Abstract：The Mg-5Sn-2Si alloy was modified by the Mg-20%Ca(mass fraction, the same below)and Mg-20%La master alloys separately. The modifying effects of Ca and La on the Mg2Si phase were investigated, and high temperature creep testing was conducted as well. The results showed that Ca and La had a good modifying effects on Mg2Si phase, granuliform primary Mg2Si phase disappeared and the morphology and distribution of the coarse dendritic Mg2Si were obviously affected and new flower-like CaMgSi and rod-like La5Si4 compounds were found in the alloys. The creep rate of the alloy with the modifying of Ca and La decreased significantly, under 250℃,60MPa stress conditions. The steady creep rate of Mg-5Sn-2Si-2Ca and Mg-5Sn-2Si-2La alloys decreased to 1/48 and 1/28 respectively, compared with the unmodified alloy. The reason for the increase of the creep resistance may have to do with that the Mg2Si phase was refined as well as dislocation slipping and grain boundary sliding were much more blocked after the new compounds generated.
张果, 杜军, 李文芳, 豆琦, 蔡添祥. Ca和La对Mg-5Sn-2Si合金组织和蠕变性能的影响[J]. 材料工程, 2013, 0(4): 81-84.
ZHANG Guo, DU Jun, LI Wen-fang, DOU Qi, CAI Tian-xiang. Effects of Ca and La on Microstructures and Creep Properties of Mg-5Sn-2Si Alloy. Journal of Materials Engineering, 2013, 0(4): 81-84.
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