Etude des propriétés microstructurales, mécaniques, thermiques et de la porosité des couches minces de CrAlN déposées par PVD sous différents pourcentages d’aluminium

Abstract

Several experimental investigations have led to the development of CrAlN (Chrome Aluminum Nitride) hard coatings by varying the aluminum target bias voltage, in preference to the traditional CrN coating. The present work enabled characterisation by physical and mechanical techniques (XRD, AFM, MEB, nano-indentation, Young’s modulus, thermal propriety, Stress, porosity, etc.). Moreover, in order to find improved the adhesion of the different deposition condition of the coatings. The results obtained in this work demonstrate that variation in proportion to aluminum alter the resulting columnar morphology and porosity of the coatings. The thermal properties and the physical property are greatly affected by these morphological alterations. The comparison between the different coating microstructures of CrAlN coatings (columnar and fine-grained) reveals advantages for the fine-grained structure. The results are better wear protection and less profile deviation. 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.