New Trends in Decorative Coatings 2 $ ? 6 ?
ecorative coatings applied with D . . sputter ion plating processes have become a widely accepted application for vacuum technology. Although the deposition itself is only one important step among others, indusmal decorative applications require a reproducible and productive coating system. Leybold, as a system manufacturer, is featuring machines with a high level of up-time as well as an extraordinary sales service. In addition, such equipment is able to control all manufacturing steps including the choice of substrate material, the proper machining of it, the advisable heat treatment, the correct surface machining, the appropriate electroplating and the right precleaning. All these factors have an important influence, since a successful product does not depend solely on film properties. All system features required in the performance portfolio need to be fulfilled. In some circumstances, features required for a satisfactory coating can only be determined in extensive field tests.
Decorative properties and chemical composition of hard coatings
Transition metal compounds (nitrides, carbides, etc.) find increasing use as decorative coatings combining intensive colours, high wear resistance and good corrosion resistance. While golden TiN and dark-grey TiC are limited in their colour variation, the addition of a second metal or a second metalloid widens the spectrum of decorative colours, e.g. to dark blue with (Ti, Al)N. In the search for new colours, a number of nitrides of binary IVa metal-based alloys were deposited by reactive magnetron sputtering. The correlation between colour and stoichiometry was determined by surface analytical methods. Proper selection of the process parameters (target composition, N2 flow rate, etc.) results in coatings with different colours exceeding the conventional spectrum of decorative coatings.
New results in d.c. reactive magnetron deposition of TiNx films
Abstract This paper deals with d.c. reactive magnetron deposition of non-stoichiometric TiNx films. A decisive influence of the nitrogen flow rate, the substrate temperature and the substrate bias on the properties of TiNx films is demonstrated. The microhardness, the phase and chemical composition, the texture, strains and macrostresses in TiNx films as a function of ON2 are presented in detail. Some results are presented concerning the hysteresis effect in reactive sputtering, the correlation between (i) the maximum microhardness of films, the maximum strains in the films and the strong decrease in preferred orientation of the crystallites and (ii) the change in the sign of the macrostress and the transition of the phase composition from α-Ti(N) to α-TiNx, an extremely high microhardness of TiNx films at x ≈ 0.6 and strong changes in the texture and lattice parameters with changes in the thickness of films prepared under the same conditions. A comparison of TiNx with (Ti, Al, V)Nx films is also given.