Unique defect evolution during the plastic deformation of a metal matrix composite

SCRIPTA MATERIALIA

卷:162

Article

Liu, Yanfang¹  Wang, Fang¹  Cao, Yang¹  Nie, Jinfeng¹  Zhou, Hao¹  Yang, Huabing²  Liu, Xiangfa²  An, Xianghai³  Liao, Xiaozhou³  Zhao, Yonghao¹  Zhu, Yuntian^1,4 

[1] Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, Nano & Heterogeneous Mat Ctr, Nanjing 210094, Jiangsu, Peoples R China

[2] Shandong Univ, Minist Educ, Key Lab Liquid Solid Struct Evolut & Proc Mat, Jinan 250061, Shandong, Peoples R China

[3] Univ Sydney, Sch Aerosp Mech & Mech Engn, Sydney, NSW 2006, Australia

[4] North Carolina State Univ, Dept Mat Sci & Engn, Raleigh, NC 27695 USA

关键词: Dislocation density;    Composite;    Strain-hardening;    Plastic deformation;    Microstructure;   

DOI  :  10.1016/j.scriptamat.2018.11.038

来源: Elsevier

【 摘 要 】

During the plastic deformation of a metal matrix composite (MMC) containing non-deformable particles, high dislocation density and strong back stresses are expected because the particles help with blocking and accumulating dislocations. Here we report that the MMC has lower, instead of higher, dislocation density than the corresponding monolithic matrix material when they are deformed to high plastic strains, because smaller sub-grains in the MMC lowered dislocation generation rate and meanwhile promoted the dislocation interaction and annihilation in the matrix. This unique defect density evolution is a hitherto unknown but important factor affecting the mechanical properties of MMCs. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

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