Evaluating the Effect of Laser Surface Modification on the Corrosion Behavior of Ni-P-SiC Electroless Coating Deposited on Al356 Alloy

Regarding their higher wear/corrosion resistance than conventional coatings, nickelphosphorus based composite coatings can reduce components’ costs and degradation. This study employed laser surface modification of Ni-P-SiC electroless coatings deposited on Al356 substrate, followed by investigating their microstructural changes and corrosion behavior. The results showed that increasing the laser power increases surface defects and causes substrate diffusion to the coating, which significantly reduces the corrosion resistance of the coating. In contrast, low-power laser operations can improve the corrosion resistance of Ni-P-SiC composite coatings by creating stable nickel phosphide phases, more uniform element distribution, and enhanced SiC particle-substrate coherence. All these factors increase the wear and corrosion resistance simultaneously.