Aluminum silicon carbide Metal Matrix Composites (Al-MMCs) are widely used in aeronautical and automobile industries due to their excellent mechanical and physical properties. However, machining these composites is difficult because of the harder reinforcement particles. Tools wear more quickly, thereby reducing their life. This paper presents an experimental investigation on turning A356 matrix metal reinforced with 10% by weight of Silicon Carbide particles (SiCp) , fabricated in-house by stir casting method. Fabricated samples are turned on medium duty lathe with Poly Crystalline Diamond (PCD) insert of 1500 grade at various cutting conditions. Parameters such as power consumed by main spindle, machined surface roughness and tool wear are studied. Scanning Electron Microscope (SEM) images support the result. It is evident that surface finish is good at higher cutting speed and tool wear is strongly dependent on abrasive hard reinforcement particles.

Metal Matrix Composites (MMCs) have found considerable applications in aerospace, automotive and electronic industries (Tomac and Tonnessen, 1992; and Kunz and Bampton, 2001) because of their improved strength, stiffness and increased wear resistance over unreinforced alloys (Weinert, 1993). However, the final conversion of these composites into engineering products is always associated with machining, either by turning or by milling. A continuing problem with MMCs is that they are difficult to machine due to the hardness and abrasive nature of the reinforcing particles (Weinert, 1993; and Joshi et al. 1999). The particles used in MMCs are harder than most of the cutting tool materials. Most of the researchers reported that diamond is the most preferred tool material for machining MMCs (Lane, 1992; Manna and Bhattacharyya, 2000; Paulo and Montiro, 2000; Pramanik et al., 2006; and Muthukrishnan and Paulo, 2008 and 2009). Most of the research on machining MMCs is concentrated mainly on the study of cutting tool wear and wear mechanism (Tomac and Tonnessen, 1992; and Weinert, 1993). Heat (1991) investigated the performance of Polycrystalline Diamond (PCD) in machining MMCs containing aluminum oxide fiber reinforcement. The author compared the tool life of cemented carbide with PCD and concluded that sub-surface damage is greater in the case of cemented carbide, compared to PCD tools.

Lane (1992) studied the performance of different PCD tools grain size. He reported that PCD tools with a grain size of 25 mm better withstand abrasion wear than tools with grain size 10 mm. He also reported that further increases in the grain size do not have any influence on the tool life but cause significant deterioration in the surface roughness.

Mechanical Engineering Journal, Performance Evaluation of PCD 1500 Grade, Aluminum Silicon Carbide Metal Matrix Composites, Aeronautical and Automobile Industries, Scanning Electron Microscope, Engineering Products, Polycrystalline Diamond, Analysis of Variance, ANOVA, Constant Parameter, Optimal Machining Parameters.