Strengthening of a CrMnFeCoNi high-entropy alloy by carbide precipitation

JOURNAL OF ALLOYS AND COMPOUNDS

卷:792

Article

Gao, N.¹  Lu, D. H.¹  Zhao, Y. Y.²  Liu, X. W.^1,3  Liu, G. H.⁴  Wu, Y.³  Liu, G.⁵  Fan, Z. T.¹  Lu, Z. P.³  George, E. P.^2,6 

[1] Huazhong Univ Sci & Technol, State Key Lab Mat Proc & Die & Mould Technol, Wuhan 430074, Hubei, Peoples R China

[2] Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA

[3] Univ Sci & Technol Beijing, State Key Lab Adv Met & Mat, Beijing 100083, Peoples R China

[4] Northeastern Univ, State Key Lab Rolling & Automat, Shenyang 110819, Liaoning, Peoples R China

[5] Xian Univ Technol, Sch Mat Sci & Engn, Xian 710048, Shaanxi, Peoples R China

[6] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN USA

关键词: High-entropy alloy;    Carbide;    Precipitation;    Tensile property;    Strengthening;   

DOI  :  10.1016/j.jallcom.2019.04.121

来源: Elsevier

【 摘 要 】

The equiatomic CrMnFeCoNi high-entropy alloy (HEA) exhibits outstanding toughness and excellent strength-ductility combination at cryogenic temperatures. However, its strength is relatively low at room temperature. In order to strengthen this HEA, microalloying additions of 0.8 at.% Nb and C were made and its properties and microstructure evaluated. It was found that the microalloying resulted in the formation of carbide precipitates and a reduction of the grain size to similar to 2.6 mu m. As a result, the room-temperature tensile yield strength (732 MPa) of the microalloyed HEA is roughly double that of the base HEA (with a concomitant increase in the ultimate strength) while its ductility is maintained at a relatively high level (elongation to fracture of similar to 32%). The strengthening is due to precipitation hardening from the nanoscale carbide particles and grain refinement. Crown Copyright (C) 2019 Published by Elsevier B.V. All rights reserved.

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