Multicomponent Ti–Zr–N and Ti–Nb–N coatings deposited by vacuum arc

• Published in: Surface & coatings technology Vol. 108; no. 1-3; pp. 154 - 159
• Main Authors: Grimberg, I, Zhitomirsky, V.M, Boxman, R.L, Goldsmith, S, Weiss, B.Z
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10.10.1998
• Subjects: Microstructure; Multicomponent coatings; Ti–Nb–N; Ti–Zr–N; Vacuum arc deposition; Multicomponent coatings; Ti–Nb–N; Ti–Zr–N; Microstructure; Vacuum arc deposition
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/S0257-8972(98)00658-6

A triple-cathode vacuum arc plasma gun was used to deposit Ti–Zr–N and Ti–Nb–N multicomponent coatings onto cemented carbide (90% WC, 8% Co, 1.8% TaC, and 0.2% NbC) substrates. The coatings were deposited at a bias voltage of −40 V relative to the anode, and a substrate temperature of 400°C. The influence of the nitrogen background pressure, which was in the range of 0.67–2 Pa, on the structure, phase composition, and microhardness was studied. It was shown that a solid solution (Ti,Zr)N was formed in the Ti–Zr–N coatings, in which the elements Ti, Zr, and N were distributed homogeneously. The films had a fine structure. The (Ti,Zr)N grains had an average diameter of 30 nm and were {111} orientated. The nitrogen concentration in the solid solution was not affected by the nitrogen pressure in the range studied. However, increasing the nitrogen pressure to 2 Pa increased the Zr concentration, while that of Ti decreased and a less dense structure is formed. The formation of a (Ti,Nb)N solid solution was observed in the Ti–Nb–N coatings. The (Ti,Nb)N grains were randomly oriented. A maximum microhardness of 51.5 GPa was obtained for the Ti–Nb–N film deposited at a nitrogen pressure of 1.33 Pa. Increasing the nitrogen pressure to 2 Pa decreased the microhardness to 31.5 GPa.