Surface microanalytical study on the tribological interface between the sputtered fluoropolymer film and a sliding ball

Abstract

The degradation mechanism of high-performance, lubricating sputtered fluoropolymer films rubbed with a stainless-steel ball is investigated using surface analytical methods such as micro-X-ray-photoelectron spectroscopy, micro-Auger-electron spectroscopy, micro-Fourier-transform-infrared spectroscopy, and laser Raman spectroscopy. The perfluorocarbon groups in the sputtered film are increased by introducing oxygen into the plasma. This technique lowers the friction coefficient of the lubricating characteristics. The film is decomposed into amorphous carbon and poorly fluorinated carbon, producing the C■C-rich wear particles. After the decomposed film is worn from the trace, abrasion between the film substrate metals and the sliding ball occurs, and the interface loses its lubricative characteristics owing to the adhesion of the fresh metals. These fresh metals react with the reactive carbon, which is a result of the mechanochemical decomposition of the film, and are oxidized in air.