Impact of hot isostatic pressing on microstructures of CMSX-4 Ni-base superalloy fabricated by selective electron beam melting
Impact of hot isostatic pressing on microstructures of CMSX-4 Ni-base superalloy fabricated by selective electron beam melting
复制标题
DOI：
10.1016/j.matdes.2016.08.041
复制
发表时间：
2016-11-15
影响因子：
8.4
通讯作者：
Theisen, W.
中科院分区：
文献类型：
--
作者：
Ruttert, B.;Ramsperger, M.;Theisen, W.
选择性电子束熔化（SEBM）是一种基于粉末床的增材制造工艺，用于从预合金和雾化粉末中生产镍基高温合金CMSX-4的圆柱形和柱状晶粒零件。SEBM的特点是在凝固过程中具有很高的温度梯度，这导致了非常精细的微观结构，比传统铸造材料小几个数量级。这为耗时的固溶热处理开辟了新的前景。然而，微观组织的不均匀性，如偏析和孔隙，仍然存在于更小的范围内，并且在焊接过程中该合金类的高脆性开裂也必须考虑在内。由于最新一代的热等静压机（HIP）由于其淬火能力能够同时热处理和消除孔隙，因此在这项工作中使用了这种HIP。研究了恒压下不同温度和时间的hipin热处理策略对sebm显微组织的影响，重点研究了偏析和孔隙度。结果表明，只需几分钟的溶解就足以溶解分离并关闭孔隙。sebm材料的初始均匀度是导致溶解时间短的原因。(C) 2016年Elsevier Ltd.出版
Selective electron beam melting (SEBM) is a powder-bed-based additive manufacturing process that was used to produce cylindrical and columnar-grained parts made of Ni-base superalloy CMSX-4 from pre-alloyed and atomized powder. SEBM is characterized by high temperature gradients during solidification, which results in a very fine microstructure that is several orders of magnitude smaller than in conventionally cast material. This opens up new perspectives regarding time-consuming solution heat treatment. Nevertheless, microstructural heterogeneities, such as segregation and porosity, are still present on a much smaller scale, and also the high susceptibility to cracking of this alloy class during welding has to be taken into account. Since the latest generation of hot isostatic presses (HIP) are able to simultaneously heat-treat and eliminate porosity owing to their quenching capability, such a HIP is used in this work. The influence of different HIPing-heat-treatment-strategies with variation of temperature and time at a constant pressure on the SEBM-microstructure was investigated with emphasis primarily on segregation and porosity. The results demonstrate that only a few minutes of solutioning are sufficient to dissolve segregations and to close pores. The initial degree of homogeneity of the SEBM-material is responsible for the short solutioning-time. (C) 2016 Published by Elsevier Ltd.