Investigation of wear and corrosion behavior of graphene nanoplatelet-coated B4C reinforced Al-Si matrix semi-ceramic hybrid composites

The present study aims to produce graphene nanoplatelet-coated B4C ceramic particle using semi-powder method and to investigate the effect of graphene nanoplatelets on wear and corrosion performance of Al-Si-based metal matrix hybrid composites. For this purpose, first graphene nanoplatelets at different ratios (0.25, 0.5, and 1 vol.%) were coated to the surfaces of B4C particles and then the Al-Si alloy was infiltrated into the reinforcements by gas pressure infiltration method. The characterization of graphene nanoplatelet-coated B4C powders and its composites was carried out by X-ray diffraction, differential scanning calorimetry, scanning electron microscope, and transmission electron microscope analysis. Tribological properties were investigated by reciprocating ball-on-flat method under three different loads (10-20-40 N) in a dry environment. The corrosion resistance was carried out with Tafel polarization method in 3.5% NaCl solution. Characterization results show that graphene coated on the B4C surface was successfully achieved by semi-powder method. After infiltration process, a new phase formation was not observed, but porosity increased with the increase of graphene content. When the boron carbide surface was coated with 0.5vol.% graphene, it was determined that the specific wear resistance increased by 55% and the corrosion resistance decreased by 12%.