Ag-La_2NiO_4不同条件直流燃弧特性研究

The Arc Erosion Characteristics of Ag-La_2NiO_4 Electric Contact Materials under Different DC Conditions

研究了Ag-La_2NiO_4电接触材料在不同条件直流电弧作用下电极表面的元素分布、材料的微观组织形貌、作用前后的形貌;探讨了Ag-La_2NiO_4电接触材料在直流电弧作用下的转移和腐蚀机理。结果表明:直流电弧引起阳极表面熔化、Ag离子向阴极转移及在阴极表面沉积;La_2NiO_4复合金属氧化物在电弧高温作用下分解成单元素,吸收了电弧能,有利于灭弧;同时La_2NiO_4、La_2O_3、NiO颗粒悬浮在阳极Ag微小熔池中,增加了熔融Ag的粘度,有利于降低Ag熔滴的飞溅,减少了电弧烧损。Ag-La_2NiO_4复合电接触材料显示出良好的综合电性能。

The element distribution in electrode surface, the microstructure, and morphology of the Ag-La2NiO4 electric material were strdied under in different DC conditions. The mechanism of transformation and erosion of the material in the DC arc was discussed. The results show that the DC arc brought about the melting of the surface in anode, the transfering of silver ion and depositing on the cathode surface. The deposition of silver in cathode surface reduced the contact resistance. The decomposition of metal oxide La2NiO4 was helpful to extinguish arc by absorbing the arc energy. Meanwhile the particles of La2NiO4, La2O3 and NiO suspended in the melt pool increasing the viscosity of the melt Ag, which, in turn, helped to reduce the splash of melt drop and arc erosion. The Ag-La2NiO4 contact material showed better performance than other materials under DC condition.