Laser Surface Modification (LSM) of Carbon Nanotube (CNT) Reinforced Al-Si Coatings Deposited on to an AA7075 Alloy Substrate

Al-Si coatings have been widely used for their low density and high strength-to-weight ratio in automobile industries; however, poor tribological such as low wear limits their applications. The development of surface modified Al-Si coatings to enhance the tribological properties is essential and so herein is presented an investigation of the effect of laser parameters on the wear performance of Al-Si-carbon nanotube (CNT) coatings deposited on AA7075 alloy substrates. Al-Si-CNT coatings were deposited on the AA7075 substrate using atmospheric plasma spraying (APS) and then subject the laser surface modification (LSM) with a nanosecond pulsed fibre laser. Wear tests were carried out under dry conditions to evaluate wear rate and coefficient of friction (COF). The laser operating parameters like laser power, scanning speed and line spacing were optimized using multi-objective optimization to achieve minimum wear rate and COF.