W-30Cu电接触材料直流电接触行为

Electrical contact behavior of W-30Cu contact material under direct current condition

采用水热-共还原法制备W-30Cu(质量分数,%)纳米复合粉末,并通过冷压制坯、真空烧结和包覆热挤压的工艺制备出纳米W-30Cu电接触材料,经挤压后致密度达到98.82%,硬度和导电率分别为224HB和44%IACS。利用JF04C型电接触试验机对其进行不同操作次数的电接触性能测试实验,利用扫描电镜(SEM)、能谱(EDS)等方法分析电弧侵蚀后触头表面微观形貌和元素分布,探讨材料在直流电弧下的转移机理。结果表明:直流电弧引起阳极材料转移,Cu相向阴极转移并在阴极沉积;材料转移引起富Cu区和富W区的存在,同时产生孔洞、裂纹、珊瑚状结构等多种电弧侵蚀形貌。接触电阻介于0.60~0.73 m?,W-30Cu电接触材料表现出良好的综合电性能。

The W-30 Cu electrical contact material was fabricated by cold isostatic pressing process,vacuum sintering and hot extrusion with W-30 Cu nanocomposite powder that was prepared by hydrothermal-coreduction method.The relative density can reach 98.82%,the hardness is up to 224 HB and conductivity is 44%IACS.In order to search the transformation mechanism of W-30 Cu electrical contact material,some contact tests were carried out through JF04 C electrical material testing system.Scanning electron microscopy(SEM),energy dispersive spectrometer(EDS) were employed to observe the microstructure and element distribution in contact surface after arc erosion.The results show that the direct current(DC) arc causes the transferring of anode material and depositing on the cathode surface;the transfer of materials leads to the existing of rich W region and rich Cu region,as well as the generating of the special morphology of pores,cracks and coral-like structure.The W-30 Cu electrical contact material has small contact resistance in the range of 0.60-0.73 m?,which shows better performance under DC condition.