Microstructure,Friction and Wear Characteristics of Brush-Plated n-Al_2O_3/Ni-P Composite Coating

Comparing with nickel-phosphorous alloy coating the microstructure, friction and wear characteristics of brush-plated nickel–phosphorous composite coatings containing nano alumina particles(n-Al2O3/Ni-P) were studied. The results showed that the composite coating has much lower surface roughness and clear tendency of refinement in microstructure. The hardness of composite coating reached maximum, about 1.3 times that of Ni-P coating, when the content of n-Al2O3 was up to 20 g/L. The wear resistance of composite coating with 20 g/L n-Al2O3 particles in brush-plating solution was also excellent, its weight loss was reduced 60 % compared with Ni-P coating.