Twinning behavior of an extruded Mg-Gd-Y-Zn-Zr alloy sheet under tension and compression

In this study, twinning behaviors of an extruded Mg-4.7Gd-3.4Y-1.2Zn-0.5Zr (wt%) alloy sheet along different directions extrusion direction (ED), 45 degrees: 45 degrees to ED and transverse direction (TD) under tension and compression were investigated. The results show that: (i) the twinning frequency of the extruded alloy sheet along different directions shows obvious anisotropy under both tension and compression while demonstrating opposite orders of ED > 45 degrees > TD under tension and TD > 45 degrees > ED under compression. Such anisotropic twinning frequencies are both in accord with their average twinning Schmid factor (TSF) orders. (ii) Under both tension and compression, the twinning variants (TVs) with the highest and the second highest TSF are frequently selected with priority. However, the TV selection law under tension has a certain difference from that of compression, which should be related to the TSF distributions of ortho-TV, meta-TV and para-TV under tension and compression. (c) 2024 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.