Transactions of Materials and Heat Treatment

Title：Research on multi-directional forging process and microstructure and mechanical properties after forging for Mg-8Gd-1Er-0.5Zr alloy

Authors： Ding Ning Du Wenbo Fu Jinlong Guo Chenglong Li Shuo Zhu Xunming

Unit： Beijing University of Technology Wanfeng Auto Holding Group Co. Ltd.

KeyWords： Mg-8Gd-1Er-0.5Zr alloy isothermal multi-directional forging forging temperature accumulated strain microstructure mechanical properties

ClassificationCode：TG316.2

year,vol(issue):pagenumber：2020,45(5):1-5

Abstract：

In order to improve the microstructure and mechanical properties of Mg-8Gd-1Er-0.5Zr alloy, the isothermal multi-directional forging experiments under various forging temperatures and accumulated strains were conducted, and the microstructure and mechanical properties of alloy were tested and analyzed. The results show that the forge-ability of Mg-8Gd-1Er-0.5Zr alloy is gradually improved by increasing the forging temperature within the experimental temperature range. When the alloy is forged at 420 ℃, a large number of twins are formed in the initial stage of forging to coordinate the deformation. By increasing the forging temperature to 480 ℃, the volume fraction of twins reduces whereas the number of recrystallized grains increases, and the average grain size becomes larger. Compared with the sample forged at 420 ℃ under the accumulated strain of 0.66, the alloy forged at 450 ℃ exhibits a slight decrease in strength, but the elongation ratio increases obviously, and its tensile strength, yield strength and elongation ratio are 295 MPa、252 MPa and 13.8%, respectively. However, the strength decreases when the alloy is forged at 480 ℃. Furthermore, when the forging temperature is constant, with the increasing of the accumulated strain, the internal structure of alloy evolves from the original coarse grains to the mixed crystal structure, and then to the fine uniform structure composed of recrystallized grains. In addition, the alloy has the best mechanical properties under the accumulated strain of 0.66, and the optimal forging temperature of Mg-8Gd-1Er-0.5Zr alloy is preferably 450 ℃.

Funds：

国家重点研发计划（2016YFB0301101）；浙江省领军型创新创业团队项目（201602007）

丁宁（1995-），男，硕士研究生，E-mail：s201709121@emails.bjut.edu.cn；通讯作者：杜文博（1964-），男，博士，教授，E-mail：duwb@bjut.edu.cn

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