不同Ca含量AM60镁合金的抗氧化性研究

Study on the Oxidation Resistance of AM60 Magnesium Alloy with Different Ca Contents

为促进镁合金在高温环境下的应用,通过XRF、XRD和TGA等分析方法,研究了不同Ca含量下AM60镁合金的抗氧化性。结果表明:添加Ca元素能够很大程度地提高AM60镁合金的高温抗氧化性。在450℃、保温1.5 h的条件下,AM60-x Ca(x=0,0.8%,1.6%,3.2%,质量分数)镁合金的氧化增重分别为1.067,0.032,0.048,0.027 mg/cm2。通过计算,CaO/AM60-x Ca(x=0.8,1.6,3.2)的Pilling-Bedworth(生成氧化膜与金属比容的比值)值分别为1.22,1.21,1.20,MgO/AM60的Pilling-Bedworth值为0.82,表明AM60镁合金氧化过程生成的MgO氧化膜对基体保护作用较弱,添加Ca元素后,能在合金表面生成致密的CaO氧化膜,阻止基体的进一步氧化。

In order facilitate the application of magnesium alloy in the high-temperature environment,the oxidation resistance of AM60 magnesium alloy with different Ca contents was investigated by XRF,XRD and TGA.Results showed that the addition of Ca element could greatly improve the high-temperature oxidation resistance of AM60 magnesium alloy.The oxidation weight gain of AM60-x Ca(x=0,0.8%,1.6%,3.2%)magnesium alloy at 450℃for 1.5 h was 1.067,0.032,0.048,0.027 mg/cm2,respectively.By calculation,the RPB(PillingsBedworth,the ratio of the generating oxidation film and the metal)of Ca O/AM60-x Ca(x=0.8,1.6,3.2)was 1.22,1.21,1.20,and the RPB of MgO/AM60 was 0.82,which suggested that the MgO film had relatively lower protective effect on the substrate.After adding Ca element,a Ca O film with dense structure could be formed on the surface to prevent further oxidation of the substrate.