Synergistic effect of r-GO on the mechanical, microstructural and high velocity impact behaviour of synthetic fibre reinforced NiTi intermetallic laminates

In this work, the effect of different concentration (0.5, 1 and 1.5 wt%) of reduced graphene oxide (r-GO) on the mechanical, microstructural and high velocity impact behaviours of novel fibre intermetallic laminates (FIL) made up of Nitinol foils and carbon/aramid fibres were experimentally investigated. The vacuum assisted resin infusion process is employed to fabricate the FILs with alternatively stacked woven fibres. The mechanical and chemical surface treatments were performed to ensure the improved adhesion and interaction between epoxy matrix and nitinol foils. The mechanical properties such as tensile, flexural and high velocity impact strengths were investigated for unreinforced, and r-GO reinforced FILs. Results revealed that the assimilation of r-GO fillers exhibit the capable of improving ultimate tensile strength of 16.5%, ultimate flexural strength of 13.9% and impact strength of 7.62% compared to unreinforced FILs. Improved tensile, flexural and impact strengths were obtained at the concentration of 1wt% r-GO infused FILs. On the contrary, the mechanical properties are deteriorated with further addition of r-GO fillers above the optimum levels. Moreover, the morphologies of surface treated Nitinol foils, nano filled epoxy matrix and the mechanical fractured surfaces were investigated with the aid of SEM to assimilate the failure mechanisms with respect to the inclusion of reduced-graphene oxide.