【摘要】 借助光学显微镜、扫描电镜、X射线衍射仪和万能拉伸测试仪研究了AM60合金中加入RE和B后的组织和性能,并分析了RE和B对合金组织和性能的影响。结果表明,RE和B都可以使合金的晶粒细化,β相的分布也变得均匀弥散,显著改善合金的显微组织,B和RE的同时加入效果最佳。0.15%(质量分数,下同)B加入AM60合金中没有形成新相,1.6%的RE加入则形成了稳定性较高的针状Al11RE3等相,B的变质作用及适当的固溶处理能使针状的稀土相钝化并变短。同时加入RE,B使合金的力学性能得到较显著的改善,其中显微硬度提高了26%,抗拉强度提高了20%。更多还原

【Abstract】 Effects of RE, B additions on microstructures and properties of AM60 alloys have been studied. The results indicated that the microstructure of AM60+0.15wt%B consisted of α-Mg solid solution and insular β-Mg17Al12 phase and no new phase was found after adding 0.15wt%B. Moreover, the needle-like Al11RE3 phase was formed at the grain boundary upon 1.6wt% RE addition and its morphology changed slightly after the solid solution treatment, but the phase was changed into rod-like upon adding B with less than 0.15wt%. The microstructure of AM60 cast magnesium alloy was effectively refined by adding small amount of RE or B. The microhardness increased upon RE or B addition, which increased by 26% upon 0.15wt% B and 1.6% RE additions. The ambient mechanical properties were also improved. The ultimate tensile strength increased by 20% upon 0.15 wt% B and 1.6% RE addition, while its elongation did not decrease.更多还原