Transactions of Materials and Heat Treatment

Title：Numerical simulation of crack initiation trends during ECAP based on Normalized Cockcroft & Latham ductile fracture criterion

Authors： CHEN Wen-jie ZHOU Qing DENG Zhu-jun ZHANG Fang-zhe

Unit： Nanjing University of Aeronautics and Aeronautics

KeyWords： ECAP numerical simulation crack damage multiple pass

ClassificationCode：TG376

year,vol(issue):pagenumber：2010,35(5):159-163

Abstract：

Based on the Normalized Cockcroft &Latham ductile fracture criterion, the crack initiation trends during equal channel angular pressing of 6061 Al alloy was simulated by Deform-2D. At the simulation of one pass ECAP, the effect of the die angle, the outer corner radius and the back pressure on the crack damage distribution were conducted. The greater the die angle is, the smaller the crack damage; the optimum outside corner radius is 6 mm：the crack damage value will increase when it is greater than 6 mm; the back pressure imposed is helpful to reduce the cracks；the greater the back pressure is, the smaller the crack damage. However, considering the efficiency of ECAP, the back-pressure shall not be too large. The simulation of multiple pass ECAP was carried out and testified with the three-pass ECAP experiments. The experimental results show that the crack damage after three-pass A route ECAP is maximum at the upper-layer of the specimen.

Funds：

南京航空航天大学基本科研业务费专项科研项目资助（NS2010149）

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