Ultrahigh hardness with exceptional thermal stability of a nanocrystalline CoCrFeNiMn high-entropy alloy prepared by inert gas condensation

SCRIPTA MATERIALIA

卷:187

Article

Wang, Junjie¹  Wu, Shangshu¹  Fu, Shu¹  Liu, Sinan¹  Yan, Mengyang¹  Lai, Qingquan¹  Lan, Si¹  Hahn, Horst^1,2  Feng, Tao¹ 

[1] Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, Herbert Gleiter Inst Nanosci, Nanjing 210094, Peoples R China

[2] Karlsruhe Inst Technol, Inst Nanotechnol, D-76021 Karlsruhe, Germany

关键词: Nanocrystalline high-entropy alloy;    Inert gas condensing;    Laser;    Thermal stability;    Hardness;    Microstructure;   

DOI  :  10.1016/j.scriptamat.2020.06.042

来源: Elsevier

【 摘 要 】

(CoCrFeNi)(93.5)Mn-6.5 nanocrystalline high-entropy alloy (nc-HEA) with an average grain size of 25 nm was prepared by inert gas condensation (IGC) using a laser evaporation source. An unprecedented increment in hardness was found from 484 HV to 791 HV after annealing at 600 degrees C for 1 h. More surprisingly, the original high hardness is maintained even after annealing at 1100 degrees C, which demonstrates superb thermal stability of the nc-HEA. The underlying strengthening mechanism is attributed to the unique microstructure of the nc-HEA and its evolution during annealing. This study provides a new preparation technique (laser-IGC) for high-performance nc-HEAs with great potential for applications. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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