Effects of Post Heat Treatments on Microstructures and Mechanical Properties of Selective Laser Melted Ti6Al4V Alloy

Metals

Zhuoran Zeng¹  Aijun Huang²  Yuman Zhu²  Kai Zhang³  Jie Liu³  Yixin Li³  Jianwen Liu³  Ruifeng Zhang⁴ 

[1] College of Engineering and Computer Science, Australian National University, Acton, ACT 2601, Australia;Monash Center for Additive Manufacturing (MCAM), Monash University, Notting Hill, VIC 3168, Australia;School of Material Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;School of Materials Science and Engineering, Central South University, Changsha 410083, China;

关键词: selective laser melting;    Ti-6Al-4V;    α lath;    grain boundary α phase;    tensile performance;   

DOI  :  10.3390/met11101593

来源: DOAJ

【 摘 要 】

The unique thermal history of selective laser melting (SLM) can lead to high residual stress and a non-equilibrium state in as-fabricated titanium alloy components and hinders their extensive use. Post heat treatment, as a classical and effective way, could transform non-equilibrium α’ martensite and achieves desirable mechanical performance in SLMed Ti alloys. In this study, we aimed to establish the correlation between the microstructure and mechanical performances of SLMed Ti6Al4V (Ti-64) by using different heat treatment processes. The columnar prior β grain morphology and grain boundary α phase (GB-α) after different heat treatment processes were characterized, with their influences on the tensile property anisotropy fully investigated. Scanning electron microscope (SEM) observation of the fracture surface and its cross-sectional analysis found that the tensile properties, especially the ductility, were affected by the GB-α along the β grain boundary. Furthermore, the discontinuous ratio of GB-α was firstly proposed to quantitatively predict the anisotropic ductility in SLMed Ti-64. This study provides a step forward for achieving the mechanical property manipulation of SLMed Ti-64 parts.

【 授权许可】

Unknown