Enhanced age-hardening response of the Mg-Sm alloy via alloying with Cd

• Published in: Materials characterization Vol. 170; p. 110669
• Main Authors: Xie, Hongbo, Lou, Weixin, Zhao, Xiaobo, Li, Shanshan, Pan, Hucheng, Xiao, Na, Li, Hongxiao, Bai, Junyuan, Ren, Yuping, Qin, Gaowu
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2020
• Subjects: DFT; Guinier-Preston zones; HAADF-STEM; Magnesium alloys; Precipitation hardening; Prismatic precipitates; Prismatic precipitates; DFT; HAADF-STEM; Precipitation hardening; Guinier-Preston zones; Magnesium alloys
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2020.110669

Compared to the basal precipitates, prismatic precipitates are considered more effective for age-hardening in magnesium alloys but happen in very limited alloy systems. Herein, we confirmed that very high density, nano-sized prismatic Guinier-Preston zones (GP-zones) precipitated in an Mg-3Sm alloy with the addition of Cd, resulting in a significant enhancement in hardness. These two-dimensional GP-zones enriched with Sm and Cd have three variants of {101¯0}α habit planes, and fully coherent with the α-Mg matrix. This finding is expected to provide a practical guidance for designing and developing novel high-strength Mg rare-earth (RE) based alloys, and would put the way forwards understanding the clustering and stacking behaviors of solute atoms in hexagonal closed-packed (hcp) crystals. •High density, nano-sized prismatic Guinier-Preston zones can precipitation in an Mg-Sm-Cd alloy.•An enhanced age-hardening response obtained twice higher than that of the binary alloy.•Fine structure of these Guinier-Preston zones is well characterized by STEM, together with theoretical confirmation.