Composition optimization of high-strength Mg-Gd-Y-Zr alloys based on the structural unit of Mg-Gd solid solution

• 作者: Rui Jiang Shengnan Qian Chuang Dong Ying Qin Yujuan Wu Jianxin Zou Xiaoqin Zeng
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2021,（13）
• 页码范围: 104-113
• 页数: 10页
• 语种: 英文

摘要

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 ofGd-containing Mg solid solution with the aid of Mg matrix and MgsGd precipitate phase.First,based on the structural homologue between Gd-containing Mg solid solution and MgsGd precipitate phase and in combination with our previously established method for calculating the glue atoms,[Gd-Mg12]Mgs 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.