The processes of vapour-phase deposition such as CVD and PVD are of growing importance for the production of high-grade coatings. Plasma- and ion-assisted processes especially have successfully expanded into the field of hard coatings against wear and friction. Various tools with hard coatings are already widely used on the basis of well-developed processes. New single and multilayer coatings with exceptional adhesive; hardness and wear properties, like binary and ternary refractory metal carbides, nitrides, borides and oxides, DLC-coatings, metal-carbon coatings and even pure extremely hard diamond coatings can nowadays be deposited by vapour-phase processes.

The processes of vapour-phase deposition such as CVD and PVD are of growing importance for the production of high-grade coatings. Plasma- and ion-assisted processes especially have successfully expanded into the field of hard coatings against wear and friction. Various tools with hard coatings are already widely used on the basis of well-developed processes. New single and multilayer coatings with exceptional adhesive; hardness and wear properties, like binary and ternary refractory metal carbides, nitrides, borides and oxides, DLC-coatings, metal-carbon coatings and even pure extremely hard diamond coatings can nowadays be deposited by vapour-phase processes.

Investigations concerning the development of a chemical vapour deposition process for the structures deposition of titanium nitride coatings onto tool steel at low substrate temperatures are presented. In order to stimulate local film growth of hard coatings, excimer and argon ion laser beams were used respectively. In the experiments with the excimer laser, the beam projection method was used. The TiNx coatings were deposited from the precursor gas tetrakis-(dimethylamido)-titanium (Ti(N(CH3)2)4), in a reactive atmosphere of nitrogen and hydrogen at the excimer wavelengths 248 nm and 351 nm in combination with an additional r.f. or d.c. discharge. Experiments using an argon ion laser were carried out with a focused laser beam, where lateral film growth was induced by laser scanning. In particular, the deposition of TiNx from TiCl4N2H2 and TiCl4NH3 gas mixtures was inves tigated.

Metal carbon (Me : C) and hydrogen-containing amorphous carbon (a-C : H) layers offer interesting possibilities for coating of tools because of their remarkable tribological features. But normally adhesion to steels used as base materials for tools is very low. A hybrid physical vapour deposition (PVD)-plasma chemical vapour deposition (PCVD) process was used to deposit zirconium (Zr)/intermediate layer/Zr : C. The a-C : H layers were deposited in a parallel plate reactor by PCVD with RF plasma. The graded Zr : C coating adheres well to various steels, very low adhesion is observed to a cobalt-containing steel and to cobalt-based hard metals. a-C : H adheres very well to silicon, glass, and aluminium (Al), but delamination in the bulk of the base material can occur due to high compressive stress. Adhesion to steel can be improved by thin layers of Al and tungsten (W), but different mechanisms seem to be the reasons for the improvement. The adhesion to hard metals increases with increasing WC content.

Different ternary compounds consisting of two metals (type (M1 M2)X) were deposited by the use of a hybrid ion-plating deposition set-up with two cathodic sources, namely an arc source and a magnetron source. Simultaneous ablation from these two elemental metallic sources allows deposition of ternary compounds in a broad range of coating compositions without using expensive alloy sources. Deposition of graded coatings with different concentrations of the individual metals M, and M2 in the thickness of the film can be easily controlled by changing the source power of the individual sources during the deposition process. The usefulness of the process is demonstrated by deposition examples of various ternary compounds, such as (Ti, A1)N, (Ti, Cr)N, (Ti, Nb)N, (Ti, Ta)N, (Ti, W)N, (Ti, Zr)N, (Cr, A1)N, (Cr, Ta)N and (Cr, W)N.

Tin was deposited on high speed tool steel (1.3343) by use of different plasma chemical vapour deposition (PCVD) methods. R.f. PCVD without and with a d.c. substrate bias, d.c. PCVD, pulsed d.c. PCVD and downstream microwave plasma excitation were used. Whilst all methods but the microwave process gave hard (Knoop hardness less than or equal to 2500 HK) well-adhering coatings on flat substrates, differences can be observed in the thickness distribution on three-dimensional samples. Here the best coating uniformity can be achieved with the d.c. methods. When coating narrow holes the d.c. pulse process has the best throwing power. So of all the PCVD methods the d.c. pulsed PCVD process is the best suited for production of TiN coatings on three-dimensional parts.

The process of vapour phase deposition such as CVD and PVD are of growing importance for the production of high grade coatings. Single and multilayer coatings with exceptional adhesive, hardness, wear and anti-corrosive properties can be produced in this way. Tools with hard coatings are already widely used on the basis of well developed processes. Coatings for more complex tools used in metal-machining processes as well as for machine tool components are still in the process of development. New variations to these processes and defined process control will significantly extend the application range of vapour phase coatings within the next years.

The work on YBa2Cu3O7 (1-2-3) at SIEMENS has established (i) processes for high quality (1-2-3) films on SrTiO3 or on ZrO2 by sputtering or laser evaporation respectively, (ii) a hypersonic spraying process to lay down (1-2-3) thick films on steel tubing, (iii) analytical tools for precise monitoring of the oxygen content in (1-2-3) and for the investigation of the defect structure on an atomic scale in films and bulk material, (iv) test wires of competitive but still moderate current densities, and (v) inductive test methods for homogeneity of films and procedures to form electrical contacts of low resistivity.

New complex coatings are discussed, which can be adapted to individual applications on special tools in the Field of chipless forming and to product components. This broadening of technological possibilities was achieved by substantial progress in PVD process technology, an increasing knowledge about physics of plasma assisted processes, and by development of new coating materials. The results achieved are highlighted by the properties of three typical films: TiAlN-films with graded composition, metal/hydrogenated carbon films with graded composition and TiN-films with graded morphology and density. Possible applications will be indicated.