Input: To investigate the influence of laser energy on the fabricated sample, the microstructure evaluation and mechanical properties are studied.

laser energy

fabricated

microstructure

mechanical properties


Input: After the input of laser energy, there are laser zones with finer grains and reduced Si segregation.

laser energy

grains

segregation

laser

Si


Input: As a result, the Si phases at grain boundaries in laser zone are smaller than that in other zones.

As

Si

grain boundaries

laser


Input: And it is found that semi-coherent interface between Al and Si phases with crystal orientation relations, [110] Al∥ [110] Si and (111) Al∥ (220) Si, indicating the Si phase tends to grow along (111) Al plane.

interface

phase

Al

Si

Si

Si

Si

Al

crystal orientation


Input: The results of mechanical properties show that the micro-hardness in laser zone is 54.3 HV0.05, with the increment of 19.08% compared to that in heat-affected zone.

mechanical properties

laser


Input: And the tensile strength, yield strength and elongation after the input of laser energy are 163.39 ± 1.68 MPa, 75.60 ± 4.91 MPa and 17.38 ± 5.44%, which are 7.56%, 8.45% and 3.45% higher than that without laser.

tensile strength

yield strength

elongation

laser energy

MPa

MPa

laser


Input: The improved mechanical properties are due to the finer gains, reduced Si segregation and the crack deflection in LAHAM samples.

mechanical properties

segregation

samples

Si


Input: The structure and properties of welded and additively manufactured alloys are affected by the microstructural evolution in the fusion zone (FZ) and heat affected zone (HAZ).

structure

properties

microstructural evolution

fusion zone

FZ

heat affected zone

HAZ

welded

additively manufactured


Input: The motion of the liquid pool and the interdependence of grain growth in both the solid and liquid regions are important in the evolution of the final grain structure.

grain growth

evolution

grain structure


Input: Previous investigations of microstructure evolution have been limited to either the HAZ or the FZ and in many cases in idealized isothermal systems.

microstructure evolution

HAZ

FZ

isothermal


Input: Here we report the evolution of grain structure and topology in three dimensions in both the FZ and the HAZ considering the motion of the liquid pool.

evolution

grain structure

topology

FZ

HAZ

dimensions


Input: Temporal and spatial distributions of temperature obtained from a well-tested heat transfer and liquid metal flow calculation are combined with Monte Carlo and topology calculations in a computationally efficient manner.

spatial distributions

temperature

heat transfer

topology

liquid metal


Input: The computed results are tested against independent experimental data for arc welding of an aluminum alloy.

experimental data

arc welding

aluminum alloy


Input: The average size of the columnar grains in the FZ and the equiaxed grains in the HAZ are shown to decrease with increasing scanning speed.

average

FZ

equiaxed grains

HAZ

columnar grains

scanning speed


Input: For a given weld, the size and aspect ratio of the columnar grains in the longitudinal and horizontal planes are shown to decrease with distance from the weld interface.

weld

aspect ratio

weld

columnar grains

interface


Input: It is further shown that the grain size distributions and topological class distributions in the HAZ are largely unaffected by the temporal and spatial variations of the temperature created by different welding parameters.

grain size

distributions

distributions

HAZ

parameters

spatial variations

temperature

welding


Input: In laser welding and other processes, such as cladding and additive manufacturing, the weld bead geometry (depth of penetration and weld width) can be controlled with different parameters.

laser welding

additive manufacturing

processes

penetration

parameters

as

be

weld bead geometry

weld


Input: A common practice is to develop process parameters for a particular application based on an engineering approach using the system parameters i.e.

process parameters

parameters

engineering


Input: laser power and travel speed.

laser power


Input: This study is focused on understanding of the phenomena controlling the weld profile in conduction welding for a wide range of beam diameters from 0.07 mm to 5.50 mm.

weld

profile

welding

mm

mm

range

beam diameters


Input: It has been shown that the weld bead geometry can be controlled by the spatial and temporal distribution of laser energy on the surface of workpiece, such as power density, interaction time and energy density.

weld bead geometry

energy density

be

as

distribution

laser energy

surface

workpiece

density


Input: This means that similar depths of penetration can be achieved with various optical set-ups.

penetration

be

optical


Input: It has been also found that it is more difficult to achieve pure conduction welds with small beam diameters, which are typically used in powder bed additive manufacturing, due to high conduction losses and low vaporisation threshold.

welds

beam diameters

powder bed additive manufacturing


Input: Ultrasonic Additive Manufacturing (UAM) is a hybrid manufacturing process that involves the layer-by-layer ultrasonic welding of metal foils in the solid state with periodic CNC machining to achieve the desired 3D shape.

Ultrasonic Additive Manufacturing

UAM

welding

CNC machining

hybrid manufacturing

layer-by-layer

solid state

metal


Input: UAM enables the fabrication of metal smart structures, because it allows the embedding of various components into the metal matrix, due to the high degree of plastic metal flow and the relatively low temperatures encountered during the layer bonding process.

UAM

fabrication

metal

plastic metal

components

metal matrix

bonding

temperatures

layer


Input: To further the embedding capabilities of UAM, in this paper we examine the ultrasonic welding of aluminium foils with features machined prior to bonding.

UAM

ultrasonic welding

machined

aluminium

bonding


Input: These pre-machined features can be stacked layer-by-layer to create pockets for the accommodation of fragile components, such as electronic circuitry, prior to encapsulation.

be

as

layer-by-layer

fragile

encapsulation

components


Input: This manufacturing approach transforms UAM into a “form-then-bond” process.

manufacturing approach

UAM

process


Input: By studying the deformation of aluminium foils during UAM, a statistical model was developed that allowed the prediction of the final location, dimensions and tolerances of pre-machined features for a set of UAM process parameters.

deformation

model

prediction

process parameters

aluminium

UAM

UAM

dimensions

tolerances

set


Input: The predictive power of the model was demonstrated by designing a cavity to accommodate an electronic component (i.e.

power

model

component


Input: a surface mount resistor) prior to its encapsulation within the metal matrix.

surface mount

resistor

encapsulation

metal matrix


Input: We also further emphasised the importance of the tensioning force in the UAM process.

force

process

UAM


Input: The current work paves the way for the creation of a novel system for the fabrication of three-dimensional electronic circuits embedded into an additively manufactured complex metal composite.

fabrication

additively manufactured

three-dimensional

metal composite


Input: Additive manufacturing of metals is an innovative near-net-shaped manufacturing technology used for producing final solid objects by depositing successive layers of material melted in powder or wire form using a focused heat source directed from an electron beam, laser beam, or plasma or electric arc.

Additive manufacturing

manufacturing technology

metals

material

powder

heat source

electron beam

laser beam

plasma

electric arc


Input: Wire arc additive manufacturing (WAAM) techniques, although have lesser precision as compared to laser or electron beam techniques but have the advantage of lower cost and lesser time required.

Wire arc additive manufacturing

WAAM

precision

as

laser

electron beam


Input: In this research, gas metal arc welding (GMAW) process has been used using AWS ER70S-6 electrode wire to create a multi-layer single pass structure after controlling the parameters including current, voltage and travel speed so that uniform height is attained throughout the weld bead.

research

process

structure

parameters

weld bead

gas metal arc welding

GMAW

electrode


Input: The resulting material may have different directional mechanical properties because of factors including different penetration properties and bonding strength and also preheating and post-heating effects of successive layers.

material

mechanical properties

penetration

bonding strength

preheating


Input: This study focuses on the impact toughness of the resulting material.

impact

material


Input: Charpy impact test is carried out on the samples taken in both along the direction of deposition and in the direction perpendicular to it to analyze the impact toughness in different directions.

impact test

samples

deposition

impact


Input: To further investigate the behavior of the structure, Brinell hardness, metallography and fractography have been performed.

structure

metallography

Brinell hardness

fractography


Input: The results show that material has high impact toughness with very ductile behavior.

material

impact

ductile


Input: High-efficiency elastocaloric refrigeration requires high-performance elastocaloric materials with both large surface areas to promote heat exchange rate and large elastocaloric effects to increase the amount of heat transfer.

materials

heat

heat transfer

surface areas


Input: Ni-Ti shape memory alloys (SMAs) are the most promising elastocaloric materials but they are difficult to process by conventional methods due to their poor manufacturability.

shape memory alloys

SMAs

materials

process

manufacturability


Input: Here, we successfully developed Ni-Ti SMAs with large elastocaloric effects by additive manufacturing which has the capability to fabricate complex geometries with large surface areas.

SMAs

additive manufacturing

fabricate

complex geometries

surface areas


Input: The phase transformation temperatures of these additively manufactured Ni-Ti SMAs, fabricated by selective laser melting (SLM), can be tuned by varying the SLM processing parameters and/or post heat treatments and thus tunable large elastocaloric effects were achieved at different temperatures, which can be used for different applications.

phase

fabricated

parameters

temperatures

temperatures

additively manufactured

selective laser melting

SLM

SLM

heat treatments

SMAs

be

be


Input: Owing to its large transformation entropy change and high yield strength as a result of precipitation hardening, the aged SLM fabricated alloy exhibits a remarkably large elastocaloric effect with an adiabatic temperature change as high as 23.2 K, which is among the highest values reported for all Ni-Ti SMAs fabricated by both conventional methods and additive manufacturing.

yield strength

as

alloy

as

as

K

SMAs

precipitation hardening

SLM

additive manufacturing

fabricated

fabricated

temperature


Input: Furthermore, by virtue of the high yield strength and low stress hysteresis of the aged alloy, this large elastocaloric effect shows good stability during cycling.

yield strength

stress hysteresis

stability

alloy


Input: The achievement of such large elastocaloric effects in alloys fabricated by near-net-shape additive manufacturing may accelerate the implementation of high-efficiency elastocaloric refrigeration.

alloys

near-net-shape

additive manufacturing


Input: This study is instructive for the development of advanced high-performance solid-state refrigeration materials by additive manufacturing.

solid-state

materials

additive manufacturing


Input: Due to the practicability of economically generating large-scale metal components with relatively high deposition rates, consequential progress has been made in the perspective of the Wire Arc Additive Manufacturing (WAAM) process.

metal

components

high deposition rates

Wire Arc Additive Manufacturing

WAAM

process


Input: This article reviews the looming research on WAAM techniques and the commonly used metallic feedstock materials.

research

WAAM

metallic

feedstock materials


Input: The frequent defects that are produced in components during the WAAM process using different alloys are characterized including deformity, porosity, and cracking.

defects

process

cracking

components

WAAM

alloys

porosity


Input: Methods for enhancing the fabrication quality of the additively manufactured components are also discussed, with the consideration of the requirements of the distinct alloys.

fabrication

additively manufactured

alloys


Input: The implementation of the standardized Conventional Heat Treatment procedure to mitigate the defects in the WAAM process and in capturing the future possibilities that are efficient has been discussed.

Heat Treatment

WAAM

defects

process


Input: The unification of materials and manufacturing process to produce defect-free and structurally-sound deposited parts remains a crucial effort in the future.

materials

manufacturing process


Input: Additive manufacturing (AM), through directed energy deposition, supports planned composition changes between locations within a single component, allowing for functionally graded materials (FGMs) to be developed and fabricated.

Additive manufacturing

AM

directed energy deposition

supports

composition

fabricated

component

functionally graded materials

be


Input: The formation of deleterious phases along a particular composition path can cause significant cracking during the AM build process that makes the composition path unviable to produce these FGMs, but it is challenging to predict which phases will be present in as-built additively manufactured parts by analyzing only equilibrium phase relations.

composition

cracking

process

composition

equilibrium

AM

additively manufactured

be


Input: Solute segregation during solidification can lead to the formation of non-equilibrium phases that are stable at compositions far from the nominal composition of the melt, leading to crack formation.

segregation

solidification

composition

melt

lead


Input: We used this tool to compare the non-equilibrium phases predicted to form during the AM build process using the Scheil-Gulliver model with experimentally measured phases at several locations with different composition in a Ti-6Al-4V to Invar-36 FGM and a commercially pure Ti to Invar-36 FGM.

tool

predicted

process

Scheil-Gulliver model

composition

AM

FGM

FGM

Ti


Input: We showed that the phases predicted to form by the Scheil-Gulliver model agree better with the experimental results than the predictions made by assuming equilibrium solidification, proving that the Scheil-Gulliver model can be applied to FGMs.

predicted

Scheil-Gulliver model

experimental

predictions

equilibrium

Scheil-Gulliver model

be


Input: Further, we demonstrated the use of our Scheil-Gulliver simulation tool as a method of designing FGMs through screening potential FGM pathways by calculating the solidification phase fractions along the experimental gradient path in composition space.

simulation

as

FGM

solidification phase

experimental

composition


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

Ultrasonic additive manufacturing

UAM

manufacturing

ultrasonic welding

fabricate

solid-state


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

reduction

strength

welding interfaces

Z-direction


Input: Here, the effect of hot isostatic pressing (HIP) on UAM builds of aluminum alloy was explored.

hot isostatic pressing

HIP

UAM

builds

aluminum alloy


Input: Tensile testing and microstructure characterization were conducted; it was established that HIP eliminated the brittle Z-direction fracture and improved the strength and ductility of the Z-direction specimens.

Tensile testing

microstructure

fracture

HIP

brittle

strength

ductility

Z-direction


Input: HIP eliminated voids and produced recrystallized structure; however, welding interfaces survived the HIP treatment.

HIP

recrystallized

HIP

voids

welding interfaces


Input: A virtual binocular vision system is designed to monitor molten pool appearance.

virtual binocular

designed

monitor

molten pool


Input: Effects of different stereo matching algorithms on reconstruction accuracy are conducted.

algorithms

reconstruction

accuracy


Input: Molten pool appearance in wire and arc additive manufacturing is reconstructed.

Molten pool

wire and arc additive manufacturing


Input: Robust measurement of layer geometry can help better understand the complex deposition process and provide feedback control to increase process stability of wire and arc additive manufacturing (WAAM).

measurement

layer

feedback

geometry

process

deposition process

wire and arc additive manufacturing

WAAM


Input: In this study, a virtual binocular vision sensing system is designed to measure the layer width and torch height from top layer simultaneously.

virtual binocular vision sensing

designed

layer

layer


Input: Considering that stereo matching is the most crucial step for 3-D reconstruction in stereovision sensing, various matching algorithms, i.e.

step

algorithms

sensing


Input: The matching algorithms are tested based on the standard datasets, indicating that the highest matching accuracy comes from the GCI matching algorithm.

algorithms

standard

algorithm

accuracy


Input: Then, a standard cylinder is taken as an example to verify the effectiveness of the sensing system and algorithms.

standard

effectiveness

algorithms

as

sensing system


Input: Finally, layer geometries in WAAM with various process parameters are determined.

layer

geometries

process parameters

WAAM


Input: The width and height errors of layer geometry with the GCI matching algorithm are less than 3.2%.

errors

geometry

algorithm

layer


Input: This study will lay a solid foundation for subsequent feedback control for layer geometry in WAAM.

lay

geometry

feedback

layer

WAAM


Input: High-strain-rate deformation in ultrasonic additive manufacturing was analyzed by performing microstructural characterization via electron microscopy.

deformation

ultrasonic additive manufacturing

microstructural characterization

electron microscopy


Input: The micro-asperities on the top tape surface, which were formed by contact with the sonotrode surface, underwent cyclic deformation in the shear direction at high strain rates during welding with an additional tape.

surface

deformation

strain rates

contact

sonotrode

shear direction

welding


Input: This caused plastic flow and crushing of the micro-asperities, and a flattened interface was formed between the upper and lower tapes.

plastic

crushing

interface


Input: Further, surface oxide films were fractured and dispersed by ultrasonic vibration, and metallurgical welding was achieved.

surface

oxide

ultrasonic vibration

metallurgical


Input: 304L stainless steel manufactured via LENS was characterized in its as-deposited state in 3D using TriBeam tomography.

stainless steel

manufactured

LENS


Input: Orientation gradients are linked to chemical segregation occurring during solidification.

Orientation

segregation

solidification


Input: A sample of 304L stainless steel manufactured by Laser Engineered Net Shaping (LENS) was characterized in 3D using TriBeam tomography.

sample

manufactured

stainless steel

Laser Engineered Net Shaping

LENS


Input: The crystallographic, structural, and chemical properties of the as-deposited microstructure have been studied in detail.

properties

microstructure


Input: 3D characterization reveals complex grain morphologies and large orientation gradients, in excess of 10∘, that are not easily interpreted from 2D cross-sections alone.

grain

orientation


Input: Misorientations were calculated via a methodology that locates the initial location and orientation of grains that grow during the build process.

methodology

orientation

grains

build


Input: For larger grains, misorientation increased along the direction of solidification.

grains

solidification


Input: For grains with complex morphologies, K-means clustering in orientation space is demonstrated as a useful approach for determining the initial growth orientation.

grains

complex morphologies

orientation

orientation

as


Input: The accumulation of misorientation is linked to the solutal and thermal solidification path, offering potential design pathways for novel alloys more suited for additive manufacturing.

solidification

design

alloys

additive manufacturing


Input: In this study, Wire Arc Additive Manufacturing (WAAM) based Directed Energy Deposition (DED) process is used to build two parts, tube and wall from 2209 Duplex Stainless Steel.

Wire Arc Additive Manufacturing

WAAM

Directed Energy Deposition

DED

process

build

Stainless Steel


Input: Duplex stainless steel is extremely effective against stress corrosion cracking due to existence of an equal portion of austenite and ferrite phases.

stainless steel

austenite

ferrite

stress corrosion cracking


Input: The challenge is monitoring of the process parameters and cooling rate to promote ferrite phase formation.

process parameters

cooling rate

ferrite


Input: To this end, three-dimensional transient thermal models of the additive manufactured (AM) parts are presented and the simulated thermal cycles are verified with the experimental results.

three-dimensional

experimental

additive manufactured

AM

thermal cycles


Input: The correlation between the calculated cooling rates and the phases formation in the WAAM parts is studied and revealed.

cooling rates

WAAM


Input: The results highlight that slow cooling rate of the built layers at elevated temperatures promote austenite formation significantly in a ferrite matrix.

cooling rate

temperatures

austenite

ferrite


Input: Furthermore, the experimental mechanical examinations will illustrate the quality of the WAAM-made parts and compare their mechanical properties with their wrought counter-parts.

experimental

quality

mechanical properties

wrought


Input: Beam-based processes are popularly used for metal additive manufacturing, but there are significant gaps between their capabilities and the demand from industry and society.

processes

metal additive manufacturing

industry


Input: Examples include solidification issues, anisotropic mechanical properties, and restrictions on powder attributes.

solidification

properties

anisotropic

powder


Input: Non-beam-based additive processes are promising to bridge these gaps.

additive

bridge


Input: In this viewpoint article, we introduce and discuss additive friction stir deposition, which is a fast, scalable, solid-state process that results in refined microstructures and has flexible options for feed materials.

additive

microstructures

deposition

solid-state process

feed


Input: With comparisons to other additive processes, we discuss its benefits and limitations along with the pathways to widespread implementation of metal additive manufacturing.

additive

metal additive manufacturing


Input: Metal additive manufacturing is nowadays a well-established technology for cutting edge applications in the automotive, aerospace, defense and medical sectors.

Metal additive manufacturing

cutting

technology

automotive

aerospace

medical


Input: Since additive metal deposition is basically a welding method, which creates parts by successively adding layers of material, there is a chance for defects like pores, cracks, inclusions and lack of fusion to develop.

additive

material

inclusions

deposition

defects

fusion

welding

pores


Input: As a matter of fact, interlayer and intralayer defects are often observed in additive manufactured components.

As

defects

additive manufactured


Input: However, if one considers the typical end applications along with the high costs involved in metal additive manufactured components, a “zero defect” target is close to mandatory for this technology.

metal

additive manufactured

defect

technology


Input: Planning an inclusion of the integrity assessment right into the additive manufacturing process would allow for quick corrective actions to be performed before the component is completed.

Planning

additive manufacturing process

inclusion

be

integrity

component


Input: Some effort has been spent in the quest of an efficient in-process flaw inspection, however, no conventional nondestructive testing (NDT) approach has been fully satisfying yet.

flaw

NDT

nondestructive testing


Input: This work suggests an experimental evaluation of the effectiveness of flying laser scanning thermography, when detecting flaws on an Additively Manufactured acetabular cup prosthesis made in titanium alloy, where some defects have been artificially created.

experimental

effectiveness

flaws

defects

laser

Additively Manufactured

titanium alloy


Input: The rough surface scanned is what’ s typically left by the additive manufacturing process, and has been left so in order to prove the efficacy of the NDT inspection in real conditions.

surface

NDT

s

additive manufacturing process

inspection


Input: Robot assisted additive manufacturing is an emerging disruptive technology.

Robot

additive manufacturing

technology


Input: Multiple robots can be used to produce multi-material large objects.

robots

be

multi-material


Input: Robotic-systems can be used to develop hybrid systems where additive and subtractive process are combined.

be

additive

hybrid systems

subtractive process


Input: The additive manufacturing and the robotic applications are tremendously increasing in the manufacturing field.

additive manufacturing

manufacturing


Input: This review paper discusses the concept of robotic-assisted additive manufacturing.

additive manufacturing


Input: The leading additive manufacturing methods that can be used with a robotic system are presented and discussed in detail.

additive manufacturing

be


Input: The information flow required to produce an object from a CAD model through a robotic-assisted system, different from the traditional information flow in a conventional additive manufacturing approach is also detailed.

CAD model

additive manufacturing


Input: Examples of the use of robotic-assisted additive manufacturing systems are presented.

additive manufacturing systems


Input: 130 mm thick welds were manufactured in a nuclear steel using gas-tungsten arc, submerged-arc and electron beam welding.

mm

electron beam welding

welds

manufactured

arc

steel


Input: Residual stresses were measured using the contour method and incremental deep-hole drilling, before and after PWHT.

Residual stresses

contour

drilling

PWHT


Input: Results show that the effectiveness of PWHT is best assessed on large weld mock-ups.

effectiveness

PWHT

weld


Input: In this study we aim to determine how the choice of welding process might impact on the through-life performance of critical nuclear components such as the reactor pressure vessel, steam generators and pressuriser in a pressurised water reactor.

welding

process

impact

performance

pressure

components

as


Input: Attention is devoted to technologies that are currently employed in the fabrication of such components, i.e.

technologies

fabrication

components


Input: narrow-gap variants of gas-tungsten arc welding (GTAW) and submerged arc welding (SAW), as well as a technology that might be applied in the future (electron beam welding).

arc welding

GTAW

submerged arc welding

SAW

electron beam welding

as

as

be

technology


Input: The residual stresses that are introduced by welding operations will have an influence on the integrity of critical components over a design lifetime that exceeds 60 years.

residual stresses

welding

integrity

components

design


Input: With a view to making an assessment based on residual stress as pertinent as possible, weld test pieces were manufactured with each process at a thickness that is representative for such components, i.e.

residual stress

as

as

weld

manufactured

process

components


Input: 130 mm.

mm


Input: Stability in robotic GTA additive manufacturing is detected by optical measurements.

Stability

additive manufacturing

optical measurements


Input: Deposition height is controlled with a feedback controller.

Deposition

feedback

controller


Input: Comparison between open and closed-loop control is conducted.

closed-loop control


Input: Additive manufacturing employing Gas Tungsten Arc (GTA) as the heat source is capable of fabricating fully dense metal components layer upon layer.

Additive manufacturing

fabricating

Gas

Arc

heat source

as

metal

components

layer


Input: In this work, a visual sensor, comprising a camera and composite filters, is developed for automatically real-time sensing of the fabrication process.

sensor

camera

composite

sensing

fabrication


Input: The aim is to keep stable manufacture, and the deviations of the deposited height are compensated by designing an integral separation PID controller to adjust the wire feed speed in the next layer.

manufacture

controller

feed

layer


Input: The optical measurement technique and the controller are estimated via building multi-layer single-pass walls.

optical measurement

controller


Input: The results show that the process stability in GTA-based additive manufacturing is well controlled when the designed visual sensor and the proposed closed-loop controller are applied.

process

additive manufacturing

designed

sensor

closed-loop controller


Input: Titanium is one of the best suitable materials for manufacturing bio implants and its application areas are orthopedics, dentistry etc.

Titanium

materials

manufacturing

implants

dentistry

areas


Input: There are many features possess by titanium which make it appropriate are its biocompatibility, resistance to corrosion, wearing, osteoporosis etc.

titanium

biocompatibility

resistance

corrosion


Input: The Cp- Titanium and titanium-based alloys are categorized in three ways depending upon its microstructure such as (α + β), α- type, β-type and comparative analysis are done its behavior, stability through SEM.

Titanium

alloys

as

microstructure

stability

SEM


Input: This review paper discussed the conventional and modern methods of fabricating the bio-implants and also summarizes the various additive manufacturing techniques.

fabricating

additive manufacturing


Input: Two NiCu alloys with various contents of Mn, Ti, Al and C were deposited in a shape of single-bead multi layered walls using wire arc additive manufacturing technology.

alloys

Mn

Ti

Al

C

wire arc additive manufacturing

technology


Input: To modify solute atom concentrations and particle number density values, the as-welded alloys were subjected to annealing at 1100 °C and age-hardening heat treatment in the 610-480 °C temperature range.

solute atom

alloys

particle

density

annealing

heat treatment

temperature range


Input: Microstructure characterisation was carried out using optical, scanning, conventional transmission and atomic resolution transmission electron microscopy.

Microstructure

scanning

optical

transmission

electron microscopy

resolution


Input: Work hardening behaviour was studied using tensile testing.

Work hardening

tensile testing


Input: For similar deposition and heat treatment conditions, an alloy with higher C and Al, and lower Mn contents exhibited a higher number density of > 20 nm TiC particles, higher number density of < 20 nm γ′-Ni3 (Al, Ti) particles, and, associated with these, superior hardness, tensile strength, strain hardening rate and toughness.

deposition

particles

particles

heat treatment

strain hardening

alloy

C

Al

Mn

Al

Ti

density

density

hardness

tensile strength

toughness


Input: The comparative effect of solid solution and precipitation strengthening on work hardening behaviour and fracture mode is discussed.

solid solution

precipitation

fracture

work hardening


Input: PCA-RF was proposed for on-line defect detection in arc welding.

defect

arc welding


Input: The classification accuracy was improved from 79.3% to 91.8%.

classification

accuracy


Input: Feature importance was qualitatively evaluated and selection pattern was given.

Feature

pattern


Input: Higher gradient of Fe might cause the greater change of Fe I (407.84 nm) Accurate on-line weld defect detection in robotic arc welding manufacturing is still challenging, due to the complexity and diversity of weld defects.

Fe

Fe

Accurate

weld

weld

defect

complexity

defects

arc welding


Input: In this study, a new real-time defect identification method is proposed for Al alloys in robotic arc welding, using arc optical spectroscopy and an integrated learning method.

defect

arc

spectroscopy

Al alloys

arc welding


Input: Spectrum feature was extracted, based on the absolute coefficients of the principal components.

feature

extracted

components


Input: Feature importance was quantitatively evaluated using the mean decrease accuracy of Principal Component Analysis-Random Forest (PCA-RF).

Feature

quantitatively

accuracy

Component


Input: The proposed PCA-RF proved to effectively identify five classes of weld defects with better performance than support vector machine and back propagation neural network.

weld

defects

performance

neural network

support

machine


Input: Finally, the selection pattern of spectrum feature subset was investigated, before revealing the correlation mechanism of the selected lines spectrum and weld process.

pattern

mechanism

process

feature

weld


Input: Barriers for the integration of additive manufacturing (AM) technologies in the commercial vehicle industry are identified.

additive manufacturing

AM

technologies

industry


Input: A cost model for estimating the manufacturing cost of a build task using selective laser melting is proposed in a cost estimation.

cost model

manufacturing cost

cost estimation

build

selective laser melting


Input: A general procedure and framework to develop a hybrid additive-subtractive process chain has been proposed.

framework

process chain


Input: A closed-loop quality control model to realize a long-term product and process quality control with AM is developed.

quality control

model

process

AM


Input: Additive Manufacturing (AM) is the umbrella term for manufacturing processes that add materials layer by layer to create parts.

Additive Manufacturing

AM

manufacturing processes

materials

layer by layer


Input: AM technologies show numerous potentials in terms of rapid prototyping, tooling and direct manufacturing of functional parts and imply revolutionary benefits for the manufacturing industry.

AM technologies

manufacturing

rapid prototyping

tooling

direct manufacturing

industry


Input: Currently, many industrial areas are marching to a more comprehensive application of AM.

industrial

areas

AM


Input: Hence, the development of new tools, methods, and concepts for guiding companies to implement AM technologies requires more research attention.

tools

companies

AM technologies

research


Input: This paper introduces the results of a research project carried out by academic and industrial partners from the German commercial vehicle industry.

research

industrial

industry


Input: The research project addressed four issues for a long-term application of AM technologies: identification of barriers for AM applications, cost estimation for AM application, design of hybrid additive-subtractive process chains, and quality management with AM.

research

cost estimation

quality

AM technologies

AM

AM

AM

design

process chains


Input: Wire and arc additive manufacturing (WAAM) is a competitive technology for fabricating metallic parts with complex structure and geometry.

Wire and arc additive manufacturing

WAAM

fabricating

technology

complex structure

geometry


Input: The basis of planning the deposition paths is the beads overlapping model (BOM).

planning

deposition paths

beads

model


Input: The existing overlapping models consider only the geometric area of adjacent beads, but ignore the spreading of the melted weld beads.

area

beads

beads

melted


Input: The objective of the research was to develop an enhanced BOM (E.BOM) for WAAM, which takes the spreading of the weld beads into consideration.

research

weld beads

WAAM


Input: A deposited bead spreads to the already deposited neighboring bead and as a consequence, its center point deviates from the center point of the fed (to be melted) wire.

deposited bead

bead

as

be


Input: Experiments were designed to explore the relationships between the geometries of the beads, and the offset distance between the center of a weld bead and the center of the fed wire.

designed

geometries

offset

weld bead

beads


Input: An artificial neural network was used to predict the offset distance of a certain weld bead based on the results of the experiments.

artificial neural network

offset

weld bead


Input: In addition, a reasoning algorithm was implemented to calculate the optimal distance between the centers of adjacent deposition paths in order to achieve a planned center distance between adjacent beads.

algorithm

deposition paths

beads


Input: The E.BOM has been tested by validation experiments.

validation


Input: On the one hand, it improves the surface flatness of layers of MLMB parts produced by WAAM.

surface

flatness

WAAM


Input: Wire + Arc Additive Manufacture is a suitable technique to manufacture large-scale unalloyed tungsten components The orientation of the wire feeding influences the occurrence of defects as lack of fusion, pores and micro-cracks The orientation of the wire feeding influences the microstructure of the tungsten deposits Front wire feeding allowed to produce fully-dense crack-free unalloyed tungsten deposits The manufacturing of refractory-metals components presents some limitations induced by the materials' characteristic low-temperature brittleness and high susceptibility to oxidation.

Wire + Arc Additive Manufacture

manufacturing

oxidation

manufacture

orientation

defects

fusion

micro-cracks

orientation

microstructure

materials

tungsten

as

tungsten

tungsten

components

components

wire feeding

wire feeding

wire feeding

pores

susceptibility


Input: Powder metallurgy is typically the manufacturing process of choice.

Powder metallurgy

manufacturing process


Input: Recently, Wire + Arc Additive Manufacture has proven capable to produce fully-dense large-scale metal parts at relatively low cost, by using high-quality wire as feedstock.

Wire + Arc Additive Manufacture

metal

as


Input: In this study, this technique has been used for the production of large-scale tungsten linear structures.

production

tungsten


Input: The orientation of the wire feeding has been studied and optimised to obtain defect-free tungsten deposits.

orientation

wire feeding

tungsten


Input: In particular, front wire feeding eliminated the occurrence of pores and micro-cracks, when compared to side wire feeding.

wire feeding

wire feeding

pores

micro-cracks


Input: The microstructure, the occurrence of defects and their relationship with the deposition process have also been discussed.

microstructure

defects

deposition process


Input: Despite the repetitive thermal cycles and the inherent brittleness of the material, the as-deposited structures were free from internal cracks and the layer dimensions were stable during the entire deposition process.

thermal cycles

layer

material

dimensions

deposition process


Input: This enabled the production of a relatively large-scale component, with the dimension of 210 × 75 × 12 mm.

production

mm

component

dimension


Input: This study has demonstrated that Wire + Arc Additive Manufacture can be used to produce large-scale parts in unalloyed tungsten by complete fusion, presenting a potential alternative to the powder metallurgy manufacturing route.

Wire + Arc Additive Manufacture

powder metallurgy

manufacturing

be

tungsten

fusion


Input: An innovative additive manufacturing (AM) system using low power pulsed laser assisted MIG arc welding (L-M) was proposed to manufacture metal products.

additive manufacturing

AM

laser assisted MIG arc welding

power

manufacture


Input: With the purpose of revealing how width and height dimension of the manufactured thin-wall component are affected by the laser power, the present study has been carried out.

dimension

manufactured

component

laser power


Input: The width decreased with the increasing of the laser power within a certain range of laser power, and the height increased proportionally under the equal deposition rate.

laser power

range

laser power

deposition rate


Input: The width and height fluctuation reduced while adding the low power laser, both the standard deviation decreased by more than 50％ when the laser power was 400 W. The coefficient of materials utilization was up to 91.12%, and increased by more than 15% while using L-M based AM to fabricate thin-wall parts with a proper laser power.

power

laser power

laser power

laser

standard deviation

materials

AM

fabricate


Input: In comparison with the common GMAW-based AM method, the L-M based AM method shows feasibility to manufacture a narrower thin-wall component with better surface quality and higher stability, and also with higher deposition efficiency.

AM

AM

feasibility

manufacture

deposition

component

surface quality

stability


Input: Wire and Arc Additive Manufacturing (WAAM) is a metal 3D printing technique based on robotic welding.

Wire and Arc Additive Manufacturing

WAAM

3D printing

robotic welding

metal


Input: This technique yields potential in decreasing material consumption due to its high material efficiency and freedom of shape.

material

material


Input: Empirical measurements of WAAM, using a deposition rate of 1 kg/h, were performed on site of MX3D.

Empirical

WAAM

deposition rate


Input: The measured power consumption per kg stainless steel is 2.72 kW, of which 1.74 is consumed by the welder, 0.44 by the robotic arm, and 0.54 by the ventilation.

power

stainless steel

robotic arm


Input: The material loss was 1.1%.

material


Input: A 98% argon 2% CO2 welding gas was used with a flow of 12 l/min.A cradle-to-gate Life Cycle Assessment (LCA) was performed.

argon

gas

Life Cycle


Input: To give this assessment context, green sand casting and CNC milling were additionally assessed, through literature and databases.

sand casting

CNC milling

databases


Input: The purpose of this study is to develop insight into the environmental impact of WAAM.

impact

WAAM


Input: Results indicate that, in terms of total ReCiPe endpoints, the environmental impact of producing a kg of stainless steel 308 l product using WAAM is comparable to green sand casting.

impact

stainless steel

WAAM

sand casting


Input: It equals CNC milling with a material utilization fraction of 0.75.

CNC milling

material utilization fraction


Input: Stainless steel is the main cause of environmental damage in all three techniques, emphasizing the importance of WAAM's mass reduction potential.

Stainless steel

damage

WAAM

reduction


Input: When environmentally comparing the three techniques for fulfilling a certain function, optimized designs should be introduced for each manufacturing technique.

designs

be

manufacturing


Input: Results can vary significantly based on product shape, function, materials, and process settings.

materials

process settings


Input: Method of tensile triangles was applied to weld shape design.

tensile

weld

design


Input: Method of tensile triangles and low transformation temperature weld metal were combined for weld joint design.

tensile

temperature

metal

weld joint

design


Input: Effect of interpass temperature on residual stress in welded joint was investigated.

interpass temperature

residual stress

welded joint


Input: Stress concentration and residual stress have a significant influence on fatigue life of welded joints.

Stress concentration

residual stress

fatigue life

welded joints


Input: In order to reduce the stress concentration of welded joints, a mathematical design method of tensile triangles (MTT) based on bionics was applied to weld shape design.

stress concentration

welded joints

design

weld

design

mathematical

tensile


Input: Accordingly, the stress concentration of various weld beads in the corner boxing welded joint and the fillet welded T-joint was dissected using our in-house FEM software JWRIAN.

stress concentration

weld beads

FEM

welded joint

fillet

T-joint


Input: It was found that there existed a large stress concentration in the conventional welded joints, whereas those welded joints with elongated weld bead were accompanied by a lower stress concentration, especially for elongated weld bead with MTT design.

stress concentration

stress concentration

welded joints

welded joints

design

weld bead

weld bead


Input: Furthermore, among the weld shapes of the corner boxing fillet welded joint, the rectangle shape of weld bead had the minimum stress concentration factor (1.05).

weld

fillet

joint

weld bead

stress concentration


Input: For the fillet welded T-joint with MTT design, the stress concentration of weld toe decreased dramatically with the increase of the index of designed shape, but there was a minor difference of stress concentration at weld root between the weld beads with MTT design.

fillet

T-joint

design

weld

designed

weld

design

stress concentration

stress concentration

weld beads


Input: In addition, application of low transformation temperature (LTT) weld metal utilizing martensitic transformation to the fillet welded T-joints can produce compressive residual stress at weld toe.

temperature

weld metal

fillet

weld

residual stress


Input: Additive-manufactured AlSi10Mg boxes were studied under lateral crushing.

crushing


Input: Experimental tests and numerical simulations were conducted.

Experimental

numerical simulations


Input: The constitutive model was calibrated using tensile tests in three directions.

model

calibrated

tensile tests


Input: The influence of the yield surface, the adopted thickness and the element type were studied.

surface

element


Input: An experimental and numerical study on the quasi-static loading of AlSi10Mg square boxes produced by selective laser melting (SLM) was carried out.

experimental

quasi-static

selective laser melting

SLM


Input: The goal was to evaluate the applicability of common finite element modelling techniques to 3D-printed parts at material and component scales, under large deformations and fracture.

finite element modelling

3D-printed parts

material

component

deformations

fracture


Input: Uniaxial tensile specimens were extracted and tested at different orientations, and a hypo-elastic–plastic model with Voce hardening and Cockcroft–Latham’ s fracture criterion was calibrated against the experimental results.

tensile specimens

extracted

orientations

model

fracture

calibrated

experimental

hardening

s


Input: The boxes were crushed laterally until failure using a spherical actuator.

failure

spherical

actuator


Input: The considered material and finite element models were proved well suited for the prediction of the structural response of the additively manufactured components in the studied scenario.

material

finite element models

prediction

additively manufactured


Input: Wire and arc additive manufacturing (WAAM) is an efficient technique for fabricating large and complex components that are applied in the manufacturing industry.

Wire and arc additive manufacturing

WAAM

fabricating

manufacturing

components

industry


Input: In this study, anisotropic mechanical properties of a low-carbon high-strength steel component fabricated by WAAM were investigated via mechanical testing, and the transversal and longitudinal deformation behavior of the component were studied using the digital image correlation (DIC) method.

anisotropic

properties

deformation

digital image correlation

DIC

steel

component

component

WAAM

mechanical testing


Input: Additionally, the features of microstructure, texture, and fracture mode of the inter-layer area and deposited area were also investigated to reveal the mechanism of anisotropy.

microstructure

fracture

mechanism

texture

area

area

anisotropy


Input: The results showed the mechanical properties of longitudinal specimens were inferior to that of the transversal specimens.

mechanical properties


Input: Several strain concentration zones in the longitudinal specimen were relevant to the inter-layer characteristics observed from the fracture surface and macrostructure, which was confirmed by the strain evolution recorded by DIC.

strain

strain

fracture

evolution

DIC


Input: The inter-layer areas were proved to be the weak link in the deposited component by scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) analysis results, including various phase composition, phase morphology, misorientation angle, grain size, Schmid factor, and texture.

areas

be

component

scanning electron microscope

SEM

electron backscatter diffraction

EBSD

phase composition

phase morphology

grain size

texture


Input: Finally, based on the fractography analysis, anisotropy resulted from inter-layer zones is also confirmed via the comparison of transversal and longitudinal fracture morphology.

fractography

anisotropy

fracture


Input: In the present work, a novel direct energy deposition method for metal additive manufacturing is developed employing laminar plasma as the heat source.

direct energy deposition

metal additive manufacturing

plasma

heat source

as


Input: With a combination of modified process parameters, a high-performance 308L stainless steel component with four hollow straight walls is prepared.

process parameters

stainless steel

component


Input: The behavior of phase formation, microstructure, density and mechanical properties of the samples with different heights were investigated.

phase

microstructure

mechanical properties

samples

density


Input: Transformation from columnar to equiaxed dendrites can be observed as the height of wall increases from the substrate to about 30 mm.

dendrites

be

as

substrate

mm


Input: The average density of the sample reaches 98.3%.

average

sample


Input: Anisotropic property is observed in the bottom and middle regions, while the top region is isotropic.

Anisotropic

isotropic


Input: Laser welding–brazing of Ti/Al butt joints was performed with coaxial Al–10Si–Mg powders feeding.

Laser

powders


Input: The experimental results indicated that a sound Ti/Al butt joint could be obtained by an additive layer approach.

experimental

joint

be

additive


Input: The influence of the laser melting deposition layers on the weld appearance, interfacial microstructure and tensile properties were investigated.

laser

deposition layers

weld

microstructure

tensile properties


Input: The morphology and thickness distributions of the interfacial intermetallic compounds (IMC) at the brazing interface along the thickness direction of the joint varied with the number of deposition layers.

morphology

distributions

joint

intermetallic compounds

brazing

deposition layers


Input: Continuous serrated IMC was obtained in joints produced by seven deposition layers, and the IMC layer was distributed homogenously along the thickness direction.

deposition layers

layer


Input: The microstructure of the IMC layer was composed of a nanosized granular Ti7Al5Si12 phase and serrated Ti (Al, Si) 3 phase.

microstructure

phase

phase

layer

Ti

Al

Si


Input: The maximum tensile joint strength reached 240 MPa, 80% of that of the aluminum base metal, and the lower tensile strength of the other joints was caused by insufficient IMC layer or a porosity defect.

tensile

tensile strength

porosity

joint

MPa

defect

aluminum

metal

layer


Input: The bypass-coupled wire arc additive manufacturing (WAAM) process was studied, and the arc characteristics and droplet transfer behavior during the deposition process were examined.

wire arc additive manufacturing

WAAM

deposition process

process

arc

droplet


Input: The effects of the bypass current, wire feeding speed, wire feeding height, and wire feeding angle on the droplet transfer mode were investigated via a single variable experiment.

wire feeding

wire feeding

wire feeding

droplet

experiment


Input: There are two primary modes of droplet transfer during the deposition process: free droplet transfer and bridging transfer.

droplet

droplet

bridging

deposition process


Input: When the transfer process is in the bridging transfer mode, a smooth deposition wall is obtained.

process

bridging

deposition


Input: As the wire feeding speed increases, the transfer mode of the droplet gradually changes from the free transfer mode to the bridging transfer mode.

As

wire feeding

droplet

bridging


Input: The larger the distance between the wire tip and the surface of the base metal, the higher the wire feed speed required to achieve bridging transfer.

surface

bridging

base metal

feed


Input: There is a linear relationship between the droplet diameter and the cubic root of the wire feeding speed.

droplet

diameter

wire feeding


Input: Finally, the droplet transfer behavior is discussed using droplet force analysis.

droplet

droplet


Input: This article describes the results of the study of optimal conditions for welding alloy products-Inconel 718, made with the method of layered laser growing (SLM).

welding

SLM

alloy

Inconel 718

laser


Input: The results of the study of the influence of linear energy, rigid fixation of parts during welding and heat treatment on microhardness, welding deformation and the microstructure of the welded joint are presented.

welding

heat treatment

welding

microhardness

deformation

microstructure

welded joint


Input: An adaptive quadrature technique for calculating linear heat conduction in metal additive manufacturing was derived.

heat conduction

metal additive manufacturing


Input: A melt pool tracking algorithm is also described for improved calculation efficiency.

melt pool

algorithm


Input: The adaptive algorithm was verified against an analytical solution and Riemann sum integration approach.

algorithm

analytical solution


Input: The adaptive integration technique is demonstrated for a highly transient scan pattern at long length and time scales.

transient

scan pattern

time scales


Input: Solidification dynamics are important for determining final microstructure in additively manufactured parts.

Solidification

microstructure

additively manufactured


Input: Recently, researchers have adopted semi-analytical approaches for predicting heat conduction effects at length and time scales not accessible to complex multi-physics numerical models.

semi-analytical approaches

heat conduction

time scales


Input: The present work focuses on improving a semi-analytical heat conduction model for additive manufacturing by designing an adaptive integration technique.

heat conduction

additive manufacturing


Input: The proposed scheme considers material properties, process conditions, and the inherent physical behavior of the transient heat conduction around both stationary and moving heat sources.

material properties

process

transient heat conduction

heat sources


Input: The full algorithm is then implemented and compared against a simple Riemann sum integration scheme for a variety of cases that highlight process and material variations relevant to additive manufacturing.

algorithm

process

simple

additive manufacturing

material


Input: The new scheme is shown to have significant improvements in computational efficiency, solution accuracy, and usability.

computational efficiency

solution

accuracy


Input: WAAM was carried out to build a flange using robotic GMAW with AA5183 wire on an AA6082 support plate.

WAAM

GMAW

build

support


Input: Some intergranular hot cracking was found in the reheated areas close to the fusion boundary.

hot cracking

fusion boundary

areas


Input: The hardness level was around 75 kg/mm2 and 70–75 kg/mm2 in the hoorisontal and vertical plane, respectively.

hardness

vertical


Input: Reasonable isotropic yield and tensile strength of 145 and 293MPa were achieved, respectively.

isotropic

tensile strength


Input: The present study addresses wire arc additive manufacturing of AA5183 aluminium alloy using conventional gas metal arc welding deposition on 20 mm thick AA6082-T6 plate as support material.

wire arc additive manufacturing

gas metal arc welding

mm

aluminium alloy

as

material

deposition


Input: Microscopic examination demonstrates that the process is feasible, but can be further optimized to reduce gas porosity and hot cracking.

process

gas

hot cracking

be


Input: Hardness measurements confirmed relative high hardness, i.e., around 75 kg/mm2 in the horizontal plane, and between 70 and 75 kg/mm2 in the vertical plane down to the AA6082 support plate with 100 kg/mm2.

Hardness

hardness

vertical

support


Input: Mechanical testing resulted in yield and tensile strength of 145 and 293 MPa, respectively, with lowest value in the through thickness (Z) direction.

Mechanical testing

tensile strength

MPa


Input: The ductility was high for orientations parallel (X) with and perpendicular (Y) to the layer deposition direction.

ductility

orientations

Y

layer

deposition direction


Input: The thickness of intermetallic compounds (IMCs) is one of the main factors affecting the weld quality.

intermetallic compounds

weld quality


Input: In addition, the IMC thickness will affect the product functionality, e.g., the thermal or electrical conductivity of the IMC layer can be the limiting factor in the related applications.

product functionality

electrical conductivity

layer

be


Input: Modeling and prediction of the IMC thickness in the friction stir welding (FSW) process is an important role that has not been elaborated in the literature.

Modeling

prediction

process

friction stir welding

FSW


Input: That model is suitable for the pure (intrinsic) diffusion process and does not consider the main unique characteristic of FSW, i.e., the stirring and subsequent linear velocity of particles (that has an impact on the diffusion process).

model

diffusion

particles

impact

diffusion

FSW


Input: To address this research gap, first, we develop a new model for the IMC thickness that takes the velocity of particles into account.

research

model

particles


Input: Second, we provide an analysis on the velocity of particles in FSW based on vortex dynamics.

particles

FSW


Input: Third, we analyze the proposed IMC thickness model with experimental data from the literature, discuss the added values of our model, and finally examine a case study.

model

experimental data

model

case study


Input: Understanding various manufacturing processes can further lead to the improvement of the existing processes and the development of novel processes.

manufacturing processes

lead

processes

processes


Input: Inconel 718 thin wall was fabricated by PPAAM.

Inconel 718

fabricated


Input: Both CET and DCT can be found in the as-built sample.

be

sample


Input: Temperature gradient and SDA remelting contribute to grain structure transformation.

Temperature gradient

grain structure


Input: The morphology of Nb-rich phases is sensitive to the grain structure and cooling rate.

morphology

grain structure

cooling rate


Input: Abundant γ′/γ″ phases precipitate during HT and enhance mechanical properties.

precipitate

mechanical properties


Input: Inconel 718 thin wall has been fabricated by pulsed plasma arc additive manufacturing (PPAAM) technology, which is more convenient and cost-saving in comparison with other high energy beam additive manufacturing technologies.

Inconel 718

fabricated

technology

pulsed plasma arc additive manufacturing

additive manufacturing

beam


Input: During PPAAM, heat input was reduced layer by layer to decrease the heat accumulation.

heat

layer by layer

heat accumulation


Input: The as-fabricated sample exhibited diverse grain morphologies at different locations.

sample

grain


Input: Columnar dendrites, cellular dendrites, cells and equiaxial dendrites accompanying many Laves phases, MC particles in the interdendritic regions can be observed.

Columnar dendrites

MC

be

dendrites

dendrites

cells

Laves phases


Input: The largest primary dendritic arm spacing (∼41.7 μm) and Nb-rich phases area fraction (3.68%) were found in the middle region of the as-fabricated sample.

dendritic arm spacing

area

sample


Input: After standard heat treatment, Laves phases dissolved into the matrix so that a number of γ′ and γ″ phases were formed.

standard

Laves phases

heat treatment


Input: Besides, some rod-like δ phases could also be found near grain boundaries.

be

grain boundaries


Input: The mechanisms of microstructural evolution and phases precipitation were analyzed in detail.

microstructural evolution

precipitation


Input: The test values of the as-fabricated sample demonstrated a slightly higher tensile strength and dramatically outstanding ductility compared with cast Inconel 718 alloy.

sample

tensile strength

ductility

cast

alloy


Input: Applying standard heat treatment could remarkably enhance the tensile strength but decrease the ductility and make them comparable with wrought Inconel 718 alloy due to the precipitation of strengthening phases.

standard

precipitation

strengthening phases

heat treatment

tensile strength

ductility

wrought Inconel 718 alloy


Input: Maraging steel microlattice was printed by SLM, crushed, and simulated using FEM.

Maraging steel

SLM

FEM


Input: SEM and micro-CT was performed on as-built samples to verify structural integrity.

SEM

micro-CT

samples

structural integrity


Input: Two modeling techniques are presented based on as-built and as-designed geometries.

modeling

geometries


Input: FESEM was performed on the crushed lattice for failure analysis.

FESEM

lattice

failure


Input: Good agreement is found between the experiment and the simulations.

experiment

simulations


Input: Additive metal manufacturing techniques, in particular laser-based powder bed fusion methods, are revolutionary in their capabilities to fabricating new classes of lightweight and complex materials called metallic microlattices.

Additive

metallic

manufacturing

powder bed fusion

fabricating

lightweight

materials


Input: In this paper, a microlattice structure was designed for energy absorption purposes and further additively manufactured using maraging steel (Maraging300) powder through Laser-powder bed fusion (L-PBF) technique.

structure

designed

energy absorption

additively manufactured

bed fusion

L-PBF

maraging steel

powder


Input: In addition, several cylindrical bars and cubes in horizontal and vertical directions were manufactured to perform uniaxial tensile and compression tests on bulk L-PBF Maraging300.

cylindrical

vertical

manufactured

tensile

compression tests

L-PBF


Input: The manufactured microlattices were characterized using different electron microscopy techniques including scanning electron microscopy and micro-CT analysis to ensure that the desired structural integrity was achieved.

manufactured

electron microscopy

scanning electron microscopy

micro-CT analysis

structural integrity


Input: In addition, the microlattice was then crushed using a universal mechanical testing machine to evaluate its performance experimentally under quasi-static uniaxial compressive loading conditions.

mechanical testing

machine

performance

quasi-static

compressive loading


Input: Along with the crush, a nonlinear finite element model with predictive capabilities was then developed using commercial package (LS-DYNA) for axial crush of the microlattice to compare its expected performance.

finite element model

performance


Input: Two finite element models are developed using the as-built geometry from the printed lattice, and the as-designed geometry.

finite element models

geometry

lattice

geometry


Input: The effect of model parameters is discussed and very good agreement between the experimental results and the finite element prediction was observed.

model

experimental

finite element


Input: Finally statistical analysis of the model and failure analysis of the crushed lattice is presented.

model

failure

lattice


Input: Hybrid Metal Extrusion and Bonding Additive Manufacturing (HYB-AM) is a new solid-state process for the production of 3D metal structures.

Metal

Extrusion

Additive Manufacturing

production

Bonding

solid-state process

3D metal structures


Input: In HYB-AM, the wire feedstock is continuously processed through an extruder and deposited in a stringer-by-stringer manner to form layers and eventually a near net-shape component.

feedstock

processed

extruder

component


Input: In this work, the layer bonding of AA6082 samples produced by this process has been investigated by means of tensile testing, hardness measurements and microscope analyses.

layer

bonding

samples

process

tensile testing

hardness

microscope


Input: Furthermore, a novel method for the fabrication of miniature tensile specimens for assessing the bond strength across the layers is presented and applied.

fabrication

tensile specimens

bond strength


Input: The test results reveal that the ultimate tensile strength is approaching that of the substrate material of the same alloy, yet with a somewhat lower elongation prior to fracture.

ultimate tensile strength

elongation

substrate material

alloy

fracture


Input: Microscope analyses show that the bonded interfaces are fully dense; however, the fracture surfaces reveal regions of kissing-bonds and lack of bonding.

Microscope

fully dense

fracture

bonding


Input: Still, these preliminary investigations indicate that the HYB-AM process, upon further optimization, has the potential of processing high quality aluminum alloy components.

process

optimization

quality

aluminum alloy


Input: Ferritic/martensitic (FM) steels are being targeted for use in a range of advanced reactor concepts as cladding and structural components.

steels

as

range

structural components


Input: FM steels for nuclear reactor applications have historically been produced using traditional methods (e.g., casting and forging), but recently, additive manufacturing processes have become of interest for making FM-based components.

steels

casting

forging

additive manufacturing processes

components


Input: Here, the laser-blown-powder additive manufacturing process was used to fabricate an FM steel, HT9, followed by microstructural and mechanical performance evaluations to determine the viability of future use of additive manufacturing for FM-based component fabrication.

additive manufacturing process

fabricate

additive manufacturing

steel

microstructural

mechanical

component


Input: Results showed that the as-built condition formed a layered structure with alternating layers of δ-ferrite and martensite, which resulted in anisotropic engineering and true-stress, true-strain mechanical performance.

layered structure

martensite

anisotropic

mechanical


Input: Post-build normalizing and tempering treatments alerted the prior austenite grain size and precipitate distributions, and drove the mechanical performance to near-isotropic properties that mimic wrought-processed properties.

normalizing

distributions

properties

properties

tempering

austenite

precipitate

mechanical

mimic


Input: A new method to forming bulk metallic glass employed ultrasonic additive manufacturing is proposed.

forming

ultrasonic additive manufacturing

metallic glass


Input: The bulk Ni-based metallic glass can be formed layer-by-layer with ultrasonic vibration energy.

metallic glass

be

layer-by-layer

ultrasonic vibration


Input: The internal hardness and modulus of the bulk metallic glass are higher with ultrasonic additive manufacturing.

hardness

metallic glass

ultrasonic additive manufacturing


Input: It is difficult to produce bulk blanks directly from metallic glass, which limits its application.

metallic glass

limits


Input: Ni-based metallic-glass thin strips that can be manufactured easily were used to manufacture bulk metallic glass additively by ultrasonic bonding.

be

metallic glass

manufacture

ultrasonic bonding


Input: The effects of ultrasonic vibration energy on the quality of the additive manufacturing of bulk Ni-based metallic glass were studied.

ultrasonic vibration

quality

additive manufacturing

metallic glass


Input: The experimental results showed that a fully amorphous structure of bulk Ni-based metallic glass can be obtained with an appropriate ultrasonic vibration energy.

experimental

amorphous structure

metallic glass

be

ultrasonic vibration


Input: The thermal properties were almost unchanged, and the hardness and elastic modulus of the Ni-based metallic glass were improved compared with the original material.

thermal properties

hardness

elastic modulus

metallic glass

material


Input: Additive manufacturing of bulk metallic glass by ultrasonic bonding can broaden the application field of metallic glass.

Additive manufacturing

ultrasonic bonding

metallic glass

metallic glass


Input: A key challenge for successful exploitation of additive manufacturing (AM) across a broad range of industries is the development of fundamental understanding of the relationships between process control and mechanical performance of manufactured components.

additive manufacturing

AM

range

industries

mechanical

process control

manufactured

components


Input: In particular, laser beam powder bed fusion (PBF-LB) is identified as a key process for manufacture of metallic AM components.

laser beam

process

manufacture

bed fusion

metallic AM

as

components


Input: Ti-6Al-4V alloy is an important metal alloy for numerous high-performance applications, including the biomedical and aerospace industries.

Ti-6Al-4V alloy

metal alloy

biomedical

aerospace industries


Input: This paper presents initial developments on a model for microstructure prediction in PBF-LB manufacturing of Ti-6Al-4V, primarily focused on solid-state phase transformation and dislocation density evolution.

model

microstructure

solid-state phase

manufacturing

dislocation density


Input: The motivation is to quantify microstructure variables which control mechanical behavior, including tensile strength and ductility.

microstructure

mechanical

tensile strength

ductility


Input: A finite element (FE) based model of the process is adopted for thermal history prediction.

finite element

model

process

prediction

FE


Input: Phase transformation kinetics for transient non-isothermal conditions are adopted and implemented within a stand-alone code, based on the FE-predicted thermal histories of sample material points.

Phase

transient

sample

material


Input: The evolution and spatial variations of phase fractions, α lath width and dislocation density are presented, to provide an assessment of the resulting microstructure-sensitivity of mechanical properties.

evolution

phase fractions

mechanical properties

spatial variations

dislocation density


Input: Friction stir processing (FSP) is combined with additive manufacturing (AM) with selective laser melting to locally enhance the material properties of a metallic part.

Friction

material properties

additive manufacturing

AM

selective laser melting

metallic part


Input: A groove inside aluminium 1060 alloy sheet is filled with an aluminium 7075 alloy powder by AM.

aluminium

alloy

aluminium

alloy

AM


Input: While the overall hardness of the stir zone (SZ) increases significantly, the heterogeneous microstructure results in a unique uneven hardness distribution in the SZ.

hardness

hardness

heterogeneous

distribution


Input: Tensile tests confirm the effectiveness of the suggested technique.

Tensile tests

effectiveness


Input: In laser-foil-printing additive manufacturing, 3D metallic glass structures can be built by laser welding of amorphous foils, layer by layer, upon a crystalline metal substrate.

additive manufacturing

laser welding

layer by layer

glass

be

metal


Input: In this paper, weldability studies for laser welding of Zr52.5Ti5Al10Ni14.6Cu17.9 amorphous foils onto a Ti-6Al-4V (Ti 6-4) or Zr 702 substrate are conducted.

weldability

laser welding

Ti

Zr

substrate


Input: After laser welding, the weldments are analyzed using X-ray diffractometer, optical microscope, scanning electron microscope equipped with energy dispersive spectroscopy and micro-hardness tester.

laser welding

X-ray

optical

energy dispersive spectroscopy

microscope

scanning electron microscope


Input: The results show that Zr 702 is a suitable substrate for Zr-based metallic glass structure since crack-free weld joints can be obtained owing to the formation of ductile α-Zr, while Ti 6-4 is not an appropriate substrate since it has high cracking susceptibility due to the formation of a large amount of hard and brittle intermetallics near the foil-substrate interface.

Zr

substrate

metallic glass

be

Ti

substrate

crack-free weld

cracking

interface

ductile

brittle


Input: It was found that the mixing between melted substrate and foil is not uniform but exhibits a distinct “swirl” pattern.

mixing

melted

pattern

foil


Input: The swirl structure is more pronounced in Ti 6-4 than in Zr 702 substrate which may contribute to its high cracking susceptibility.

structure

cracking

Ti

Zr

substrate


Input: The aforementioned mixing leads to partial crystallization of the first amorphous layer; however, fully amorphous is achieved in the additional welding layers.

mixing

crystallization

layer

welding


Input: The deposition process of wire and arc additive manufacturing (WAAM) is usually planned based on a bead geometry model (BGM), which represents the relationship between bead geometries (e.g.

deposition process

wire and arc additive manufacturing

WAAM

bead geometry

bead geometries


Input: width, height) and required deposition parameters.

deposition


Input: However, the actual deposition situation may deviate from the one in which the BGM is built, such as varied heat dissipation conditions, resulting in morphological changes of deposited beads and geometrical errors in the formed parts.

deposition

heat dissipation

errors

as

deposited beads


Input: In this paper, a novel control mechanism for enhancing the fabrication accuracy of WAAM based on fuzzy-logic inference is proposed.

mechanism

inference

fabrication

WAAM

accuracy


Input: It considers the geometrical errors measured on already deposited layers and deposition context to adjust deposition parameters of beads in the subsequent layer, forming an interlayer closed-loop control (ICLC) mechanism.

errors

deposition

deposition

mechanism

deposited layers

beads

layer

forming

closed-loop control


Input: This paper not only presents the theoretical fundamentals of the ICLC mechanism but also reports the technical details about utilizing this mechanism to control the forming height of multi-layer multi-bead (MLMB) components.

theoretical

mechanism

mechanism

forming

components


Input: A fuzzy-logic inference machine was applied as the core component for calculating speed change of bead deposition based on height error and previously applied change.

inference

error

as

core component

bead


Input: In terms of validation, the effectiveness of the proposed control mechanism and the implemented controller was investigated through both simulative studies and real-life experiments.

validation

effectiveness

mechanism

controller


Input: The fabricated cuboid blocks showed good accuracy in height with a maximum error of 0.20 mm.

fabricated

error

accuracy

mm


Input: The experimental results implied that the proposed ICLC approach facilitates deposition continuity of WAAM, and thus enables process automation for robotic manufacturing.

experimental

deposition

process automation

WAAM

manufacturing


Input: A hybrid additive manufacturing technology for fabricating functionally graded materials (FGMs) is proposed in this paper.

additive manufacturing

fabricating

materials


Input: The new process represents a combination of two existing additive manufacturing processes, selective laser melting (SLM) and cold spraying (CS).

process

additive manufacturing processes

selective laser melting

SLM


Input: The targeted experiment of Al and Al + Al2O3 deposited onto SLM Ti6Al4V via CS reveals that the hybrid additive manufacturing process can produce thick, dense and machinable FGMs composed of non-weldable metals without intermetallic phase formation at the multi-materials interface.

experiment

interface

Al

Al

metals

intermetallic

SLM

additive manufacturing process


Input: The SLM Ti6Al4V part exhibited fully acicular martensitic microstructure in contrast with α + β microstructure in the Ti6Al4V feedstock, while the grain structure of the CS Al part had no significant change as compared with the Al feedstock.

SLM

microstructure

microstructure

grain structure

Ti6Al4V feedstock

Al

as

Al


Input: Due to the phase transformation of the SLM part and work hardening of the CS part, the overall hardness of the FMGs was higher than that of the feedstock.

phase

SLM

work hardening

hardness

feedstock


Input: The emerging trend of manufacturing is keenly focused on increasing the productivity.

trend

productivity

manufacturing


Input: Many alternatives to enhance the productivity of a manufacturing industry involves reformation of production cycle, increasing the life of cutting tool, reducing the design complexity, etc.

productivity

complexity

manufacturing

production

industry

cutting tool

design


Input: However, the increasing nature of size reduction and complexion in design seeks alternate method of manufacturing.

reduction

design

manufacturing


Input: The additive manufacturing is an emerging methodology used for meeting the needs of growing demand.

additive manufacturing

methodology


Input: It is a process of manufacturing parts by depositing materials which is contrary to that of conventional.

process

materials

manufacturing


Input: This work presents a complete investigational survey on various additive manufacturing techniques, integration of digital pre-processing procedures, and product-based process designing.

additive manufacturing

process


Input: The process of creating models with reduced development and manufacturing time is discussed in an absolute manner.

process

manufacturing


Input: Several application-based materials are described in details along with few properties at the end of rapid manufacturing.

materials

properties

rapid manufacturing


Input: Additive manufacturing (AM) processes such as Wire-Arc Additive Manufacturing (WAAM) are highly flexible and particularly suited for manufacturing complex geometries in small batch-sizes.

Additive manufacturing

AM

Additive Manufacturing

WAAM

manufacturing

processes

complex geometries

as


Input: In the case of large batch-sizes, the low production rate of WAAM is a bottleneck, and therefore forming processes with higher production rates are more suitable.

production

WAAM

forming processes

production

bottleneck


Input: However, forming processes such as closed die forging require dedicated tooling and hence lack the flexibility needed to produce product variants.

forming processes

as

die

tooling

flexibility


Input: The current study proposes to combine additive manufacturing with forging to form hybrid components with high complexity and acceptable production rates.

additive manufacturing

forging

production

components

complexity


Input: However, the main challenge in achieving a combination of these manufacturing technologies is the design of the process chain, ensuring that the final properties meet the specifications of the part.

manufacturing technologies

design

process chain

properties

specifications


Input: In this regard, the process sequence of forming followed by WAAM is investigated.

process

forming

WAAM


Input: The base material EN AW-6082 was formed to a preform by forging, followed by the deposition of different aluminum alloys by WAAM.

material

aluminum alloys

forging

WAAM

deposition


Input: The evolution of mechanical properties such as hardness and microstructure was analyzed.

evolution

mechanical properties

microstructure

as


Input: Based on the experimental observations, strategies to improve the performance of the hybrid components are presented.

experimental

performance

components


Input: In order to achieve a polytropic expansion through a reciprocating machine, an extremely compact heat exchanger is designed.

machine

compact

designed


Input: It is a Mini Channel Heat Exchanger (MCHE), cross-flow configuration, aluminium made.

Channel

configuration

aluminium


Input: So, the additive manufacturing DMLS technique was used to make the exchanger.

additive manufacturing


Input: Then a simplified design calculation is used to roughly predict its performance.

design

performance


Input: Finally, the experimental test rig and the experimental data are shown.

experimental

experimental data


Input: The rapid prototyping has been developed from the 1980s to produce models and prototypes until the technologies evolution today.

rapid prototyping

prototypes

technologies evolution


Input: Nowadays, these technologies have other names such as 3D printing or additive manufacturing, and so forth, but they all have the same origins from rapid prototyping.

technologies

as

3D printing

additive manufacturing

rapid prototyping


Input: The design and manufacturing process stood the same until new requirements such as a better integration on production line, a largest series of manufacturing or the reduce weight of products due to heavy costs of machines and materials.

design

manufacturing process

production line

manufacturing

as

weight

machines

materials


Input: The ability to produce complex geometries allows proposing of design and manufacturing solutions in the industrial field in order to be ever more effective.

complex geometries

design

manufacturing

industrial

be


Input: The additive manufacturing (AM) technology develops rapidly with news solutions and markets which sometimes need to demonstrate their reliability.

additive manufacturing

AM

technology

reliability


Input: The community needs to survey some evolutions such as the new exchange format, the faster 3D printing systems, the advanced numerical simulation or the emergence of new use.

evolutions

exchange format

as

3D printing

numerical simulation


Input: We propose to review the different AM technologies and the new trends to get a global overview through the engineering and manufacturing process.

AM technologies

manufacturing process

trends

engineering


Input: This article describes the engineering and manufacturing cycle with the 3D model management and the most recent technologies from the evolution of additive manufacturing.

engineering

3D model

manufacturing cycle

technologies

evolution

additive manufacturing


Input: Finally, the use of AM resulted in new trends that are exposed below with the description of some new economic activities.

AM

trends

economic activities


Input: The first method to create a three-dimensional object layer by layer using computer-aided design (CAD) was rapid prototyping, developed in the 1980s to produce models and prototype parts.

three-dimensional

layer by layer

prototype

computer-aided design

CAD

rapid prototyping


Input: The main advantage of the Additive Manufacturing (AM) is its ability to create almost any possible shape and this capacity is run by the layer-by-layer manufacturing.

Additive Manufacturing

AM

capacity

layer-by-layer


Input: AM technology is most commonly used for modelling, prototyping, tooling through an exclusive machine or 3D printer.

AM technology

modelling

prototyping

tooling

machine

3D printer


Input: AM is largely used for manufacturing short-term prototypes but it is also used for small-scale series production and tooling applications (Rapid Tooling).

AM

manufacturing

production

Rapid Tooling

prototypes

tooling


Input: This technology was created to help and support the engineers in their conceptualisation.

technology

conceptualisation

support


Input: Among the major advances that this process presented to product development are the time and cost reduction, human interaction, and consequently the product cycle development.

process

product development

cost reduction

human interaction

product cycle


Input: Those shapes could indeed be very difficult to manufacture with other processes (e.g.

be

manufacture

processes


Input: milling, moulding).

milling

moulding


Input: The complex geometries or the curved surfaces needed have to be maintained with a support material.

complex geometries

curved surfaces

be

support material


Input: The feedback has a great influence on the quality or effectiveness of the manufactured model.

feedback

quality

effectiveness

manufactured


Input: From one technology to another, the manufacture direction, the model orientation and the material behaviour are important to get an accurate model and an efficient production.

technology

manufacture direction

model orientation

material

accurate

production


Input: Nowadays, these technologies have other names such as 3D printing, and so forth, but they all have the same origins from rapid prototyping.

technologies

as

3D printing

rapid prototyping


Input: The demand of AM machines is increasingly growing since the 1990s.

AM machines


Input: Due to the evolution of rapid prototyping technologies, it has become possible to obtain parts representative of a mass production within a very short time.

evolution

mass production

rapid prototyping


Input: AM perfectly fits into the numerical design and manufacturing chain.

AM

fits

numerical design

manufacturing chain


Input: AM is very complementary with the reverse engineering to reproduce or repair a model.

AM

reverse engineering

model


Input: Many rapid prototyping technologies have appeared on the market based on the same layers manufacturing approach.

rapid prototyping

layers manufacturing


Input: AM or 3D printing have strongly been developed and currently propose several solutions.

AM

3D printing


Input: Use of AM leads to new practices in different domains which push the manufacturer to adapt.

AM

manufacturer


Input: The evolution of AM technologies also leads to news solutions driven by very strong demand.

evolution

AM technologies


Input: Use and evolution change gradually the product life cycle in order to reducing the manufacturing cost and time while increasing reliability.

evolution

product life cycle

manufacturing cost

reliability


Input: We propose to realise a technologic review of manufacturing processes followed by their illustrative scheme.

technologic

manufacturing processes


Input: We have chosen to classify the AM by manufacturing technologies to explain them.

AM

manufacturing technologies


Input: First of all, we will describe the design process before the technologies description while involving some industrial and academic trends.

design process

technologies

trends

industrial


Input: The stages involved to the product design and the rapid prototyping show that the cycle development is specific.

product design

rapid prototyping

cycle development


Input: These rapid prototyping processes generally consist of a substance, such as fluids, waxes, powders or laminates, which serve as basis for model construction as well as sophisticated computer-automated equipment to control the processing techniques such as deposition, sintering, lasing, etc.

rapid prototyping

lasing

processes

substance

laminates

processing techniques

as

waxes

powders

as

as

as

as

model construction

sintering

computer-automated equipment


Input: There exist two possibilities to start an AM cycle, begin with a virtual model or a physical model.

AM

virtual model

physical model


Input: The virtual model created by a CAD software can be either a surface or a solid model.

virtual model

CAD

be

surface

solid model


Input: On the other hand, 3D data from the physical model is not at all straightforward and it requires data acquisition through a method known as a reverse engineering.

3D data

physical model

reverse engineering

data acquisition

as


Input: The process begins with a 3D model in CAD software before converting it in STL format file.

process

3D model

CAD

STL format

file


Input: This format is treated by specific software, own to the AM technology, which cuts the piece in slices to get a new file containing the information for each layer.

software

slices

AM technology

file

layer


Input: The specific software generates the hold to maintain the complex geometries automatically with sometimes the possibility to choose some parameters.

software

complex geometries

parameters


Input: We can decompose the engineering and manufacturing cycle by Part design in CAD or reverse engineering by 3D scanning.

engineering

manufacturing cycle

reverse engineering

design

CAD

3D scanning


Input: Skills optimisation in CAE to adapt the part to the manufacturing technology chosen.

CAE

manufacturing technology


Input: Conversion of part geometry in exchange format (STL).

geometry

exchange format

STL


Input: Exchange file implementation into the specific software of the AM machine.

file

software

AM machine


Input: Configuration and orientation of the set (parts and supports).

Configuration

orientation

set

supports


Input: Slicing of the part by the specific software.

Slicing

software


Input: Computation and layers manufacturing.

Computation

layers manufacturing


Input: Post-processing.

Post-processing


Input: This new file is often proprietary of the machine manufacturer.

file

machine


Input: Rapid manufacturing machine implement the last file to realise the layer-by-layer manufacturing.

Rapid manufacturing

machine

file

layer-by-layer


Input: The operator has to prepare the machine with its raw material (powder, resin cartridge (s), polymer spool (s), etc) and the manufacturing source (laser, printing head (s), binder cartridge (s), etc).

machine

cartridge

printing head

raw material

powder

resin

s

polymer

s

s

binder

s

manufacturing

laser


Input: For the manufacturing, the support material maintains the external and internal surfaces to keep a steady geometry with a structure using scaffolding.

manufacturing

support material

surfaces

geometry

structure

scaffolding


Input: In most cases, the support material is cleaned during the finishing (ex.

support material

finishing


Input: MJM Technology) or recycled during the post-processing (e.g.

MJM

recycled

post-processing


Input: SLS, SLM, CJD/3DP Technologies).

SLS

SLM


Input: This step depends on the complex geometry fabricated and if there is need an additional hold resulting in a loss of material.

step

complex geometry

material


Input: Some technologies allow extracting of the main material, thanks to holes inside closed geometry.

technologies

extracting

geometry

material


Input: The post-processing step sometimes includes a hardening or infiltration of the main material to obtain the final piece.

post-processing

infiltration

hardening

material


Input: Several manufacturing constraints require a feedback while involving rules to get a precisely and compliant model.

manufacturing constraints

model

feedback


Input: Rapid prototyping techniques are classified in two categories: subtractive, and additive.

Rapid prototyping

subtractive

additive


Input: Subtractive technologies work by removing raw material out of a workpiece until the desired shape is obtained.

Subtractive

raw material

workpiece


Input: They include cutting (laser-cutting or water-jet cutting) and machining (lathing and milling).

cutting

laser-cutting

water-jet cutting

machining

lathing

milling


Input: Conversely, the additive technologies work by adding of the raw material.

additive technologies

raw material


Input: Modelling is a very important step in AM because it shapes the product but it also must take in account some knowledge since the experiments and equipment are costly.

Modelling

step

AM

equipment


Input: Various potential empirical modelling techniques coexist so that the choice of an appropriate modelling technique for a given AM process can be made.

empirical

modelling

AM process

be


Input: To develop models based on only given data, several well-known statistical methods such as regression analysis or response surface methodology can be applied.

data

statistical methods

response surface methodology

as

be


Input: The formulation of the physics-based models requires in-depth understanding of the process and is not an easy task in presence of partial information about the process.

physics-based models

process

partial information

process


Input: Few research studies have been conducted to improve the prediction ability of the GP (Genetic Programming) and the MGGP (Multi-Gene Genetic Programming) models by hybridising them with the other potential computational intelligence methods such as artificial neural network (ANN), fuzzy logic, M5’ regression trees and support vector regression.

research

prediction

GP

hybridising

computational intelligence

fuzzy logic

regression

support vector regression

Genetic Programming

MGGP

Multi-Gene Genetic Programming

artificial neural network

ANN

as


Input: MGGP is the most popular variant of GP used recently.

MGGP

GP


Input: Those approaches provide a model in the form of a mathematical equation reflecting the relationship between the mechanical behaviours and the given input parameters.

model

mathematical equation

mechanical behaviours

parameters


Input: The performance of ANN is found to be better than those of GP and regression, showing the effectiveness of ANN in predicting the performance characteristics of prototype.

performance

GP

regression

effectiveness

performance

prototype

ANN

ANN

be


Input: The STL (STereoLithography or Standard Tessellation Language) file format was created by 3D Systems in 1987 and became a standard for the additive manufacturing.

STL

Standard Tessellation Language

file

STereoLithography

additive manufacturing

3D Systems

standard


Input: The STL file creation process mainly converts the continuous geometry in the CAD file into a header, small triangles or coordinates triplet list of x, y and z coordinates and the normal vector to the triangles.

STL

file

CAD file

process

geometry

header

coordinates triplet

normal vector

y

coordinates


Input: Each facet is uniquely identified by a normal vector and three vertices.

facet

normal vector

vertices


Input: The facets define the surfaces of a 3D object.

facets

surfaces

3D object


Input: Each facet is part of the boundary between the interior and the exterior of the object and each triangle facet must share two vertices with each of its adjacent triangles.

facet

facet

adjacent triangles

boundary

vertices


Input: The surface creation can generate errors because of holes or intersecting triangles and it is sometimes necessary to repair the STL model.

surface

errors

model

STL


Input: The slicing process also introduces inaccuracy to the file because here the algorithm replaces the continuous contour with discrete stair steps.

slicing process

algorithm

discrete stair steps

file

contour


Input: Edges are added after the slicing process.

slicing process


Input: Today, the computation data and the mesh generation is no longer an obstacle to process models.

computation

mesh generation

process models


Input: The computer power used is sufficient to get a refined STL file with many triangles.

computer

STL

file


Input: More the 3D model refined is high, the clearer the details are and the bigger the file size is.

3D model

file size


Input: According to the 2014 Wohlers Report, consumers of 3D printers are classified as those that cost less than $5000.

3D printers

as


Input: The Cornell University and the University of Bath have designed the first open-source 3D printers which are widely recognised in the area: Fab @home and RepRap.

designed

open-source

3D printers

area

RepRap


Input: The entered range 3D printers are predominantly based on Fused Deposition Modeling (FDM) technology, but more recently machines derived from stereolithography have entered the market due to expiring patents.

range

3D printers

machines

Fused Deposition Modeling

FDM

stereolithography

technology

patents


Input: It is typically to demonstrate that low-cost machines have a low performance.

machines

performance


Input: For example, the FDM consumer technology suffers from anisotropic mechanical properties as well as a limited selection of thermoplastic materials.

FDM

technology

properties

anisotropic

as

as

thermoplastic materials


Input: A FDM professional printer costs between $10,000 and $300,000.

FDM

printer


Input: Typical laser and electron beam-based systems can cost anywhere between $500,000 and $1 M. While these machines are typically high in performance, they come at a high cost.

laser

electron beam-based

machines

performance


Input: The commercial 3D printers that use more advanced techniques to print objects are usually equipped with proprietary software which slice the 3D model and command the machine.

3D printers

machine

print

software

slice

3D model


Input: Companies that sell professional 3D printers include 3D Systems, Stratasys, Solido LTD, Voxeljet and ExOne.

Companies

3D Systems

Stratasys

Solido LTD

3D printers