Ca对Mg-5.5Al-1.2Y镁合金显微组织和力学性能的影响

Effects of Ca on Microstructure and Mechanical Properties of Mg-5.5Al-1.2Y Alloy

采用XRD、OM、SEM和EDS等方法研究了Ca对Mg-5.5Al-1.2Y合金显微组织和力学性能的影响。结果表明,加入适量Ca后,Mg17Al12相数量减少,Al2Y相得到细化,同时在基体中出现高熔点Al2Ca和Al4Ca相;随着Ca含量的增加,合金的室温(25℃)和高温(150、175℃)力学性能先升高后降低,且在Ca含量为0.8%时达到最佳。

The effects of Ca on the microstructure and mechanical properties of Mg-5.5Al-1.2Y alloy were investigated by OM,SEM,EDS and XRD.The results show that adding appropriate addition of Ca into Mg-5.5Al-1.2Y alloy can reduce the quantity of β-Mg17Al12 phase,refine Al2Y phase and cause the formation of high-melting-point phase Al2Ca and Al4Ca in the matrix.With the increase of Ca addition,the mechanical properties of the alloy at room and elevation temperature（150 ℃ and 175 ℃） increase and then decrease,which can reach the peak at the alloy with 0.8%Ca.