添加Al_2O_3对CuW70合金阴极斑点运动特性的影响

Influence of Al_2O_3 Addition on Motion of Cathode Spot for CuW70 Alloy

采用熔渗法制备了不同Al2O3添加量的CuW70合金,研究了Al2O3对CuW70合金组织和真空击穿性能的影响,利用高速摄影观察了CuW70合金表面阴极斑点运动规律。结果表明:未添加Al2O3的CuW70合金烧蚀主要集中在Cu聚集区;在放电过程中,阴极斑点运动表现为原地重复的燃烧,合金表面烧蚀严重。添加Al2O3后,CuW70首击穿相发生转移,集中在Al2O3颗粒上,阴极斑点更为分散,合金主烧蚀区面积明显减少;Al2O3的添加延长了电弧寿命,降低了截流值。

CuW70 alloys with different additions of Al2O3 were prepared by infiltrating method.The effects of Al2O3 addition on microstructure and vacuum breakdown were investigated,and the motion of cathode spots of CuW70 alloys was observed utilizing high speed photography.The results show that the cathode spots of CuW70 alloys without Al2O3 addition are concentrated on the copper phases.The generation and extinguishment of cathode spots cause the serious erosion around the original site on the surface.For the CuW70 alloys with Al2O3 addition,the cathode spots are more dispersed,the first breakdown phase shift from copper to Al2O3 phase,and the erosion area decreases significantly.So,the arc-resistant life of CuW70 alloys is prolonged and the chopping current decreases with Al2O3 addition.