热处理对挤压态Mg-9Sn-1.5Y-0.4Zr镁合金显微组织与力学性能的影响

Effects of heat treatment on microstructure and mechanical properties of as-extruded Mg-9Sn-1.5Y-0.4Zr magnesium alloy

摘要:

本文对热处理对挤压态Mg-9Sn-1.5Y-0.4Zr镁合金显微组织与力学性能的影响进行了实验性探究。结果显示热处理对挤压态Mg-9Sn-1.5Y-0.4Zr镁合金显微组织与力学性能具有显著影响。挤压态合金主要由非均匀分布的Mg2Sn相组成。经过495℃，10h固溶处理之后，大部分Mg2Sn相溶入到基体中。时效处理能大幅改善Mg-9Sn-1.5Y-0.4Zr合金的力学性能，最佳时效工艺为：在250℃条件下时效60h。实验最终力学性能参数为：维氏硬度89HV，极限抗拉强度262MPa，屈服强度218MPa，延伸率10.4%。基于实验结果分析，可以发现对于经时效处理的挤压态Mg-9Sn-1.5Y-0.4Zr合金，沉淀强化是主要的强化因素（~51.76%）。

Abstract:

The effects of heat treatment on microstructure and mechanical properties of the as-extruded Mg-9Sn-1.5Y-0.4Zr (wt%) alloy were investigated experimentally in this study. The results showed that the heat treatment plays an important role on the microstructure and mechanical properties of the as-extruded Mg-9Sn-1.5Y-0.4Zr alloy. The as-extruded alloy is mainly composed of non-uniform Mg2Sn phase. After the solution treated at 495℃for 10h, a majority of the Mg2Sn phases in the alloy were dissolved into the matrix. Aging treatment can highly improve the mechanical properties of the Mg-9Sn-1.5Y-0.4Zr alloy with the optimized experimental condition of aging at 250℃for 60h after solution treated at 495℃for 10h. The corresponding mechanical property parameters are: hardness of 89HV, ultimate tensile strength of 262MPa, yield strength of 218MPa, elongation of 10.4%. Based on the experimental results analysis, it is found that the precipitation strengthening is the main contributor (~51.76%) to the total yield strength in the aged experimental alloy.