固溶和挤压对Mg-2.0Zn-1.0Y-0.5Zr合金组织与性能的影响

Influence of solution treatment and extrusion on microstructure and properties of Mg-2.0Zn-1.0Y-0.5Zr alloy

通过扫描电镜(SEM)、X射线衍射仪(XRD)、电子背散射衍射(EBSD)、拉伸实验和浸泡测试等研究了固溶和挤压对Mg-2.0Zn-1.0Y-0.5Zr(mass%)合金组织和性能的影响。结果表明:固溶处理可以明显降低合金中的第二相数量,提高合金的屈服强度、极限抗拉强度、伸长率和耐蚀性;热挤压可明显细化合金晶粒,大幅提高合金的屈服强度和极限抗拉强度,但却降低其伸长率和耐蚀性。440℃固溶10 h的合金有较低的腐蚀速率,为(0.304±0.021)mm/y;进一步460℃挤压后合金的力学性能最好,其屈服强度、极限抗拉强度和伸长率分别为(293.9±4.8)MPa、(317.1±5.5)MPa和(16.7±1.5)%。

Effect of solution treatment and extrusion on microstructure and properties of Mg-2.0Zn-1.0Y-0.5Zr(mass%)alloy was studied by means of scanning electron microscopy(SEM),X-ray diffraction(XRD),electron backscatter diffraction(EBSD)technique,tensile test and immersion test.The results show that solution treatment can significantly reduce the number of second phases in the alloy,improve the yield strength,ultimate tensile strength,elongation and corrosion resistance of the alloy.Hot extrusion can significantly refine the alloy grains,significantly increase the yield strength and ultimate tensile strength of the alloy,but reduce its elongation and corrosion resistance.The alloy after solution treatment at 440℃for 10 h has a lower corrosion rate,which is(0.304±0.021)mm/y.After further extrusion at 460℃,the mechanical properties of the alloy are the best,with yield strength,ultimate tensile strength and elongation of(293.9±4.8)MPa,(317.1±5.5)MPa and(16.7±1.5)%,respectively.