Correlation between the Surface Properties and the BreakdownPhenomena of Alumina Ceramics

本项目旨在确定绝缘子表面特性， 在微观层面上，控制着电子倍增 在电激励下导致表面击穿的过程。 单晶（无缺陷）的表面性质和 多晶氧化铝（99.9%Al2O3）将系统地 改变 通过机械、热和化学处理。 不同 治疗的目的是改变，在一个故意和控制 的方式，如表面的物理和化学性质， 微损伤，残余应力，表面介电常数， 氧化态、表面电位和局域化的密度 带隙中的（缺陷）能级。 第一阶段包括三个 小节：（a）机械处理，（B）热处理，以及 (c)表面退火。 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的综合研究 现象，具有很高的科学含量。 的 计划材料变量基于前期工作， 预计将产生重大成果。 研究结果可 可用于电气设备和电子工业。 他们 应该扩展对表面放电过程的理解，而不是 不仅用于真空间隙，而且用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.