Fabrication and heat treatment of graphene nanoplatelets reinforced aluminium nanocomposites

The present work reports fabrication of graphene nanoplatelets (0.1, 0.3 and 0.5 wt%) reinforced aluminium matrix naocomposites through non-contact ultrasonic vibrations assisted stir casting process. Microstructure, tensile strength, microhardness and tribological properties of fabricated samples have been examined. The influence of T6 heat treatment on mechanical properties of developed samples was also investigated. Incorporation of graphene in base matrix resulted in grain refinement and an increase of about 37% in ultimate tensile strength and 27% in micro hardness of cast composites. Strength and grain refining action of graphene was attributed as the reason for increment in mechanical properties. Heat treatment causes further improvement of about 83% and 34% in ultimate tensile strength and microhardness of fabricated composites as compared to heat treated base matrix. The enhancement in properties of heat-treated samples was attributed to age hardening. Addition of self-lubricating graphene in aluminium matrix resulted in improved wear behavior of prepared composites. Reduction of about 24% in coefficient of friction of graphene-aluminium composites as compared to base matrix is reported.