Influence of Al(Er) interlayer on the mechanical properties of AlN(Er) coatings

AIN(Er) thin films were deposited by sputtering on M2 steel (AISI) and Si substrates with different thickness of an AI(Er) interlayer. No significant variations were observed in the chemical composition and structure of the AIN(Er) films. The films in all cases presented excess nitrogen in relation to AIN stoichiometry. The diffraction peaks were strongly shifted to lower angles due to the presence of Er. The hardness of the films is approximately 32 GPa and does not change with the thickness of the AI(Er) interlayer. The cohesion and adhesion of the AIN(Er) films were improved with the inclusion of the AI(Er) interlayer; the cohesive and adhesive critical load values increased from 7 and 17 N to 15 and 27 N, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.