Investigation the Machinability of Al-15%SiC Composite Produced by Powder Extrusion

Metal matrix composites (MMCs) have received considerable attention due to their excellent engineering properties, however, poor machinability has been the main deterrent to their substitution for metal parts. The hardness and abrasive nature of reinforcement phase causes rapid tool wear during machining and consequently, high machining costs. This paper discusses the experimental investigation on the machinability of Al-15%SiC particulate metal matrix composite produced by powder metallurgical process. Continuous dry turning of round composite bars using titanium carbide inserts has been selected as the test method. The influence of machining parameters, e.g. cutting speed, feed rate and depth of cut on the tool wear, cutting forces and finished surface criteria were investigated during the experiments and compared with similar works. The results show that the cutting speed and depth of cut are more dominant factors on machinability than feed rate. Tool wear, surface roughness & machining force, in machining of MMCs produced by powder extrusion are higher than those in machining of similar \ MMCs produced by casting process. The optimum condition for the tool wear, cutting force and surface finish criteria can be achieved by low values of feed rate and depth of cut and moderate values of cutting speed.