Sm、Ti复合变质对AM60合金显微组织和力学性能的影响

Effect of Sm and Ti Compound Inoculation on Microstructure and Mechanical Properties of AM60 Alloy

摘要:

采用 XRD、OM和 SEM等手段研究AM60合金中加入Sm和Ti后的组织和性能，并分别分析Sm和Ti对合金组织和性能的影响。结果表明，适量加入Sm和Ti都可以使合金组织得到极大地细化，减少了β相的析出，加入Ti后合金有少量的Al3Ti生成；Sm、Ti的复合加入则形成颗粒状Al2Sm、Mg41Sm5相和晕圈状球形化合物Al18Ti2Mg3，Ti的变质作用和适当的T6处理使合金中的杆状相钝化或者消失，粗大颗粒相变得圆整细小。复合添加比单独添加得到更优的力学性能，同时加入1.0%Sm和0.4%Ti，合金室温抗拉强度和伸长率分别达到226 MPa和6.7%，比母合金分别提高了34.5%和39.6%；200 ℃高温抗拉强度和伸长率分别达到170 MPa和10.4%，比母合金分别提高53.2%和82.5%。T6处理可以进一步提高该合金的力学性能。

Abstract:

Microstructures and mechanical properties of AM60 magnesium alloy with Sm and Ti addition were investigated through OM, SEM, XRD and DNS100 electronic universal testing machines and the effect of Sm and Ti addition was analyzed. The results show that the alloy grains can be refined greatly by the proper addition of Sm or Ti and reduce the precipitation of β. There are some Al3Ti phases formed after the addition of Ti. However, the β-Mg17A112 phase of the AM60 alloy changes from discontinuous netlike form to cobble or particulate form and even dispersed after 1%Sm addition. Particle phase of Al2Sm, Mg41Sm5 and spherical phase of Al18Ti2Mg3 are formed when adding Sm and Ti together. The rod-shaped phases in the alloy dismiss or transform roundly and massive particles become smaller by the inoculation of Ti and subsequent T6 process. With addition of 1.0%Sm and 0.4%Ti, the tensile strength and elongation reach 226 MPa and 6.7% , elevated by 34.5% and 39.6% respectively; the heat tensile strength and elongation at 200 oC reach 170 MPa and 10.4%, elevated by 53.2% and 82.5% respectively. T6 process can further enhance the mechanical properties of AM60 alloy.