scholarly journals Effect of the Ti6Al4V Alloy Track Trajectories on Mechanical Properties in Direct Metal Deposition

Machines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 79
Author(s):  
Ivan Erdakov ◽  
Lev Glebov ◽  
Kirill Pashkeev ◽  
Vitaly Bykov ◽  
Anastasia Bryk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ultimate Strength ◽  
Ti6al4v Alloy ◽  
Laser Deposition ◽  
Laser Alloying ◽  
Laser Melting ◽  
Two Phase ◽  
Phase Condition ◽  
Direct Laser ◽  
First Time

The TiAl6V4 alloy is widely used in selective laser melting and direct laser melting. In turn, works devoted to the issue of how the track stacking scheme affects the value of mechanical properties is not enough. The influence of the Ti6Al4V alloy track trajectories on the microstructure and mechanical properties during direct laser deposition is studied in this article for the first time. The results were obtained on the influence of «parallel» and «perpendicular» technique of laying tracks in direct laser synthesis. All studied samples have a microstructure typical of the hardened two-phase condition titanium. Here, it is shown that the method of laying tracks and the direction of load application during compression testing relative to the location of the tracks leads to a change in the ultimate strength of the Ti-6Al-4V alloy from 1794 to 1910 MPa. The plasticity of the Ti-6Al-4V alloy obtained by direct laser alloying can vary from 21.3 to 33.0% depending on the direction of laying the tracks and the direction of the compression test. The hardness of alloys varies in the range from 409 to 511 HV and depends on the method of laying the tracks and the direction of hardness measurements.

Determination of mechanical properties of two-phase and hybrid nanocomposites: experimental determination and multiscale modeling

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud Haghighi ◽  
Hossein Golestanian ◽  
Farshid Aghadavoudi
Keyword(s):  
Mechanical Properties ◽  
Ultimate Strength ◽  
Multiscale Modeling ◽  
Filler Content ◽  
Hybrid Nanocomposites ◽  
Dynamics Simulation ◽  
Strength Increase ◽  
Two Phase ◽  
Macro Scale ◽  
Elongation To Failure

Abstract In this paper, the effects of filler content and the use of hybrid nanofillers on agglomeration and nanocomposite mechanical properties such as elastic moduli, ultimate strength and elongation to failure are investigated experimentally. In addition, thermoset epoxy-based two-phase and hybrid nanocomposites are simulated using multiscale modeling techniques. First, molecular dynamics simulation is carried out at nanoscale considering the interphase. Next, finite element method and micromechanical modeling are used for micro and macro scale modeling of nanocomposites. Nanocomposite samples containing carbon nanotubes, graphene nanoplatelets, and hybrid nanofillers with different filler contents are prepared and are tested. Also, field emission scanning electron microscopy is used to take micrographs from samples’ fracture surfaces. The results indicate that in two-phase nanocomposites, elastic modulus and ultimate strength increase while nanocomposite elongation to failure decreases with reinforcement weight fraction. In addition, nanofiller agglomeration occurred at high nanofiller contents especially higher than 0.75 wt% in the two-phase nanocomposites. Nanofiller agglomeration was observed to be much lower in the hybrid nanocomposite samples. Therefore, using hybrid nanofillers delays/prevents agglomeration and improves mechanical properties of nanocomposite at the same total filler content.

Direct laser deposition of Cu alloy on forming tool surfaces—Process window and mechanical properties

CIRP Annals ◽  
2010 ◽  
Vol 59 (1) ◽  
pp. 211-214 ◽  
Author(s):  
M. Schmidt ◽  
R. Kolleck ◽  
A. Grimm ◽  
R. Veit ◽  
K. Bartkowiak
Keyword(s):  
Mechanical Properties ◽  
Laser Deposition ◽  
Process Window ◽  
Direct Laser Deposition ◽  
Cu Alloy ◽  
Direct Laser

Microstructure Control of Co3AlC-Base Heat Resistant Alloys Using Optical Floating Zone Melting

2005 ◽  
Vol 475-479 ◽  
pp. 833-836 ◽  
Author(s):  
Yoshisato Kimura ◽  
Kiichi Sakai ◽  
Shinya Teramoto ◽  
Yoshinao Mishima
Keyword(s):  
Mechanical Properties ◽  
Single Phase ◽  
Zone Melting ◽  
Floating Zone ◽  
Compression Tests ◽  
Microstructure Control ◽  
Two Phase ◽  
Elevated Temperature Strength ◽  
Heat Resistant ◽  
First Time

Aiming for further improvement of mechanical properties of Co3AlC-based heat resistant alloys, microstructure control was conducted using optical floating zone (OFZ) melting. Unidirectional solidification was performed to align Co3AlC/a(Co) two-phase eutectic microstructure. Co3AlC single phase poly-crystal alloys were successfully fabricated for the first time by taking advantage of OFZ. Mechanical properties were evaluated for selected alloys by compression tests at ambient temperature, 1073 K and 1273 K. Excellent elevated temperature strength is achieved in Co3AlC single phase alloys and ductility is sufficiently improved in Co3AlC/a(Co) two-phase alloys.

scholarly journals Effects processing parameters and building orientation on the microstructural and mechanical properties of AlSilOMg parts printed by selective laser melting

2021 ◽  
Vol 121 (7) ◽  
Author(s):  
C. Phetolo ◽  
V. Matjeke ◽  
J. van der Merwe
Keyword(s):  
Mechanical Properties ◽  
Selective Laser Melting ◽  
Processing Parameters ◽  
Fractographic Analysis ◽  
Lower Percentage ◽  
Laser Melting ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Homogeneous Microstructure ◽  
Building Orientation

SYNOPSIS The mechanical properties and microstructure of AlSilOMg alloy samples that were printed by selective laser melting (SLM) were studied to determine the effect of processing parameters and building orientation. After printing, the alloy was stress relieved at 250°C for 2 hours. The microstructures were analysed by optical microscopy and scanning electron microscopy (SEM) to determine the alloy phases and distribution. Phase transformation characteristics of the material were evaluated using differential scanning calorimetry (DSC). Mechanical properties were determined by subjecting the XY- and Z-built samples to tensile and nano-indentation testing. The samples from the tensile tests were then used to perform fractographic analysis by SEM. The microstructural properties in each orientation revealed a non-homogeneous microstructure which was characterized by a semi-elliptical tract and fine silicon precipitates, which were found to be softer along the fusion zone. The DSC thermograms revealed that the material underwent two phase transformations during the first heating cycle. The mechanical properties revealed a higher UTS, higher yield strength, and a lower percentage elongation in the Z orientation than in the XY orientation. Fractographic analysis showed that crack initiation in both orientations started from the surface in a brittle manner due to surface flows, and then propagated via microvoid coalescence. Keywords: AlSi10Mg alloy, additive manufacturing, mechanical propeerties, microstructure.

Experimental Investigation on Laser Peening of Additively Manufactured Ti6Al4V Alloy

2019 ◽  
Author(s):  
Yongxiang Hu ◽  
Mengqi Lai ◽  
Zhenqiang Yao
Keyword(s):  
Surface Layer ◽  
Ti6al4v Alloy ◽  
Laser Deposition ◽  
Laser Peening ◽  
Laser Additive Manufacturing ◽  
Maximum Value ◽  
Average Porosity ◽  
Direct Laser ◽  
Critical Components ◽  
Compressive Residual Stresses

Abstract Laser additive manufacturing is widely utilized to fabricate Ti6Al4V alloy, but post-processing is necessary to improve its performance for fatigue resistance of some critical components. This paper proposes laser peening (LP) as an effective way to improve the surface integrity of Ti6Al4V alloy fabricated by direct laser deposition (DLD). After laser peening, little difference of surface roughness is observed. Compressive residual stresses are induced on the top surface layer. The maximum value of compressive residual stress is about −520 MPa and the compressive state extends to the depth of 0.60 mm. In addition, the relative densities of specimen are measured using the Archimedes method. The average porosity is observed to decrease due to plastic deformation at the surface layer. Results of fatigue test show that the service cycle can be improved about three times.

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