Investigation on characterization and machinability of Al-4032/SiC metal matrix composite

Abstract

The Aluminium based metal matrix composites (AMCs) are quite popular for their superior mechanical properties, lightweight, and enhanced corrosion resistance. An increase in the reinforcement fraction enhances the mechanical properties of the base alloy but badly disturbs the ductility. The stir casting method has been employed for the fabrication of SiC reinforced aluminum metal matrix composite (MMC). Optical micrographs (OM) and scanning electron microscopy (SEM) with energy dispersive x-ray analysis (EDAX) have been used for analysis of the composite microstructure, surface topography, and fracture behavior. Also, mechanical (tensile strength, micro-hardness, impact strength) characterization of the fabricated AMC has been attempted. The MMC has been machined with various combinations of machining parameters making use of a carbide cutter. The surface roughness (Ra value) has been measured to evaluate the surface quality. Response surface methodology (RSM) has been applied for optimizing the surface finish. The occurrence of hard reinforcement in base Al-alloy makes the MMC difficult to machine. But machining turns relatively easier at high cutting speed and low feed rate, causing improved surface finish. The best surface finish (Ra = 1.145 μm) was achieved at 0.066 feed rate (mm/tooth), 157 cutting speed (m/min), and 0.528 depth of cut (mm).