Study on the influence of kerosene content on burn in high speed–wire cut electrical discharge machining dielectric fluid

Abstract

The vaporization of dielectric fluid between electrodes is very significant in high speed–wire cut electrical discharge machining (HS-WEDM) under high-energy conditions. Inter-polar corrosion products cannot be expelled in time, resulting in serious burn on the surface of the workpiece. To solve this problem, a certain proportion of kerosene is added to the dielectric fluid. The heat absorbed by kerosene chemical decomposition can effectively reduce the gasification of inter-electrode dielectric fluid. This ensures that there is sufficient dielectric fluid between the poles, and guarantees that the corrosion products produced between electrodes can be expelled in time, reducing the burn on the workpiece surface. Through theoretical calculation and comparative analysis, it is concluded that the heat absorbed by kerosene chemical decomposition is 24 to 211 times that absorbed by dielectric fluid gasification under the same volume condition. In this research, two cooling modes, kerosene chemical decomposition endothermic cooling and physical gasification endothermic cooling, are proposed. The important role of chemical decomposition endothermic cooling in inter-pole cooling is proved. The optimum proportion of kerosene in dielectric fluid is about 1%, as determined by experimentation. When the kerosene content exceeds 1%, carbon deposition will occur. When the kerosene content is around 1%, the cutting efficiency is 23% higher than that when kerosene is not added, and the burn area of the workpiece surface is reduced by 91%.