Influence of Processes Parameter on the Machinability of Wire Electrical Discharge Machining for Tool Steel Grade JIS SKD 11

Wire electrical discharge machining is a modern manufacturing process that is widely used on difficult-to-cut materials with a controlled discharge current in order to erode a conductive workpiece. An adjustment of the controlled parameters can possibly effect the machinability of the machining process. Therefore, this study aims to investigate the influence of controlled parameters on the machinability of wire electrical discharge machining for cutting JIS SKD11 grade tool steel. The controlled parameters consist of feed rate and pulse duty factor. The machinability was evaluated in terms of cutting speed and kerf width. In addition the quality of the machined surface was evaluated by arithmetic average roughness. The results showed that cutting speed directly increased with the feed rate for the workpiece at a thickness of 10 mm. However, an approximately 63.50% reduction in the cutting speed was found at the highest feed rate of 5 mm/min and 27.0% for the workpiece thickness at 50 and 25 mm, respectively. The kerf width and surface roughness slightly decreased with the feed rate. The lowest roughness levels were shown at approximately 2.48, 2.40 and 2.46 µm and for the feed rates of 3, 4 and 5 mm/min for the workpiece thickness of 10, 25 and 50 mm, respectively. In addition, the cutting speed, kerf width and roughness of the machined surface increased with the pulse duty factor due to greater duration of pulse on time in the discharge cycle.