Investigating the Thermo-Mechanical Properties of Aluminum/Graphene Nano-Platelets Composites Developed by Friction Stir Processing

Ultra-high concentration dispersion of graphene of nano-platelets (GNPs) was incorporated into Aluminum alloy AA5052-H32 using friction stir processing (FSP) to form metal matrix composite (MMC). For this purpose, grooves made in the AA5052-H32 were packed with the graphene nano-platelets and then FSP was applied in two steps; first using pinless tool at constant processing parameters of 1200 rpm and 100 traverse speed, second using conventional tool with pin and shoulder at the same processing parameters of (1200 rpm and 100 mm/min traverse speed). Scanning electron microscopy, Raman spectroscopy and X-ray diffraction analyses were used to examine the GNPs dispersion. The thermo-mechanical properties of the fabricated MMC were studied. Thermal conductivity, micro-hardness, tensile strength and fracture surface were examined before and after FSP. The measured thermal conductivity was improved by about 75% compared to the base metal due to the MMC with GNPs. Meanwhile, the hardness was increased from 67 Hv to 94 Hv and the ultimate tensile strength decreased from 238 to 196 MPa.