Wear and corrosion resistance performance of UHMWPE/GNPs nanocomposite coatings on AA2028 Al alloys

A green and healthy environment with less pollution and a pleasant climate has become a major global interest. However, the environment is currently threatened by several types of automobile pollution. Various international organizations are adopting and enforcing regulatory measures that are getting stricter yearly to minimize automotive emissions. Therefore, steel components in automobiles are being replaced with light metals such as aluminum as a means to minimize emission. Though aluminum's major advantage is its high strength to weight ratio, it does suffer high wear and corrosion in automotive operations. Therefore, the aim of the present research is to synthesize graphene nanoplatelets (GNPs) reinforced Ultra-high molecular weight polyethylene (UHMWPE) nanocomposite coatings on AA2028 Al alloy substrate to provide both wear and corrosion protection. To achieve uniform nanocomposite coating, GNPs and UHMWPE were solution mixed and deposited using the electrostatic spray method. The results showed that UHMWPE/ 1 wt. % GNPs coating performed best in terms of friction and wear rate reduction while UHMWPE/ 2 wt. % GNPs coating provided the highest corrosion resistant performance in 3.5 % NaCl solution. UHMWPE/ 1 wt. % GNPs coating was further tested at higher speeds to establish the pressure and velocity limit of the coating.