Microstructure and Friction Wear Performance of a Laser Thermal Sprayed Cu–10Al Alloy Coating Under Oil Lubricated Condition
L–F. Shao, X-Y. Shao and D-J. Kong
A Cu–10Al coating was fabricated on Q235 steel using laser thermal spraying (LTS). The surface morphologies, phases, chemical composition and surface roughness of the resulting coating were analysed using a scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X–ray diffraction (XRD) and an atomic force microscope (AFM), respectively. The friction wear performances under the different loads and speeds were investigated to analyse the wear mechanisms. The results show that the Cu–10Al coating is mainly composed of hard phase Cu9Al4 and phase Cu0.78Al0.22, which is metallurgically bonded with the substrate. The average coefficient of friction (COF) of the Cu–10 Al coating under the wear loads of 1, 2 and 3 N are 0.122, 0.164 and 0.173, respectively, the wear mechanism is scratch wear and abrasive wear. The COFs of Cu–10 Al coating at the wear speeds of 5.0, 6.7 and 8.3 Hz are 0.132, 0.153 and 0.114, respectively, the wear mechanism at 5 Hz is abrasive wear, while those at 6.7 and 8.3 Hz are accompanied by adhesive wear.
Keywords: Fibre-coupled laser, Q235 steel, Cu–10Al, laser thermal spraying (LTS), coating, remanufacturing, microstructure, wear load, friction speed, coefficient of friction (COF), wear mechanism