Microstructure evolution and mechanical properties of Mg-10Gd-3Y-xZn-0.6Zr alloys

作者：Ding, Zhibing; Zhao, Yuhong^*; Lu, Ruopeng; Pei, Haixiang; Hou, Hua

来源：Journal of Materials Research, 2018, 33(12): 1797-1805.

DOI：10.1557/jmr.2018.100

• Y-ZN ALLOYS
• STACKING ORDERED STRUCTURES
• SOLIDIFIED MG97ZN1Y2 ALLOY
• ZR ALLOYS
• AS-CAST
• HIGH-STRENGTH
• HIGH-TEMPERATURE
• MAGNESIUM ALLOY
• MG ALLOY
• 773 K

The microstructure evolution and mechanical properties of Mg-10Gd-3Y-xZn-0.6Zr (x = 0.5, 1, and 1.5 wt%) alloys in the as-cast, solution-treated, and peak-aged conditions have been investigated systematically. The results indicate that the microstructure of the as-cast alloy with 0.5% Zn consists of alpha-Mg, (Mg,Zn)(3) RE and Mg-24(RE,Zn)(5) phases, while the alloy with 1.0 and 1.5% Zn consists of alpha-Mg, (Mg,Zn)(3) RE and some stacking faults. Moreover, 18R-LPSO phases are observed in the as-cast alloy with 1.5% Zn. The formation of LPSO phases involves not only stacking sequence ordered but also chemical composition ordered. After solution treatment, the Mg-24 (RE,Zn)(5), (Mg,Zn)(3) RE, stacking faults, and 18R-LPSO phases transform into 14H-LPSO phases. The 14H-LPSO phase plays an important role in the improvement of mechanical properties, especially for the ductility. The beta' phase with a bco structure precipitates in the peak-aged alloys results in precipitation hardening, significantly improving the tensile strength, but it leads to poor ductility.

• 出版日期2018-6-28
• 单位中北大学