Determining rational process parameters for selective laser melting of powder titanium alloy VT6

TC4, which is one of the most widely used titanium alloy, is frequently used in biomedical field due to its biocompatible. In this work, selective laser melting (SLM) was used to manufacture TC4 parts and the printed parts were heat-treated using laser rescanning technology. The experimental results showed that laser rescanning had a high impact on the quality of SLMed part, and a different performance on wear resistance can be found on the basis. It can be seen that the volume porosity of the sample was 7.6 ± 0.5% without using any further processing technology. The volume porosity of the sample processed using laser rescanning strategy was decreased and the square-framed rescanning strategy had a relative optimal volume porosity (1.5 ± 0.3%) in all these five samples. With the further decreasing of volume porosity, the wear resistance decreased at the same time. As its excellent bio-tribological properties, the square-framed rescanning may be a potential suitable strategy to forming TC4 which used in human body.

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Influence of Selective Laser Melting on the Microporosity of Cellular Materials Based on Ti6Al4V Titanium Alloy

Russian Engineering Research ◽

10.3103/s1068798x21090148 ◽

2021 ◽

Vol 41 (9) ◽

pp. 871-873

Author(s):

P. N. Kilina ◽

L. D. Sirotenko ◽

K. R. Muratov ◽

T. R. Ablyaz

Keyword(s):

Titanium Alloy ◽

Selective Laser Melting ◽

Cellular Materials ◽

Laser Melting ◽

Ti6al4v Titanium Alloy

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Martensite decomposition during post-heat treatments and the aging response of near-α Ti–6Al–2Sn–4Zr–2Mo (Ti-6242) titanium alloy processed by selective laser melting (SLM)

Journal of Micromechanics and Molecular Physics ◽

10.1142/s2424913020500186 ◽

2021 ◽

pp. 2050018

Author(s):

Haiyang Fan ◽

Yahui Liu ◽

Shoufeng Yang

Keyword(s):

Titanium Alloy ◽

High Temperature ◽

Titanium Alloys ◽

Selective Laser Melting ◽

Room Temperature ◽

Elevated Temperatures ◽

Aging Treatment ◽

Water Quenching ◽

Laser Melting ◽

Aging Response

Ti–6Al–2Sn–4Zr–2Mo (Ti-6242), a near-[Formula: see text] titanium alloy explicitly designed for high-temperature applications, consists of a martensitic structure after selective laser melting (SLM). However, martensite is thermally unstable and thus adverse to the long-term service at high temperatures. Hence, understanding martensite decomposition is a high priority for seeking post-heat treatment for SLMed Ti-6242. Besides, compared to the room-temperature titanium alloys like Ti–6Al–4V, aging treatment is indispensable to high-temperature near-[Formula: see text] titanium alloys so that their microstructures and mechanical properties are pre-stabilized before working at elevated temperatures. Therefore, the aging response of the material is another concern of this study. To elaborate the two concerns, SLMed Ti-6242 was first isothermally annealed at 650[Formula: see text]C and then water-quenched to room temperature, followed by standard aging at 595[Formula: see text]C. The microstructure analysis revealed a temperature-dependent martensite decomposition, which proceeded sluggishly at [Formula: see text]C despite a long duration but rapidly transformed into lamellar [Formula: see text] above the martensite transition zone (770[Formula: see text]C). As heating to [Formula: see text]C), it produced a coarse microstructure containing new martensites formed in water quenching. The subsequent mechanical testing indicated that SLM-built Ti-6242 is excellent in terms of both room- and high-temperature tensile properties, with around 1400 MPa (UTS)[Formula: see text]5% elongation and 1150 MPa (UTS)[Formula: see text]10% elongation, respectively. However, the combination of water quenching and aging embrittled the as-built material severely.

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Effect of Process Parameters and High-Temperature Preheating on Residual Stress and Relative Density of Ti6Al4V Processed by Selective Laser Melting

Materials ◽

10.3390/ma12060930 ◽

2019 ◽

Vol 12 (6) ◽

pp. 930 ◽

Cited By ~ 12

Author(s):

Martin Malý ◽

Christian Höller ◽

Mateusz Skalon ◽

Benjamin Meier ◽

Daniel Koutný ◽

...

Keyword(s):

Residual Stress ◽

High Temperature ◽

Residual Stresses ◽

Relative Density ◽

Selective Laser Melting ◽

Process Parameters ◽

Stress Reduction ◽

Laser Melting ◽

Preheating Temperature ◽

Laser Velocity

The aim of this study is to observe the effect of process parameters on residual stresses and relative density of Ti6Al4V samples produced by Selective Laser Melting. The investigated parameters were hatch laser power, hatch laser velocity, border laser velocity, high-temperature preheating and time delay. Residual stresses were evaluated by the bridge curvature method and relative density by the optical method. The effect of the observed process parameters was estimated by the design of experiment and surface response methods. It was found that for an effective residual stress reduction, the high preheating temperature was the most significant parameter. High preheating temperature also increased the relative density but caused changes in the chemical composition of Ti6Al4V unmelted powder. Chemical analysis proved that after one build job with high preheating temperature, oxygen and hydrogen content exceeded the ASTM B348 limits for Grade 5 titanium.

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