Effect of Casting Process Parameters of Al6061-Cu- SiCp metal matrix Composite on Material Removal Rate by Electrical Discharge Machining

Abstract

Instead of lots of developments in ceramic metal matrix composites field still its uses are restricted due to the high cost of production and difficult to machine with traditional machining processes. In present experimentation an attempt is made to find the parameters which affect the material removal rate of metal matrix composite casting through Electric Discharge Machining (EDM). The effect of stirring speed and pouring temperature on mechanical, microstructure and machining properties of Al6061-Cu reinforced SiC MMC by stir casting technique were under investigation. The input parameters are five level of stirring speed viz. 50 rpm, 200rpm, 400 rpm, 600 rpm and 800rpm and five level of pouring temperature are 675 o C, 700 o C, 725 o C, 750 o C and 775 o C. The dependent variables are hardness, impact strength and metal removal rate of MMC by electro-discharge machining while the independent parameters are five level of stirring speed and five level of pouring temperature. It is observed from experimentation that with increase in stirring speed increases the impact strength and hardness of MMC up to a certain limit after that these properties decrease drastically. The optimal value of hardness and impact strength for MMC is obtained at pouring temperature of 725˚C and 400 rpm and impact strength of MMC are least at 800 rpm and 775˚C and followed by 50 rpm and 675˚C. It is observed from an SEM study that at stirring speed 400 rpm better homogeneity can be obtained compared to 200 and 600 rpm.