Effect of rescanning on microstructure and properties of TC4 titanium alloy prepared by selective laser melting

doi:10.13251/j.issn.0254-6051.2020.08.018

Abstract

Abstract: TC4 (Ti-6Al-4V) alloy parts were prepared by selective laser melting (SLM) equipment, and effect of rescanning laser power on microstructure and properties was studied. The microstructure was analyzed by means of optical microscope. The dense degree, defect size and hardness of the alloy were measured by means of drainage method, white light interferometer and hardness tester. The results show that the rescanning with laser power of 85 W makes the β phase grain coarse and the grain width can be up to 150 μm, and the grain width decreases to 120 μm as the rescanning laser power further increases. The rescanning can significantly improve the dense degree of the alloy parts. After rescanning with laser power of 145 W, the dense degree of the alloy improves to 99.6%. Rescanning can reduce the defect opening size from 25 μm to about 7 μm on average, but have little effect on the defect depth. The decrease of porosity caused by rescanning can improve the hardness of the alloy parts.

Key words: rescanning, selective laser melting (SLM), TC4 titanium alloy, microstructure, dense degree

CLC Number:

TG146.23

Li Haohao, Wu Meiping, Ma Yiqing, Han Jitai. Effect of rescanning on microstructure and properties of TC4 titanium alloy prepared by selective laser melting[J]. Heat Treatment of Metals, 2020, 45(8): 91-96.

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