Observation of macroscopic shear band in aluminum-based alloy
during equal-channel angular pressing
during equal-channel angular pressing
(1. School of Mechanical Engineering, Xi′an Jiaotong University,
Xi′an 710049, China;
2. Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China)
Xi′an 710049, China;
2. Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China)
Abstract: Equal-channel angular pressing（ECAP） is now recognized as an effective technique for fabricating ultrafine grained materials. The results show that prevalent macroscopic shear banding occurs in ECAP as long as the pressing passes reach 2, and the severe macroscopic shear band extends from bottom to top surface and slants to the longitudinal axis of specimen at an angle of about 45°, develops at regular intervals, with a high shear strain accommodation of about 3.7 within the band. Different families of macroscopic shear bands may cut across each other, and over 60% of sample volume is occupied by macroscopic shear band when the ECAP reaches 4 passes.
Key words: equal-channel angular pressing（ECAP）; macroscopic shear banding; ultrafine grained material