Tribological properties of WS2 coatings deposited on textured surfaces by electrohydrodynamic atomization

WS2 coating additive and surface micro texturing were investigated in order to improve the tribological properties of the cemented carbide tool surfaces. Laser surface texturing technology (LST) was employed to fabricate three kinds of textures (dimple array, line array and four-leaf clover array) on cemented carbide surfaces. Characterizations such as micromorphology, surface roughness, wettability of the surfaces with different micro-textures were examined. Electrohydrodynamic atomization technology (EHDA) was used to deposit WS2 coatings on the substrate surfaces. The influence of the atomization parameters (flow rate, operating voltage and atomizing distance) on the characteristics of deposited coatings was examined. Uniform and dense coating, with a thickness of ~20 μm, was produced under the optimized conditions. The friction and wear properties of textured surfaces before and after depositing WS2 coatings were evaluated by reciprocating sliding friction tests. The coating-substrate adhesion was evaluated by scratch tests. The results show that the friction and wear properties would be improved by EHDA deposited WS2 coating or micro-textures, and the samples combined with deposited WS2 coatings and textured surfaces exhibited the best efficiency. Additionally, laser surface micro-texturing can improve the coating-substrate adhesion strength and then prolong the wear life of WS2 coatings.