再扫描对选区激光熔化成形TC4钛合金组织与性能的影响

doi:10.13251/j.issn.0254-6051.2020.08.018

摘要/Abstract

摘要： 通过选区激光熔化(SLM)设备制备了TC4(Ti-6Al-4V)合金制件,研究了再扫描激光功率对合金组织及性能的影响。利用光学显微镜对组织进行了分析,通过排水法、白光干涉仪及硬度计等对合金的密实度、缺陷尺寸及硬度进行了测量。结果发现,85 W 激光功率的再扫描会使合金β相晶粒粗化,晶粒宽度最大可达150 μm;随着再扫描功率进一步提高,晶粒宽度降低到120 μm。再扫描会显著提升合金制件的密实度,经过145 W的再扫描,合金制件的密实度提高到99.6%。再扫描使合金缺陷开口宽度下降,平均宽度从25 μm降低到7 μm左右,但对缺陷深度影响不大。再扫描对合金孔隙率的降低使合金的硬度有所提高。

关键词: 再扫描, 激光选区熔化, TC4钛合金, 显微组织, 密实度

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

中图分类号:

TG146.23

李浩浩, 武美萍, 马毅青, 韩基泰. 再扫描对选区激光熔化成形TC4钛合金组织与性能的影响[J]. 金属热处理, 2020, 45(8): 91-96.

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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