镁-稀土合金的显微组织和力学性能研究

Microstructure and Mechanical Properties of the Mg-Rare-Earth Alloys

通过光学显微镜、扫描电子显微镜及X射线衍射和拉伸试验对Mg-RE(Ce,Nd,Y)-Zn-Zr合金的显微组织和力学性能进行了分析研究,揭示了试验合金在不同稀土元素作用下的结构特点及断裂行为。试验结果表明,铸态时镁铈、镁钕中间相(Mg-Ce、Mg-Nd相)主要以共晶形式分布在合金的晶界,稀土钇(Y)则部分固溶于晶内;经固溶处理及时效后,中间相以细小颗粒状分布在整个Mg基体中,明显提高了合金的室温综合力学性能及高温抗蠕变性能。

The microstructure and mechanical properties of Mg-RE （Ce, Nd, Y ）-Zn-Zr alloys were investigated through optical microscopy, scanning electron microscopy, X-ray diffraction analysis and tensile test. The structure characteristics and fracture behavior of the investigated alloys were revealed. The results show that the intermediate phases Mg-Ce and Mg-Nd in eutectic is mainly distributed in grain boundary of the tested alloys,however the rare earth yttrium is partly solved in the intracrystal. After solution treatment and ageing, the intermediate phases distribute in dispersion, and this makes the room temperature mechanical properties and high temperature creep strength be enhanced greatly.