Micromechanical mechanism of yielding in dual nano-phase metallic glass

SCRIPTA MATERIALIA

卷:154

Article

Li, F. C.^1,2  Wang, T. Y.^1,2  He, Q. F.^1,2  Sun, B. A.^1,2,3  Guo, C. Y.³  Feng, T.³  Yang, Y.^1,2 

[1] City Univ Hong Kong, Coll Sci & Engn, Ctr Adv Struct Mat, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China

[2] City Univ Hong Kong, Dept Mech & Biomed Engn, Tat Chee Ave, Kowloon, Hong Kong, Peoples R China

[3] Nanjing Univ Sci & Technol, Herbert Gleiter Inst Nanosci, Nanchang, Jiangsu, Peoples R China

关键词: Amorphous alloys;    Nanocomposites;    Shear bands;    Size effect;   

DOI  :  10.1016/j.scriptamat.2018.05.050

来源: Elsevier

【 摘 要 】

Through detailed experimental and theoretical analyses, here we uncover the mechanism of plasticity initiation in the Ni-P nano-grained metallic glass (NGMG) which contains nano-sized hard amorphous inclusions and soft amorphous inter-granular regions. In this dual nano-phase amorphous structure, plasticity is mainly initiated through the elongation and coalescence of the amorphous nano-grains, resulting in a shear band much wider than in its monolithic counterpart. Consequently, the NGMG turns out to be softer at the microscopic scale. At the fundamental level, our finding provides a universal mechanism which explains the unusual strength weakening observed in a variety of dual nano-phase amorphous systems. (C) 2018 Acta Materialia Inc Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free