Crack Initiation Mechanism and Experiment Study of Process Optimization of TiAl Alloy Formed by Selective Laser Melting

被引：0
|
作者：
Shi W. [1 ]
Wang P. [1 ]
Liu Y. [1 ]
Shi X. [2 ]
机构：
[1] School of Materials Science and Mechanical Engineering, Beijing Technology and Business University, Beijing
[2] School of Naval Architecture and Mechanical-Electrical Engineering, Zhejiang Ocean University, Zhoushan
来源：
Xiyou Jinshu/Chinese Journal of Rare Metals | 2019年 / 43卷 / 04期
关键词：
Cracks; Pre-sintering; Remelting; Selective laser melting; TiAl alloy;
D O I：
10.13373/j.cnki.cjrm.XY18090040
中图分类号：
学科分类号：
摘要：
TiAl alloy was widely used because of its excellent overall properties. However, the traditional processing technology was prone to defects, so the further application of TiAl alloy was restricted. As an advanced technology, selective laser melting (SLM) was used to form TiAl alloy. Firstly, the development and forming technology of TiAl alloys were summarized. The crack initiation mechanism such as the temperature gradient and residual stress was studied in the process of forming TiAl alloys by SLM and the technology of how to lease the crack was also proposed and used in the experiment. Then the effects of various forming processes on crack suppression were studied by using auxiliary processes such as substrate preheating, pre-sintering, remelting and combination technology. The experiment of single melting channel and block was studied and the results showed that the effect without any auxiliary process was the worst, the best technology was the preheating on the substrate, and followed by pre-sintering. The best combination technology was pre-sintering process and substrate preheating at 200 ℃ although the effect of auxiliary pre-sintering or remelting process was beneficial to the elimination of cracks, and the combination of pre-sintering process and substrate preheating at 200 ℃ obviously delayed the occurrence of cracks because the residual stress was reduced by substrate preheating, and the temperature gradient was reduced by pre sintering. © Editorial Office of Chinese Journal of Rare Metals. All right reserved.
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页码：349 / 358
页数：9
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