纳米CuCr50触头材料电弧侵蚀特性

近年来,纳米CuCr触头材料在截流水平、耐压能力等方面的表现优于微晶CuCr触头材料。笔者利用真空触点模拟装置和基于虚拟仪器的电器电寿命测试系统,研究了直流低电压、小电流下的纳米CuCr50触头材料的电弧侵蚀量与分断燃弧时间和触头表面形貌之间的关系,同时采用两种微晶CuCr50触头材料作为对比。利用电光分析天平纳米CuCr50触头材料的侵蚀量,利用电子扫描显微镜测量触头表面形貌。结果表明:纳米CuCr50触头材料的平均分断燃弧时间和侵蚀量均高于两种微晶CuCr50触头材料。纳米CuCr50触头表面Cr颗粒细化及均匀分布,有利于分散电弧。纳米CuCr50阴极触头表面电弧烧蚀比较均匀,而两种微晶CuCr50触头阴极表面电弧局部烧蚀严重,出现明显的凹坑侵蚀。

Arc Erosion Characteristics of Nanocrystalline CuCr50 Contact Material

In recent years,nanocrystalline copper-chromium(Cu-Cr) contact material performed well in high withstand voltage,low chopping current,and so forth.Therefore,it has a big potential application in vacuum switches.The objective of this paper was to investigate vacuum arc erosion characteristics of a nanocrystalline CuCr(Cr50 wt.%) contact material.The vacuum contact simulation device was used to conduct contact materials arc erosion tests,and voltage waveforms of making and breaking arcs between the electrodes were recorded with LabVIEW.Using electric-light analytical balance and scanning electron microscopy,the mass loss and the surface structure of CuCr contact materials were obtained.Experiments indicated that the average break arcing time and the contact mass loss of nanocrystalline CuCr50 material were higher than those of two microcrystalline CuCr50 materials.The eroded contact surface structure showed a clear difference that the cathode contact surface of nanocrystalline CuCr50 contact material was uniform,while each cathode contact surface of two microcrystalline CuCr50 materials had an obvious arc erosion pit.