研究稀土元素La对铜合金的电弧侵蚀行为和氧化行为的影响。结果表明:稀土元素La的加入有利于铜合金抗氧化性能和电弧侵蚀性能的改善,并有效地降低了接触电阻和温升。通过对CuLa合金的高温抗氧化性能机理分析表明,富集在晶界的La元素形成La2O3或者CuLa合金,起到了界面包裹的作用,从而抑制了铜的进一步氧化。通过热力学计算可知,CuLa合金中的La择优氧化形成La2O3,对铜基体起到了保护作用。动力学分析表明,CuLa合金的激活能较纯铜的高,说明其抗氧化性能更好。
Cu with and without La addition was prepared and the effect of a trace amount of La on the arc erosion behaviors and oxidation resistance of Cu alloys was investigated. The results indicate that CuLa alloy exhibits superior oxidation resistance and arc erosion resistance. The contact resistance and temperature rise were obviously improved. The oxidation resistance of CuLa alloy mainly is due to the interface wrapping of La2O3 particles and CuLa alloy phase on Cu atoms. Thermodynamic calculation indicated that La2O3 could form preferentially in the CuLa alloy, which was beneficial for the protection of the Cu substrate. According to kinetics analysis, the activation energy of CuLa alloy was higher than that of pure Cu, indicating the better oxidation resistance of CuLa alloys.