Microstructure and properties of ultrafine grained structure of Cu-Zn-Si alloy fabricated by heavy cold rolling

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Miura, H.^1 ; Kobayashi, T.^2 ; Kobayashi, M.^1

Department of Mechanical Engineering, Toyohashi University of Technology, 1-1, Tempaku-cho, 441-8580 Toyohashi, Japan^1

Department of Mechanical Engineering and Intelligent Systems, UEC-Tokyo, Chofu, 182-8585 Tokyo, Japan^2

关键词: Annealing twins;    Microstructure and properties;    Multidirectional forging;    Severe plastic deformations;    Static recrystallization;    Ultimate tensile strength;    Ultra-fine-grained;    Ultrafine grained structure;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012095/pdf
DOI  :  10.1088/1757-899X/63/1/012095

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Cu-18.2Zn-1.5Si-0.25Fe (mass%) alloy was heavily cold rolled. Ultrafine grained (UFGed) structure, containing a mixture of lamellar and mechanical twins, was easily and homogeneously formed. The average grain size was approximately 100 nm. The as-rolled sample showed quite high ultimate tensile strength (UTS) over 1 GPa. The UTS was higher than those obtained by multi directional forging. When the samples were annealed at relatively low temperatures between 553 K and 653 K, they showed slight hardening followed by large softening due to occurrence of static recrystallization (SRX). Annealing of UFGed structure at relatively low temperature of around 0.4 Tm caused extensive SRX that, in turn, induces ultrafine RXed grained structure. The grain size of the RXed sample was as fine as 200 nm. Although the annealing induced recovery of ductility while UTS gradually reduces, UTS over 1 GPa with ductility of 15 % were attained. The RXed grains mainly contained ultrafine annealing twins. Therefore, UFGed structure and superior mechanical properties could be achieved by a simple process of cold rolling, i.e., without severe plastic deformation.