Composition optimization of high-strength Mg-Gd-Y-Zr alloys based on the structural unit of Mg-Gd solid solution. (10th May 2021)

• Record Type: Journal Article
• Authors: Jiang, Rui; Qian, Shengnan; Dong, Chuang; Qin, Ying; Wu, Yujuan; Zou, Jianxin; Zeng, Xiaoqin
• Is Part Of: Journal of materials science & technology. Volume 72(2021)
• Page Start: 104
• Page End: 113
• Publication Date: 2021-05-10
• Subjects: Mg-Gd solid solution -- Chemical unit -- Cluster-plus-glue-atom unit -- Mg-Gd-Y-Zr cast alloys; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2020.08.041
• Languages: English
• ISSNs: 1005-0302

Abstract

Abstract: Mg-Gd-Y-Zr alloys with high strength fall within narrow composition range. The present paper explains their composition rule by establishing the cluster-plus-glue-atom unit of Gd-containing Mg solid solution with the aid of Mg matrix and Mg5 Gd precipitate phase. First, based on the structural homologue between Gd-containing Mg solid solution and Mg5 Gd precipitate phase and in combination with our previously established method for calculating the glue atoms, [Gd-Mg12 ]Mg5 is obtained as the chemical unit of Gd-containing Mg solid solution. Then, seven compositions are designed using different combinations of this unit and that of pure Mg [Mg-Mg12 ]Mg3 . After a systematic experimental investigation on the microstructure and mechanical property evolutions as a function of the unit proportions, it is revealed that the Mg-10.1Gd-3.3Y-0.9Zr alloy, being issued from equi-proportion mixing of the two units, shows the strongest tendency of precipitation and reaches the highest strength of 374 MPa after aging. The composition and strength of this alloy are quite close to GW103K which is well recognized for its general mechanical performance in Mg-Gd-Y-Zr system.