EFFECT OF POURING TEMPERATURE AND STIRRING SPEED ON MECHANICAL, MICROSTRUCTURE AND MACHINING PROPERTIES OF AL6061-CU REINFORCED SICP METAL MATRIX COMPOSITES

Abstract

The major challenges in the fabrication of MMC are the difficulties of achieving uniform distribution of reinforcing material and possible chemical reactions between reinforcement material and matrix. Therefore, the present research was conducted to investigate the effect of stirring speed and pouring temperature on mechanical, microstructure and machining properties of Al6061-Cu reinforced SiC MMC by stir casting technique. The dependent variables are hardness, impact strength and metal removal rate of MMC by electro-discharge machining while the independent parameters are five levels of stirring speed and five levels of pouring temperature. It is observed from experimentation that with the 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.