Effects of hole taper on high speed steel workpiece using EDM injection flushing

Abstract

Electrical Discharge Machining (EDM) is a controlled metal-removal process used to remove metal by means of electrical spark erosion. The objective of this paper is to determine the effects of injection flushing on the angle taper of a workpiece. One of the most important factors in a successful EDM operation is the removal particles from the working gap. Flushing these particles out of the gap between the workpiece and electrode are very important to prevent them from forming bridges that cause short circuits. Secondary discharge occurs easily on the hole’s side wall workpiece when using injection flushing. The secondary discharge will cause the hole taper because of small diameter hole and depth of machining. This study develops the EDM injection flushing on the hole taper of high speed steel (HSS) M35. Machining parameters are constant while the pressure flushing varies from 0.03 MPa to 0.15 MPa. Copper electrode with kerosene dielectric fluid was used to machine the high speed steel M35. The effects of hole taper by using injection flushing was being analyzed and discussed. Injection flushing pressure found at most 0° angle of taper occurs between 0.07 MPa.