Study of Surface Properties in Particulate-Reinforced Metal Matrix Composites (MMCs) Using Powder-Mixed Electrical Discharge Machining (EDM)

This article investigates the surface modification of three different types of metal matrix composites (MMCs) 65vol%SiC/A356.2, 10vol%SiC-5vol%quartz/Al, and 30vol%SiC/A359 using powder-mixed electrical discharge machining (PMEDM) process. Microhardness and surface integrity were evaluated after each trial, and contributing process parameters were identified. It was found that microhardness increased primarily with increase in the density of reinforced particles in the matrix. Each workpiece was examined by X-ray diffraction (XRD) followed by scanning electron microscope (SEM) for surface integrity and material deposition. The results show the significant amount of metal transfer from the copper electrode as compared to graphite.