Ablation characteristics is a key factor in the surface flashover of insulation materials for vacuum insulators. The influence of nano/micro Al2O3 and Al(OH)3 fillers on the ablative resistance of epoxy vacuum insulation material has been investigated by repeated flashovers in vacuum under microsecond pulses. It was found that the ablative resistance of Al(OH)3 filler is much better than that of Al2O3 and that the nano-filler is more effective than the micro-filler in the case of Al(OH)3, whereas in Al2O3 the opposite applies. A thermal-electrical coupled 3-dimensional finite element simulation model has been developed to describe the results and analyze them in terms of the thermal characteristics of the particles. The model shows that although both Al2O3 and Al(OH)3 fillers can improve the ablative resistance of the epoxy composites, with Al(OH)3 being the better material. The mechanism whereby this occurs is different in the two cases, with the dehydration reaction dominating for Al(OH)3 and the mass degradation dominating for Al2O3.

中文翻译：

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真空绝缘子用纳米/微米填料环氧复合材料耐烧蚀性能研究


烧蚀特性是真空绝缘子绝缘材料表面闪络的关键因素。通过微秒脉冲下真空中反复闪络研究了纳米/微米Al2O3和Al(OH)3填料对环氧真空绝缘材料耐烧蚀性能的影响。结果发现，Al(OH)3 填料的耐烧蚀性比 Al2O3 好得多，并且在 Al(OH)3 的情况下，纳米填料比微米填料更有效，而在 Al2O3 中则相反适用。我们开发了热电耦合三维有限元模拟模型来描述结果并根据颗粒的热特性对其进行分析。模型表明，虽然Al2O3和Al(OH)3填料都能提高环氧复合材料的耐烧蚀性能，但其中Al(OH)3是更好的材料。这两种情况发生的机制不同，对于 Al(OH)3 来说，脱水反应占主导地位，而对于 Al2O3 来说，质量降解占主导地位。