Surface finishing of micropins produced by WEDG

This paper presents a new method of surface finishing for micropin products. Precision micropins thinner than phi 100 mu m can be produced by WEDG (wire electrodischarge grinding). However, the surface quality of the products is not sufficient for applications that require mirrorlike surface and/or a surface without a heat-affected zone. A succession of two processes, WEDG and lapping, is proposed and tested for its feasibility. In order to ensure the control of the lapping conditions, micropins were WEDGed and lapped on the same machine. The wire electrode for WEDG was used as the lapping tool. A smooth, craterless surface with Ra= 18 nm was achieved.