Synthesis and characterisation of sputtered hard coatings of Cr–N/MoS_x

Abstract

For protective coatings to be applied to engine components, a combination of high wear resistance with low friction is needful to increase performance and lifetime. Auspicious candidates have to conjoin the properties of a conventional hard coating with the low friction coefficient of a solid lubricant.

This study reports about thin films synthesised by reactive magnetron sputtering of a Cr target with 25 area-%MoS₂ inlays. Nitrogen at different partial pressures was used as reactive gas. The chemical composition and microstructure were analysed by electron probe microanalysis, X-ray diffractometry and X-ray photoelectron spectroscopy. Residual stress was determined with the substrate curvature method and the mechanical properties were investigated by microindentation. To examine the tribological behaviour, ball on disc tests were performed at room temperature. The desired low friction behaviour could not be observed due to an insufficient content and lack of crystalline structure of the MoS₂ phase in the coatings.

Keywords:

• SPUTTERING
• HARD COATINGS
• MOLYBDENUM DISULFIDE
• CHROMIUM NITRIDE
• NANOCOMPOSITE