Dynamic testing at high strain rates of an ultrafine-grained magnesium alloy processed by ECAP

被引：91

作者：

Li, B. ^{[1
]}

Joshi, S. ^{[1
,5
]}

Azevedo, K. ^{[1
]}

Ma, E. ^{[1
]}

Ramesh, K. T. ^{[1
]}

Figueiredo, R. B. ^{[2
,3
]}

Langdon, T. G. ^{[2
,3
,4
]}

机构：

[1] Johns Hopkins Univ, Ctr Adv Metall & Ceram Syst, Baltimore, MD 21218 USA

[2] Univ So Calif, Dept Aerosp & Mech Engn, Los Angeles, CA 90089 USA

[3] Univ So Calif, Dept Mat Sci, Los Angeles, CA 90089 USA

[4] Univ Southampton, Sch Engn Sci, Mat Res Grp, Southampton SO17 1BJ, Hants, England

[5] Natl Univ Singapore, Dept Mech Engn, Singapore 117576, Singapore

来源：

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2009年 / 517卷 / 1-2期

关键词：

Dynamic testing; Equal-channel angular pressing; Magnesium alloy; Twinning; Ultrafine-grained structure; LOW-TEMPERATURE SUPERPLASTICITY; PLASTIC-DEFORMATION; ENHANCED DUCTILITY; ROOM-TEMPERATURE; MG ALLOY; REFINEMENT; EXTRUSION; TEXTURE; PRINCIPLES; EVOLUTION;

D O I：

10.1016/j.msea.2009.03.032

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

A ZK60 magnesium alloy was processed by equal-channel angular pressing (ECAP) at 473 K to produce a grain size of similar to 0.8 mu m and it was then tested under dynamic conditions at strain rates up to 4.0 x 10(3) s(-1) using a split-Hopkinson bar. The stress-strain curves in dynamic testing exhibited upwards concave curvature suggesting the occurrence of twinning. Examination by transmission electron microscopy showed that dislocation slip played a major role in the flow behavior with dislocation accumulation as the main source of work hardening. An identification of Burgers vectors revealed the extensive presence of prismatic dislocations. Rod-shaped Mg-1 (Zn,Zr)(1) precipitates present in the as-received alloy become fragmented and overaged during ECAP. (C) 2009 Elsevier B.V. All rights reserved,

引用

页码：24 / 29

页数：6