稀土钕对ZK20镁合金铸态组织和力学性能的影响

Effects of Nd on cast microstructure and mechanical properties of ZK20 magnesium alloy

采用常规金相、XRD分析、SEM分析、常温拉伸以及高温压缩实验,研究了稀土Nd对低锌的ZK20镁合金铸态组织和力学性能的影响及机理,分析了ZK20镁合金中含Nd相的类型随Nd含量的变化规律。结果表明随着钕含量的增多,ZK20镁合金铸态组织在枝晶间或晶界上出现了较多的合金相,且随钕添加量的增多,合金中的Mg-Zn-Nd三元合金相数量不断增多,其形态也由不连续的网状逐渐转变为完整的网状形态,合金的断裂方式由穿晶断裂逐渐转变成沿晶断裂。

In this paper, the effects of Nd addition on microstructure and mechanical properties of cast ZK20 magnesium alloy were investigated by the use of OM, XRD, SEM and tensile test at room temperature etc. Studying of cast microstructure and mechanical properties of low zinc magnesium alloy ZK20 effects and mecha- nism analysis of ZK20 magnesium alloy containing the type of phase with the variation of Nd content. The re- sults show that with the increase of neodymium content, ZK20 magnesium alloy east mierostructure of the alloy phase there are more on the dendrites occasional grain boundaries, and increased with the addition amount of neodymium alloy of Mg-Zn-Nd ternary alloy with an increasing number, but also by its shape discontinuous dis- continuous mesh gradually transformed into a full mesh form, the alloy fracture mode from transgranular frac- ture transformed into intergranular fracture.