Influence of μm-level profile slopes on vacuum DC flashover: a model guided design optimization

作者：Yuhang Huang, SiLe CHEN, Chao Wang, Yuying Wang, Zhaoquan Chen, Kehan Cao, Baipeng Song, Xiong Yang, Guanjun Zhang, Guangyu Sun · 发表于：IEEE Transactions on Dielectrics and Electrical Insulation · 年份：2026 · DOI：10.1109/tdei.2026.3691149 · 研究领域：High voltage insulation and dielectric phenomena、Aerogels and thermal insulation、Vacuum and Plasma Arcs

Surface microstructures (Ra), cannot distinguish complex microstructures, potentially resulting in different insulation performances of materials with the same roughness. This study proposes a parameter, the sum of unit-length profile slopes (denoted asRk), which is suitable for characterizing the surface roughness, especially the surface with a structure of regular grooves. Alumina ceramic samples with the sameRaand differentRkare obtained by laser surface grooving, and the effect ofRkon surface insulation performance is studied systematically. It is found that asRkincreased, the surface conductivity showed an upward trend, the surface potential decay of the samples accelerated, the secondary electron yield decreased, and the vacuum flashover voltage increased. Properly adjustingRkcan effectively enhance the strength of the surface insulation of alumina ceramic. The combination ofRaandRkcan serve as a useful tool for the design of surface structures on insulating materials.