Comparison between different methods for experimental analysis of surface integrity in die-sinking electro-discharge machining processes

摘要

Advanced manufacturing techniques such as die-sinking electro-discharge machining have been introduced in different industries such as the naval, automotive and product manufacturing. The surface finish of the parts subjected to these processes is influenced by diverse factors related to geometrical parameters, electric circuit, lubrication system and materials. For that reason, this work is focused on the analysis of the surface morphology of machined part that can be achieved by electro-discharge machining, as a function of some of the main process parameters such as the current intensity and penetration depth. In this work, three different methods for experimental analysis of surface quality, based on the measuring of surface roughness, material profile ratio and crater diameter, were applied and compared. The experimental phase included tests with copper tools on AISI 316 stainless steel workpieces. The surface roughness and accumulated material profile were recorded using measurements made with a profilometer, and for the purpose of measuring the diameter of the craters, scanning electron microscopy technology was used. According to the results, crater diameter can be adopted as a better indicator to characterize the surface quality in electro-discharge machining, because it exhibits a clearer tendency as a function of current intensity and penetration depth.