Unveiling the underlying mechanism of forming edge cracks upon high strain-rate rolling of magnesium alloy
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第15期
论文作者：Biwu Zhu Xiao Liu Chao Xie Jing Su Pengcheng Guo Changping Tang Wenhui Liu
文章页码：59 - 65
摘 要：In the current study,high strain-rate rolling(≥10 s-1) has been successfully employed to produce Mg-3 A1-1 Zn alloy sheets to a high reduction of 82% with a fine grain structure in a single pass.The underlying mechanism of forming primary and secondary edge cracks has been investigated.It is found that dynamic recrystallization（DRX） induced by subgrains tends to blunt cracks,while twinning-induced D RX is mainly observed around sharp crack tips.The motion of emitted dislocations from blunted cracks is inhibited by the DRX grain boundaries.This,on one hand,increases local work hardening,and on the other hand,causes stress concentration alo ng grain boundaries especially in the triple junctions leading to the formation of secondary cracks.
Biwu Zhu1，Xiao Liu1，Chao Xie2，Jing Su3，Pengcheng Guo4，Changping Tang1，Wenhui Liu1
1. Key Laboratory of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province,Hunan University of Science and Technology2. Faculty of Mechanical Engineering and Mechanics,Ningbo University3. Max-Planck-Institut für Eisenforschung Gmb H4. College of Mechanical and Electrical Engineering,Central South University of Forestry and Technology
摘 要：In the current study,high strain-rate rolling(≥10 s-1) has been successfully employed to produce Mg-3 A1-1 Zn alloy sheets to a high reduction of 82% with a fine grain structure in a single pass.The underlying mechanism of forming primary and secondary edge cracks has been investigated.It is found that dynamic recrystallization（DRX） induced by subgrains tends to blunt cracks,while twinning-induced D RX is mainly observed around sharp crack tips.The motion of emitted dislocations from blunted cracks is inhibited by the DRX grain boundaries.This,on one hand,increases local work hardening,and on the other hand,causes stress concentration alo ng grain boundaries especially in the triple junctions leading to the formation of secondary cracks.
关键词：
