Investigation of the Machinability of SiC Reinforced MMC materials produced by Molten Metal Stirring and Conventional Casting Technique in Die-Sinking Electrical Discharge Machine

Abstract In this study, MMC materials were produced by stir casting method using AA7075 alloy matrix and silicon carbide (SiC) as reinforcement elements in order to investigate the effect of die-sinking electric discharge machining (EDM) process parameters for various weight percentage reinforcement (10% 14% and 18%) used MMC. EDM with three different pulse-on time (Time on) (25, 50 &75 µs) and discharge current value (2, 4 & 6 Amperes) and at constant dwell time (20 µs) and depth of cut (0.5 mm). After machining process, the effects of process parameters on processing time, average surface roughness, hole diameter and the weight loss were investigated. As a result of the study, highest values, the lowest values of processing time, hole diameter and average surface roughness were obtained for various weight percentage reinforcement MMC respectively. Ideal MMC, discharge current value and time-on duration for average surface roughness, hole diameter, processing time and material wear loss according to signal to noise ratio were determined. According to ANOVA results, R2 values for the average surface roughness, hole diameter, processing time and material wear loss were calculated as 89.55%, 98.46%, 89.85% and 24.06% respectively.