Preparation, mechanical property and wear resistance of Ni-W/Al2O3 composite coatings

Ni-W/Al(2)O(3) composite coatings were prepared by electrodeposition in Ni-W plating solution containing Al(2)O(3) particulates. The content of codeposited Al(2)O(3) particulates in the composite coatings was controlled by the addition of different Al(2)O(3) concentrations in the solution. The mechanical property and wear resistance of Ni-W/Al(2)O(3) composite coatings and Ni-W alloy coating were comparatively investigated. The results indicated that addition of Al(2)O(3) particulates would lead to an increase in microhardness of the composite coatings. The present study shows that the codeposited Al(2)O(3) particulates in deposit increase the wear resistance and reduce the wear weight loss. Moreover, the wear resistance of Ni-W/Al(2)O(3) composite coatings is closely related with Al(2)O(3) content in deposit. Namely, the composite coating with a lower Al(2)O(3) content of 3.3 wt-% shows somewhat increased wear resistance compared with the Ni-W alloy coating, while the composite coating with a higher Al(2)O(3) content has much better wear resistance than the Ni-W coating.