With the development of MEMS, the machining demand and requirements for difficult-to-machine metal micro parts are getting higher. Microelectric discharge machining is an effective method to process difficult-to-machine metals. However, the recast layer caused by high temperatures in microelectric discharge machining affects the properties of machined materials. Here, we propose the wire electrochemical discharge micro-machining (WECDMM) and develop a new electrolyte system, which removes the recast layer. In this study, the mechanism of WECDMM was elucidated. The electrolyte was optimized through a comparison experiment, and NaNO3-glycol solution was determined as the best electrolyte. The influences of key process parameters including the conductivity of the electrolyte, pulse voltage, pulse-on time and wire feed rate were analyzed on the slit width, standard deviation, the radius of fillet at the entrance of the slit and roughness. Typical microstructures were machined, which verified the machining ability of WECDMM.
Keywords: discharge; electrochemical; micro hybrid machining; wire electrochemical discharge machining.