As cast microstructure and mechanical properties of Mg-6Al-1Zn-0.7Si magnesium alloys modified by Sn and Sr additions

作者：Peng J M; Yang M B^*

来源：International Journal of Cast Metals Research, 2012, 25(2): 103-109.

DOI：10.1179/1743133611Y.0000000031

• Magnesium alloy
• Mg-6Al-1Zn-0.7Si alloy
• Sr
• Sn
• Mg2Si phase

The as cast microstructure and mechanical properties of Mg-6Al-1Zn-0.7Si (wt-%) alloys modified by Sn and Sr additions are investigated and compared. The results indicate that adding 0.56 wt-% Sn to Mg-6Al-1Zn-0.7Si can refine the Chinese script shaped Mg2Si phase in the alloy, but the modification of the Mg2Si phase is not obvious. Oppositely, adding 0.027-0.086 wt-% Sr can effectively refine and modify the Chinese script shaped Mg2Si phase in the Mg-6Al-1Zn-0.7Si alloy. After adding 0.027-0.086 wt-% Sr, the morphology of the Mg2Si phase in the Mg-6Al-1Zn- 0.7Si alloy changes from coarse Chinese script shape to fine granule and/or irregular polygonal shapes. Accordingly, the Sr containing alloys obtain the relatively higher tensile and creep properties than the Sn containing alloy. The difference of Sn and Sr additions in the modification and refinement of the Chinese script shaped Mg2Si phase in the Mg-6Al-1Zn-0.7Si alloy is possibly related to the different effects of the two elements on the undercooling degree.

• 出版日期2012-4
• 单位福建工程学院; 重庆理工大学