Remarkable age-hardening response and microstructural evolution of Mg–7Sn alloy

Lin Tong; Jing Jiang; Guangli Bi; Zuocheng Xu; Yuandong Li; Tijun Chen; Xiaoru Zhang; Wei Fu; Daqing Fang

Journal of Materials Research and Technology (May 2023)

Remarkable age-hardening response and microstructural evolution of Mg–7Sn alloy

Lin Tong,
Jing Jiang,
Guangli Bi,
Zuocheng Xu,
Yuandong Li,
Tijun Chen,
Xiaoru Zhang,
Wei Fu,
Daqing Fang

Affiliations

Lin Tong: State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, China; School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
Jing Jiang: State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, China; School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, China; Corresponding author.
Guangli Bi: State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, China; School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, China; Corresponding author.
Zuocheng Xu: Erzhong (Deyang) Heavy Equipment Co., Ltd, Deyang, 618000, PR China
Yuandong Li: State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, China; School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
Tijun Chen: State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou, 730050, China; School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
Xiaoru Zhang: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, PR China
Wei Fu: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, PR China
Daqing Fang: State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, PR China

Journal volume & issue: Vol. 24
pp. 1442 – 1453

Abstract

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The poor age-hardening response of Mg alloys limited their development and applications. In this study, the age-hardening response of Mg–7Sn alloy has been improved significantly by a 40 MPa compressive stress aging at 220 °C. Phase transition from metastable βˈ (Mg3Sn) phase to β (Mg2Sn) phase occurs during the stress aging. The βˈ with L12 structure has an orientation relationship with the Mg matrix of (11¯0)β＇//(112¯0)α and [1¯1¯0]β＇//⌈0001¯⌉α. The precipitated sequence in the stress-aged alloy is S.S.S. (supersaturated solid solution)→GP→βˈ(Mg3Sn)→β(Mg2Sn). The stress-aged alloy exhibits a high peak-aged hardness (∼71 HV) and short time to reach the peak hardness (12 h) as compared with the aged alloy without the stress. Interestingly, a long-time aging platform with 71 HV for 96 h is observed during stress aging. The formation of the platform is related to a balance of hardening and softening arisen from microstructure evolution during stress aging. The stress aging provides a promising heat treatment way to improve aging hardening response of Mg alloys.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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