Machinability of Al-4%wt Mg-Al2O3-Graphite Composites Produced by Compo-Casting Technique

Aluminium-4%wt Magnesium-Alumina-Graphite particulate metal matrix composites, with different percentage weights of alumina and graphite particles, were produced by the process of compo-casting. The method of casting has been briefly described in the present study. The magnesium was added to the aluminium as wetting agent to enhance the bond between the matrix (aluminium) and the reinforcement particles (alumina and graphite). Machinability of the considered composites was indicated by the values of the drilling thrust forces and torques, using a moderate speed drilling machine. The cutting tools were made of high speed steel, while the other cutting parameters were held constant during the drilling process. The results showed that the change in the volume percentage of both alumina and graphite particles have remarkable effect on the measured drilling thrust forces and torques, which in turn affect the machinability of the studied particulate metal matrix composites.