La对AZ61镁合金组织及性能的影响

研究添加稀土La含量为(0,0.5,1.0,1.5)％对AZ61合金的微观组织及室温力学性能的影响.结果表明:加入0.5％ ～1.5％的稀土后,铸态AZ61合金组织中的β-Mg17Al12相明显变得细小,形成了针状的Al11La3相.当稀土含量超过1.0％时,针状的Al11 La3相开始粗化长大,β-Mg17 Al12相的网状结构开始分离,变得细小；La的加入可以提高AZ61合金力学性能,当加入的La含量为1.0％时,AZ61合金的力学性能最好.因此,AZ61合金中加入La的质量分数为1.0％时,为合金化的最佳值.

Effect of La on microstructure and properties of AZ61 magnesium alloy

The effect of adding La with(0~1.5)% on microstructure and mechanical properties of AZ61 magnesium alloy was investigated.The results show that addition of 0.5%~1.5% La can refine the phase of β-Mg17Al12 in the cast AZ61 magnesium alloys and form the needle-like phase of Al11La3 in the matrix;The needle-like phase of Al11La3 starts to coarsen and grow up and the phase of β-Mg17Al12’s network structure begin to separate and refine when the content of La exceed 1.0%;The addition of La can improve the mechanical properties of AZ61 magnesium alloys,when the content of La up to 1.0%,the mechanical properties of AZ61 magnesium alloy is best.Therefore,The best value of micro-alloying is the mass fraction of La in AZ61 magnesium alloys reaches to 1.0%.