W-Cu材料的显微结构对电弧阴极斑点的影响

Influence of Microstructure of W-Cu Composites on Movement of Cathode Spots

采用扫描电子显微镜观察了W-Cu复合电弧阴极材料首击穿后的表面形貌,研究了复合阴极材料微观结构对阴极烧蚀形貌和阴极斑点运动的影响。结果显示:纳米材料的阴极斑点分布在较为分散的面上,而且阴极表面烧蚀比较轻微,而常规材料的阴极斑点局域在个别点上,阴极表面烧蚀比较严重。分析表明:这是由于不同微观结构的W-Cu复合材料中的相界所占比例不同,阴极表面上相邻相界之间的平均距离不同,引起阴极表面的阴极斑点运动的难易程度不同,从而导致不同的烧蚀形貌。

The tracks of cathode spots produced after the first discharge on the surfaces of nanostructured and conventional W-Cu cathodes were investigated using a scanning electron microscope (SEM), and the influence of microstructure of composites on the morphology and movement of cathode spots was studied. It is found that slight erosion disperses over an area for nanostructured W-Cu and severe erosion locates on several sites for conventional W-Cu cathodes. The analysis suggest that different average distance bet...