Experimental investigation of the mechanical micro structural and thermal properties of thin CrAIN layers deposited by PVD technique for various aluminum percentages

The thin film of chromium nitride and their derivatives obtained by the filing process physical vapour deposition attract more and more attention from industry given their high resistance to wear. This quality of these coatings may be linked to their good mechanical and tribological properties. Several experimental investigations have led to the development of CrAlN (Chronium Aluminum Nitride) hard coatings by varying the aluminium target bias voltage, in preference to the traditional CrN coating. The present work is based on the investigation of physical and mechanical properties of CrAlN coating deposited on a silicon substrate and the effect of the aluminium proportion on their variation. The results demonstrate that variation in aluminum proportion alters the resulting columnar morphology, porosity and the thermal properties. The correlation between aluminum proportions in CrAlN coatings and his thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by decrease of the stitch parameter dimension. (C) 2009 Elsevier B.V. All rights reserved