material.

welding

laser welding

material

material

strength

weld


Input: However, AlSi10Mg can be found to be challenging due to its composition.

be

be

composition


Input: Additive manufacturing has experienced a remarkably growth over the last few years, making possible not only to make prototypes, but also to produce final products, so nowadays most of recent works are focused in metal additive manufacturing.

Additive manufacturing

metal additive manufacturing

prototypes


Input: The main objective of this work is to show the first experiences in the development of a cost effective metal additive manufacturing system on the basis of gas metal arc welding (GMAW).

metal additive manufacturing

gas metal arc welding

GMAW


Input: The proposed system, wire and arc additive manufacturing (WAAM), integrates a cold metal transfer (CMT) welding equipment patented by Fronius®, and a CNC milling machine Optimus with three axis and it presents the advantages to reduce the heat accumulation originated using a conventional GMAW equipment and the possibility to implement surface finish operations by milling.

wire and arc additive manufacturing

WAAM

cold metal transfer

CMT

welding

CNC milling

GMAW

milling

equipment

equipment

heat accumulation

surface finish


Input: Additive processes show a smaller amount of wasted material.

Additive

material


Input: For material removal ratios over 55% additive processes show less demand of energy.

material

additive


Input: For material removal ratios over 75% additive processes show less processing time.

material

additive


Input: This paper aims to analyze and compare the electrical energy and material efficiency of machining, additive and hybrid manufacturing.

electrical

material

additive

machining

hybrid manufacturing


Input: The analysis of the manufacturing processes is based on machine tool data from a sample process.

manufacturing processes

machine tool

data

sample

process


Input: To get a generalized statement about the energy consumption of the investigated processes the electrical energy demand was extrapolated as a function of the material removal ratio.

processes

electrical

as

material


Input: The results indicate that hybrid manufacturing becomes beneficial from an environmental point of view compared to milling, when the material removal ratio exceeds 55%.

hybrid manufacturing

milling

material


Input: The electrical break-even point for selective laser melting is approximated to 82% material removal ratio from data extrapolation.

electrical

selective laser melting

material

data


Input: Subsequently, opportunities for electrical energy and material efficiency improvements are presented for these technologies to gain an understanding of how each can contribute to a more sustainable manufacturing landscape.

electrical

material

technologies

sustainable manufacturing

gain


Input: The chemical composition of the deposited metal could be estimated.

chemical composition

metal

be


Input: The chemical composition could be changed gradually using proposed process.

chemical composition

process

be


Input: Wire and arc-based additive manufacturing (AM) is an additive manufacturing technique applying arc welding technology, where the metal melted by the arc discharge is accumulated and deposited.

additive manufacturing

AM

additive manufacturing

arc welding

metal

melted

arc


Input: High-performance products with an excellent mechanical or chemical properties can be obtained using more than two materials through wire and arc-based AM.

mechanical

properties

materials

be

AM


Input: However, thermal stress and residual stress can form around the interface between two materials.

thermal stress

residual stress

interface

materials


Input: Therefore, the objective of this study is to control the chemical composition of the deposited metal so that it changes gradually near the interface.

chemical composition

interface

metal


Input: Intermediate layers, with controlled chemical compositions, were inserted between the materials boundary.

chemical compositions

materials boundary


Input: To regulate the chemical composition of the deposited metal, a filler wire was added into the molten pool during the deposition process.

chemical composition

molten pool

metal

deposition process


Input: Results revealed that the chemical composition changed gradually near the interface using the proposed method.

chemical composition

interface


Input: Selective laser melting (SLM) is gaining increasing relevance in industry.

Selective laser melting

SLM

industry


Input: Residual deformations and internal stresses caused by the repeated layerwise melting of the metal powder and transient cooling of the solidified layers still presents a significant challenge to the profitability and quality of the process.

Residual deformations

transient

quality

process

internal stresses

melting

cooling

metal powder


Input: Excessive distortions or cracking may lead to expensive rejects.

cracking

lead


Input: In practice, critical additively manufactured parts are either iteratively pre-compensated or redesigned based on production experience.

additively manufactured

production


Input: To satisfy the need for improved understanding of this complex manufacturing process, CAE software providers have recently developed solutions to simulate the SLM process.

manufacturing process

SLM

CAE

process


Input: ANSYS Additive Print and ANSYS Additive Suite.ANSYS Additive Print (AAP), a user-oriented software, and ANSYS Additive Suite (AAS), a software requiring advanced experience with Finite Element Methods (FEM), are investigated and validated with regard to residual deformations.

ANSYS

ANSYS

ANSYS

Additive

Additive

Additive

Additive

software

software

Finite Element Methods

FEM

residual deformations


Input: For the evaluation of the two programs, calibration and validation geometries were printed by SLM in Ti–6Al–4V and residual deformations have been measured by 3D scanning.

calibration

validation geometries

residual deformations

SLM

3D scanning


Input: The results have been used for the calibration of isotropic and anisotropic strain scaling factors in AAP, and for sensitivity analyses on the effect of basic model parameters in AAS.

calibration

sensitivity analyses

model

isotropic

anisotropic


Input: The actual validation of the programs is performed on the basis of different sample geometries with varying wall thickness and deformation characteristic.While both simulation approaches, AAP and AAS, are capable of predicting the qualitative characteristics of the residual deformations sufficiently well, accurate quantitative results are difficult to obtain.

validation

sample

geometries

deformation

qualitative

residual deformations

wall thickness

simulation

accurate


Input: AAP is more accessible and yields accurate results within the calibrated regime.

accurate

calibrated


Input: Extrapolation to other geometries introduces uncertainties, however.

geometries


Input: Numerical efforts and modelling uncertainties as well as requirements for an extensive set of material parameters reduce its practicality, however.

modelling

as

as

material

set


Input: More appropriate calibration geometries, continuing extension of a more reliable material database, improved user guidelines and increased numerical efficiency are key in the future establishment of the process simulation approaches in the industrial practice.

calibration

material

database

process simulation

industrial


Input: The loss of elemental Mg was non-negligible during WAAM.

Mg

WAAM


Input: With the loss rate of elemental Mg increasing, the tensile strength and hardness of WAAM component decreased.

Mg

tensile strength

hardness

WAAM

component


Input: In WAAM component of Al-Mg alloy, the lattice parameters decreased with the Mg loss rate increasing.

WAAM

component

Al-Mg alloy

Mg

lattice


Input: Elemental Mg is easily evaporated or burnt during welding or wire + arc additive manufacturing (WAAM), and results in a fluctuation of the composition and mechanical performances.

Mg

evaporated

welding

wire + arc additive manufacturing

WAAM

composition

mechanical


Input: Elemental Mg loss during the WAAM of Al–Mg alloy was investigated and the effect of Mg loss on the mechanical properties was discussed based on results from the chemical composition measurement and mechanical properties test.

Mg

alloy

Mg

WAAM

mechanical properties

chemical composition

mechanical properties


Input: The elemental Mg distribution in the WAAM component was uniform, but obvious element enrichment occurred near the fusion zone of the substrate.

Mg

element

substrate

distribution

fusion zone

WAAM

component


Input: With an increase in the loss rate of elemental Mg, the tensile strength and average hardness of the WAAM component decreased, whereas the elongation increased.

Mg

tensile strength

elongation

average

WAAM

component


Input: During the WAAM of the Al–Mg alloy, with an increase in the Mg loss rate, the lattice parameters decreased because the solid solubility decreased in the Al matrix during the WAAM.

WAAM

WAAM

alloy

Mg

Al

lattice

solubility


Input: Ring rolling is a flexible forming process used to produce seamless rings with various dimensions and cross sections.

Ring rolling

forming process

dimensions

cross sections


Input: For smaller rings of up to 500 mm diameter, mechanical ring rolling machines can be used.

mm

rolling

diameter

mechanical

machines

be


Input: A special design is a 4-mandrel-table rolling mill, which achieves high productivity due to the fact that the precursor rings are continuously conveyed through the roll gap by rotation of the table.

design

rolling mill

productivity

precursor


Input: The mechanical machines are usually integrated into a process chain that involves shearing of blocks, forging of blanks and ring rolling as the final process step.

mechanical

machines

process chain

shearing

forging

ring rolling

as

process


Input: Especially profiled cross sections may require multiple forming steps to reach the final ring geometry.

cross sections

geometry

forming


Input: To increase the flexibility of the process, it seems viable to use highly productive additive manufacturing processes such as wire-arc additive manufacturing (WAAM) to produce pre-forms for the ring rolling process.

flexibility

process

process

additive manufacturing processes

additive manufacturing

WAAM

ring rolling

as


Input: WAAM is based on arc welding and allows for processing various materials with high deposition rates.

WAAM

arc welding

various materials

high deposition rates


Input: In this case, a more complex cross section can be manufactured, so that a single ring rolling stage may be sufficient.

cross section

be

be

ring rolling


Input: However, no previous research on ring rolling of additively manufactured pre-form is known.

research

ring rolling

additively manufactured


Input: The present contribution aims at analyzing the hot forming behavior of pre-forms made by WAAM during ring rolling.

hot forming

WAAM

ring rolling


Input: The microstructure evolution and the achieved mechanical properties will be evaluated.

microstructure evolution

mechanical properties

be


Input: The goal of this project is to determine the efficiency of 3D printed welding jigs in pre-series body shops.

3D printed

jigs


Input: The design of these jigs and how they function compared to conventional jig systems is analyzed.

design

jigs

jig


Input: Additive manufactured parts possess the advantage of easier production of complex parts which would serve the purpose of designing custom jigs for different intricate detailed parts with odd orientations.

Additive manufactured parts

production

jigs

orientations


Input: While machining custom jigs can be costly, 3D printing these jigs provides precision as well as reduces costs and setup time since they are designed for their specific application.

machining

3D printing

jigs

jigs

be

as

as

precision

designed


Input: Large components can be made by laser welding EBM-built plates to wrought counterparts.

components

be

laser welding

wrought


Input: Influence of the welding angles between EBM build direction and weld bead was studied.

welding

EBM

build direction

weld bead


Input: Microhardness of each zone is determined by the local microstructure.

Microhardness

microstructure


Input: Tensile properties depend on the EBM base metal due to the internal defects.

Tensile properties

EBM

base metal

defects


Input: The mechanism of stress during uniaxial tension is discussed based on columnar grains and the internal defects.

mechanism

defects

stress

columnar grains


Input: Electron beam melting (EBM) is an established powder-bed additive manufacturing process for small-to-medium-sized components of Ti-6Al-4V.

Electron beam melting

EBM

additive manufacturing process

components


Input: For further employing EBM on fabricating large-scale components, an effort has been made by joining EBM-built Ti-6Al-4V plates to wrought counterparts using laser welding, and the welding angles between EBM build direction and weld bead have been chosen as 0°, 30° and 45°.

EBM

fabricating

joining

laser welding

welding

EBM

components

as

wrought

weld bead

build direction


Input: The influence of the welding angles on the microstructure, microhardness of base metals, fusion zone, and heat-affected zones, as well as the macro tensile test have been characterized.

welding

microstructure

microhardness

fusion zone

base metals

as

as

macro


Input: The microhardness of each zone is determined by the local microstructure, and the macro tensile properties largely depend on the EBM base metal due to the internal defects generated during the EBM process.

microhardness

microstructure

properties

defects

macro

EBM

EBM

base metal


Input: The effect of welding angles on tensile strengths is not significant, while the elongation drops from 9.4% to 5.8% as the welding angle increases from 0° to 45°.

welding

welding

tensile strengths

elongation

as


Input: The mechanism of stress during uniaxial tension on EBM base metal is discussed based on the stress state of columnar grains and the internal defects.

mechanism

defects

stress

stress

columnar grains

EBM

base metal


Input: Wire-arc additive manufacturing (WAAM) has received substantial attention in recent years due to the very high build rates.

Wire-arc additive manufacturing

WAAM

build rates


Input: When bulky structures are generated using standard layer-by-layer tool paths, the build rate in the outer contour of the part may lag behind the build rate in the interior.

standard

layer-by-layer

build rate

build rate

contour


Input: In WAAM, the profile of a single weld bead resembles a parabola.

WAAM

profile

weld bead


Input: In order to keep the build rate constant at each point of the layer, optimal overlapping distances can be determined.

build rate

layer

be


Input: This paper presents novel multi-bead overlapping models for tool path generation.

tool path


Input: Mathematical models are established to minimize valleys between adjacent weld beads by accounting for the overlapping volume.

Mathematical

weld beads

volume


Input: The proposed models are validated by manufacturing solid blocks from mild steel with the recommended overlapping distances.

manufacturing

mild steel


Input: Macrographs are recorded to analyze the boundary profiles.

boundary


Input: High-integrity ceramic-metal composites combine electrical, thermal, and corrosion resistance with excellent mechanical robustness.

ceramic-metal

electrical

mechanical

corrosion resistance


Input: Ultrasonic additive manufacturing (UAM) is a low temperature process that enables dissimilar material welds without inducing brittle phases.

Ultrasonic additive manufacturing

UAM

temperature

process

material

brittle


Input: In this study, multiple layers of Yttria-stabilized zirconia (YSZ) films are jointed between layers of Al 6061-H18 matrix using a 9 kW UAM system.

zirconia

YSZ

Al

UAM


Input: UAM is advantageous over existing metal-ceramic composite fabrication techniques by continuously joining ceramics to metals at a speed of 2 m/min while requiring a moderate temperature that is 55% of the melting point of aluminum.

UAM

joining

composite

ceramics

metals

aluminum

temperature

melting point


Input: The welding interface, which is found to include a 10 nm thick diffusion zone, is investigated using optical microscopy and energy-dispersive X-ray (EDX) spectroscopy.

welding interface

diffusion

spectroscopy

optical microscopy

X-ray

EDX


Input: The shear strengths of the as-welded and heat-treated composites are 72 MPa and 103 MPa, respectively.

shear strengths

heat-treated

composites

MPa

MPa


Input: The shear deformation and failure mechanism of the YSZ-Al composites are investigated via finite element modeling.

deformation

finite element

failure mechanism

composites


Input: Additive manufacturing based method was used to join Polypropylene to Al-Mg alloy.

Additive manufacturing

Polypropylene

Al-Mg alloy


Input: Obtained joint was a combination of welding and mechanical lock among constituents.

joint

welding

mechanical


Input: Additive filling pattern and printing temperature affected mechanical behavior.

Additive

pattern

temperature

mechanical


Input: Introduced method was a fast and versatile technique for joining metal to polymer.

joining

polymer


Input: Fused Deposition Modeling with Polypropylene filament was employed to make a lap joint between Polypropylene and pre-punched Al-Mg alloy sheets, in the form of bonds between the polymeric substrate and the additive part and mechanical lock between the additive part and aluminum base sheet.

Fused Deposition Modeling

Polypropylene filament

Polypropylene

Al-Mg alloy

substrate

additive

additive

aluminum

sheet

lap

joint

mechanical


Input: Effects of the joint interface area (hole diameter of 5–13 mm) and preheating of the substrates (room temperature, 50 and 90℃) were investigated on the mechanical properties of the joints.

joint interface

diameter

mechanical properties

area

temperature

mm

preheating


Input: Peak load in the tensile-shear and cross-tension tests increased with enhancement of the joint interface area (up to ˜280 N and ˜160 N, respectively).

joint interface

area

N

N


Input: Preheating of the substrates increased the joint strength via improvement in the bonds between the polymer sheet and the additive part and increase in the adhesion force between the printed layers.

Preheating

joint

polymer

additive

adhesion


Input: Tungsten is receiving increasing interest as a plasma facing material in the ITER fusion reactor, collimators, and other structural, high temperature applications.

Tungsten

as

plasma

fusion

facing

temperature


Input: Concurrently, there is a demand for manufacturing techniques capable of processing tungsten into the desired geometries.

manufacturing

tungsten

geometries


Input: Additive manufacturing is a promising technique able to produce complex parts, but the structural integrity is compromised by microcracking.

Additive manufacturing

structural integrity


Input: This work combines thermomechanical simulations with in situ high-speed video of microcracking in single laser-melted tracks, visualizing the ductile-to-brittle transition.

thermomechanical

in situ

transition

simulations


Input: Microcracking is shown to occur in a narrow temperature interval between 450 K–650 K, and to be strain rate dependent.

temperature

K

K

be


Input: The size of the crack-affected area around the scan track is determined by the maximum Von Mises residual stress, whereas crack network morphology depends on the local orientation of the principal stress.

area

residual stress

principal stress

morphology

local orientation


Input: The fundamental understanding provided by this work contributes to future efforts in crack free, additively manufactured tungsten.

additively manufactured


Input: Due to rapid, localized heating and cooling, distortions accumulate in additive manufactured laser metal deposition (LMD) components, leading to a loss of dimensional accuracy or even cracking.

heating

cooling

additive manufactured

LMD

metal deposition

cracking

components

dimensional accuracy


Input: Numerical welding simulations allow the prediction of these deviations and their optimization before conducting experiments.

welding

simulations

prediction

optimization


Input: To assess the viability of the simulation tool for the use in a predictive manner, comprehensive validations with experimental results on the newly-built part need to be conducted.In this contribution, a predictive, mechanical simulation of a thin-walled, curved LMD geometry is shown for a 30-layer sample of 1.4404 stainless steel.

simulation

experimental

geometry

sample

be

stainless steel

mechanical

LMD


Input: The part distortions are determined experimentally via an in-situ digital image correlation measurement using the GOM Aramis system and compared with the simulation results.

in-situ

digital image correlation

simulation


Input: With this benchmark, the performance of a numerical welding simulation in additive manufacturing is discussed in terms of result accuracy and usability.

benchmark

performance

welding

additive manufacturing

simulation

accuracy


Input: Welding of dissimilar metals is challenging, particularly between crystalline metals and metallic glasses (MGs).

Welding

metals

metals

metallic glasses


Input: In this study, Zr65.7Cu15.6Ni11.7Al3.7Ti3.3 (wt%) MG structures were built on 304 stainless steel (SS) substrates by laser-foil-printing (LFP) additive manufacturing technology in which MG foils were laser welded layer-by-layer onto the SS substrate with a transition route, i.e., SS → V → Ti → Zr → MG.

MG

stainless steel

SS

LFP

MG

SS

SS

V

Ti

Zr

MG

additive manufacturing

laser

layer-by-layer

transition


Input: The direct welding of MG on SS would lead to the formation of various brittle intermetallics and the consequent peeling off of the welded MG foils from the SS substrate, which could be resolved via the use of V/Ti/Zr intermediate layers.

welding

welded

MG

SS

lead

MG

SS

be

brittle


Input: The chemical composition, formed phases, and micro-hardness were characterized in the dissimilar joints by energy dispersive spectroscopy, X-ray diffraction, and micro-indentation.

chemical composition

energy dispersive spectroscopy

X-ray diffraction


Input: Since the intermediate materials were highly compatible with the base metals or the adjacent intermediate metals, undesirable intermetallics were not detected in the dissimilar joint.

materials

joint

base metals

metals

intermetallics


Input: The bonding tensile strength between the SS substrate and the MG part with intermediate layers was measured about 477 MPa.

bonding

MPa

strength

SS

MG


Input: The manufacturing of components from the titanium alloy Ti-6Al-4 V is of great significance for many industrial sectors.

manufacturing

components

titanium alloy Ti-6Al-4 V

industrial sectors


Input: The production of high-performance Ti-6Al-4 V components typically requires multiple hot forging steps and leads to parts with tolerances that need extensive machining to create the final shape.

production

forging

machining

Ti-6Al-4 V

components

tolerances


Input: For many applications, net-shape technologies such as additive manufacturing (AM) could enable a higher material yield.

technologies

as

material

additive manufacturing

AM


Input: Thus, the advantages of AM and forging operations could be exploited by combining both processes to new hybrid process chains.

AM

forging

be

processes

process chains


Input: The present study investigates the use of Wire-Arc additive manufacturing (WAAM) for hybrid manufacturing of Ti-6Al-4 V aerospace components.

investigates

hybrid manufacturing

Wire-Arc additive manufacturing

WAAM

Ti-6Al-4 V

aerospace components


Input: Two process routes are investigated that combine forming and AM processes.

process

forming

AM processes


Input: In the first process route, a WAAM process is used to generate a pre-shaped semi-finished part.

process

process

WAAM


Input: The semi-finished part will then be forged using a single forming tool to obtain the final part contour.

be

forming

contour


Input: The second process route utilizes a conventionally forged pre-form, onto which features of the final workpiece are added using WAAM.

process

workpiece

WAAM


Input: The results confirm that hybrid technologies combining WAAM and forging are very promising for Ti-6Al-4 V part production.

hybrid technologies

WAAM

forging

production

Ti-6Al-4 V


Input: A jet engine blade produced by WAAM and subsequent forging shows microstructures typically produced in conventional processing of Ti-6Al-4 V alloy and exhibits tensile properties, which exceed the specification level of cast and forged Ti-6Al-4 V material.

WAAM

forging

cast

microstructures

Ti-6Al-4 V alloy

Ti-6Al-4 V

material

tensile properties

specification


Input: Features created by WAAM on forged pre-forms are shown to reach the mechanical properties required to combine both technologies.

WAAM

mechanical properties

technologies


Input: The combination of WAAM and forging may hence be used to develop new manufacturing chains that allow for higher material yield and flexibility than conventional forging.

WAAM

forging

forging

be

material

manufacturing chains

flexibility


Input: This paper explores the application of the ‘mortise-and-tenon’ concept for joining hollow section aluminium profiles to composite strips or sheets.

joining

aluminium

composite

sheets


Input: Wire arc additive manufacturing is combined with joining by forming to fabricate the tenons and to obtain the mechanical interlocking with the mortises available in the strips (or sheets).

Wire arc additive manufacturing

joining

forming

fabricate

mechanical

sheets


Input: The workability limits are established by means of an analytical model that combines plastic deformation, instability and fracture.

limits

model

fracture

plastic deformation


Input: Experimental and finite element modelling are utilized to develop the overall joining process and to validate the round ‘mortise-and-tenon’ design resulting from the analytical model.

Experimental

model

finite element modelling

joining

design


Input: The proposed joining process also circumvents the need to design extra fixing and interlocking features in low cost hollow section aluminium profiles for easy assembling.

joining

design

aluminium


Input: There exist several variants of Additive Manufacturing (AM) applicable for metals and alloys.

Additive Manufacturing

AM

metals

alloys


Input: The two main groups are Directed Energy Deposition (DED) and Powder Bed Fusion (PBF).

Directed Energy Deposition

DED

Powder Bed Fusion

PBF


Input: AM has advantages and disadvantages when compared to more traditional manufacturing methods.

AM

traditional manufacturing


Input: The best candidate products are those with complex shape and small series and particularly individualized product.

complex shape


Input: Repair welding is often individualized as defects may occur at various instances in a component.

welding

as

component


Input: This method was used before it became categorized as AM and in most cases, it is a DED process.

as

AM

DED


Input: PBF processes are more useful for smaller items and can give a finer surface.

PBF

surface


Input: Both DED and PBF products require subsequent surface finishing for high performance components and sometimes there is also a need for post heat treatment.

DED

PBF

surface finishing

heat treatment

performance

components


Input: Modelling of AM as well as eventual post-processes can be of use in order to improve product quality, reducing costs and material waste.

Modelling

AM

as

be

material

product quality


Input: The paper describes the use of the finite element method to simulate these processes with focus on superalloys.

finite element method

processes

superalloys


Input: Additive Manufacturing has recently emerged as an important industrial process that is capable of manufacturing parts with complex geometry.

Additive Manufacturing

manufacturing

as

industrial

complex geometry


Input: One of the drawbacks of metal additive manufacturing processes is the thermo-mechanical distortion of the parts during and after build due to heat effects.

metal additive manufacturing

thermo-mechanical distortion

heat

build


Input: Inherent strain is widely adopted by researchers as the basis to predict part distortions during Metal Powder Bed Fusion Additive Manufacturing (PBFAM) process and is highly dependent on the laser hatch pattern sintering on each layer during the printing process.

strain

as

Metal Powder Bed Fusion Additive Manufacturing

printing process

process

pattern

laser

layer


Input: There is a clear need to predict inherent strains for a given arbitrary hatch pattern for a part model so that hatch patterns can be optimized for achieving part quality.

pattern

model

quality

be


Input: In this paper, we propose a neural network based method to predict inherent strain for any given hatch pattern that is adopted during the part build.

neural network

pattern

strain

build


Input: The authors assumed that the temperature profile inside the heat affected zone within each layer is the same if the part model is reasonably large.

temperature

layer

profile

heat affected zone

model


Input: To start with, inherent strains of two hatch pattern pools with different hatch angles were obtained by thermo-mechanical simulation with temperature profiles obtained through translation and rotation of a single layer of simulation.

pattern

thermo-mechanical

simulation

simulation

temperature

layer

profiles


Input: A feedforward backpropagation neural network was created and trained with data obtained from an initial hatch pattern pool for predicting inherent strains.

neural network

data

pattern


Input: The data from a second hatch pattern pool was then utilized to validate the network and test the efficacy of the prediction of the trained neural network.

data

pattern

prediction

neural network


Input: The results show that the trained neural network is capable of predicting the inherent strain of any arbitrary hatch pattern within an acceptable error.

neural network

pattern

error

strain


Input: Since the trained neural network can predict inherent strain quickly for any given hatch pattern, this could provide the basis for hatch pattern optimization of any part model to increase part build accuracy and achieve part GD & T callouts.

neural network

pattern

pattern optimization

model

strain

build

accuracy

GD


Input: An innovative manufacturing process among the metal 3D printing techniques for stainless steel material is first introduced in Structural Engineering field.

manufacturing process

3D printing

metal

stainless steel

material

Structural Engineering


Input: For structural design purposes, the main issues in the realization of Wire-and-Arc Additive Manufactured stainless steel concern inherent geometrical imperfections to be properly characterized and the main material properties, influenced by the orientation of the elements.

structural design

Additive Manufactured

steel

be

elements

imperfections

material properties

orientation


Input: The first results of a wide experimental campaign devoted to assess the geometrical and mechanical characterization of Wire-and-Arc Additive Manufactured stainless steel elements evidence the need of proper evaluation of an effective geometry to derive the main mechanical parameters, which differ from the traditionally manufactured stainless steel material.

experimental

geometry

manufactured

mechanical

mechanical

Additive Manufactured

steel elements

steel material


Input: Additive Manufacturing has recently gained great importance to produce metallic structural elements for civil engineering applications.

Additive Manufacturing

metallic

elements

engineering


Input: While a lot of research effort has been focused on different technologies (such as Powder Bed Fusion), there is still quite limited knowledge concerning the structural response of Wire-and-Arc Additive Manufactured (WAAM) metallic elements, as very few experimental campaigns aimed at assessing their geometrical and mechanical properties have been carried out.

research

technologies

experimental

mechanical properties

as

metallic elements

as

Bed Fusion

Additive Manufactured

WAAM


Input: The paper presents selected results of a wide experimental campaign focused on the assessment of the main geometrical and mechanical properties of Wire-and-Arc Additive Manufactured (WAAM) stainless steel material, carried out at the Topography and Structural Engineering Labs of University of Bologna.

experimental

mechanical properties

Structural Engineering

Additive Manufactured

WAAM

stainless steel

material

Topography


Input: In detail, the focus is on the characterization of the surface irregularities by means of various measuring techniques and on the evaluation of the main material mechanical properties, including tensile and compressive strengths, Young's modulus and post elastic behavior.

surface

properties

material

tensile

compressive strengths

elastic


Input: Tests results have been interpreted through statistical tools in order to derive mean values and gather information about the variability of both geometrical and mechanical parameters.

tools

variability

mechanical


Input: In this work, rapid prototyping and physical modelling are used to evaluate four different extruder and deposition concepts for the Hybrid Metal Extrusion & Bonding (HYB) additive manufacturing (AM) process for aluminium alloys.

rapid prototyping

modelling

extruder

deposition

Bonding

process

Metal

aluminium alloys

Extrusion

additive manufacturing

AM


Input: The HYB-AM process is a branch of the HYB joining technology and is currently utilizing an extruder design that was initially developed for welding purposes.

process

joining

welding

extruder

design


Input: However, due to the different operating conditions of an AM process compared to a welding process, it is of interest to compare the current extruder to that of other alternatives to identify the optimal design.

AM process

welding

process

extruder

design


Input: Plastic models of the different extruders have been produced by rapid prototyping and attached to a CNC-machine.

Plastic

rapid prototyping


Input: To test the performance of each design, plasticine has been processed through the extruders and deposited on the machine bed.

performance

processed

design

machine

bed


Input: Key learnings from each cycle of designing, building and testing have been used as inputs for the next iteration, to finally end up with a design and the associated requirements upon which the further development process will be based.

testing

as

be

design

process


Input: Qualitative study of the mechanism of surface tension driven flow.

Qualitative

mechanism

surface tension


Input: Analysis of driving forces and driving mechanism.

forces

mechanism


Input: Quantitative investigation of surface tension and surface shear stress distribution.

Quantitative

surface

distribution

surface tension

shear stress


Input: 3D distribution of solidification parameters.

solidification parameters


Input: Semi-qualitatively prediction of solidified microstructure.

prediction

solidified microstructure


Input: A transient three-dimensional thermal-fluid-metallurgy model was proposed to study the surface tension driven flow and welding metallurgical behavior during laser linear welding of 304 stainless steel.

transient three-dimensional

model

surface tension

welding

welding

metallurgical

laser

stainless steel


Input: Numerical simulation and experimental method were both used to investigate the thermal behavior, surface tension driven flow, driving mechanism and solidification characteristics.

Numerical simulation

experimental

mechanism

solidification

surface tension


Input: The temperature related driving force was qualitatively analyzed, and surface tension and surface shear stress were quantitatively studied.

temperature

force

surface

quantitatively

surface tension

shear stress


Input: Numerical method and dimensional analysis were also carried out to understand the importance of different driving forces, respectively.

dimensional analysis

forces


Input: The metallurgical model was sequentially coupled to the thermal-fluid model to calculate four solidification parameters.

metallurgical

model

solidification parameters


Input: Temperature gradient was observed to be much larger at the front of the melt pool due to the effect of thermal conductivity, and decreased from center to the periphery.

Temperature gradient

be

melt pool

thermal conductivity


Input: Both the surface tension and surface tension driven flow were found smaller in the central area.

surface tension

surface tension

area


Input: The maximum shear stress may reach 2500 N/m2 and pushed an intense outward convection.

shear stress


Input: The solidification parameters were used to predict the solidified morphology, and the prediction was well validated by experimental results.

solidification parameters

morphology

prediction

experimental


Input: The obtained basic conclusions in this work demonstrated that this study of thermal-fluid-metallurgical behavior could provide an improved understanding of the surface tension driven flow and solidification behavior inside the melt pool of welding and additive manufacturing process.

surface tension

solidification

melt pool

welding

additive manufacturing process


Input: The microstructure evolution and tensile properties of laser-additive welded Ti2AlNb joints under different heat treatments were investigated in this paper.

microstructure evolution

tensile properties

welded

heat treatments


Input: The heat treatment was conducted in the B2 + O (HT1) and B2 + α2 + O (HT2) phase field to obtain different microstructural characteristics.

heat treatment

O

O

phase

microstructural


Input: For HT1, due to the B2 → O transformation, the microstructure of heat affected zone was B2 + α2 + O, B2 + residual α2 + O, and B2 + O as the distance from the base metal increased.

O

O

O

O

as

base metal

microstructure

heat affected zone

residual


Input: As for HT2, the microstructure of heat affected zone was composed of B2 + α2 + rim-O + primary O + acicular O in the region close to the base metal, B2 + intergranular α2 + transformed O + primary O + acicular O in the region close to the fusion zone.

As

O

O

base metal

O

O

O

microstructure

heat affected zone

fusion zone


Input: The fusion zone was composed of B2 + O laths after HT1, and B2 + intergranular α2 + transformed O + primary O + acicular O after HT2.

fusion zone

O

O

O

O


Input: The joints composed of B2 + O phase exhibited higher tensile strength compared with the as-welded joints due to the strengthening effects of O phase.

O

O

tensile strength

strengthening


Input: The intergranular α2 phase formed during HT2 was detrimental for the tensile strength.

phase

tensile strength


Input: The joints exhibited no plastic deformation at room temperature after both heat treatments on account of the lack of independent slip systems in the O phase.

plastic deformation

temperature

heat treatments

O


Input: The ductility of the heat-treated joints at 650 °C was better than that at room temperature because more slip systems were activated in the O phase.

ductility

heat-treated

temperature

O


Input: Compared with the joints heat-treated in HT1, the joints after HT2 exhibited better ductility at 650 °C resulting from the coarse primary O laths and lower volume fraction of O phase.

heat-treated

ductility

O

O

volume fraction


Input: Corrosion resistance of carbon steel cladding is better than high speed steel.

Corrosion resistance

carbon steel

high speed steel


Input: Wear resistance of specific carbon steel cladding is close to high speed steel.

Wear resistance

carbon steel

high speed steel


Input: Submerged arc welding is available technology to improve wear and corrosion resistance of carbon steel.

Submerged arc welding

technology

wear

corrosion resistance

carbon steel


Input: High-speed steel (HSS), traditionally used in the hot rolling industry, suffers from the problem of wear and corrosion.

steel

HSS

hot rolling

wear

corrosion


Input: For modifying the surface property of metal materials, submerged arc welding, among the industrial additive manufacturing technologies, is employed.

surface

property

metal materials

submerged arc welding

additive manufacturing

industrial


Input: In this study, we aim at improving the resistance of carbon steel cladding against corrosion and wear.

resistance

carbon steel

corrosion

wear


Input: To reduce cost, the HSS matrix is replaced by carbon steel.

HSS

carbon steel


Input: Electrochemical corrosion and high-temperature dry sliding wear experiments are implemented to study the corrosion and tribological behavior of HSS and surface-modified claddings.

Electrochemical corrosion

wear

corrosion

tribological

HSS


Input: The wear and corrosion behaviors are characterized by potentiodynamic polarization, electrochemical impedance spectroscopy, wear rate, coefficient of friction, and worn surface morphology.

wear

electrochemical

spectroscopy

wear

corrosion behaviors

coefficient of friction

potentiodynamic polarization

surface morphology


Input: The experimental results indicate that the corrosion current density (Icorr) of carbon steel claddings, ranging from 11.023 × 10−3 to 3.372 × 10−3 mA∙cm−2, is lower than that of the HSS alloy (19.247 × 10−3 mA∙cm−2).

experimental

corrosion

density

carbon steel

HSS

alloy


Input: The passive film resistance of prepared carbon steel cladding-3 (1870 Ω∙cm2) is in fact larger than the resistance of HSS (1075 Ω∙cm2).

resistance

resistance

carbon steel

HSS


Input: The corrosion resistance of surface-modified carbon steel claddings is better than that of the HSS.

corrosion resistance

carbon steel

HSS


Input: The wear rates of carbon steel cladding-2 (1.99 × 10−7 mm3·N−1·mm−1) and carbon steel cladding-3 (2.49 × 10−7 mm3·N−1·mm−1) approximate the wear rate of HSS (1.59 × 10−7 mm3·N−1·mm−1).

wear

wear

carbon steel

carbon steel

HSS


Input: Moreover, the wear width of prepared carbon steel cladding-3 (550 μm) is slightly larger than that of HSS (500 μm).

wear

carbon steel

HSS


Input: The wear resistance of carbon steel cladding-3 approximates that of HSS.

wear resistance

carbon steel

HSS


Input: With the increase in the deposition height, the heat dissipation changes from three-dimensional on the substrate to one-dimensional on the depositing layer.

deposition

heat dissipation

three-dimensional

substrate

layer


Input: The residual distortion can be effectively reduced by changing the depositing direction.

residual distortion

be


Input: The distortion of the reverse directions can be reduced by 25%.

distortion

be


Input: The stress concentration at the end of the arc point and the stress produced by the reverse depositing model are more uniform than those produced by the same depositing model.

stress concentration

arc

model

model

stress


Input: The complex residual stress and distortion experienced in wire arc additive manufacturing (WAAM) can have a serious impact on production.

residual stress

distortion

impact

wire arc additive manufacturing

WAAM

production


Input: In this paper, a series of ten-layer depositing walls were deposited by WAAM using the same depositing direction and reverse depositing direction to study the effect of different heat conditions on the residual stress and distortion of the deposition wall.

WAAM

heat

distortion

deposition

residual stress


Input: The temperature field, distortion, and residual stress under different paths were obtained by performing experiments.

temperature

distortion

residual stress


Input: Meanwhile, to calculate the variations in the temperature, stress, and distortion under different depositing paths, a model of wire arc additive manufacturing was established by using a numerical model.

variations

distortion

model

model

temperature

stress

wire arc additive manufacturing


Input: The stress distribution in the reverse directions is more uniform than that in the same directions.

stress distribution


Input: By comparison with the results from an experimental and numerical analysis, the same depositing directions have a large temperature gradient and produce greater plastic distortion during solidification.

experimental

distortion

solidification

temperature gradient

plastic


Input: A concept of layer by layer constrained optimisation of multi-axis additive manufacturing trajectory for parts of revolution is presented.

layer by layer

additive manufacturing


Input: For a constrained device configuration, the use of non-optimised trajectories can lead to manufacturing failure due to an axis overtravel or singularity state; problem which can be avoided thanks to the proposed methodology.

configuration

failure

methodology

lead

be

manufacturing


Input: The methodology has been validated by manufacturing parts of revolution on a multi-axis additive manufacturing device using a coaxial PLA deposition system.

methodology

deposition

manufacturing

additive manufacturing

PLA


Input: Parts manufactured with an optimised trajectory provide better geometrical accuracy and less results dispersion than parts manufactured without optimisation.

manufactured

dispersion

manufactured

accuracy


Input: This work focuses on additive manufacturing by Directed Energy Deposition (DED) using a 6-axis robot.

additive manufacturing

Directed Energy Deposition

DED

robot


Input: To achieve this goal, a new layer-by-layer method coupled with a trajectory constrained optimization is presented.

layer-by-layer

optimization


Input: The layer-by-layer generation of optimized trajectories is validated experimentally on a 6-axis robot using a PLA extrusion system.

layer-by-layer

robot

PLA

extrusion


Input: Experimental results show that the layer-by-layer trajectory optimization strategy applied to parts of revolution provides better geometrical accuracy while improving the efficiency of the manufacturing device compared to non-optimized solutions.

Experimental

layer-by-layer

optimization

accuracy

manufacturing


Input: In the cold metal transfer additive manufacturing process of Ti-6Al-4V thin wall structure, ultrasonic peening treatment (UPT) in three directions is proposed to refine the large columnar prior-β grains and secondary α grains, and to improve anisotropy in tensile properties.

cold metal transfer additive manufacturing

ultrasonic peening

structure

grains

grains

anisotropy

tensile properties


Input: The experimental results showed that UPT in three directions applied to each weld right after arc extinguishing has a minor influence on the surface appearance, which shows no apparent plastic deformation, but has a great improvement in grain refinement.

experimental

arc

surface

weld

plastic deformation

grain refinement


Input: The changes in microstructure and dislocations of thin wall structure treated by UPT in three directions were observed.

microstructure

dislocations

structure


Input: By comparing with those without UPT, the main causes for refinement of columnar prior-β and secondary α grains was explored, namely mechanical effects of ultrasonic at the temperature range of α’ dissolution temperature Tdiss–liquidus temperature Tl.

grains

liquidus

mechanical

temperature range

temperature

Tl


Input: Specimens with UPT have better properties, higher loads with the same indentation displacement in nano-indentation tests, an increase in ultimate tensile strength and a reduction in anisotropic percentage in tensile tests.

properties

indentation

reduction

ultimate tensile strength

anisotropic

tensile tests


Input: 2Cr13 thin-wall part with defect-free was additively manufactured by robot-assisted CMT technology.

additively manufactured

CMT


Input: Martensite coarsened gradually from FZ to CZ while only ultra-fine acicular martensite in the top layer.

Martensite

martensite

FZ

layer


Input: A random crystallographic orientation in the middle region while a slightly fiber texture in the top layer Mechanical properties were evolved periodically due to the periodic microstructural evolution.

orientation

properties

microstructural evolution

fiber

layer


Input: Based on cold metal transfer (CMT) welding, wire-arc additive manufacturing (WAAM) technology was adopted to manufacture 2Cr13 part.

cold metal transfer

CMT

welding

wire-arc additive manufacturing

WAAM

technology

manufacture


Input: The spatial periodicity of the microstructural evolution and the anti-indentation properties was explored.

microstructural evolution

properties


Input: The results show that the as-deposited part was featured by periodic martensite laths within the block-shaped ferrite matrix in the inner layers, followed by epitaxial ferrite grains containing ultra-fine acicular martensite in the top layer only.

martensite

ferrite

martensite

epitaxial

grains

layer


Input: A slightly decreased Fe intensity was caused by local elemental segregation during the re-melting process; the homogeneity of Fe and Cr was attributed to similar cooling conditions in the top layer.

Fe

Fe

Cr

segregation

process

cooling

layer


Input: Elongated ferrite grains exhibited a slight fiber texture in the top layer and a random crystallographic orientation in the middle region.

ferrite

fiber

layer

orientation


Input: The anti-indentation properties evolved periodically due to the periodic microstructural characteristics.

properties

microstructural


Input: The obtained experimental results confirmed higher anti-indentation properties of the as-deposited part following comparison with the as-annealed base metal, while the elastic moduli of samples were not significantly different.

experimental

properties

samples

base metal

elastic moduli


Input: Titanium alloys have high strength to low weight ratio, good creep resistance and high temperature strength properties.

Titanium alloys

strength

creep

strength properties

weight

temperature


Input: Based on these properties, Ti alloys are used as a ‘workhorse’ material in the aerospace industry such as engine blades, landing gear assemblies, large structural parts, airframe and drums etc.

properties

Ti alloys

as

material

as

aerospace industry

gear


Input: Traditional fabrication methods of Ti alloy are expensive and inferior in their mechanical properties.

fabrication

Ti alloy

mechanical properties


Input: Due to continuous development in science and technology, many researchers have been attracted towards Wire Feed Additive Manufacturing (WFAM) for the fabrication of titanium and its alloys.

technology

Feed

Additive Manufacturing

fabrication

titanium

alloys


Input: WFAM has set a new trend by accomplishing the production demand of components from medium to large scale with moderate complexity.

set

trend

complexity

production

components


Input: This additive manufacturing technology generally employes for high material utilization and higher deposition.

additive manufacturing

material utilization

deposition


Input: This state of art highlights the remarkable achievements of WFAM processes followed by their effect of process parameters, microstructural changes, residual stresses and mechanical properties of Ti-6Al-4V alloy.

art

processes

process parameters

microstructural

mechanical properties

residual stresses

Ti-6Al-4V alloy


Input: Accurate on-line weld defects detection is still challenging for robotic welding manufacturing due to the complexity of weld defects.

Accurate

weld

weld

defects

complexity

defects

robotic welding manufacturing


Input: This paper studied deep learning–based on-line defects detection for aluminum alloy in robotic arc welding using Convolutional Neural Networks (CNN) and weld images.

defects

Neural Networks

images

aluminum alloy

arc welding

weld


Input: Firstly, an image acquisition system was developed to simultaneously collect weld images, which can provide more information of the real-time weld images from different angles including top front, top back and back seam.

image

images

images

weld

weld

seam


Input: Then, a new CNN classification model with 11 layers based on weld image was designed to identify weld penetration defects.

classification

image

weld penetration defects

weld

designed


Input: In order to improve the robustness and generalization ability of the CNN model, weld images from different welding current and feeding speed were captured for the CNN model.

robustness

model

images

model

weld

welding


Input: Based on the actual industry challenges such as the instability of welding arc, the complexity of the welding environment and the random changing of plate gap condition, two kinds of data augmentation including noise adding and image rotation were used to boost the CNN dataset while parameters optimization was carried out.

industry

as

welding

welding

arc

complexity

data

image

parameters optimization


Input: Instead of decreasing the interference from arc light as in traditional way, the CNN model has taken full use of those arc lights by combining them in a various way to form the complementary features.

arc

model

arc

as


Input: Test results shows that the CNN model has better performance than our previous work with the mean classification accuracy of 99.38%.

model

performance

classification

accuracy


Input: This paper can provide some guidance for on-line detection of manufacturing quality in metal additive manufacturing (AM) and laser welding.

manufacturing

metal additive manufacturing

AM

laser welding


Input: A high temperature gas-to-gas manifold-microchannel heat exchanger was fabricated.

temperature

heat exchanger

fabricated


Input: The heat exchanger core was 3D printed using Inconel 718 through DMLS.

heat exchanger

core

3D printed

DMLS

Inconel 718


Input: The heat exchanger was tested at 600 °C with inlet pressure of 450 kPa.

heat exchanger

inlet


Input: The experimental results validated the numerical model.

experimental

model


Input: 25% higher heat transfer density compared to conventional plate fin heat exchangers.

heat transfer density

heat exchangers


Input: This work presents an additively manufactured manifold-microchannel heat exchanger made of Inconel 718 and experimentally tested for high temperature aerospace applications.

additively manufactured

heat exchanger

Inconel 718

temperature

aerospace


Input: The heat exchanger core with a size of 66 mm × 74 mm × 27 mm was fabricated as a single piece through the direct metal laser sintering process.

heat exchanger

core

mm

mm

mm

direct metal laser sintering

fabricated

as


Input: Successful welding of additively manufactured headers with the heat exchanger core and conventionally manufactured flanges was demonstrated through the fabrication of the unit.

welding

additively manufactured

fabrication

heat exchanger

core

manufactured


Input: The heat exchanger was tested using nitrogen (N2) on the hot-side and air on the cold-side as the working fluids.

heat exchanger

nitrogen

as

fluids


Input: A maximum heat duty of 2.78 kW and a maximum overall heat transfer coefficient of 1000 W/m2K were achieved during the experiments.

heat

heat transfer


Input: The decent agreement between the experimental and the numerical results demonstrates the validity of the numerical analysis model used for heat transfer and pressure drop prediction of the additively manufactured manifold-microchannel heat exchanger.

experimental

model

heat transfer

pressure

prediction

additively manufactured

heat exchanger


Input: Compared to conventional plate fin heat exchangers, nearly 25% improvement in heat transfer density— the ratio between heat duty and mass (Q/m) —was noted at a coefficient of performance (COP) of 62.

heat exchangers

heat transfer

heat

performance


Input: A 3D heat and fluid flow model is developed for the multilayer deposition of wire and arc additive manufacture.

deposition

fluid flow

wire and arc additive manufacture


Input: Utilizing a modified double ellipsoidal heat source model which shows better adaptability to free surface deformation.

heat source

free surface

deformation


Input: Predicting the morphology of molten pool and deposited bead in WAAM process using CFD model for the first time.

morphology

molten pool

process

deposited bead

WAAM

CFD


Input: Conduction is the dominant method of heat dissipation compared to convection and radiation to the air during deposition.

heat dissipation

deposition

radiation


Input: A three-dimensional numerical model has been developed to investigate the fluid flow and heat transfer behaviors in multilayer deposition of plasma arc welding (PAW) based wire and arc additive manufacture (WAAM).

three-dimensional

model

heat transfer

deposition

fluid flow

plasma arc welding

PAW

wire and arc additive manufacture

WAAM


Input: The volume of fluid (VOF) and porosity enthalpy methods are employed to track the molten pool free surface and solidification front, respectively.

volume of fluid

VOF

molten pool free surface

solidification

porosity


Input: A modified double ellipsoidal heat source model is utilized to ensure constant arc heat input in calculation in the case that molten pool surface dynamically changes.

heat source

arc

molten pool


Input: Transient simulations were conducted for the 1st, 2nd and 21st layer depositions.

Transient

simulations

layer


Input: The shape and size of deposited bead and weld pool were predicted and compared with experimental results.

deposited bead

weld pool

predicted

experimental


Input: The results show that for each layer of deposition the Marangoni force plays the most important role in affecting fluid flow, conduction is the dominant method of heat dissipation compared to convection and radiation to the air.

layer

deposition

force

heat dissipation

fluid flow

radiation


Input: As the layer number increases, the length and width of molten pool and the width of deposited bead increase, whilst the layer height decreases.

As

layer

layer height

molten pool

deposited bead


Input: In high layer deposition, where side support is absent, the depth of the molten pool at the rear part is almost flat in the Y direction.

layer

deposition

molten pool

support

Y


Input: The profile of the deposited bead is mainly determined by static pressure caused by gravity and surface tension pressure, therefore the bead profile is nearly circular.

profile

deposited bead

bead

pressure

pressure

surface tension


Input: The simulated profiles and size dimensions of deposited bead and molten pool were validated with experimental weld appearance, cross-sectional images and process camera images.

profiles

dimensions

deposited bead

molten pool

experimental

images

process

camera


Input: Wire-based directed energy deposition additive manufacturing techniques (AM) permit the rapid production of large-scale structural components which are not currently possible using the more common powder bed fusion (PBF) AM methods.

directed energy deposition additive manufacturing

AM

production

powder bed fusion

PBF

AM

structural components


Input: However, due to larger melt pool widths and higher energy inputs than PBF methods, local thermal history effects produce significant location-dependent microstructure, porosity, and mechanical behavior that necessitates thorough quantification of this emergent technology.

melt pool

PBF

microstructure

technology

porosity

mechanical


Input: Wire + Arc Additive Manufacturing (WAAM) was used to produce austenitic stainless-steel single bead walls in order to statistically quantify the variation of critical material properties within the build.

Wire + Arc Additive Manufacturing

WAAM

austenitic

bead

variation

material properties

build


Input: Individual grain geometric properties evaluated using electron back scatter diffraction at different points in the build were well fit by a three-parameter Weibull cumulative distribution function, yet sufficiently different from averaged values.

grain

properties

fit

distribution

electron back scatter diffraction

build


Input: X-ray diffraction for each location disclosed a strong wire texture in the build direction, leading to anisotropic elastic moduli values that were well described by directionally-dependent modulus predictions obtained from diffraction peak analysis.

X-ray diffraction

diffraction

texture

build direction

anisotropic

predictions


Input: Location-dependent mechanical behavior was examined and accurately captured by an elasto-viscoplastic model based on the Fast-Fourier Transforms (EvpFFT) using the local microstructure orientation data as input.

mechanical

accurately

model

microstructure

data

as


Input: Overall, a high-quality build was realized, with minimal porosity of less than 0.32%, and median yield and tensile strength values of approximately 320.4 ± 8.0 MPa and 531.6 ± 8.2 MPa, respectively.

build

porosity

tensile strength

MPa

MPa


Input: Additively manufactured components made of metallic material are subject to special consideration for many R & D departments, since the process control is not yet sufficiently reliable and therefore an extensive quality assurance is necessary.

Additively manufactured

metallic material

process control

quality


Input: For this reason, few structural components for aviation have been established so far.

structural components


Input: In this paper, a feasibility study for the use of laser metal deposition (LMD) for the additive manufacturing of a fuselage made of aluminum is carried out.

feasibility

laser metal deposition

LMD

additive manufacturing

fuselage

aluminum


Input: The redistribution of alloying elements and the crystallographic characterizations in wire and arc additive manufactured (WAAM) super duplex stainless steel (SDSS) was investigated from the wire to the final as-deposited structure.

alloying elements

stainless steel

arc

structure

additive manufactured

WAAM


Input: The results showed that elemental partitioning between austenite and ferrite was suppressed in the last layer and the solidified droplet.

austenite

ferrite

layer

droplet


Input: The high Ni content but low Cr and N contents in the initial state of the intragranular austenite (IGA) confirmed the predominance of the chromium nitrides acted as the nucleation sites.

Ni

Cr

N

austenite

chromium

as

nucleation


Input: Gathering of nitrogen was found more distinct in the coarsening IGA, Widmanstätten austenite (WA) than the grain boundary austenite (GBA).

nitrogen

austenite

austenite

WA

grain boundary


Input: The columnar epitaxial ferrite presented a strong < 001 > texture in the deposition direction, while the < 001 > and < 101 > orientations was found in the austenite.

epitaxial

texture

deposition direction

orientations

austenite


Input: Random orientations of the intragranular secondary austenite was revealed.

orientations

austenite


Input: The Rotated Cube texture of the austenite grains were consumed by the “recrystallization” textures (Brass, Rotated Brass, Cu, R, E, and F) caused by the austenite reformation.

Cube

recrystallization

austenite

Brass

Brass

Cu

austenite

F


Input: The low-angle interphase boundaries between austenite and ferrite were predominated in the as-deposited wall, and, at which, the K–S orientation took the crucial part.

interphase

orientation

boundaries

austenite

ferrite


Input: A Taylor factor analysis revealed that through fabrication via additive process, the austenite became oriented “harder” and contributed most to good mechanical properties.

fabrication

additive

austenite

mechanical properties


Input: The textured microstructure contributed about a 2.6% higher engineering strain in the Z direction and a 27.8 MPa higher yield strength in the X direction.

microstructure

MPa

engineering

yield strength


Input: As-deposited Wire + Arc Additively Manufactured (WAAM) Inconel (IN) 718 contains Laves phase in the microstructure.

Wire + Arc Additively Manufactured

WAAM

Inconel

Laves phase

microstructure


Input: A modified post-deposition heat treatment successfully dissolved Laves phase without precipitating δ phase.

heat treatment

Laves phase

phase


Input: Changes to the grain structure through heat treatments reduced anisotropy in elevated temperature tensile properties.

grain structure

properties

heat treatments

anisotropy

temperature


Input: Elevated temperature tensile properties of WAAM IN 718 meet minimum specifications for cast but not for wrought material.

temperature

specifications

properties

WAAM

cast

wrought material


Input: Wire + Arc Additive Manufacturing (WAAM) can be used to create large free-form components out of specialist materials such as nickel-base superalloys.

Wire + Arc Additive Manufacturing

WAAM

be

as

superalloys

components

materials


Input: Inconel (IN) 718 is well suited for the WAAM process due to its excellent weldability.

Inconel

WAAM

process

weldability


Input: However, during deposition, WAAM IN718 is susceptible to micro-segregation, leading to undesirable Laves phase formation in the interdendritic regions.

deposition

micro-segregation

Laves phase

WAAM


Input: Further, the WAAM process encourages columnar grain growth and the development of a strong fibre texture, leading to anisotropy in grain structure.

WAAM

process

grain structure

columnar grain

anisotropy

fibre


Input: This unfavourable microstructure can be addressed through specialised post-deposition homogenisation heat treatments.

microstructure

be

heat treatments


Input: A new modified heat treatment was found to be effective in dissolving Laves phase, whereas a standard treatment precipitated δ phase.

heat treatment

be

Laves phase

standard

phase


Input: Tensile test results revealed that Laves and δ phases lead to low ductility when present in a precipitation-hardened matrix.

Tensile test

Laves

lead

ductility


Input: The modified heat treatment also reduced the anisotropy in grain structure, leading to almost isotropic elevated temperature tensile properties, which meet minimum specifications for conventional cast but not for wrought material.

heat treatment

cast

anisotropy

isotropic

grain structure

properties

temperature

specifications

wrought material


Input: Specialised post-deposition heat treatments, which address the unique microstructure of WAAM IN718, are crucial to achieving optimal mechanical properties.

heat treatments

WAAM

microstructure

mechanical properties


Input: Powder bed fusion process is one of the basic technique associated with additive manufacturing.

Powder bed fusion process

additive manufacturing


Input: It follows the basic principle of manufacturing the product layer by layer and their fusion.

manufacturing

layer by layer

fusion


Input: A heat source focuses its heat over a powder base material and heats the selected cross section area.

heat source

heat

cross section

powder

material

area


Input: Sources like laser beam, electron beam and infrared beam are used as heating tool.

laser beam

electron beam

infrared

beam

tool

as


Input: The process of heating allows the powder to take the shape of the intended object.

process

heating

powder


Input: Powder bed fusion process is compatible to every engineering material such as metals, ceramics polymers, composites etc.

Powder bed fusion process

engineering material

as

ceramics

composites


Input: this technique is widely used in many industrial sectors such as aerospace, energy sector, transportation etc.

industrial sectors

as

aerospace


Input: A comprehensive overview on powder bed fusion process is presented in this review paper.

powder bed fusion process


Input: Other popular techniques like selective laser melting (SLM), selective laser sintering (SLS), and electron beam melting (EBM) are also reviewed.

selective laser melting

SLM

selective laser sintering

SLS

electron beam melting

EBM


Input: Wire and arc additive manufacturing (WAAM), using cold metal transfer (CMT) as heat source, exhibits a great potential for additive manufacturing of magnesium alloys due to low heat input.

Wire and arc additive manufacturing

WAAM

cold metal transfer

CMT

additive manufacturing

as

magnesium alloys

source

heat


Input: With the purpose of revealing the relationship between the microstructure and mechanical properties of WAAMed AZ31 material, the present study has been carried out.

microstructure

mechanical properties

material


Input: The average primary dendrite arm spacing increases from 17 μm at the bottom to 39 μm at the top of the deposit, and the volume fraction of the interdendritic eutectic decreases from 52.1% to 39.3%.

average

eutectic

dendrite

volume fraction


Input: The microstructure of each layer except the top layer consists of vertical columnar dendrites and direction-changed columnar dendrites in sequence.

microstructure

vertical

layer

layer

columnar dendrites

columnar dendrites


Input: The top layer appears equiaxed dendrites due to columnar to equiaxed transition (CET).

layer

dendrites

transition


Input: The tensile properties present obvious anisotropic characteristics because of the epitaxial columnar dendritic growth along the building direction.

tensile properties

anisotropic

epitaxial

building direction


Input: The tensile properties also show obvious variation from the bottom to the top of the deposit because of the differing microstructures in different regions.

tensile properties

variation

microstructures


Input: The results are further analyzed in detail through the microstructure evolution resulted from the new manufacturing method.

microstructure evolution

manufacturing


Input: Using Electrical Discharge Machining in combination with forming is an option to manufacture a U-shaped First Wall without welding.

Electrical Discharge Machining

forming

welding

manufacture


Input: Additive Manufacturing (e.g.

Additive Manufacturing


Input: Selective Laser Melting and Metal Powder Application) provides promising options for nuclear fusion applications.

Selective Laser Melting

Metal Powder

fusion


Input: Selective Laser Melting is suitable to manufacture high complex and thin walled segments with internal channel structures.

Selective Laser Melting

manufacture

channel


Input: Metal Powder Application provides cost effective options to build First Wall relevant components.

Metal Powder

build

components


Input: Different manufacturing routes are investigated at the KIT INR for the realization of First Walls (FW) for nuclear fusion components, such as the ITER Test Blanket Module (TBM) and DEMO Breeding Blankets (BB) for the Helium Cooled Pebble Bed (HCPB) Breeding concept.

manufacturing

fusion

components

Bed

as

Helium


Input: One conventional manufacturing route mainly basing of Electrical Discharge Machining (EDM) and forming was demonstrated successfully.

conventional manufacturing

Electrical Discharge Machining

EDM

forming


Input: Therefore, options also to apply Additive Manufacturing (AM) as alternative were investigated.

Additive Manufacturing

AM

as


Input: This paper compares the HCPB reference concept for FW fabrication to innovative concepts basing on AM.

fabrication

AM


Input: The solid-state friction stir welding (FSW) process was used to join Al–Si12 parts fabricated via the selective laser melting (SLM) technique.

solid-state

process

fabricated

friction stir welding

FSW

selective laser melting

SLM


Input: The effect of the welding process on microstructural evolution and mechanical properties of the samples is investigated in present work.

welding

process

microstructural evolution

mechanical properties

samples


Input: Microstructural studies demonstrate that FSW is capable of changing Si phase morphologies (i.e.

Microstructural

phase morphologies

FSW

Si


Input: shape and size) resulting in various mechanical properties.

mechanical properties


Input: The stir zone of the welded joint shows significantly lower micro-hardness in comparison to the as-built SLM samples.

welded joint

SLM

samples


Input: Correspondingly, the friction stir welding process results in significant reduction of tensile strength, while ductility is strongly improved.

friction stir welding

reduction

tensile strength

ductility


Input: The fully-reversed strain-controlled low-cycle fatigue (LCF) tests imply that at low strain amplitudes the FSW and SLM samples show almost the same fatigue life, while at the high strain amplitudes the SLM samples show superior LCF performance.

fatigue

strain

fatigue life

strain

FSW

SLM

SLM

samples

samples

performance


Input: Fracture analysis of fatigued samples reveals that the near-surface pores lead to the crack initiation in both SLM and FSW cases.

Fracture

samples

pores

lead

SLM

FSW


Input: Various methods have been reported to join carbon fiber reinforced polymer (CFRP) composites with aluminum alloy (AA), with strengths ranging from 13 MPa to 112 MPa.

carbon fiber

polymer

composites

aluminum alloy

strengths

MPa

MPa


Input: This paper presents a new method for joining carbon fiber reinforced composites and metals using ultrasonic additive manufacturing (UAM).

joining

ultrasonic additive manufacturing

UAM

carbon fiber

composites

metals


Input: Although UAM is a metal 3D printing process, it is applied here to produce continuous CF-AA transition joints that can have uniform thickness across the CF and AA constituents.

UAM

3D printing

metal

transition


Input: Joint strength is achieved by mechanical interlocking of CF loops within the AA matrix; tensile tests demonstrate that UAM CFRP-AA joints reach strengths of 129.5 MPa.

Joint

MPa

mechanical

tensile tests

UAM

strengths


Input: The dry CF fabric extending from these joints can be laid up and cured into a CFRP part, whereas the AA can be welded to metal structures using traditional metal welding techniques–hence their designation as “transition joints.” This approach enables the incorporation of CFRP parts into vehicle structures without requiring modifications to existing metal welding infrastructure.

be

be

metal

metal

as

metal

cured

transition


Input: Two failure modes, CF tow failure and AA failure, have been identified.

failure modes

failure

failure


Input: It is shown that the joint failure mode can be designed for maximum strength or maximum energy dissipation by adjusting the ratio of embedded CF to AA matrix.

joint failure

be

strength


Input: Welded joints of SLM and CR stainless steels were produced by laser welding.

Welded joints

SLM

laser welding

CR

steels


Input: A comparison of keyhole and heat conduction laser welding was performed.

heat conduction

welding


Input: The influence of pre-heat treatment on the strength and weldability was revealed.

pre-heat treatment

strength

weldability


Input: The hardness of welding seams produced by head conduction is 500 HV, by keyhole–280 HV.

hardness

welding


Input: The welded joints strength is comparable to the SLM metal strength (1450 MPa).

welded joints

strength

SLM

metal

MPa


Input: The details produced by additive manufacturing have limitations in sizes, if you produce large details then there are large residual stresses.

additive manufacturing

residual stresses


Input: It is also economically advantageous to produce complexly configured details by additive manufacturing and then weld them to rolled or wrought cheaper details.

additive manufacturing

weld

wrought


Input: The aim of this study is to investigate the influence of pre-heat treatment on laser beam weldability of Selective Laser Welding (SLM) stainless steel to Cold Rolled (CR) stainless steel.

pre-heat treatment

Selective Laser

SLM

Cold Rolled

laser beam

stainless steel

CR

stainless steel


Input: The results of metallographic studies and mechanical tests of produced welds are presented.

mechanical tests

welds


Input: The results showed that the pre-heat treatment of SLM workpieces affects the welded joint strength.

pre-heat treatment

SLM

welded joint

strength


Input: The laser welding mode, keyhole or conduction, affected the microstructure and microhardness of the welds.

laser welding

microstructure

microhardness

welds


Input: With the recent rise in the demand for additive manufacturing (AM), the need for reliable simulation tools to support experimental efforts grows steadily.

additive manufacturing

AM

simulation

support

experimental


Input: Computational welding mechanics approaches can simulate the AM processes but are generally not validated for AM-specific effects originating from multiple heating and cooling cycles.

welding

AM processes

heating

cooling


Input: To increase confidence in the outcomes and to use numerical simulation reliably, the result quality needs to be validated against experiments for in-situ and post-process cases.

numerical simulation

quality

in-situ

post-process

be


Input: In this article, a validation is demonstrated for a structural thermomechanical simulation model on an arbitrarily curved Directed Energy Deposition (DED) part: at first, the validity of the heat input is ensured and subsequently, the model’ s predictive quality for in-situ deformation and the bulging behaviour is investigated.

validation

thermomechanical

model

heat

model

quality

in-situ deformation

simulation

Directed Energy Deposition

DED

s


Input: For the in-situ deformations, 3D-Digital Image Correlation measurements are conducted that quantify periodic expansion and shrinkage as they occur.

in-situ deformations

Image

shrinkage

as


Input: The results show a strong dependency of the local stiffness of the surrounding geometry.

stiffness

geometry


Input: The numerical simulation model is set up in accordance with the experiment and can reproduce the measured 3-dimensional in-situ displacements.

numerical simulation

model

experiment

in-situ

set


Input: Furthermore, the deformations due to removal from the substrate are quantified via 3D-scanning, exhibiting considerable distortions due to stress relaxation.

deformations

stress relaxation

substrate


Input: Finally, the prediction of the deformed shape is discussed in regards to bulging simulation: to improve the accuracy of the calculated final shape, a novel extension of the model relying on the modified stiffness of inactive upper layers is proposed and the experimentally observed bulging could be reproduced in the finite element model.

prediction

model

finite element model

deformed shape

stiffness

simulation

accuracy

be


Input: High-performance components from titanium alloy Ti-6Al-4V are used in many industries, particularly in aerospace, but also in the automotive and medical market.

components

titanium alloy

industries

aerospace

automotive

medical


Input: Traditionally, such components are produced by hot forging and subsequent post processing.

components

forging

post processing


Input: The multi-stage forging process requires several expensive dies and leads to components with a high material oversize.

forging

dies

components

material


Input: Therefore, costly machining operations with machining removal up to more than 90% are necessary to produce the final geometry.

machining

machining

geometry


Input: New technologies, such as additive manufacturing (AM), could support traditional process chains and could enable a more resource-efficient production.

technologies

as

additive manufacturing

AM

production

support

process chains


Input: However, in additive manufacturing production cycles are still long and manufacturing costs are very high, especially for larger parts.

additive manufacturing

manufacturing costs


Input: Thus, the production by AM is often limited to low quantities and smaller components.

production

AM

components


Input: To overcome the above-mentioned disadvantages the present study proposes a hybrid manufacturing route, combining the advantages of forging and AM.

hybrid manufacturing

forging

AM


Input: The new manufacturing route could reduce the number of processing steps and forging dies, and additionally could provide efficient near-net-shape production.

manufacturing

forging

near-net-shape

dies


Input: These features, such as ribs or other structural or functional geometries, will be added by additive manufacturing.

as

be

geometries

additive manufacturing


Input: The present study investigates the use of powder laser metal deposition (p-LMD) and wire-arc additive manufacturing (WAAM) for hybrid manufacturing of Ti-6Al-4V aerospace forgings.

investigates

hybrid manufacturing

powder

laser metal deposition

wire-arc additive manufacturing

WAAM

aerospace


Input: BackgroundAdditive manufacturing (AM) is a rapidly expanding new technology involving challenges to occupational health.

manufacturing

AM

technology


Input: Here, metal exposure in an AM facility with large-scale metallic component production was investigated during two consecutive years with preventive actions in between.MethodsGravimetric analyzes measured airborne particle concentrations, and filters were analyzed for metal content.

metal

metallic

metal

exposure

particle

AM

component

filters


Input: Particles from recycled powder were characterized.

Particles

recycled

powder


Input: Airborne particle concentrations (< 300 nm) showed transient peaks in the AM facility but were lower than those of the welding facility.

particle

transient

AM

welding


Input: Particle characterization of recycled powder showed fragmentation and condensates enriched in volatile metals.

Particle

recycled

powder

metals


Input: Biomonitoring showed a nonsignificant increase in the level of metals in urine in AM operators.

metals

AM


Input: Dermal cobalt and a trend for increasing urine metals during Workweek Year 1, but not in Year 2, indicated reduced exposure after preventive actions.ConclusionGravimetric analyses showed low total and inhalable dust exposure in AM operators.

cobalt

metals

trend

exposure

exposure

AM


Input: However, transient emission of smaller particles constitutes exposure risks.

transient

particles

exposure

emission


Input: Preventive actions implemented by the company reduced the workers' metal exposure despite unchanged emissions of particles, indicating a need for careful design and regulation of the AM environments.

company

metal

exposure

particles

design

AM


Input: HDPE polymer HX is fabricated using layer-by-layer line welding of plastic sheets.

HDPE

plastic

fabricated

layer-by-layer

welding


Input: The polymer HX shows superior air-side performance over plane plate fin surface.

polymer

performance

surface


Input: In addition to their low cost and weight, polymer heat exchangers offer good anticorrosion and antifouling properties.

weight

polymer

heat exchangers

properties


Input: In this work, a cost effective air-water polymer heat exchanger made of thin polymer sheets using layer-by-layer line welding with a laser through an additive manufacturing process was fabricated and experimentally tested.

polymer

polymer

heat exchanger

layer-by-layer

fabricated

welding

additive manufacturing process

laser


Input: The flow channels were made of 150 μm-thick high density polyethylene sheets, which were 15.5 cm wide and 29 cm long.

high density polyethylene


Input: The experimental results show that the overall heat transfer coefficient of 35–120 W/m2 K is achievable for an air-water fluid combination for air-side flow rate of 3–24 L/s and water-side flow rate of 12.5 mL/s.

experimental

heat transfer

K

fluid

flow rate

flow rate


Input: In addition, by fabricating a very thin wall heat exchanger (150 μm), the wall thermal resistance, which usually becomes the limiting factor on polymer heat exchangers, was calculated to account for only 3% of the total thermal resistance.

fabricating

heat exchanger

heat exchangers

resistance

resistance

polymer


Input: A comparison of the air-side heat transfer coefficient of the present polymer heat exchanger with some of the commercially available plain plate fin heat exchanger surfaces suggests that its performance in general is superior to that of common plain plate fin surfaces.

heat transfer

performance

surfaces

polymer

heat exchanger

heat exchanger


Input: Additive manufacturing (AM) offers the possibility of locally reinforcing sheet metal or sheet metal products by adding patches that are metallurgically bonded to the substrate.

Additive manufacturing

AM

sheet metal

sheet metal

substrate


Input: Due to the high design freedom of AM, patches can be easily adapted to loads in geometry and thickness.

design freedom

geometry

AM

be


Input: However, the heat input and the high cooling rates during AM processes have a strong influence on the microstructure in the patch as well as in the substrate, which will affect forming properties.

heat

microstructure

cooling rates

AM processes

forming

as

as

substrate


Input: The aim of this work is to investigate the influence of patches produced by laser material deposition (LMD) on formability of micro-alloyed sheet metals.

laser

deposition

LMD

formability

sheet metals


Input: After determining a suitable process window for metallurgically bonded patches without cracks and pores, investigations were carried out on the microstructure and mechanical properties of reinforced samples.

process

microstructure

mechanical properties

reinforced

pores


Input: This work includes metallographic examinations using optical microscopy, hardness measurements and tensile tests.

optical microscopy

tensile tests

hardness


Input: The formability of sheets with local reinforcement was investigated by stretching and Nakajima tests.

formability

sheets

reinforcement


Input: The heat input creates a heat affected zone (HAZ) directly next to the patches with a reduced strength, caused by recrystallization that may lead to failure in the forming process and thus limits the forming capacity of locally reinforced sheet metals.

heat

heat affected zone

HAZ

recrystallization

failure

limits

capacity

reinforced

strength

lead

metals

forming process

forming


Input: A subsequent laser heat treatment can homogenize the properties in the HAZ.

laser heat

properties

HAZ


Input: Ti-6Al-4V samples produced by electron beam melting (EBM) are welded using solid-state friction welding (FW) process.

samples

solid-state

process

electron beam melting

EBM

welded

friction welding


Input: The microstructure of the weld sample shows the presence of fine equiaxed α grains with irregular β phase.

microstructure

sample

grains

phase

weld


Input: Microstructural investigations reveal a pronounced change in the shape and size of the α phase in the weld metal as-compared to the base material along with the disappearance of columnar prior β grains.

Microstructural

phase

grains

weld metal

material


Input: Such variations in the microstructure significantly change the mechanical properties of the FW material.

variations

microstructure

mechanical properties

material


Input: The hardness in the weld zone increases and a decrease of hardness is observed along the heat affected zone (HAZ) with respect to the base metal as expected.

hardness

hardness

weld zone

heat affected zone

HAZ

base metal

as


Input: Similarly, the room temperature tensile tests show an improvement of ductility in the welded EBM samples.

temperature

ductility

welded EBM

samples


Input: However, the yield and the ultimate strength show a marginal drop in the welded samples compared to the as-prepared EBM specimens.

ultimate strength

welded

EBM

samples


Input: The present work demonstrates that solid-state FW process not only permits successful joining of additively manufactured materials, but also helps in improving their ductility.

solid-state

process

joining

additively manufactured

ductility


Input: Laser zone with refined grains and more uniform element distribution forms by laser-arc hybrid additive manufacturing.

Laser

grains

distribution

element

additive manufacturing


Input: Outstanding micro-hardness and tensile strength can be obtained by laser-arc hybrid additive manufacturing.

tensile strength

be

additive manufacturing


Input: Finer grains and significant decreasing of element segregation in laser zone can help to strengthen mechanical properties.

grains

mechanical properties

element

laser


Input: 4043 AlSi alloy samples are fabricated by laser-arc hybrid additive manufacturing and wire arc additive manufacturing.

alloy

fabricated

additive manufacturing

wire arc additive manufacturing