Li Yongfeng, Zhang Ang, Li Chuangming, Xie Hecong, Hu Hengrui, Gao Yuyang, Cui Yuhong, Dong Zhihua, Li Tian, Jiang Bin
National Engineering Research Center for Magnesium Alloys, National Key Laboratory of Advanced Casting Technologies, College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
Qinghai Salt Lake Teli Magnesium Co., Ltd., Xining 810000, China.
Materials (Basel). 2025 May 25;18(11):2475. doi: 10.3390/ma18112475.
This paper investigates the effects of Y content on the microstructure and mechanical properties of Mg-9Gd-Y-0.5Zr alloys. The mechanical properties, together with the grain size, first increase and then decrease, exhibiting a non-monotonous change with the increase in Y content. The alloy with 3 wt.% Y exhibits the best mechanical properties compared to the Y free alloy, with an increase in ultimate tensile strength and yield strength of 33.4% and 19.2%, respectively. However, further increase in the Y content (5 wt.%) does not enhance the strength but promotes the growth of the Mg(Gd,Y), becoming nucleation points and propagation paths for cracks, leading to a decrease in performance. The cubic phase REH and oxide are not the reasons for the poor ductility in as-cast Mg-9Gd-Y-0.5Zr alloys due to low content, and the crystallographic orientation relationship between REH and α-Mg is (220)//(112¯0), and the interface mismatch is 9.13%. This paper systematically prepares and investigates the high-strength as-cast Mg-Gd-Y-Zr alloy, which has important guiding significance.
本文研究了Y含量对Mg-9Gd-Y-0.5Zr合金微观组织和力学性能的影响。力学性能与晶粒尺寸随Y含量增加先升高后降低，呈现非单调变化。与不含Y的合金相比，含3 wt.% Y的合金表现出最佳力学性能，其抗拉强度和屈服强度分别提高了33.4%和19.2%。然而，Y含量进一步增加（5 wt.%）并未提高强度，反而促进了Mg(Gd,Y)的长大，成为裂纹形核点和扩展路径，导致性能下降。立方相REH和氧化物由于含量低，并非铸态Mg-9Gd-Y-0.5Zr合金塑性差的原因，且REH与α-Mg的晶体取向关系为(220)//(112¯0)，界面错配度为9.13%。本文系统地制备并研究了高强度铸态Mg-Gd-Y-Zr合金，具有重要的指导意义。
