Enhancement of Mechanical Properties of Graphite Particulate Aluminum Metal Matrix Composites by Magnesium Addition

In the present work, effect of 1% Magnesium (Mg) addition on Graphite (Gr) particulate Aluminum metal matrix composites (AMMCs) has been studied. Achieving good wettability and uniform distribution of particles in the metal matrix are major challenges for the fabrication of metal matrix composites and this problem can be overcome by two step-mixing stir casting method. Literature suggests that Mg is a strong surface agent which removes oxygen from the dispersoids surface so gas layers (which are responsible for the poor wettability) will be reduced hence wettability between the reinforcement particles and metal melt will be improved. So to obtain good wettability of solid particles with Aluminum (Al) melt 1% Mg was added in the Gr particles. AMMCs were prepared by varying Gr content as 2, 4 and 6 weight percentage of Al with and without addition of Mg. By comparing both of the composites, it was observed that Gr-1 wt.% Mg admixture reinforced composites have better mechanical properties, better conductivity and better thermal stability than the unreinforced Mg composites and best results were obtained for 4 wt% of Gr-1 wt.% Mg admixture composite. (C) 2017 Elsevier Ltd. All rights reserved.