Elemental distributions and substrate rotation in industrial TiAlN/VN superlattice hard PVD coatings

• Published in: Surface & coatings technology Vol. 183; no. 2; pp. 275 - 282
• Main Authors: Zhou, Z, Rainforth, W.M, Rother, B, Ehiasarian, A.P, Hovsepian, P.Eh, Münz, W.-D
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 24.05.2004; Elsevier
• Subjects: Composition and phase identification; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deposition by sputtering; Energy-filtered TEM; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Numerical prediction; Physics; Substrate rotation; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; TiAlN/VN multilayers; Substrate rotation; TiAlN/VN multilayers; Energy-filtered TEM; Numerical prediction; Titanium Aluminium Nitrides; Vanadium nitrides; Growth rate; Electron diffraction; Ternary compounds; Binary compounds; Experimental study; Field emission microscopy; Transmission electron microscopy; Superlattices; Physical vapor deposition; Microstructure; Hard coating
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2003.09.060

Chemical distribution of individual layers within a TiAlN/VN multilayer structure was characterised using a field emission gun transmission electron microscope, coupled with energy-filtered elemental mapping and high-angle annular dark field imaging. Bright field TEM micrographs using zero-loss electrons indicated the presence of alternating TiAlN and VN layers with a periodicity of ∼3 nm. Electron spectroscopic images (ESI) using the Ti-L 2,3 and V-L 2,3 edges were used to determine the Ti and V composition profiles of layers and confirmed the complementary distribution of Ti and V. ESI demonstrated an additional modulation super-imposed on the basic period of the coatings, which was confirmed by Z-contrast imaging using scanning transmission electron microscopy. The additional modulation was related to the threefold rotational geometry used in the deposition process. Film growth and elemental distributions were therefore theoretically predicted in association with substrate rotation. The experimental compositional profiles and the prediction showed good agreement. The implications of the compositional modulation on key process parameters are discussed.