Microsliding wear behaviour of HVOF sprayed conventional and nanostructured WC–12Cocoatings at elevated temperatures

Conventional and nanostructured WC–12Co coatings were deposited on 1Cr18Ni9Ti substrateusing high velocity oxy-fuel spraying. The surface roughness and microhardness of as sprayedcoatings were measured, while the phase compositions and microstructures of WC–12Cofeedstock powders and corresponding coatings were respectively analysed by means of X-raydiffraction and scanning electron microscopy. Moreover, the microsliding wear behaviour of bothcoatings sliding against Si3N4 ball from room temperature to 500uC was evaluated underunlubricated condition with an oscillating SRV tribotester. Results reveal that nanostructured WC–12Co coating not only had better wear-resistance than the conventional WC–12Co coating butalso led to reduced wear of the Si3N4 counterpart under the same test condition, which could beattributed to the fine microstructure and improved mechanical properties of the nanostructuredcoating. The detailed wear mechanisms for both coatings have also been discussed.