铸造Mg-6Zn-3Sn-0.5Mn镁合金组织和力学性能

Microstructure and Mechanical Properties of As-cast Mg-6Zn-3Sn-0.5Mn Alloy

通过OM、SEM、XRD和力学性能测试等手段研究了半连续铸造Mg-6Zn-3Sn-0.5Mn(ZTM630)镁合金铸锭的组织和力学性能。结果表明,铸态显微组织主要由α-Mg相、Mg_2Sn相、Mg_7Zn_3相组成;经过420℃×8 h固溶处理,Mg_7Zn_3相和绝大部分的Mg_2Sn相全部溶解到基体中,剩余少量Mg_2Sn相呈颗粒状分布在晶界或晶粒内部;固溶处理后实验合金的抗拉强度、屈服强度和伸长率均有所提高。

The microstructure and mechanical properties of as-cast and heat-treated Mg-6Zn-3Sn-0.5Mn （ZTM630） alloy were investigated by the means of OM, XRD, SEM and tensile property test. The results show that the phase composition of as-cast ZTM630 alloy are α-Mg, divorced eutectic Mg2Sn phase, eutectic Mg7Zn3 phase. The phase compositions change after solution treatment of 420℃×8 h. Mg7Zn3 phase and most of the Mg2Sn phase are dissolved into the matrix and a small amount of Mg2Sn phase distributing in the grain interior or boundaries. The tensile strength, yield strength and elongation are all improved after solution treatment by solution treatment.