钕对AZ91镁合金组织及机械性能的影响

采用微观分析、机械性能测试及断口分析等方法研究了钕对AZ91-Nd镁合金(w(Nd)=0,0.1%,0.3%,0.5%,1.0%,1.5%)的微观组织和机械性能的影响。结果表明:Nd以固溶和金属间化合物(A l11Nd3)的形式存在时具有细化晶粒、抑制二次β相析出、使不完全离异共晶转化为离异共晶的作用;Nd通过固溶强化、析出强化和细晶强化增加了合金强度和硬度,并改善了塑性;加入Nd后合金的断裂机制从脆性解理断裂转变为准解理断裂。

Effect of neodymium on microstructure and mechanical properties of AZ91 magnesium alloy

The microstructure and mechanical properties of as cast AZ91-Nd(neodymium) magnesium alloys were studied by microstructure analysis,mechanical property testing and analysis of fracture surface,where w(Nd) is 0,0.1%,0.3%,0.5%,1.0%,1.5%.The results reveal that the element Nd added into AZ91 exists in the forms of both solid solution and intermetallics Al_(11)Nd_3.It has great effects on refining grains of α-Mg and β-Mg_(17)Al_(12),depressing the precipitation of secondary β-Mg_(17)Al_(12) and transforming the partially divorced eutectic into the fully divorced.Nd effectively improves the tensile strength,ductility and hardness of AZ91 alloy due to the effects of solid-solution strengthening,precipitation strengthening as well as fine-grained strengthening.