Tailoring of the interface morphology of WS2/CrN bilayered thin film for enhanced tribological property

The WS2/CrN bilayered films with different interface morphologies between WS2 and CrN layer were prepared by physical vapor deposition. By controlling the deposition parameters, the surface of CrN interlayer exhibited compact granular structure when deposited under low partial pressure of Ar while a cone array-like surface appeared under high Ar partial pressure. The surface texture of the CrN interlayer had a great effect on the tribological performance of the WS2/CrN film. The compact CrN textured WS2 film exhibited a wear life about 2.6 × 105 cycles while the optimal cone array-like CrN textured WS2 film showed a much longer wear life reaching to 6.8 × 105 cycles, which was more than 2.6 times of that for compact CrN textured WS2 film and 3.5 times of that for WS2 film without the CrN interlayer. The improved tribological property of the optimal cone array-like CrN textured WS2 film was attributed to the high adhesion between the WS2 layer and the CrN interlayer. Meanwhile, the reservoir and replenishment of the WS2 lubricant by the CrN nanocones during the friction made a significant contribution for the long wear life.