Tribological behavior of ZrO2/WS2 coating surfaces with biomimetic shark-skin structure

This study demonstrated the dry friction and wear behavior of sol-gel ZrO 2 /WS 2 coatings with biomimetic shark-skin textured surfaces. The effect of added WS 2 on the microstructure and mechanical properties of ZrO 2 coatings was examined and the dry sliding wear and friction behaviors against commercial AISI1045 steel balls were investigated. After adding WS 2 , the micro hardness of ZrO 2 coating decreased by ~39% (from 23.7 GPa to 14.5 GPa), and the average steady state friction coefficient was decreased from ~0.43 to ~ 0.2. When the ZrO 2 /WS 2 coating surface was textured biomimetic shark skin, nearly 66% decrease of the average steady state friction coefficient and 82% decrease of ball wear rate were obtained as compared with the pure ZrO 2 coatings. The possible frictional mechanism of the biomimetic shark-skin structures was discussed.