Effect of wire cathode surface hydrophilia when using a travelling wire in wire electrochemical micro machining

Wire electrochemical micro machining (WEMM) is receiving considerable attention in the production of metal micro structures because it produces smooth, burr-free surfaces without heat damaged layer and the tool is not worn out. As the machining gap is so small in WEMM, the process of mass transport is important, and its consideration becomes necessary when attempting to improve productivity and processing quality. The travelling wire method has been used in previous studies to enhance mass transport in WEMM. However, the ability of the travelling wire was underutilized because wire cathodes with smooth surfaces were used. Tungsten wires with rough surfaces have better hydrophilia than those with smooth surfaces, which is good for enhancing mass transport. In this paper, tungsten wire with a rough surface is prepared using chemical etching, and is adopted as the cathode in cobalt base alloy machining. The influence of the smoothness and hydrophilia of the wire cathode surface on WEMM is discussed theoretically, and the effects on process stability and processing quality are studied experimentally.