Correlation between the Surface Properties and the BreakdownPhenomena of Alumina Ceramics

这个项目的目的是在微观层面上确定绝缘子表面的属性，这些属性控制着在电激励下导致表面击穿的电子倍增过程。单晶(无缺陷)和多晶氧化铝(99.9%Al_2O_3)的表面性质将通过机械、热处理和化学处理来系统地改变。不同的处理旨在以有意和可控的方式改变表面的物理和化学性质，例如微损伤、残余应力、表面介电常数、氧化态、表面电位和带隙中的局域(缺陷)能级密度。第一阶段包括三个部分：(A)机械处理、(B)热处理和(C)表面退火热处理。第二阶段将包括(D)化学处理和(E)表面清洁。本项目是对高压闪络现象的综合研究，具有较高的科学含量。计划的材料变量以前期工作为基础，可以预期产生显著的结果。研究结果对电气设备和电子行业有一定的参考价值。他们应该扩展对表面放电过程的理解，不仅对于真空间隙，而且对于一般的气体绝缘问题。

This project aims to identify the insulator surface properties, at the microscopic level, that control the electron multiplication process leading to surface breakdown under electric excitation. The surface properties of single crystal (defect free) and polycrystalline alumina (99.9% Al2O3) will be systematically altered by mechanical, thermal, and chemical treatments. Different treatments are intended to modify, in a deliberate and controlled manner, such surface physical and chemical properties as a microdamage, residual stress, surface dielectric constant, oxidation state, surface potential, and density of localized (defect) levels in the band gap. Phase I consists of three subsections: (a) Mechanical treatment, (b) Thermal treatment, and (c) Surface annealing. Phase II will consist of (d) Chemical treatment, and (e) Surface cleaning. %%%% This project is a comprehensive study of high voltage flashover phenomena, which have high merits in scientific contents. The planned materials variables are based on preliminary work, and can be expected to yield significant results. The results can be useful to the electrical equipment and electronic industries. They should extend the understanding of surface discharge processes, not only for vacuum gaps but also for general gas insulation problems.