Effects of n-Al2O3 Particles Content on Structure and Performance of Electro-Brush Plating Ni-Co Alloy Composite Coatings

The composite electronic brush plating technique was used to prepare alloy nanocomposite coatings with different nano-Al2O3 particles contents. The effects of nanoparticles content in the electrolyte on the deposition rate, nanoparticles content in coating, microhardness and tribological property of composite coatings were investigated by scanning electron microscopy, microhardness tester and attrition testing machine. It is found that with the increase of nano-Al2O3 particles content in the electrolyte, the deposition rate of coatings drops, the surface morphology of the coating becomes flat, the microhardness first increases and then decreases, and wear scar depth and friction coefficient decrease first and then increase. When the nano-Al2O3 particles concentration in the electrolyte is 20 g/L, the coating reaches its optimized structure and performance.