Microstructure and mechanical properties of graphene-reinforced aluminum-matrix composites

Abstract

Graphene has a high fracture strength, good ductility and low coefficient of thermal expansion, making it an ideal reinforcement for composite materials.This paper reports on an aluminum-matrix composite reinforced with graphene (graphene/Al) using ball milling and hot-press sintering.The effect of the graphene content on the microstructures, mechanical properties and fracture mechanisms of the composites were investigated.It is shown that 0.25 w/% and 0.5 w/% graphene contents modified with copper are homogeneously dispersed into the aluminum matrix.The composite with the 0.5 w/% graphene content exhibits the highest tensile strength and elongation; its improvement over the unreinforced aluminum matrix is 31.0% and 30.6 %, respectively.With the increasing graphene content up to 1.0 w/%, the aggregation of graphene in the composite is apparent, seriously reducing the tensile properties.The fracture mechanism of the composites changes from ductile to brittle.