METHOD OF SUPER-MIRROR FINISHING WITH ELECTROLYTIC GRINDING FOR INTERNAL SURFACE OF SMALL-DIAMETER TUBE

摘要

The method comprises a. rough grinding process and a mirror grinding process. In the rough grinding process, an electrode tool (14) for rough finishing having non-woven nylon fabric wound around a core electrode (15) is used. Electrolytic grinding is applied to the inner surface of a small-diameter tube (10) with a minute electric current supplied through an electrolytic solution and is continued until the roughness of the inner surface of the tube is lowered to 0.5 micro m Rmax or below while rotating the electrode tool (14) and the tube (10) relatively to each other and reciprocating relatively in the axial direction. In the subsequent mirror grinding process, finishing operation similar to the above operation is repeated with the use of an electrode tool for mirror finishing having urethane material wound around a core electrode. According to this method, the surface roughness of about 3 micro m Rmax i mirror-finished to about several tens of nm Rmax on account of exceedingly effective actions.