Strengthening CoCrNi medium-entropy alloy by tuning lattice defects

SCRIPTA MATERIALIA

卷:188

Article

Huang, Hua¹  Wang, Jianying¹  Yang, Hailin¹  Ji, Shouxun²  Yu, Hailiang³  Liu, Zhilin³ 

[1] Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China

[2] Brunel Univ London, BCAST, Uxbridge UB8 3PH, Middx, England

[3] Cent South Univ, Coll Mech & Elect Engn, Light Alloy Res Inst, Changsha 410083, Peoples R China

关键词: Medium-entropy alloys;    Microstructure;    High strength;    Lattice defects;    Strengthening mechanisms;   

DOI  :  10.1016/j.scriptamat.2020.07.027

来源: Elsevier

【 摘 要 】

The CrCoNi medium-entropy alloy is not fully utilized at room temperature circumstance due to its low strength, despite excellent cryogenic mechanical properties. Here we report that, a superior room temperature strength (1.6 GPa and 407.6 Hv) has been obtained in the single phase CoCrNi medium-entropy alloy, by carefully tuning the formation of multiple lattice defects. Electron microscopy characterizations show that such high-strength CoCrNi alloy contains favorable heterostructures of coarsening grains (similar to 30 mu m) and ultrafine grains (similar to 1 mu m), together with the high density of dislocation cells, small stacking faults, ultrafine nanotwins (similar to 9 nm in thickness) and Lomer-Cottrell locks. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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