Wear resistance of electroless deposited Ni–P and Ni–P/SiC composite coatings on low alloy cast iron

Abstract

Nickel–phosphorus alloy and Ni–P/SiC composite coatings were prepared on low alloy cast iron surfaces using the electroless deposition method. The wear properties of both coatings were evaluated and compared with those of cast iron, phosphate coating, and chromium plating. The results indicate that the electroless deposited Ni–7·0 wt-%P coating is a supersaturated solid solution, and the Ni₃ P phase can be precipitated when heat treated at a temperature of 350°C, which increases the hardness. However, when the heat treatment temperature is higher than 400°C the hardness decreases rapidly, but the wear volume still decreases continuously. Not only is the hardness of the Ni–P/SiC composite coating high, but its wear resistance is better than that of the Ni–P coating, chromium plating, cast iron substrate, and the phosphatising coating. Under the given experimental conditions, the wear volume of the Ni–P/SiC composite coating is the lowest.