Spark Plasma Sintering of Magnesium Matrix Composites

Abstract

Magnesium (Mg) is widely used as a structural material due to its low density (1.74 g/cm3), high specific strength and good machinability. Due to these intrinsic properties, magnesium is being used in aerospace and automobile industries as a replacement of steel and aluminum. Moreover, it is also used as a replacement of plastics in electronics and computer industries. However, Mg shows poor wear resistance. In this thesis, efforts are directed towards synthesizing high strength magnesium matrix composites having excellent wear resistance. In this work, graphene platelets (GPL) and nano SiC reinforced Mg matrix composites were synthesized using spark plasma sintering (SPS) technique. SPS is a novel nanoprocessing method where uniaxial pressure and pulse direct current are applied simultaneously to consolidate powders. Mg-GPL matrix composites exhibited improved hardness and ductility. In Mg-nano SiC composites, significant improvement of hardness and ultimate compressive strength was observed. GPL and nano-SiC particles also resulted in substantial improvement in tribological properties due to the lubrication effect of GPL and the defensive mechanism by hard nano-SiC particles.