Effect of deformation speed on microstructure evolution and mechanical property of Mg-Gd alloys. (December 2020)

• Record Type: Journal Article
• Authors: Shi, Hong; Xia, Zhiping; Peng, Fuguan; Wan, Manhua; Liu, Zhongping
• Is Part Of: Materials today communications. Volume 25(2020)
• Publication Date: 2020-12
• Subjects: Magnesium alloy -- Deformation speed -- Twinning -- Mechanical property -- Segregation -- Recovery; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2020.101555
• Languages: English
• ISSNs: 2352-4928

Abstract

Highlights: Twinning was a dominant mechanism during high-speed compression of Mg-Gd alloys. Amounts of different twins varied in low-speed and high-speed deformed samples. 10 1 ¯ 2 tension twins or 10 1 ¯ 2 - 10 1 ¯ 2 twin boundaries showed a positive strain rate sensitivity. High alloying amount contributed to high hardening rate and extended hardening stage. Abstract: The effect of deformation speed on microstructure and mechanical property was investigated in Mg1Gd and Mg3Gd alloys, and annealing of high-speed deformed samples was studied. Twinning was a dominant deformation mechanism after low-speed and high-speed compressions, while twin variant and type diversities were observed. Low-speed and high-speed deformed samples showed difference in twin amounts instead of twin types. Low-speed deformed samples exhibited more 10 1 ¯ 2 tension twins (including unusual tension twins), while amount of 10 1 ¯ 2 - 10 1 ¯ 2 twin boundaries soared in high-speed deformed samples that contained less tension twins. 10 1 ¯ 1 contraction twins and 10 1 ¯ 1 - 10 1 ¯ 2 double twins were relatively less activated after both low-speed and high-speed deformations. During annealing, hardness fluctuated because of competition between twin boundary segregation and recovery, while a higher alloying content would lead to a higher hardening rate as well as an extended hardening stage.