Nanoindentation and nanoscratch investigations on graphene-based nanocomposites

The effect of graphene nano-platelets (GNPs) on mechanical properties of polymer nanocomposites were investigated using nanoindentation and nanoscratch methods. The GNPs at different weight fractions namely 0, 0.05, 0.1, 0.25 and 0.5% were dispersed in the polymer matrix using a mechanical stirrer and ultrasonic apparatus. A standard Berkovich indenter was used for indentation at three different normal loads, i.e., 400, 600 and 800 μN. Both elastic modulus and hardness increased with the addition of 0.05 wt% GNP. The tribological behavior of nanocomposites was investigated by a nanoscratch test in conjunction with atomic force microscopy (AFM); less pile ups and high wear resistance were observed in the nanocomposites. Based on this research, mechanical properties of pure polymer matrix are improved significantly with addition of low amounts of the graphene nano-platelets.