石墨坩埚铸造Mg-4Al-0.5Me合金的凝固组织与性能

Solidification Microstructure and Properties of Mg-4Al-0.5Me Alloys Cast by Graphite Crucible

摘要: 利用SEM、EDS、XRD研究了利用石墨坩埚铸造Mg-4Al-0.5Me（Nd，Y，Ca）合金的凝固组织以及性能。结果表明，合金的凝固组织主要由α-Mg和β-Mg₁₇Al₁₂组成。Mg-4Al-0.5Nd和Mg-4Al-0.5Y合金的组织较为粗大，且沿晶界有析出的颗粒相；在Mg-4Al中添加少量Ca元素后，组织得到了有效细化。Mg-4Al-0.5Nd与Mg-4Al-0.5Y合金的显微硬度分别为50.78、50.82 HV；Mg-4Al-0.5Ca合金的显微硬度则有显著提升，达到60.8 HV；三种合金的抗压强度分别为330.14、334.56、361.77 MPa。

Abstract: The solidification structure and properties of Mg-4Al-0.5Me (Nd, Y, Ca) alloys cast by graphite crucible were studied by SEM, EDS and XRD.The results show that the solidification structure of the alloys is mainly composed of α-Mg and β-Mg₁₇Al₁₂.The structure of Mg-4Al-0.5Nd and Mg-4Al-0.5Y alloys is coarse and has granular phase precipitated along the grain boundary.After adding a small number of Ca element to Mg-4Al, the structure is effectively refined.The micro-hardness of Mg-4Al-0.5Nd and Mg-4 Al-0.5Y alloy is 50.78 HV and 50.82 HV, respectively.The micro-hardness of Mg-4Al-0.5Ca alloy is significantly improved to 60.8 HV.The pressure strength of the three alloys is 330.14 MPa, 334.56 MPa and 361.77 MPa, respectively.