Input: Low viscosity ink preparation.

viscosity

ink


Input: Processing-enabled manipulation of matrix morphology.

morphology


Input: Cured epoxy resin kinetically traps low molecular weight gelator.

Cured

resin

weight


Input: Direct writing a thermosetting resin typically requires a rheological modifier or peripheral reaction rate-modulating equipment to enable shape fidelity during parts fabrication.

resin

rheological

equipment

shape fidelity

fabrication


Input: These low molecular weight gelators (LMWG) are thermally activated to produce sufficient yield stress for self-supporting, reactive, physical gels.

weight

LMWG

thermally activated

yield stress

self-supporting


Input: Physical gelation occurs by assembly of the LMWG into supramolecular morphologies that vary by mode of processing.

assembly

LMWG

supramolecular morphologies


Input: Flow of the form-stable epoxy resin is induced by yielding of the physical gel structure.

epoxy

gel


Input: When the physical gel is cured at temperatures below the melt transition of the organic gelator, the network structure likely kinetically traps the organic gelator in a metastable state.

gel

cured

temperatures

melt

structure

metastable


Input: Recrystallization of the kinetically trapped organic gelator is impeded when the network is post-cured above the melt transition temperature of the organic gelator.

Recrystallization

melt

temperature


Input: The use of low molecular weight agents that physically gel by thermal activation, generates low viscosity solution processability and suggests that this platform may be suitable for high solids loading applications amenable to direct writing.

weight

gel

be

viscosity

solution

platform


Input: The effect on fatigue resistance of additively manufactured (AM) AlSi10Mg specimens fabricated by selective laser melting (SLM) following surface treatment by shot-peening was investigated.

fatigue

additively manufactured

AM

selective laser melting

SLM

surface treatment

fabricated


Input: Specimen surface was shot-peened with either steel or ceramic balls.

surface

steel

ceramic


Input: Nano-indentation measurements revealed that shot-peening caused surface hardening, with the hardness profile from the surface to the interior of the bulk disappearing 50 μm below the surface.

surface hardening

hardness

surface

surface


Input: Surfaces polished before shot-peening or following removal of about 25–30 μm from the surface after shot-peening by either mechanical or electrolytic polishing showed improved fatigue resistance and fatigue limit.

Surfaces

surface

mechanical

polishing

fatigue

fatigue


Input: The fracture area of AM-SLM AlSi10Mg specimens before and after shot-peening displayed a ductile fracture with relatively deep dimples.

fracture

ductile fracture

area


Input: In contrast to AM specimens, the final fracture area of die-cast samples exhibited a brittle fracture surface, containing numerous cleavage facets and micro-cracks.

AM

fracture

samples

brittle fracture

facets

micro-cracks

area


Input: The extrusion-based additive manufacturing (AM) of moisture-cured silicone elastomer with minimal voids and high strength, elongation, and fatigue life is presented.

additive manufacturing

AM

silicone elastomer

voids

strength

elongation

fatigue life


Input: Due to the soft nature and extended cure time of moisture-cured silicone, AM is technically challenging.

cure

silicone

AM


Input: This compression is exploited to prevent void formation in silicone AM.

compression

void

silicone

AM


Input: This research aims to explore process parameters for voidless silicone AM of solid and thin-wall structures for pneumatic actuators.

research

process parameters

silicone

AM

actuators


Input: Experiments were performed to study effects of flowrate, layer height, and distance between adjacent silicone lines on the solid and thin-wall vertical layer deformation and void generation.

layer height

layer

silicone

vertical

deformation

void


Input: The results were then applied in AM of two thin-walled hollow silicone pneumatic parts: the sphere-like balloons and finger pneumatic actuators.

AM

silicone

actuators


Input: The sphere-like balloons exhibited diametric expansion between 152 and 207% with burst stress between 1.46 and 2.55 MPa (which is comparable to the base material properties) while the pneumatic finger actuators were able to fully articulate over 30,000 cycles before failure.

stress

MPa

material properties

failure

actuators


Input: Fiber trajectory of composite structures is optimized for Additive manufacturing.

Fiber

composite structures

Additive manufacturing


Input: The stiffness and strength were simultaneously improved by the proposed method.

stiffness

strength


Input: A methodology of fiber trajectory optimization is proposed for Additive Manufacturing of composites.

methodology

optimization

fiber

composites

Additive Manufacturing


Input: The present method aligns fiber with a physically-determined load path to simultaneously increase the stiffness and strength of the composite structures.

fiber

stiffness

strength

composite structures


Input: In the case of open-hole panel, the deformation and the failure index were decreased by 8% and 55% compared to those obtained by the unidirectional structure.

deformation

failure

unidirectional structure


Input: In the case of PAF, the decrease in failure index was 76%, but the reduction of deformation was not significant (6%).

failure

reduction

deformation


Input: The present method also identified the structural members that did not contribute to strength and rigidity, which in turn realized the appropriate weight savings and increased the specific strength and specific stiffness.

strength

specific strength

specific stiffness

weight


Input: Microstructures with spatially-varying properties such as trabecular bone are widely seen in nature.

Microstructures

as

properties

bone


Input: These functionally graded materials possess smoothly changing microstructural topologies that enable excellent micro and macroscale performance.

functionally graded materials

microstructural

macroscale


Input: The fabrication of such microstructural materials is now enabled by additive manufacturing (AM).

fabrication

additive manufacturing

AM

microstructural materials


Input: A challenging aspect in the computational design of such materials is ensuring compatibility between adjacent microstructures.

design

materials

microstructures


Input: Existing works address this problem by ensuring geometric connectivity between adjacent microstructural unit cells.

microstructural

cells


Input: In this paper, we aim to find the optimal connectivity between topology optimized microstructures.

topology

microstructures


Input: Recognizing the fact that the optimality of connectivity can be evaluated by the resulting physical properties of the assemblies, we propose to consider the assembly of adjacent cells together with the optimization of individual cells.

be

physical properties

assembly

cells

cells

optimization


Input: In particular, our method simultaneously optimizes the physical properties of the individual cells as well as those of neighbouring pairs, to ensure material connectivity and smoothly varying physical properties.

physical properties

physical properties

cells

as

as

material


Input: We demonstrate the application of our method in the design of functionally graded materials for implant design (including an implant prototype made by AM), and in the multiscale optimization of structures.

design

design

functionally graded materials

implant

implant

AM

optimization


Input: An analytical model was created to illustrate the powder stream distribution under the four-jet nozzles in direct energy deposition (DED).

model

distribution

powder

nozzles

direct energy deposition

DED


Input: Weight measurement method was used to validate the powder flow distributions at different positions under the nozzle.

Weight

measurement

powder

distributions

nozzle


Input: Analyzed the effects of the input variables on the powder stream distribution.

powder

distribution


Input: Estimated the powder deposition efficiency (PDE) based on the simulation results.

powder

deposition

simulation


Input: As an important factor during direct energy deposition (DED) additive manufacturing process, powder stream distribution will not only affect the deposition rate, but also the powder-gas and power-powder interactions, and thus the consequent quality and property of the fabricated part.

As

powder

direct energy deposition

DED

additive manufacturing process

distribution

quality

property

fabricated

deposition rate


Input: This paper created an analytical model to illustrate the powder stream distribution under the four-jet nozzles in the DED.

model

distribution

powder

nozzles

DED


Input: To validate the proposed model, weight measurement method was used to track the powder stream distributions at different positions under the nozzle.

model

distributions

weight

measurement

powder

nozzle


Input: Additionally, the effects of the input variables, including powder flow rate, gas flow rate and particle size, on the powder stream distribution were also analyzed.

powder flow rate

gas flow rate

particle

distribution

powder


Input: The results suggest a relatively good agreement between the modelling and experimental measurements.

modelling

experimental


Input: At the end, the powder deposition efficiency (PDE) was estimated based on the simulation results.

powder

deposition

simulation


Input: The influence of build orientation, layer thickness, strain rate and size effect on the Young’ s modulus, ultimate tensile strength and fracture strains in vat photopolymerization based additively manufactured specimens is investigated.

build orientation

layer thickness

strain rate

size effect

fracture

s

ultimate tensile strength

vat photopolymerization

additively manufactured


Input: Mechanical testing and subsequent scanning electron microscopy tests on additively manufactured specimens are conducted.

Mechanical testing

scanning electron microscopy

additively manufactured


Input: Anisotropy in mechanical behavior is only observed in specimens fabricated in different planes.

Anisotropy

mechanical

fabricated


Input: An increase in layer thickness and decrease in strain rate resulted in lower strength, stiffness and higher fracture strains.

layer thickness

strain rate

fracture

strength

stiffness


Input: No significant size effect on strength and failure strains is observed.

size effect

failure

strength


Input: Cure kinetics is found to have significant influence on mechanical properties of additively manufactured specimens.

Cure

mechanical properties

additively manufactured


Input: Warping and delamination in material extrusion additive manufacturing (MatEx) parts are well documented and irreversible thermal strain (ITε) has also recently been reported.

Warping

delamination

material extrusion additive manufacturing

strain


Input: As parts are built up as a collection of roads, they are analogous to fiber reinforced composites.

As

as

fiber reinforced composites


Input: However, the lack of bonding between the matrix, air, and the reinforcing phase, polymer roads, necessitates the development of a micromechanical model for these parts.

bonding

model

reinforcing phase

polymer


Input: In this work, a micromechanical model for MatEx parts is developed to describe bulk part behavior that incorporates void fraction, road morphology, and bonding between and within layers.

model

void fraction

morphology

bonding


Input: Combining stress accumulation within roads with the micromechanical model successfully predicted ITε and provided a rationale for ITε dependence on both layer thickness and raster angle.

stress

model

predicted

layer thickness


Input: Additionally, the micromechanical model developed can be used to explain bonding limitations in MatEx based on road and bond geometry.

model

bonding

geometry

be


Input: Material anisotropy model formulation for the full three dimensional space.

Material

anisotropy


Input: Efficient optimization of lattice structures with respect to material anisotropy.

optimization

lattice structures

material

anisotropy


Input: Effects of the material anisotropy on lightweight lattice structures.

material

anisotropy

lightweight lattice


Input: Finding the optimized build orientation with respect to the material anisotropy.

build orientation

material

anisotropy


Input: Large increase in accuracy, hence, safety compared to conventional approaches.

accuracy

safety


Input: The build orientation is one the most influential factors on material properties in additively manufactured parts.

build orientation

material properties

additively manufactured


Input: Advanced applications, such as lattice structures optimized for lightweight, often rely on small safety margins and are, hence, particularly affected, but research has not gone far beyond the pure empirical characterization.

as

lightweight

safety

research

empirical


Input: The focus of this paper is to investigate in detail the influence of anisotropy induced through fabrication on the mechanical performance and build orientation of whole structures when subject to optimization.

anisotropy

fabrication

mechanical

build orientation

optimization


Input: First, a material property model for both compression and tension states is formulated.

material property

compression


Input: Then, the Generalized Optimality Criteria method is extended for fixed topology lattice structures with respect to constraints in displacement, stress, and Euler buckling.

topology lattice

stress

buckling


Input: The two latter are formulated as local constraints that are handled in combination with Fully-Stressed Design recursion.

as

Design


Input: The results reveal significant safety threads likely leading to premature failure when using properties from one-directional tests, as is so far the case, rather than the full anisotropy model developed herein.

safety

failure

properties

as

anisotropy


Input: If used inversely, the algorithm yields the optimal orientation of a structure on the build platform, allowing further weight reduction while maintaining the mechanical properties.

algorithm

orientation

structure

reduction

mechanical properties

build platform

weight


Input: Selective Laser Melting (SLM) facilitates the formation of complex, stochastic or non-stochastic, metallic cellular structures.

Selective Laser Melting

SLM

stochastic

metallic

cellular structures


Input: There is a high level of interest in these structures recently, particularly due to their high strength to weight ratios and osteoconductive properties.

strength to weight ratios

osteoconductive


Input: While the ability to in-situ monitor the SLM process is of key importance for future quality control methods.In this work lattice structures were fabricated, using the single exposure scanning strategy, on a Renishaw 500M SLM machine.

in-situ

process

quality control

fabricated

exposure

SLM

SLM

lattice structures

machine


Input: The build process was also monitored using a co-axial in-situ process monitoring system.It was found that by increasing the energy input, through increasing the laser power and/or exposure time, the lattice strut diameters, within the 1.5 mm diamond unit cells, increased from 119 to 293 μm, resulting in the major pore diameter decreasing from 1106 to 932 μm.

build

laser power

in-situ

exposure

lattice

diameter

mm

diamond

cells

pore


Input: The effect of systematically altering the laser beam spot size on the cellular structures was also evaluated.

laser beam

cellular structures


Input: It was observed that by doubling the laser beam spot size, that there was a 17% reduction in strut diameter and a 22% reduction in mechanical strength of the structures.

laser beam

reduction

reduction

strut diameter

mechanical strength


Input: It was also observed that at constant energy input levels, the lattice structures created using a focused laser exhibited an 81% lower mechanical strength than the structures created using a de-focused laser.

lattice structures

laser

laser

mechanical strength


Input: Thus, demonstrating that the mode of energy input is critical to achieving the desired strength in these structures.Based on the outputs from the in-situ monitoring system, a broadly linear correlation was obtained between the laser input energy, the associated process monitoring data generated and the mechanical strength of the lattice structures.

strength

mechanical strength

in-situ

process monitoring

data

laser

lattice structures


Input: Elevated heat-treatment temperatures increased mechanical properties.

temperatures

mechanical properties


Input: Long heat-treatment times decreased ductility and Young’ s modulus.

ductility

s


Input: All elevated temperature heat-treatments yielded similar percent crystallinity.

temperature


Input: Increasing print and heat-treatment temperature increased inter-road bonding.

print

temperature

bonding


Input: Post-processing heat-treatments increased mechanical properties of printed parts.

Post-processing

mechanical properties


Input: Material extrusion additive manufacturing (MEAM) and other additive manufacturing methods provide part design options that would be difficult or impossible to realize with conventional manufacturing methods.

Material extrusion additive manufacturing

additive manufacturing

conventional manufacturing

design

be


Input: However, the mechanical properties of parts produced with MEAM are lower than bulk material properties because of the interfaces between roads and layers inherent to the additive build technique of MEAM.

mechanical properties

material properties

additive


Input: The effects of material dependent MEAM process parameters on the interlayer bonding and percent crystallinity of MEAM parts fabricated with polyphenylene sulfide (PPS) were examined in this study using a design of experiments technique known as the Taguchi method.

material

as

process parameters

bonding

fabricated

design of experiments

Taguchi method


Input: The MEAM parameters studied were print temperature, heat-treatment time, and heat-treatment temperature.

parameters

print

temperature


Input: Heat-treatment temperature was shown to be the most influential parameter on all the studied properties.

temperature

be

parameter

properties


Input: Utilizing heat-treatments on MEAM parts increased the ultimate tensile strength (UTS) from 52% of the PPS film UTS to 80%.

ultimate tensile strength

UTS

UTS


Input: The study showed that utilizing post-processing heat-treatments on MEAM parts could improve the interlayer bonding in these parts.

post-processing

bonding


Input: Ultra High Molecular Weight Polyethylene (UHMWPE) is a semi-crystalline polymer that has remarkable properties of high mechanical properties, excellent wear resistance, low friction and chemical resistance, and it is found in many applications such sporting goods, medical artificial joints, bullet proof jackets and armours, ropes and fishing lines [1].

Weight

Polyethylene

polymer

properties

mechanical properties

friction

wear resistance

chemical resistance

medical

artificial joints


Input: UHMWPE parts can not be produced easily by many conventional processes because of its very high melt viscosity resulting from its very long chains [2].

be

processes

melt


Input: Additive Manufacturing (AM) is moving from being an industrial rapid prototyping process to becoming a mainstream manufacturing process in a wide range of applications.

Additive Manufacturing

AM

manufacturing process

industrial

prototyping process

range


Input: Laser sintering of polymers is one of the AM techniques that is most promising process owing to its ability to produce parts with complex geometries, accurate dimensions, and good mechanical strength [3].

Laser sintering

AM techniques

polymers

process

complex geometries

accurate

mechanical strength


Input: This paper reports attempts to laser-sinter UHMWPE and assesses the effects of laser energy density on the flexural properties of the sintered parts.

laser energy density

properties

sintered


Input: The properties of the UHMWPE sintered parts were evaluated by performing flexural three point bending tests and were compared in terms of flexural strength, flexural modulus and ductility (deflection).

properties

three point bending

sintered

flexural strength

ductility


Input: Part dimensions and relative density were evaluated in order to optimise the laser sintering parameters.

dimensions

relative density

laser sintering


Input: Thermal analysis of samples was made by differential scanning calorimetry (DSC) for the virgin powder.

Thermal analysis

DSC

samples

scanning

virgin powder


Input: Results show that flexural strength, modulus and ductility are influenced by laser energy density and flexural strength and modulus of 1.37 MPa and 32.12 MPa respectively are still achievable at a lower laser energy density of 0.016 J/mm2 (Laser power of 6 W).

flexural strength

ductility

flexural strength

laser energy density

laser energy density

Laser power

MPa

MPa


Input: Part dimensions and bulk density are also influenced by laser energy density.

dimensions

density

laser energy density


Input: γ-Fe phase increase with the increasing SS316L content.

phase


Input: The increase of SS316L content improves general and pitting corrosion resistance.

pitting corrosion


Input: Graded material with SS316L content ≥50 wt.% still has relatively high microhardness.

material

microhardness


Input: Graded material with SS316L content ≥50 wt.% has lower pitting susceptibility.

material

pitting


Input: Composition-graded materials could be designed to rapidly establish the structure-property with high-throughput methods.

materials

be


Input: In this study, stainless steel 316L (SS316L)-431 (SS431) graded material with the SS316L content ranging from 0 to 100 wt.% was fabricated by directed energy deposition additive manufacturing.

stainless steel

material

fabricated

directed energy deposition additive manufacturing


Input: Composition, phase constitution, microstructure and corrosion behavior of the graded material were characterized by laser-induced breakdown spectroscopy (LIBS), micro-beam X-ray diffraction (XRD), scanning electron microscope (SEM) and high-throughput local electrochemical techniques respectively.

Composition

phase

microstructure

spectroscopy

electrochemical

corrosion behavior

material

X-ray diffraction

XRD

SEM

scanning electron microscope


Input: Accordingly, the dominant microstructure varies from equiaxed dendrites to a mixture of dendritic and cellular structures.

microstructure

dendrites

cellular structures


Input: As the content of SS316L increases, the reduced carbides at grain boundaries and the increasing compactness of passive film improve the general and pitting corrosion resistance of the material.

As

carbides

material

grain boundaries

pitting corrosion


Input: Such a high-throughput screening process allows one to reliably select the constituents with the presence of SS316L over 50 wt.% as a potential component under the requirement of high corrosion resistance and wear resistance.

process

corrosion resistance

as

component

wear resistance


Input: Fused Filament Fabrication (FFF) is an additive manufacturing (AM) method that relies on the thermal extrusion of a thermoplastic feedstock from a mobile deposition head.

Fused Filament Fabrication

FFF

additive manufacturing

AM

extrusion

thermoplastic feedstock

deposition


Input: Conventional FFF constructs components from stacks of individual extruded layers using tool paths with fixed z-values in each individual layer.

FFF

extruded

components

tool paths

layer


Input: Consequently, the manufactured components often contain inherent weaknesses in the z-axis due to the relatively weak thermal fusion bonding that occurs between individual layers, as well as poor surface finish in shallow sloped contours.

manufactured

z-axis

fusion bonding

components

as

as

surface finish

contours


Input: This study demonstrates the use of Curved Layer FFF (CLFFF) tool paths in tandem with a commercially available parallel, or delta, style FFF system to allow the deposition head to follow the topology of the component.

Layer

FFF

FFF

tool paths

deposition

topology

component


Input: By incorporating a delta robot and CLFFF tool paths in this way, improvements in the surface finish of the manufactured parts has been observed, and time costs associated with Cartesian robot based CLFFF manufacturing have been notably reduced.

robot

robot

tool paths

manufactured

surface finish

manufacturing


Input: Furthermore, employing a delta robot provides additional flexibility to CLFFF manufacturing and increases the feasibility of its application for advanced manufacturing.

robot

flexibility

manufacturing

manufacturing

feasibility


Input: The study has also demonstrated a viable approach to multi-material FFF by decoupling support structure and part manufacture into regions of CLFFF and static z tool pathing in an appropriate fashion.

multi-material

manufacture

fashion

FFF

support structure

tool


Input: Reducing the relative quality of lattice materials is a key factor in expanding their scope of application.

quality

lattice


Input: Experimental samples of Ti6Al4V, including both VPOS and a body-centered cubic (BCC) octahedral model, are prepared by selective laser melting (SLM).

Experimental

BCC

model

selective laser melting

SLM


Input: The influence of pose (θ) on the relative density of the lattice structures is evaluated analytically.

relative density

lattice structures


Input: The mechanical response and specific energy absorption (SEA) of these structures under compression are investigated.

mechanical response

specific energy absorption

compression


Input: Compared with the experimental BCC data, the relative density of the VPOS samples is reduced, and their SEA values are improved.

experimental BCC

data

samples

relative density


Input: The mechanical properties of the VPOSs in the z and y directions are optimized when θ=43°.

mechanical properties

y


Input: When θ = 10°, the z-direction SEA is maximum (∼2.4 times the BCC value).

z-direction

BCC


Input: Among the various Ti6Al4V octahedral lattice structures, the structure with θ = 43° exhibits the best mechanical properties at unit density.

lattice structures

structure

mechanical properties

density


Input: This study demonstrates that the performance of lattice structures can be improved to different degrees by varying the unit cell pose.

performance

unit cell

lattice structures

be


Input: Additive manufacturing (AM) has gone through major developments in the past decade, enabling the rapid manufacture of complex geometries from traditional engineering materials.

Additive manufacturing

AM

manufacture

complex geometries

engineering materials


Input: This study aims to facilitate the development and additive manufacturing of a new generation of fast and simple digital components with integrated magnetic shape memory (MSM) alloy sections that can be actuated by an external magnetic field.

additive manufacturing

simple

components

alloy

be

magnetic field


Input: Here, we employ a systematic design of experiments (DoE) approach for investigating laser powder bed fusion (L-PBF) of a Ni-Mn-Ga based MSM alloy.

design of experiments

laser powder bed fusion

L-PBF

alloy


Input: The effects of the applied process parameters on the chemical composition and relative density are determined, and detailed investigations are conducted on the microstructural properties of the as-deposited material obtained using optimized parameters.

process parameters

chemical composition

microstructural

parameters

relative density

material


Input: The results show that although the L-PBF of Ni-Mn-Ga is characterized by an ever-present loss of Mn, deposition of Ni-Mn-Ga with a high relative density of 98.3% and a minimal loss of Mn at ∼1.1 at.% is feasible.

L-PBF

Mn

Mn

deposition

relative density


Input: However, combined measurements by the low-field ac magnetic susceptibility method (LFMS) and DSC revealed that the phase transformation of the as-deposited material from martensite to austenite, and vice versa, was broad and occurred in a paramagnetic state.

magnetic susceptibility

DSC

phase

material

martensite

austenite


Input: Inspection by SEM revealed a layered microstructure with a stripe-like surface relief that originated from the presence of martensitic twins within the sample.

Inspection

SEM

microstructure

surface

sample


Input: Overall, L-PBF shows high potential for the production of functional Ni-Mn-Ga based MSM alloys.

L-PBF

production

alloys


Input: Fabricated Schwarz P unit cell-based scaffolds underwent geometrical transformations in the form of shrinkage.

Fabricated

shrinkage

P

scaffolds


Input: Computational effective modulus of the original Schwarz P unit cell under-estimated the experimental modulus by 86.05%.

P

cell

experimental


Input: Computational effective modulus of the reconstructed unit cell over-estimated the experimental modulus by 6.94%.

unit cell

experimental


Input: Micromechanical analysis was able to accommodate geometrical transformations of the Schwarz P unit cell.

P

cell


Input: Schwarz P unit cell-based tissue scaffolds comprised of poly (D, L-lactide-co- ε -caprolactone) (PLCL) fabricated via the additive manufacturing technique, two-photon polymerisation (2PP) were found to undergo geometrical transformations from the original input design.

P

scaffolds

design

fabricated

additive manufacturing

two-photon polymerisation


Input: A Schwarz P unit cell surface geometry CAD model was reconstructed to take into account the geometrical transformations through CAD modeling techniques using measurements obtained from an image-based averaging technique before its implementation for micromechanical analysis.

P

cell

geometry

CAD model

CAD


Input: Effective modulus results obtained from computational mechanical characterization via micromechanical analysis of the reconstructed unit cell assigned with the same material model making up the fabricated scaffolds demonstrated excellent agreement with a small margin of error at 6.94% from the experimental mean modulus (0.69 ± 0.29 MPa).

mechanical

unit cell

fabricated

error

experimental

MPa

material


Input: The inter-relationships between different dimensional parameters making up the Schwarz P architecture and resulting effective modulus are also assessed and discussed.

parameters

P

architecture


Input: With the ability to accommodate the geometrical transformations, maintain efficiency in terms of time and computational resources, micromechanical analysis has the potential to be implemented in tissue scaffolds with a periodic microstructure as well as other structures outside the field of tissue engineering in general.

be

as

as

scaffolds

microstructure

tissue engineering


Input: Nanoparticle-enhanced Al 7075 can be used to make crack-free welds, overlays, and multi-layer parts via arc welding.

Nanoparticle-enhanced Al 7075

be

crack-free welds

overlays

arc welding


Input: Hardness of deposited nanoparticle-enhanced Al 7075 weld material return to that of parent alloy after T73 heat treatment.

Hardness

nanoparticle-enhanced Al 7075

material

alloy

T73 heat treatment


Input: Post-weld T73 heat treatment of nanoparticle-enhanced Al 7075 results in tensile properties indiscernible from parent alloy.

T73 heat treatment

nanoparticle-enhanced Al 7075

alloy

tensile properties


Input: Aluminum alloy 7075 (Al 7075) with a T73 heat treatment is commonly used in aerospace applications due to exceptional specific strength properties.

Aluminum alloy 7075

Al 7075

T73 heat treatment

aerospace

specific strength

properties


Input: Challenges with manufacturing the material from the melt has previously limited the processing of Al 7075 via welding, casting, and additive manufacturing.

manufacturing

welding

casting

additive manufacturing

material

Al 7075

melt


Input: Recent research has shown the capabilities of nanoparticle additives to control the solidification behavior of high-strength aluminum alloys, showcasing the first Al 7075 components processed via casting, welding, and AM.

research

solidification

processed

nanoparticle additives

aluminum alloys

Al 7075

casting

welding

AM


Input: In this work, the properties of nanoparticle-enhanced aluminum 7075 are investigated on welded parts, overlays and through wire-based additive manufacturing.

properties

nanoparticle-enhanced aluminum 7075

welded parts

overlays

wire-based additive manufacturing


Input: The hardness and tensile strength of the deposited materials were measured in the as-welded and T73 heat-treated conditions showing that the properties of Al 7075 T73 can be recovered in welded and layer-deposited parts.

hardness

tensile strength

materials

properties

T73 heat-treated

welded

Al 7075 T73

be


Input: The work shows that Al 7075 now has the potential to be conventionally welded or additively manufactured from wire into high-strength, crack-free parts.

Al 7075

be

welded

additively manufactured

crack-free parts


Input: The dissimilar resistance spot welding of additively manufactured steel to conventional automotive steel has attracted significant attention from automotive manufacturer.

resistance spot welding

additively manufactured steel

conventional automotive steel

automotive


Input: However, the mechanical properties of dissimilar spot welds could be affected by the printed properties of additively manufactured steels, limiting the further application of 3D printing process in auto-body assembly line.

mechanical properties

properties

spot welds

be

additively manufactured steels

3D printing

auto-body assembly line


Input: This paper proposed an approach to improve the mechanical properties of spot-welded joints of additive manufactured steels by the design of binder jetting printed steels with the addition of nanoparticles.

mechanical properties

nanoparticles

spot-welded joints

additive manufactured steels

steels

design

binder jetting


Input: Cu-Sn nanoparticles have been injected to the stainless steel via binder jetting process, aiming to fill the voids between steel particles and reduce the microstructure heterogeneity in the spot welds.

Cu-Sn nanoparticles

stainless steel

steel

binder jetting

voids

particles

microstructure heterogeneity

spot welds


Input: The microstructure evolution, sintering behavior of nanoparticles and mechanical properties of resistance spot welded stainless steel were characterized and analyzed.

microstructure evolution

nanoparticles

mechanical properties

sintering

resistance spot welded

steel


Input: The sintering behavior of Cu-Sn nanoparticles during welding process attributes to the formation of transition zone with homogenous microstructure, resulting to the improvement of hardness property and lap-shear strength of spot-welded joints.

sintering

welding

Cu-Sn nanoparticles

process

transition

microstructure

hardness

lap-shear strength

spot-welded joints


Input: Compared to the spot welds of selective laser melting printed stainless steels, the resistance spot welded stainless steel via binder jetting process shows better mechanical properties with 48% increase of energy absorption and 19% increase of peak load.

spot welds

selective laser melting

resistance spot welded

binder jetting

stainless steels

steel

mechanical properties

energy absorption


Input: Additively manufactured plates are successfully joined using FSW for the first time.

Additively manufactured

FSW


Input: Weld microstructure consists of (α + β) phase and very fine equiaxed α grain with a refined β phase at the grain boundary.

Weld microstructure

phase

grain

phase

grain boundary


Input: The tensile strength of the FSW is nearly equal to the base material at a relatively higher tool rotation speed.

tensile strength

FSW

material

tool rotation speed


Input: Significant tool wear is observed at lower tool rotation speeds, resulting in lower weld strength.

tool wear

tool rotation speeds

weld strength


Input: Additive manufacturing of titanium alloy Ti-6Al-4 V has significantly increased over the past few years, primarily due to its broad application over the conventional manufacturing process for complex and near net shape production.

Additive manufacturing

conventional manufacturing

near net shape

titanium alloy Ti-6Al-4 V


Input: We study the feasibility of friction stir welding of Ti-6Al-4 V plates made by electron beam melting, performing both microstructural and mechanical analysis.

feasibility

microstructural

mechanical analysis

friction stir welding

electron beam melting

Ti-6Al-4 V


Input: Microstructures for all the welds reveal lamellar (α + β) phase and very fine equiaxed α grain with the prior β phase at grain boundaries in the stirred zone.

Microstructures

welds

lamellar

phase

grain

phase

grain boundaries


Input: Microhardness at different depths of the joint is measured and the strength of the joint is determined using a tensile test.

Microhardness

joint

joint

strength

tensile test


Input: The results obtained prove the feasibility of the process and provide the necessary processing conditions.

feasibility

process


Input: The Additive manufacturing technologies familiarize many innovative and monetary gains when compared to conservative subtractive manufacturing methods in rapid prototyping (RP) and small production capacity.

Additive manufacturing

subtractive manufacturing

rapid prototyping

RP

production capacity


Input: In other exceedingly industrialized fields including aerospace, automobile, and bio-medical industries, additive manufacturing has turned out to be a subject of high interest.

aerospace

automobile

bio-medical industries

additive manufacturing

be


Input: Nowadays, Additive manufacturing (AM) of Titanium alloys has grown into an imperative field of study.

Additive manufacturing

AM

Titanium alloys


Input: The foremost prominence of Titanium alloys is excellent strength to weight ratio, high weathering resistance, and admirable characteristics involving high tensile strength and toughness with comparatively low electrical and thermal conductivity.

Titanium alloys

strength to weight ratio

weathering resistance

tensile strength

toughness

thermal conductivity

electrical


Input: The manufacturing of Titanium through AM technology is marginally expensive and durable as it enables to create freedom in design community to fabricate user defined and complex structures which is hard to produce through other conventional manufacturing methods.

manufacturing

AM technology

fabricate

conventional manufacturing

Titanium

as

design

complex structures


Input: The Ti-6Al-4V alloy is popularly known as the “work horse” of titanium is comprehensively used in aerospace and biomedical industries.

Ti-6Al-4V alloy

as

titanium

aerospace

biomedical industries


Input: At present, several studies have focused on hybrid manufacturing and enhancing the mechanical properties of Ti-6Al-4V with additive manufacturing techniques.

hybrid manufacturing

mechanical properties

additive manufacturing


Input: In this research work, a short review on additive manufacturing of Ti-6Al-4V alloys has been investigated to define its mechanical and metallurgical properties in both as-built and heat treated conditions.

research

heat

additive manufacturing

Ti-6Al-4V alloys

mechanical

metallurgical


Input: Using tungsten inert gas welding, a simple technique to additively construct single-channel multilayer Ti alloy (Ti-6Al-4V) was developed.

tungsten inert gas welding

simple

Ti alloy


Input: In the manufacturing process, the flow rate of nitrogen is used to control the microstructure and composition of each individual layer.

manufacturing process

flow rate

layer

nitrogen

microstructure

composition


Input: The use of nitrogen leads to the formation of TiN particles, whose amount increases with the flow rate of nitrogen.

nitrogen

TiN

nitrogen

particles

flow rate


Input: There is no significant difference in the elastic moduli among individual layers.

elastic moduli


Input: Increasing the flow rate of nitrogen results in an increase in the compression strength of the individual layers and a decrease in the ductility of individual layers.

flow rate

nitrogen

compression strength

ductility


Input: The Vickers hardness increases gradually from 300 to 400 HV for the base metal to ∼1000 HV for the top layer of the Ti alloy, and the compressive strength of the Ti alloy reaches 1.92 GPa at a 1.5 L/min nitrogen flow rate.

Vickers hardness

compressive strength

GPa

base metal

Ti alloy

Ti alloy

layer

nitrogen flow rate


Input: The technique developed in this work provides a feasible route to additively construct single-channel multilayer structures with spatial distributions of the composition and microstructures.

spatial distributions

composition

microstructures


Input: Direct observation of pore formation dynamics during LPBF additive manufacturing.

pore

LPBF

additive manufacturing


Input: Revealed three new pore formation mechanisms.

pore


Input: Reconfirmed three previously studied pore formation mechanisms Laser powder bed fusion (LPBF) is a 3D printing technology that can print parts with complex geometries that are unachievable by conventional manufacturing technologies.

pore

Laser powder bed fusion

LPBF

print

conventional manufacturing

3D printing technology

complex geometries


Input: However, pores formed during the printing process impair the mechanical performance of the printed parts, severely hindering their widespread application.

pores

printing process

mechanical


Input: Here, we report six pore formation mechanisms that were observed during the LPBF process.

pore

LPBF


Input: Our results reconfirm three pore formation mechanisms-keyhole induced pores, pore formation from feedstock powder and pore formation along the melting boundary during laser melting from vaporization of a volatile substance or an expansion of a tiny trapped gas.

pore

pores

pore

pore

feedstock

melting boundary

substance

gas

laser


Input: We also observe three new pore formation mechanisms: (1) pore trapped by surface fluctuation, (2) pore formation due to depression zone fluctuation when the depression zone is shallow and (3) pore formation from a crack.

pore

pore

pore

pore

surface


Input: The results presented here provide direct evidence and insight into pore formation mechanisms during the LPBF process, which may guide the development of pore elimination/mitigation approaches.

pore

pore

LPBF


Input: Since certain laser processing conditions studied here are similar to the situations in high energy density laser welding, the results presented here also have implications for laser welding.

laser processing

energy density

welding

laser welding


Input: The processes of ultrasonic spot welding and ultrasonic additive manufacturing are modelled by approximating the weld interface as rough metallic surfaces in sliding contact.

processes

interface

ultrasonic spot welding

ultrasonic additive manufacturing

weld

as

metallic

contact


Input: It is assumed that bonding is due to athermal plastic deformation of surface asperities and the associated growth of metallic junctions along the weld interface.

bonding

athermal plastic deformation

surface asperities

interface

metallic

junctions

weld


Input: To link the process variables and the extent of junction growth, an expression for the real contact area at the weld interface is combined with process-specific frictional heating models developed here.

process

interface

junction

contact

area

weld

heating


Input: The resulting framework is validated by comparing its predictions of the weld strength with data from the ultrasonic welding literature.

framework

predictions

data

weld strength

ultrasonic welding


Input: The close agreement between the framework's predictions and the experimental data demonstrates that the surface asperities soften due to frictional heating, while acoustic softening effects are insignificant.

framework

predictions

experimental data

surface asperities

acoustic softening effects

heating


Input: The junction growth model is used to identify parameter sets for ultrasonic spot welding and ultrasonic additive manufacturing that maximize the weld strength while simultaneously minimizing the thermal excursion at the weld interface.

junction

model

parameter

interface

ultrasonic spot welding

ultrasonic additive manufacturing

weld strength

weld


Input: It is found that in ultrasonic spot welding, certain processing conditions can cause interfacial melting, although melting is not required to form strong bonds.

ultrasonic spot welding

melting

interfacial melting


Input: It is also shown that in ultrasonic additive manufacturing, the deposition rate is highest when the positions of the peak temperature and complete interfacial bonding coincide underneath the sonotrode.

ultrasonic additive manufacturing

deposition rate

temperature

interfacial bonding

sonotrode


Input: If the position of complete interfacial bonding leads the position of the peak temperature, there is excessive heating of the build, and the sonotrode velocity can be increased without degrading bond quality.

interfacial bonding

bond quality

temperature

build

heating

sonotrode

be


Input: Although Additive Manufacturing implementation is rapidly growing, industrial sectors are demanding an increase of manufactured part size which most extended processes, such as Selective Laser Melting (SLM) or Laser Metal Deposition (LMD), are not able to offer.

Additive Manufacturing

SLM

Laser Metal Deposition

LMD

industrial sectors

manufactured

processes

as

Laser


Input: In this sense, Wire-Arc Additive Manufacturing (WAAM) offers high deposition rates and quality without size limits, becoming the best alternative for additive manufacturing of medium-large size parts with high mechanical requirements such as structural parts in the aeronautical industry.WAAM technology adds material in form of wire using an arc welding process in order to melt both the wire and the substrate.

Wire-Arc Additive Manufacturing

WAAM

additive manufacturing

arc welding

high deposition rates

quality

limits

technology

melt

mechanical

aeronautical

as

material

substrate


Input: There are three welding processes that are mainly used in WAAM: Plasma Arc Welding (PAW), Gas Tungsten Arc Welding (GTAW or TIG) and Gas Metal Arc Welding (GMAW or MIG).

welding

WAAM

Plasma Arc Welding

PAW

Gas Tungsten Arc Welding

GTAW

TIG

Gas Metal Arc Welding

GMAW

MIG

processes


Input: This paper studies these processes regarding on their capabilities for additive manufacturing and compares the mechanical properties obtained by the different welding technologies applied in WAAM.

processes

mechanical properties

technologies

additive manufacturing

welding

WAAM


Input: Obtained results show the applicability of the technology as an alternative of traditional metallic preforms manufacturing processes, such as casting or forging.

technology

as

metallic

as

manufacturing processes

forging


Input: A weak coupling modeling method is developed for arc welding based additive manufacturing.

weak coupling modeling method

arc welding

additive manufacturing


Input: This weak coupling modeling method is capable of simulating the complex heat and mass transfer effectively and efficiently.

weak coupling modeling method

heat and mass transfer


Input: In arc welding based additive manufacturing, the surface topographies of deposited layer are more complex than conventional welding, therefore, the distribution of the electromagnetic force in molten pool, arc pressure, plasma shear stress and heat flux on molten pool surface are not the same as the conventional welding.

arc welding

additive manufacturing

conventional welding

conventional welding

surface topographies

distribution

electromagnetic force

molten pool

plasma

heat flux

molten pool

deposited layer

arc pressure

stress

as


Input: A three-dimensional weak coupling modeling method of the arc and metal transport is developed to simulate the arc, molten pool dynamic and droplet impingement in arc welding based additive manufacturing.

three-dimensional

arc

metal transport

arc

molten pool

dynamic

droplet

modeling

arc welding

additive manufacturing


Input: In the arc model, the molten pool is simplified to be solid state on the basis of experimentally observed results.

arc

molten pool

be


Input: The arc is simulated firstly, and then the electromagnetic force, arc pressure, plasma shear stress and heat flux are extracted and transmitted to metal transport model.

arc

electromagnetic force

plasma

heat flux

extracted

metal transport

arc pressure

stress


Input: The volume of fluid (VOF) method is employed to track free surface of molten pool and droplet, and the continuum surface force (CSF) method is applied to transform all the surface forces on free surface as localized body forces.

volume of fluid

VOF

free surface

molten pool

droplet

continuum surface force

CSF

surface forces

free surface

body forces

as


Input: This weak coupling model has better accuracy than empirical model and decreases computational consumption.

weak coupling model

empirical

accuracy


Input: The molten pool morphology and cross-sectional profile of simulated results accord well with experimental results in both single-bead deposition and overlapping deposition, which indicates that this weak coupling modeling method is capable of simulating the complex heat and mass transfer phenomena in arc welding based additive manufacturing.

molten pool

experimental

deposition

deposition

weak coupling modeling method

heat and mass transfer

profile

arc welding

additive manufacturing


Input: Laser additive manufacturing is an advanced, very perspective technology with potentially wide industrial applications, one of them being an improvement of durability of forms and dies.

Laser additive manufacturing

technology

industrial

durability

dies


Input: The aim is to improve surface properties like wear resistance using special layers of powder sintered or remelted by laser beam.

surface

properties

laser beam

wear resistance

powder


Input: At present, dies are manufactured by machining with following bulk heat treatment, which is an expensive process.

dies

manufactured

process

machining

bulk heat treatment


Input: Concerning repairs of dies, they are usually performed manually, using arc or plasma welding with numerous difficulties and disadvantages in comparison with promising and advanced laser overlaying.

dies

arc

plasma welding

laser


Input: The paper contains results of a comprehensive evaluation of several types of hard overlayed powder of H13 tool steel on a S355 structural steel using laser beam.

powder

H13 tool steel

S355 structural steel

laser beam