This study focused on optimizing turning process parameters such as spindle speed ,feed rate ,depth of cut and nose radius for performance characteristics, namely, surface roughness and material removal rate during turning of aluminium based MMCs using a coated tungsten carbide tool. Experiments were carried out as per Taguchi's orthogonal L16 array. Taguchi's signal to noise ratio and analysis of variance methods were used to find out the most significant parameter that effects on surface roughness and material removal rate. This work also focuses on the chip formation during the turning of aluminium metal matrix composites and to study the influence of machining conditions and surface roughness on the chip geometry. Based on the experimental results on chip formation mechanism in machining of Al/SiC composites. Statistical analysis was found that coolant, spindle speed, feed rate, depth of cut and nose radius are most significant process parameters.