The effect of sputtered gold electrode on surface flashover characteristics of A12O3 (alumina) ceramic, under nanosecond pulsed high voltage in vacuum environment, is investigated. And the mechanism is clarified by the discussion for effects of surface roughness, surface traps, surface energy band structure and charge injection. Six kinds of 95 % A12O3 ceramics with different surface roughness and electrode contacting types are prepared. The flashover voltage is measured under 50 ns (rise time)/l. 2 fxs (half-height width time) unipolar pulse and 5X10~3 Pa vacuum degree. It is found that the flashover voltage for the samples with sputtered gold contact electrode gets lower than ones without gold contact electrode, because the surface state induced by sputtered gold-electrode can affect the electron emission and charge injection on the sample surface.%研究了溅射金膜对氧化铝陶瓷在真空环境中、纳秒脉冲高电压作用下沿面闪络特性的影响规律.通过对氧化铝陶瓷表面粗糙度、电极接触形式的研究,并结合表面态陷阱、界面能带结构、电荷注入过程的分析,探究了影响氧化铝陶瓷溅射金膜后沿面闪络电压的主要原因.在50 ns/1.2μs脉冲下、电极间距10 mm时,测量各试样的闪络电压60次,取后30次平均值作为稳定的闪络电压.研究结果发现,氧化铝陶瓷在溅射金膜电极试样的闪络电压比直接压接电极试样的闪络电压低,这是因为在不同电极接触方式下,氧化铝陶瓷材料的表面态对真空中的电子发射和材料表层的电荷注入的影响不同所致.
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