Effect of physio-chemically functionalized graphene nanoplatelet reinforcement on tensile properties of aluminum nanocomposite synthesized via spark plasma sintering

Abstract

The present study aims to understand the effect of physio-chemically functionalized graphene nanoplatelet (GNP) reinforcement on tensile properties of aluminum nanocomposite synthesized via spark plasma sintering (SPS). Aluminum matrix was reinforced with different weight percentage of functionalized GNPs (0.25, 0.5 and 1.0 wt%). The novel GNP dispersion technique, i.e. the physio-chemical functionalization of GNPs along with improvised Al powder – GNP particle mixing method resulted in homogeneous distribution of GNPs throughout the Al matrix. The optimization of SPS parameters assisted in achieving a very good densification (up to 99%) in the nanocomposite. Tensile test revealed 98% increment in yield strength of Al-0.5 wt% GNP nanocomposite. Further increase in GNP content (1.0 wt%) resulted in deterioration in the tensile properties attributed to agglomeration of GNPs in the Al matrix. A theoretical prediction of the yield strength of the Al-GNP nanocomposites was carried out considering the various strengthening mechanisms. Fractographs of pure Al and Al-GNP nano composites indicate change of fracture mode from ductile to brittle with increase in the GNP amount.