Cabbage-like WS2/Ni bilayer thin film for improved tribological property

摘要

A novel approach by texturing the WS2 film with the nanocone-array Ni interlayer was adopted to improve the tribological property of WS2 film particularly prolonging the wear life for application in space. The WS2/Ni bilayer films were prepared by sputtering WS2 layer onto electrodeposited Ni interlayers with different surface morphologies. The micro-structures and the tribological properties of the prepared WS2/Ni bilayer films were investigated. The results showed that with the existence of the nanocone-array Ni interlayer, the textured WS2 film showed a cabbage-like structure due to the growth of the WS2 columnar plates surrounding the Ni nano cones. The cabbage-like WS2/Ni bilayer thin film was benefited for improving the lubrication properties with a long wear life of 4.9 x 10(5) cycles while the wear life was only 0.7 x 10(5) cycles for the pure WS2 and 3.2 x 10(5) cycles for rough Ni textured WS2 film. The improved tribological property was mainly attributed to the reserve of the WS2 lubricate by the Ni nanocones as well as the relative low friction coefficient of the nanocone-array Ni interlayer due to the obvious reduced real contact area.