Mechanical and thermal properties of graphene-carbon nanotube-reinforced metal matrix composites: A molecular dynamics study

Single layer graphene sheets and carbon nanotubes have resulted in the development of new materials for a variety of applications. Though there are a large number of experimental and numerical studies related to these nanofillers, still there is a lack of understanding of the effect of geometrical characteristics of these nanofillers on their mechanical properties. In this study, molecular dynamics simulation has been used to assess this issue. Two different computational models, single layer graphene sheets-copper and carbon nanotube-copper composites have been examined to study the effect of nanofiller geometry on Young's modulus and thermal conductivity of these nanocomposites. Effect of increase in temperature on Young's modulus has also been predicted using molecular dynamics. The effect of nanofiller volume fraction (V-f) on Young's modulus and thermal conductivity has also been studied. Results of thermal conductivity obtained using molecular dynamics have been compared with theoretical models. Results show that with increase in V-f the Young's modulus as well as thermal conductivity of single layer graphene sheets-Cu composites increases at a faster rate than that for carbon nanotube-Cu composite. For the same V-f, the Young's modulus of single layer graphene sheets-Cu composite is higher than carbon nanotube-Cu composite.