Study of ultrasonic assisted cryogenically cooled EDM process using sintered (Cu-TiC) tooltip

In most EDM operations, the maximum contribution in the total operation cost is the tool cost. Electrode wear is a major problem in EDM process. Therefore, in this paper, the process performance of sintered copper (Cu)-titanium carbide (TiC) electrode tip in ultrasonic assisted cryogenically cooled electrical discharge machining (UACEDM) has been studied. The performance parameters studied in this paper are electrode wear ratio (EWR), material removal rate (MRR), surface roughness (SR), out of roundness and surface integrity. The process parameters considered in this study are discharge current, pulse on time, duty cycle and gap voltage. Cermet was fabricated, having copper content of 75% and titanium carbide content of 25%, by mixing, pressing, and sintering. The performance of the newly formed cermet electrode tip is compared with conventional copper electrode tip for UACEDM process and analyzed. It has been observed that EWR and out of roundness decreases when cermet electrode tip is used as compared to conventional tooltip. It has also been observed that MRR and SR increase when cermet tooltip is used. The surface cracks density and crack width on workpiece machined by cermet tooltip have been found to be lesser as compared to the specimen machined by conventional tooltip. (c) 2012 The Society of Manufacturing Engineers. Published by Elsevier Ltd. All rights reserved.