The effect of hot isostatic pressing on crack healing, microstructure, mechanical properties of Rene88DT superalloy prepared by laser solid forming
The effect of hot isostatic pressing on crack healing, microstructure, mechanical properties of Rene88DT superalloy prepared by laser solid forming
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DOI：
10.1016/j.msea.2008.12.024
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发表时间：
2009-03
期刊：
影响因子：
6.4
通讯作者：
Xiaoming Zhao;Xin Lin;J. Chen;Lei Xue;Weidong Huang
中科院分区：
文献类型：
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作者：
Xiaoming Zhao;Xin Lin;J. Chen;Lei Xue;Weidong Huang
研究了激光固态成形（LSF）技术制备的Rene88DT高温合金的裂纹特征，分析了热等静压（HIP）工艺对裂纹愈合、显微组织和力学性能的影响。结果表明，激光熔敷Rene88DT中的裂纹主要在激光熔敷道次的搭接区形核和扩展，并可归因于液化裂纹。激光熔覆Rene88DT中裂纹的大小和数量受熔覆道次的重叠影响很大。通过热等静压处理，裂纹发生愈合，导致LSF处理的Rene88DT高温合金的力学性能得到了显著改善。但是，不充分的搭接会导致存款中出现非常大的裂纹，这使得HIP过程中的扩散连接不能完全消除裂纹愈合区Ti和Nb的局部偏析。
Crack characterization in Rene88DT superalloy prepared by laser solid forming (LSF) was investigated; the effect of hot isostatic pressing (HIP) on crack healing, microstructure and mechanical properties was also analyzed. It was found that cracks in LSFed Rene88DT mainly nucleate and propagate in the overlap zone of laser-deposited passes, and can be attributed to the liquation cracks. The size and amount of the cracks in LSFed Rene88DT are significantly affected by the overlap of as-deposited passes. Through HIP processing, crack healing occurred, which leads to a substantial improvement of the mechanical properties of LSFed Rene88DT superalloy. However, the insufficient overlap will result in very large cracks in the deposit, which makes the diffusion bonding during HIP not completely eliminate the local segregation of Ti and Nb in the crack healing region.