As the widely implemented electrode material, graphite has the characteristic of sublimation by the thermal shock of the switching arc, and the produced carbon vapor is easy to condense into carbon powders and deposit in the switch. The impact of the type of dilution gas in a mixture of 20% oxygen and 80% dilution gas on the sublimation and oxidation characteristics of the graphite electrode is investigated. It is found that when nitrogen dilution gas was replaced by argon, the heat flux to the electrodes decreased, which led to a 63% reduction of graphite sublimation. At the same time, the cooling rate of the arc was slower in argon, which promotes oxidation of the carbon vapor. The residual solid carbon can be reduced by 70%–85% by using argon as the dilution gas. Consequently, it is demonstrated that the stability and working life of the switch could be increased by appropriate selection of the dilution gas.

作为广泛应用的电极材料，石墨具有因开关电弧的热冲击而升华的特性，产生的碳蒸气容易凝结成碳粉并沉积在开关中。研究了在 20% 氧气和 80% 稀释气体的混合物中稀释气体类型对石墨电极升华和氧化特性的影响。结果表明，当用氩气代替氮气稀释气体时，电极的热通量降低，导致石墨升华减少 63%。同时，氩气中电弧的冷却速度较慢，促进了碳蒸气的氧化。使用氩气作为稀释气体可以减少 70%–85% 的残留固体碳。最后，