To investigate the effect of pores on the dielectric breakdown (DB) of alumina ceramics under AC voltage, we implant pores at different positions (surface, interior, and the whole body) of the ceramic samples by adding the polyvinyl alcohol solid particles at different positions in the green bodies. Meanwhile, two electrode setups are used to test the dielectric breakdown strength (DBS), in order to analyze the effect of pore distribution on the DB, and the morphology of the DB channels is characterized. The results reveal both the pores on the surface and in the bulk reduce the DBS, and the pore distribution affects the shape and position of the DB channel. Besides, pre-breakdown in a low-DBS layer is found when the voltage is not high enough to produce DB. It confirms that the effect of pores on the DB is a combination of the volume effect and the surface effect.

为了研究孔对交流电压下氧化铝陶瓷介电击穿（DB）的影响，我们通过在不同位置添加聚乙烯醇固体颗粒，在陶瓷样品的不同位置（表面，内部和整个主体）注入孔在绿色的身体。同时，使用两个电极装置测试介电击穿强度（DBS），以分析孔分布对DB的影响，并表征DB通道的形态。结果表明，表面和整体中的孔都减少了DBS，并且孔分布影响了DB通道的形状和位置。此外，当电压不足以产生DB时，会在低DBS层中发现预击穿。