Ultrahigh hardness with exceptional thermal stability of a nanocrystalline CoCrFeNiMn high-entropy alloy prepared by inert gas condensation. (October 2020)

• Record Type: Journal Article
• Authors: Wang, Junjie; Wu, Shangshu; Fu, Shu; Liu, Sinan; Yan, Mengyang; Lai, Qingquan; Lan, Si; Hahn, Horst; Feng, Tao
• Is Part Of: Scripta materialia. Number 187(2020)
• Page Start: 335
• Page End: 339
• Publication Date: 2020-10
• Subjects: Nanocrystalline high-entropy alloy -- Inert gas condensing -- Laser -- Thermal stability -- Hardness -- Microstructure; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2020.06.042
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: (CoCrFeNi)93.5 Mn6.5 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 °C for 1 h. More surprisingly, the original high hardness is maintained even after annealing at 1100 °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. Graphical abstract: Image, graphical abstract