电磁继电器触点磨损的理化分析

Physical and Chemical Analysis of Contact Points Wear of Electromagnetic Relay

电磁继电器是各类自动化系统中重要的一种基础元件．由于它频繁工作在开关状态，外部振动或温度变化可能引起继电器触点表面氧化或磨损，从而电接触电阻增大，对电接触性能产生不良影响．借助扫描电镜（ＳＥＭ）和Ｘ射线衍射仪（ＸＲＤ）对电接触表面进行观察和测量．实验结果表明，经长期连续使用后触点表面变得粗糙并发生磨损，其组分中含有Ｃ、Ｃｅ、Ａｇ等原子．最后对继电器早期失效机理进行了讨论．

Electromagnetic relay is an essential element in various automatic systems.Because of freguent operation in the condition of on off state,external vibration or temperature rising may cause oxidation or wear of the surface of contact points.Therefore,the electrical contact resistance increased,which induced a bad effect on the electrical performance.The scanning electron microscopy(SEM) and X ray diffraction (XRD) were used to observe and measure the electrical contact surface.The experimental results show that the surface of contact points after continual operation for a long time became rough.The surface layer contained C,Ce,Ag elements etc.Thereafter the mechanism of efficacy losing of electromagnetic relay in early stage was discussed.