Deposition, structure, and hardness of polycrystalline transition-metal nitride superlattice films

Journal Article · Tue Jun 01 04:00:00 EDT 1999 · Journal of Materials Research

DOI:https://doi.org/10.1557/JMR.1999.0335· OSTI ID:354518

Chu, X; Wong, M S; Sproul, W D; Barnett, S A ^[1]

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1. Department of Materials Science and Engineering and the Advanced Coating Technology Group, Northwestern University, Evanston, Illinois 60208 (United States)

Polycrystalline TiN/VN, NbN/VN, and TiN/NbN superlattices with periods {Lambda} between 2 and 160 nm were deposited onto steel substrates using an opposed-cathode reactive magnetron sputtering system. The nitrogen partial pressure and the substrate bias values were optimized in order to obtain dense stoichiometric films, which yielded the highest Vickers hardnesses H{sub V}. H{sub V} for TiN/VN and TiN/NbN superlattices reached maximum values of {approx}5000 kgf/mm{sup 2} at {Lambda}{approx}5{endash}10&hthinsp;nm, compared with {approx}2000 kgf/mm{sup 2} for homogeneous TiN, NbN, and VN films. In contrast, H{sub V}{approx}2000&hthinsp;kgf/mm{sup 2} was obtained for VN/NbN superlattices independent of {Lambda}. Model calculations in which the hardness enhancement was proportional to the difference in layer shear moduli gave good agreement with the data. The lack of hardness enhancement in VN/NbN indicates that any other hardening mechanisms, such as coherency strains and dislocation blocking by interfacial misfit dislocations, were not important. {copyright} {ital 1999 Materials Research Society.}

• DOE Contract Number: FG02-90ER45434
• OSTI ID: 354518
• Journal Information: Journal of Materials Research, Journal Name: Journal of Materials Research Journal Issue: 6 Vol. 14; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

1-NITROSO-2-NAPHTHOL
36 MATERIALS SCIENCE
CATHODE SPUTTERING
DEPOSITION
DISLOCATIONS
HARDNESS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITROGEN COMPOUNDS
POLYCRYSTALS
PROTECTIVE COATINGS
SHEAR PROPERTIES
STRAINS
SUPERLATTICES
THIN FILMS
TITANIUM COMPOUNDS
TITANIUM NITRIDES
USES
VANADIUM COMPOUNDS
VANADIUM NITRIDES