Influence of process parameters and temperature on the solid state fabrication of multilayered graphene-aluminium surface nanocomposites

Abstract

Electrical resistance heat assisted mechanical impregnation of nanomaterials can be effectively utilized as a solid state surface modification technique for soft materials like Aluminium. The quantity of heat generated at the interface and the extent of diffusion of nanomaterials depends on the contact pressure, electrode geometry, magnitude of current and the duration for which the current is applied. In this paper, we evaluate the influence of these process parameters on the mechanical impregnation of graphene on Aluminium substrates. The results are used to explain the experimentally observed microstructural and surface mechanical properties. The measured microhardness variation is in accordance with the temperature at various processing conditions and maximum surface hardness is observed at those conditions where the surface temperature is near the melting point of Aluminium. Influence of temperature on the possible strengthening mechanisms prevailing in Aluminium-graphene composites are elucidated in detail. Raman spectroscopic analysis provides insights into the temperature dependence of the change in intensities and shift in peak positions of respective G, D and 2D bands. X-ray diffraction analysis was carried out and the variation in lattice strain and crystallite size is correlated with the temperature data. The analysis presented herein provides encouraging results for realizing Aluminium-Graphene surface nanocomposites through a highly versatile, rapid and easily automatable solid state processing technique.