Investigation on the migration of material from tool to workpiece in micro-EDM drilling

Electrical Discharge Machining (EDM) is a contactless process used to remove material by means of the erosion effect of electrical discharges of short duration occurring between the tool electrode and the workpiece. During the removal process, particles of the tool material migrates to the workpiece surfaces and vice versa, causing contamination. This phenomenon can result in modification of the physical and mechanical properties of the workpiece surface. Aim of this work is to study the migration of material from the tool to the workpiece surface during the execution of micro holes using micro-EDM technology. In particular, different conditions in terms of workpiece and electrode materials were taken into account: stainless steel and titanium for the workpiece, brass and tungsten carbide for the electrode.