Study on Microstructure and Mechanical Properties of Thixoforged Mg-5Sn-3Bi-2Cu Alloy
MENG Shuaiju1,2,3,*, WANG Menglu1, DU Ciwei1, GUI Jinqi1, YANG Guirong1, YU Haicun1,*, BI Guangli1, CHEN Tijun1, CAO Chi2
1 State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China 2 Wenzhou Engineering Institute of Pump and Valve, Lanzhou University of Technology, Wenzhou 325000, Zhejiang, China 3 CITIC Dicastal Co., Ltd., Qinhuangdao 066011, Hebei, China
Abstract: In order to reveal the microstructure and mechanical properties of thixoformed Mg-Sn-Bi alloys, fine-grained Mg-5Sn-3Bi-2Cu (TBC532) alloys were selected for semi-solid thixoforging. The microstructure and mechanical properties of thixoforged TBC532 alloy were studied by OM, SEM, XRD, EPMA and tensile test. The results indicate that a bimodal structure composed of near-spherical coarse grains and fine secon-dary solidification microstructure is formed in the thixoforged TBC532 alloy, significantly different from the equiaxed dendrites in the as-cast sample. The spherical α1-Mg grains account for about 60.8% with average grain size and shape factor of～98.5 μm and 1.26, respectively. The se-condary solidification region is composed of greatly refined α2-Mg with secondary dendrite arm spacing of ～4.6 μm and continuous network-like compound phases including Mg3Bi2, Mg2Sn, Mg2Cu, and BiSn. The secondary solidification region mainly distributed between spherical α1-Mg grains. Besides, there is a small amount of secondary solidification microstructure located inside the spherical α2-Mg grains. Due to the significant grain-boundary strengthening effect from fine α2-Mg grains in the bimodal structure and the synergistic effect between coarse and fine grain regions, the thixoforged TBC532 alloy exhibits superior mechanical properties. The ultimate tensile strength and elongation are (292.3±5.2) MPa and (14.7±0.3)%, respectively, which are 17.0% and 36.1% higher than that of the as-cast sample, respectively. The fracture surface of the thixoforged TBC532 alloy displays transcrystalline and ductile features.
1 Yin L, Huang H, Yuan G Y, et al. Materials China, 2019, 38(2), 126(in Chinese). 尹林, 黄华, 袁广银, 等. 中国材料进展, 2019, 38(2), 126. 2 Liu L, Yang W, Wu Z K, et al. Materials Reports, 2023, 37(12), 190(in Chinese). 刘灵, 杨伟, 吴宗锴, 等. 材料导报, 2023, 37(12), 190. 3 Meng S J, Xiao H R, Song J L, et al. Journal of Materials Research and Technology, 2024, 30, 9007. 4 Meng S J, Yu H, Cui H W, et al. The Chinese Journal of Nonferrous Metals, 2017, 27(5), 894(in Chinese). 孟帅举, 余晖, 崔红卫, 等. 中国有色金属学报, 2017, 27(5), 894. 5 Meng S J, Song J L, Chen K Y, et al. Rare Metal Materials and Engineering, 2025, 54(12), 3091(in Chinese). 孟帅举, 宋金龙, 陈可意, 等. 稀有金属材料与工程, 2025, 54(12), 3091. 6 Cheng W L, Ma S C, Bai Y, et al. Journal of Alloys and Compounds, 2017, 731, 945. 7 Meng S J, Yu H, Li L H, et al. Journal of Alloys and Compounds, 2020, 834, 155216. 8 Luo Y H, Cheng W L, Han L, et al. Materials Science and Engineering A, 2022, 834, 17(2), 142623. 9 Yang D L, Chen X Y, Liu H R, et al. Journal of Functional Materials, 2024, 55(7), 7038(in Chinese). 杨东来, 陈晓亚, 刘浩锐, 等. 功能材料, 2024, 55(7), 7038. 10 Yuan G Y. Effects of Cu and/or Zn addition on the microstructure, mechanical and corrosion behaviors of Mg, Chongqing University, China, 2018 (in Chinese). 袁光宇. Cu、Zn对Mg微观组织和性能的影响. 硕士学位论文, 重庆大学, 2018. 11 Li A W, Liu J W, Wu C L, et al. The Chinese Journal of Nonferrous Metals, 2010, 20(8), 1487(in Chinese). 李爱文, 刘江文, 伍翠兰, 等. 中国有色金属学报, 2010, 20(8), 1487. 12 Meng S J, Wang M L, Song J L, et al. The Chinese Journal of Nonferrous Metals, 2024, 34(10), 3352(in Chinese). 孟帅举, 王孟璐, 宋金龙, 等. 中国有色金属学报, 2024, 34(10), 3352(in Chinese). 13 Chen G S, Wu G H, Wang Y X, et al. Materials Reports, 2008(7), 99(in Chinese). 陈广森, 吴国华, 王迎新, 等. 材料导报, 2008(7), 99. 14 Huang X F, Wei L L, Yang J Q, et al. Materials Reports, 2020, 34(14), 14116(in Chinese). 黄晓锋, 魏浪浪, 杨剑桥, 等. 材料导报, 2020, 34(14), 14116. 15 Kang Y L, Mao W M, Hu Z Q. Theory and technology of semi-solid processing of metal materials, Science Press, China, 2004, pp. 198(in Chinese). 康永林, 毛卫民, 胡壮麒. 金属材料半固态加工理论与技术, 科学出版社, 2004, pp. 198. 16 Kleiner S, Beffort O, Wahlen A, et al. Journal of Light Metals, 2002, 2(4), 277. 17 Li Y D, Chen T J, Ma Y, et al. The Chinese Journal of Nonferrous Metals, 2008(1), 18(in Chinese). 李元东, 陈体军, 马颖, 等. 中国有色金属学报, 2008(1), 18. 18 Lukasz R, Grzegorz G. Journal of Materials Processing Technology, 2019, 264, 352. 19 Huang X F, Zhang Q Q, Ma Y J, et al. Materials Reports, 2019, 33(10), 3441(in Chinese). 黄晓锋, 张乔乔, 马亚杰, 等. 材料导报, 2019, 33(10), 3441. 20 Huang X F, Zhang S, Yang F, et al. The Chinese Journal of Nonferrous Metals, 2022, 32(6), 1561(in Chinese). 黄晓锋, 张胜, 杨凡, 等. 中国有色金属学报, 2022, 32(6), 1561. 21 Yue Q C, Cui J Z, Lu G M, et al. The Chinese Journal of Nonferrous Metals, 2003(6), 1488(in Chinese). 乐启炽, 崔建忠, 路贵民, 等. 中国有色金属学报, 2003(6), 1488. 22 Xu H, Zhang X, Wang C S, et al. Materials Science Forum, 2016, 850(7), 790. 23 Yu Z Y. Mechanical properties and strengthening mechanisms of bimodal microstructural Mg-Al-Zn alloys. Master's Thesis, Jilin University, China, 2019 (in Chinese). 余志远. 混晶结构Mg-Al-Zn合金力学性能及强韧化机制. 硕士学位论文, 吉林大学, 2019. 24 Meng S J, Wang M L, Zhu M L, et al. The Chinese Journal of Nonferrous Metals, 2024, 34(12), 3959. 孟帅举, 王孟璐, 朱明亮, 等. 中国有色金属学报, 2024, 34(12), 3959. 25 Meng S J, Song J L, Chen K Y, et al. Rare Metal Materials and Engineering, DOI:10. 12442/j. issn. 1002-185X. 20240480. 26 Kim W J, Jeong H G, Jeong H T. Scripta Materialia, 2009, 61(11), 1040.
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2026, Vol. 40 
