Wire electrochemical discharge machining of glass using a surface roughened tool

A new method is proposed to improve the surface integrity and spark discharge distribution of wire electrochemical discharge machining (wire-ECDM) process by roughening the wire tool surface. Limitation of the conventional wire-ECDM processes was the low cutting depth because of the low spark discharge occurrence on the wire surface. Preliminary investigation demonstrated that using the conventional wire with fine surface roughness (R_a=0.14 .m) the machining with 1.1 mm cutting depth was not available because of serious lack of spark distribution around the wire surface. In this paper, wire surface roughening is proposed to enhance spark discharge distribution over the tool surface and lower the working voltage. Side insulation of the wire is also introduced to minimize the reactive wire surface area. Experimental results demonstrate that roughened surface (R_a=1.45 .m) of the wire takes a role of spark discharge location due to the local electric field intensification effects. Using the proposed method precision cutting of glass with 1.1 mm thickness is successfully achieved with high surface integrity.