【摘要】 系统研究了经过研磨加工、陶瓷表面施釉及表面涂覆等工艺处理后,氧化铝陶瓷表面状态对其真空耐压性能的影响。结果发现,表面未加工的95%Al2O3陶瓷的可靠电压波动较大,波动幅度可达50%,但经过研磨加工后可靠电压值趋于一致;表面涂覆可以改善氧化铝陶瓷的真空耐压性能,并且改善的情况与涂覆的结构有关;而表面施釉不仅不能改善陶瓷的真空耐压性能,而且还降低了其真空耐压性能。更多还原

【Abstract】 The surfaces of 95% alumina insulatorswere modified by grinding,coating and glazing to improve its surface flashover characteristics in vacuum. The influence of the coating modes of metals( Mn,Cr,and Ti) layer on the surface flashover behavior was investigated. The Al2O3 surfaces were characterized with scanning electron microscopy. The results show that surface grinding and coating have a positive impact,whereas surface-glazing has a negative impact on the surface flashover behavior of alumina insulators. For example,surface-glazing considerably lowers the flashover and breakdown voltages,possibly because of a decreased resistivity and localized leakage current in the porous glazed layer. Surface grinding effectively stabilizes the reliable voltage at 18 k V by removing the fluctuationbetween 12 and 18 k V on the control sample’s surface; the flashover voltage of the surfaces,coated with metals layers on both ends of an Al2O3hollow-cylinder,increases by 50%,and the breakdown and reliable voltages increase up to 28. 5 and 27 k V,respectively.更多还原