Structural, mechanical and tribological properties of AlxCr1-xN coatings

Abstract

The aim of this study was to check the influence of Al content into CrN films on their properties. CrAlN films were deposited by reactive magnetron sputtering using chromium and aluminum pure targets. The atomic content of aluminum in CrAlN films was varied from 0 to 51 at. %. It was found that the addition of Al improved the stoichiometry and the structural properties of the films. Indeed, CrAlN morphology was changed from amorphous to columnar structure. The CrAlN films present compressive residual stresses from -1.1 to -3.58 GPa. The maximum value of stress was obtained at 30 at.% of aluminum content in the films. The coatings showed a high hardness and Young's modulus, which varied between 15-36 GPA and 331-520 GPa respectively. The friction coefficient of the CrAlN films varied from 0.55 to 0.7. All the CrAlN films showed a high friction and a high wear resistance as we observed parts of the pin-on-disk ball on their surface.