Interrelation Among Morphology, Mechanical Properties and Oxidation Behavior of NbxAlyNz Thin Films

Abstract

Nb x Al y N z thin films were deposited by magnetron sputtering reactive technique with (y/x+y) ratio varying from 0 to 0.4, in order to maintain aluminum atoms inside NbN matrix in solid solution. GAXRD analyses revealed that the crystalline phase obtained for Nb x Al y N z thin films was B1-NbN with a lattice constant shrinkage as Al concentration at these coatings was increased. Due to similarity in electro negativity values between Nb and Al, XPS analyses could not verify pronounced changes among as deposited Nb x Al y N z coatings. The average hardness values evidenced that solid solution strengthening mechanism did not increase hardness significantly. The oxidation resistance increased with Al content and no oxide phases were registered by GAXRD analyses for coating with more aluminum added. However, SEM images revealed bubbles after oxidation at high temperatures for all samples.

Corrosion resistance of NbN and NbxAlyN coatings on stainless steel

“…The addition of aluminium in MeN has been increasingly explored in the literature. Coatings composed of MeAlN have shown significant improvements in mechanical properties, oxidation, wear and corrosion resistance [5,[9][10][11][12][13][14][15]. This was attributed to an increase in film density and the formation of a passive layer composed of Al 2 O 3 , preventing electrolyte penetration [12].…”