Structure and hardness of vacuum arc deposited multi-component nitride coatings of Ti, Zr and Nb

doi:10.1016/S0257-8972(99)00570-8

Surface and Coatings Technology

Volume 125, Issues 1–3, March 2000, Pages 257-262

https://doi.org/10.1016/S0257-8972(99)00570-8 Get rights and content

Abstract

Ternary transition-metal nitride coatings of (Ti,Zr)N, (Ti,Nb)N and (Zr,Nb)N were deposited using a triple cathode vacuum arc deposition system by simultaneously operating two cathodes of the appropriate metals in a low-pressure nitrogen background. The magnetically collimated plasma flux distribution was measured using a 13-element ion saturation current probe. The microstructure, composition, and hardness of the coatings were determined using X-ray diffraction, Auger electron spectroscopy, and Vickers indentation, respectively.

The plasma flux distribution had two peaks whose relative positions were related to the two cathodes. Coatings applied to extended substrates had a compositional gradient. In almost all cases, the ternary nitrides had a single-phase solid-solution microstructure, whose lattice constants had values intermediate between those of the parent binary nitrides. The ternary coatings were considerably harder than either of the parent binary nitrides. (Ti,Nb)N had the highest microhardness: ∼50 GPa.

Introduction

Hard coatings of TiN and similar materials are widely used to increase the work life and productivity of cutting and forming tools. Initially, simple binary materials such as TiN, CrN, and ZrN were favored for these applications. Increasingly, however, more complicated materials are being studied and used, including multi-layer coatings [1], [2], [3], and ternary materials including Ti(C,N) and (Ti,Al)N [4], [5], [6]. Coatings with multiple gas components are readily fabricated reactively, by admitting a mixture of the requisite gases into the deposition chamber. Deposition of coatings with multiple metallic components requires the use of an alloy source [5], [6], [7], a segmented source [8], [9], or co-deposition from multiple sources [9], [10].

Co-deposition of hard multi-component nitride coatings has been relatively little explored, albeit that it affords research flexibility. Various compositions can be fabricated by varying the relative strength of the various sources in a sequence of deposition cycles, or by arranging the substrates within the deposition apparatus such that they are exposed to varying relative fluxes from the sources during a single deposition run. The present group, in a previous report, described the co-deposition of Ti–Zr–N and Ti–Nb–N coatings in a multi-cathode vacuum arc deposition apparatus, and their microstructure and morphology [10]. Solid solutions were found to form in both systems, with crystalline grain sizes in the 20–30 nm range. Although the configuration used led to a composition gradient across the coated substrate [11], [12], the properties of the coatings as a function of the composition were not explored. In this paper we present the dependence of the structure and microhardness of multi-component coatings on composition. In addition, the previously developed methodology is extended to investigate also the Zr–Nb–N system.

Section snippets

Experimental setup and apparatus

The coatings were prepared in a triple-cathode vacuum arc deposition system [13], [14]. The cathodes were fabricated of Ti (99.9%), Zr (99.95%) and Nb (99.5%). Each cathode was 54 mm in diameter, and the three cathodes were equally spaced on a 50 mm diameter circle on the end flange of the system (Fig. 1). Each cathode had a separate trigger electrode that physically contacted the side of the cathode to ignite the arc. In any given experiment, one or two cathodes were operated simultaneously,

Plasma flux distribution

The plasma flux distribution obtained when operating the Nb and Zr cathodes shown in Fig. 1 is illustrated in Fig. 2 — the ‘gray level’ representing each element of the 13-element probe is proportional to the average ion current detected at that probe. The distribution apparently had a peak to the right of and below element 2, and a weaker peak below element 12. Presumably these peaks correspond to the center of the Nb and Zr plasma beams respectively.

Structure

The phase composition, angular positions of

Discussion

It is known that in the ternary nitride systems of Group IV–VI transition metals, continuous ranges of solid solutions (MeI_xMeII_1−x)N with NaCl-type face-centered cubic structures exist. Such solid solutions may be considered as quasi-binary systems of two cubic nitrides, e.g. δ-(MeI)N and δ(MeII)N [15].

In the Ti–Zr–N coatings, only single-phase ternary nitrides, with different Ti:Zr ratios depending on the nitrogen pressure and sample position, were found. Columnar grains with a strongly

Conclusions

Vacuum arc deposited ternary nitride coatings had a single-phase solid solution structure. Their lattice constants were between those of their parent binary compounds. The hardest of the ternary coatings was harder than either of the parent binary materials.

Acknowledgments

The authors gratefully acknowledge the technical assistance of Mr. H. Yaloz, and the financial support of the Israel Ministry of Science, Strategic Infrastructure Program.

References (21)

H. Holleck et al.
Surf. Coat. Technol.
(1995)
O. Knotek et al.
Surf. Coat. Technol.
(1992)
E. Vancoille et al.
Thin Solid Films
(1993)
O. Knotek et al.
Surf. Coat. Technol.
(1992)
I. Sakamoto et al.
Thin Solid Films
(1993)
L.A. Donohue et al.
Surf. Coat. Technol.
(1995)
I. Grimberg et al.
Surf. Coat. Technol.
(1998)
V.N. Zhitomirsky et al.
Surf. Coat. Technol.
(1997)
V.N. Zhitomirsky et al.
Thin Solid Films
(1998)
O. Knotek et al.
Thin Solid Films
(1989)

There are more references available in the full text version of this article.

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Structure and hardness of vacuum arc deposited multi-component nitride coatings of Ti, Zr and Nb

Abstract

Introduction

Section snippets

Experimental setup and apparatus

Plasma flux distribution

Structure

Discussion

Conclusions

Acknowledgments

Surf. Coat. Technol.

Surf. Coat. Technol.

Thin Solid Films

Surf. Coat. Technol.

Thin Solid Films

Surf. Coat. Technol.

Surf. Coat. Technol.

Surf. Coat. Technol.

Thin Solid Films

Thin Solid Films