On Geometrical Characteristics of WC-Co Round Cavities After ED-Machining with Different Grades of CuW Electrodes

Abstract Cemented carbides (WC-Co) are difficult to be processed by conventional machining processes. Electrical discharge machining (EDM) appears as an efficient technology to manufacture WC-Co products with high accuracy. In EDM literature no research works investigating the influences of different grades of CuW electrodes on geometrical characteristics when ED-machining the same cemented carbide was found. This work presents an investigation on ED-Machining of cemented carbide (WC-Co) with 10% Co using two grades of coper-tungsten (CuW) electrodes with 65% and 85% of tungsten. ED-Machining experiments were carried out under rough, semifinish and finish regimes with input variables discharge current ie, discharge duration te and pulse interval time to using analysis of variance (ANOVA) based on design of experiments with complete factorial 32. Output variables evaluated were WC-Co workpiece geometrical characteristics 3D surface roughness and round cavities circularity measures. Results showed that ED-Machining regime is the most significant parameter on both WC-Co workpiece circularity and surface roughness measures. Electrodes grades CuW65 and CuW85 presented similar results on workpiece circularity and 3D surface roughness.