A Preliminary Study on the Effects of Aging Temperature on the Microstructure and Mechanical Properties of As-Extruded Mg-12Gd-4Y-1Zn Magnesium Alloy

The effects of the aging temperature on the microstructure and mechanical properties of the as-extruded Mg-12Gd-4Y-1Zn alloy were preliminarily investigated. The results indicate that the as-extruded alloy is mainly composed of the alpha-Mg, Mg5.05(Gd,Y,Zn), Mg3(Gd,Y,Zn) and LPSO Mg12(Gd,Y)Zn phases. For a given aging time of 48 h, the aging temperature had no obvious effect on the alloy phase type of the as-extruded alloy, but had a significant effect on the tensile properties. Moreover, some difference in the amount and morphology of the precipitated secondary phases for the as-aged alloys with the different aging temperatures, still exist. In addition, among the three aging temperatures of 175 degrees C, 200 degrees C, and 250 degrees C, the aging temperature of 200 degrees C is relatively optimal for the as-extrude alloy. After being aged at 200 degrees C for 48 h, the tensile and yield strengths at room temperature for the as-extruded alloy could reach 517 MPa and 395 MPa, respectively.