| Title： | Microstructures and tensile properties of as-cast Mg-5Sn-1Si magnesium alloy modified with trace elements of Y, Bi, Sb and Sr | |
| Author： | He-shuai Yu1,2, *Xue-feng Guo1,2, Hong-bao Cui1,2 | |
| Address： | 1. School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, Henan, China; 2. Henan International Joint Research Laboratory for High-Performance Light Metallic Materials and Numerical Simulations, Henan Polytechnic University, Jiaozuo 454000, Henan, China | |
| Key words： | magnesium alloy; Mg-5Sn-1Si alloy; Y, Bi, Sb, Sr; Mg2Si phase | |
| CLC Nmuber： | TG146.22 | |
| Document Code： | A | |
| Article ID： | 1672-6421(2021)01-009-09 | |
| Abstract： |
The microstructures and mechanical properties of as-cast Mg-5Sn-1Si magnesium alloy modified with trace elements Y, Bi, Sb and Sr were investigated and compared. Results show that the microstructure of the as-cast Mg-5Sn-1Si alloy consists of α-Mg, Mg2Si, Mg2Sn and Mg2(SixSn1-x) phases. After adding 0.8wt.% Y, 0.3wt.% Bi, 0.9wt.% Sb and 0.9wt.% Sr, respectively into the Mg-5Sn-1Si magnesium alloy, Mg24Y5, Mg3Bi2, Mg3Sb2 and Mg2Sr phases are precipitated accordingly. Trace elements can refine α-Mg grain and Chinese scriptshaped Mg2Si phase. Refinement efficiency of different trace elements on α-Mg grain and Mg2Si phase is varied. Sr element has the best refinement effect, followed by Sb and Bi, while Y has the least refinement effect. Mg-5Sn- 1Si-0.9Sr alloy has higher tensile properties than the other three modified alloys. The refinement mechanism of Y, Bi and Sr elements on Mg-5Sn-1Si magnesium alloy can be explained by the growth restriction factors and the solute undercooling. For Mg-5Sn-1Si-0.9Sb alloy, the heterogeneous nuclei of Mg3Sb2 phase is the main reason for the refinement of grains and second phases.
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