Suppression of grain boundary migration at cryogenic temperature in an extremely fine nanograined Ni-Mo alloy

• 作者: J.Hu J.X.Li Y.-N.Shi
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2020,（22）
• 页码范围: 65-69
• 页数: 5页
• 语种: 英文

摘要

Microindentation creep tests on an electrodeposited extremely fine (4.9 nm) nanograined (ng) Ni-14.2 at.％ Mo (Ni-14.2Mo) at both room temperature (RT) and liquid nitrogen temperature (LNT) demonstrated that lowering temperature retarded softening in the ng Ni-Mo alloy.The obtained strain rate sensitivity at LNT was one order of magnitude lower than that at RT.Microstructural characterization revealed that mechanically-driven grain boundary (GB) migration was greatly suppressed by lowering temperature,which might be ascribed to the presence of solute Mo atoms that significantly retarded coupled GB motion at LNT.Deformation was instead carried by shear bands.