Phase separation of metastable CoCrFeNi high entropy alloy at intermediate temperatures

SCRIPTA MATERIALIA

卷:126

Article

He, Feng¹  Wang, Zhijun¹  Wu, Qingfeng¹  Li, Junjie¹  Wang, Jincheng¹  Liu, C. T.² 

[1] Northwestern Polytech Univ, State Key Lab Solidificat Proc, Xian 710072, Peoples R China

[2] City Univ Hong Kong, Coll Sci & Engn, Dept Mech & Biomed Engn, Ctr Adv Struct Mat, Kowloon, Hong Kong, Peoples R China

关键词: Phase separation;    High entropy alloys;    Annealing;   

DOI  :  10.1016/j.scriptamat.2016.08.008

来源: Elsevier

【 摘 要 】

CoCrFeNi alloy is an exemplary stable base for high entropy alloys (HEAs), but its phase stability is still suspicious. Here, the CoCrFeNi HEA was firstly identified to be thermally metastable at 750 degrees C. Composition decomposition occurred after annealed at 750 degrees C for 800 h. The minor addition of Al accelerated the composition decomposition and a second fcc phase with a different lattice constant occurred in the long time annealed CoCrFeNiAl0.(1) HEA. The CoCrFeNi HEA cannot be seen as stable alloys anymore and researchers should be very careful when using the current phase selection models to predict stability of HEAs at intermediate temperatures. (C) 2016 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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