Microstructure, Hardness and Machinability Analysis of Gravity Cast AA6061/SiC Composites

In the present work, machinability analysis of AA6061/SiC composites developed using gravity die casting technique. The microstructure of composites and the chip formed are studied using optical and electron microscopes. Brinell hardness measurements were carried out to check the effect of varying SiC particle content for both the composites. The machinability analysis was carried out by varying feed rate, depth of cut and speed for all composites. From optical studies it was confirmed that addition and increase in SiC content led to grain refinement of AA6061 matrix. The hardness of composites was found to higher than that of unreinforced owing to addition of SiC particles. Machinability studies revealed that increase in feed rate, depth of cut and cutting speed led to increase in the tangential force. The increase in tangential force was attributed to increase in chip thickness and width during the machining operation.