Title of Invention

WORK-PIECE WITH AICR-CONTAINING HARD SUBSTANCE COATING AND PROCESS FOR ITS PRODUCTION

Abstract

Work piece coated with a system of film layers comprising at least one film composed of (AlyCr1-y)X, where X = N,C,B,CN, BN, CBN, NO, CO, BO, CNO, BNO or CBNO and 0.66 < y < 0.695, with the composition within (AlyCr1-y)X film being either essentially constant or varying over the thickness of the (AlyCr1-y)X film continually or in steps, said (AlyCr1-y)X film having a cubic crystal structure and said work piece constituting one of the following tools: a milling tool, (spherical-head) ball nose mill, planar or profiling cutter, a clearing tool, reamer, (indexable tip) insert for turning and milling, a die or an injection mold.

Full Text

Work-piece with AlCr-Containing Hard Substance Coating and Process for its Production The invention pertains to the technical area of work-pieces which are coated with a coating system that at least contains one layer of the composition (AlyCr1-y) X according to claim 1 and 2. The invention further pertains to a PVD-process for depositing at least one (AlyCr1-y) X-layer on a work-piece according to claim 16. The invention covers the following: Hard substance coated work-pieces with one or a sequence of several different aluminium-chromium nitride or carbonitride coatings. Tools, particularly cutting and deforming tools (drills, mills, reversible cutting plates, thread-borers, thread-formers, hob cutters, punches, dies, draw- punches etc.) and application of these tools with aluminium-chromium nitride or aluminium-chromium carbonitride coatings. Components, especially components in mechanical engineering, e.g. sprocket wheels, pumps, cup-tappets, piston rings, injector needles, complete bearing sets or their individual components and application of these components with AlCrN or AlCrCN coatings. A process for producing aluminium-chromium nitride or -carbonitride coating having a defined coating structure. From the state-of-the-art technology, various AlCrN coatings are known. Thus the document JP 09-041127 describes a wear resistant hard substance coating having the following composition: (Al1-y Xy) Z, whereby X = Cr, V or Mg, Z = N, C, B, CN, BN or CBN and 0 cutting plates. D. Schulz and R. Wilberg describe in "Multi-component hard thin films...", Thin films (Proc 4th int Sympos. Trends and New Applications of Thin Films 1993) DGM Info.gesellschaft Oberursel, 1993, page 73, a CrAIN coating, which during a drilling test achieved twice the tool edge life of a TiAIN coated drill. Depositing of the coating took place in a hollow cathode process that however on account of a discontinuous vaporisation process causes a strong fluctuation in chromium/aluminium distribution in the (CrAl) N-coating. M. Kawate et. al mentions in "Oxidation Resistance of Cr1-x A1XN & Ti1-x A1XN films" Surf. & Coat. Tech.Vol. 165 to (2003), pages 163 - 167 a Cri-XA1XN coating, which with high Al-content and Wurtzit-structure reveals an improved oxidation resistance as compared to traditional TiAlN-coatings. E. Lugscheider, K. Bobzin, K. Lackner compare in investigations of Mechanical and Tribol Properties of CrAIN + C Thin Coatings Deposited on Cutting Tools " arced CrAlN-coatings and CrAlN-coatings that are additionally provided with even harder, carbon containing cover coating. All coatings have coefficients of friction rapidly rising to high values. It is the technical task of this invention to present (AlyCr1-y) X-coated work-pieces, e.g. chipping tools, cutting and forging tools or components for machining and forging, as well as a process for depositing of such coatings on a work-piece, and thereby avoid the disadvantages of the state-of-the-art technology. This includes work-pieces, which at least with respect to the Al/Cr-ratio have an adjustable uniform or variable coating composition, and at least for certain applications, reveal a higher wear resistance than work-pieces provided with coatings known so far. In order to investigate the wear resistance of (AlyCr1-y) N or -CN coatings on different tools, Cr-coatings with varying aluminium content was deposited on different work- pieces in an industrial coating plant of the type RCS of the company Balzer, as described also in EP 1186681 in figures 3-6, description on page 12, line 26 to page 14 line 9. The mentioned document is hereby declared as an integral part of this application. Additionally, the cleaned work-pieces were fixed, depending on the diameter, on double- rotating substrate carriers, or on triple-rotating substrate carriers for diameters lesser than 50 mm, and two titanium-metallurgic and four powder-metallurgic produced targets of different AlCr alloys were mounted in six cathode arc sources attached to the walls of the coating plants. Subsequently the work-pieces were first brought to a temperature of approx. 500° C by means of radiation heaters connected to the plant and the surface was subjected to etch- cleaning with Ar-ions by introducing a bias-voltage of-100 to -200 V under Ar- atmosphere at a pressure of 0.2 Pa. Thereafter, by operating the two Ti-sources with a power of 3.5 KW (140 A) in pure nitrogen atmosphere at a pressure of 3 Pa and a substrate voltage of-50 V over a period of 5 min., an approx. 0.2 urn thick TiN adhesive coating was deposited; subsequently, by operating the four AlCr-sources with a power of 3 KW for a duration of 120 min., an AlCrN-coating was deposited. In order to achieve an optimum coating transition, the sources were operated together for a period of 2 min. Then a nitride coating on AlCr- base in pure nitrogen atmosphere, similarly at a pressure of 3 Pa and a substrate voltage of-50 V, was deposited. Basically, the process pressure in each of these steps can be adjusted in a range of 0.5 to approx. 8 Pa, preferably between 2.5 and 5 Pa, whereby either a pure nitrogen atmosphere or a mixture of nitrogen and an inert gas, e.g. argon for nitride coatings, or a mixture of nitrogen and carbon-containing gas that can be mixed with an inert gas if required, can be used for carbonitride coatings. Correspondingly, for depositing oxygen- or boron-containing coatings, oxygen or a known boron-containing gas can be mixed. Coating properties like crystal structure of the coating, coating thickness, coating hardness, wear resistance and adhesion of AlCrN-coatings in relation to the chemical composition and crystal structure, as well as composition of the used targets are listed in table 1. Process parameters like target capacity, substrate pre-stress, process pressure and temperature are summarized in table 2. Table 3 shows a measurement series, during which AlCrN-coatings were deposited using targets with Al/Cr-ratio equal to 3, under application of different substrate voltages. The wear resistance was determined with a precision wear tester of the Fraunhofer Institut- IST/Braunschweig, whereby a modified spherical grinding method based on DIN EN 1071-2 was applied to determine the rate of wear. Details of the process can be found in Michler, Surf. & Coat.Tech., vol. 163-164 (2003), page 547, col. 1 and fig. 1. The mentioned document is hereby declared as an integral part of this application. The invention is described in details below on the basis of figures. The following are shown: Fig. 1 XRD-spectrum of an AlCrN with B1 and B4 structure Fig.2 XRD-spectrum of AlCrN-coatings in relation to the chemical composition Al/Cr: A = 75/25, C = 50/50, D = 25/75. As one can see from table 1 and fig. 1 and from Kawate's, "Micro-hardness and lattice parameter of Cr1-xAlxN films", J. Vac. Sci. Technol. A 20 (2), March/April 2002; pages 569-571. for Al-concentration of greater than 70 At% share of metal content in the coating, a hexagonal (B4) layer structure could be determined, and for lower Al- concentrations a cubical (B1) layer structure was determined. For hexagonal layers, HV- values of approx. 2100 HV0.03 could be measured, and for cubic layer structures however higher HV-values of approx. 2800-3100 HV0.03 (see table 1). For higher Cr-contents (sample D) a hardness of approx. 2300 HV0.03 was determined. For this composition, different from the AIN-lattice of the high aluminium-containing coatings as shown in fig. 2A, one finds a CrN-lattice as shown in fig. 2D. Subsequently the tool edge lives of 6 mm HSS-drills coated with AlCrN were determined as shown in example 1 below, on a steel material DIN 1.2080 having hardness of 230 HV, with a shear thrust of 0.12 mm and cutting velocity of 35 m/min. It was seen that, in contrast to the range of AlyCr1-yN l document JP 09-041127, a chromium content of greater than 0.3 proved to be more advantageous. For chromium contents greater than or equal to 0.8, the performance capacity dropped on account of the CrN-lattice present for this application area. The increase in tool edge life of cubic layers as compared to hexagonal AlCrN-layers was 235% in this test. For coating in a transition region with an Al-content between 60% and 75%, not only the preferred orientation but also the basic structure of the crystal lattice can be adjusted through the process parameters. Thus, for example, in experiment B (table 2), a hexagonal structure is generated at a low pressure of 1 Pa and a substrate voltage of-50 V, whereas a cubic structure gets generated in a pressure range of 3 Pa and substrate voltage of-50 V. Thus the hexagonal structure gets deposited at relatively lower bias voltage and low pressure, whereas the preferred cubic structure is deposited at higher pressure or at higher bias voltage. With higher Al-contents it is no longer possible to generate a cubic layer structure. Work-pieces as per the invention therefore have a special feature of a cubic (AlyCr1-y) X coating with the following composition: X = N or CN, preferably however N, and 0.2 Y with an average grain size of approx. 20 - 120 nm. Methods as per the invention have the special feature of process conducting, in which a cubic (AlyCr1-y) X layer with a composition as defined above is deposited. For the described cathode arc method one could use target compositions of 75 to 15% aluminium contents. In case of higher aluminium contents, the process parameters will have to be adjusted as described above, in order to generate a cubic crystalline structure. Advantageous thereby is the application of powder-metallurgic targets produced by cold pressing, that have a higher stability than AlCr-targets produced in a fusion-metallurgic or sinter-metallurgic manner, which especially with high Al-contents mostly contains brittle phases. Such targets are cold-pressed by mixing starting materials in powder form and then subsequently through several deformations, e.g. in a forging press, at temperatures below 660° C, compressed by rheology and cold-welding and brought to a final condition with a theoretical density of about 96 - 100%. It can further be seen that for an AlCrN-coating that was deposited with targets having composition of Al/Cr = 3, the wear resistance can be influenced by the substrate pre- stress. With increasing substrate pre-stress the resistance to abrasive wear gets reduced (see table 3). Already in case of a very small negative substrate voltage, which is not explicitly shown in the table, say of only a few Volts (3 - 10 V and random intermediate values), one can achieve a marked improvement as compared to floating substrates (no external voltage supply). At approx. -20 V the wear resistance for Al/Cr = 3 reaches a maximum and again drops at higher voltages. From the experiments for determining the wear behaviour, one can derive an optimum range of substrate voltage between 3 and 150 V, particularly between 5 and 40 V, in which a very small wear rate between 0.4 and 1.0, particularly between 0.4 and 0.8 m3 m-1 N-1 1015, was measured. The same holds good also for cubic coatings as per the invention having different Al/Cr-composition, in which no wear rates above 1.5 m3 m-1 N-1 10-15 was measured. However, it should be noted that also the wear resistance of floating coatings deposited with high substrate voltage is significantly greater than the wear resistance of known TiAIN-coatings, whose wear co- efficient is significantly higher. For example, for a TiAIN-coating deposited analogous to the AlCrN-coatings (experiment 2, Al 47 at%, Ti 53 at%), a wear rate of 3.47 m3 m-1 N-1 10-15 was measured. With the help of the above described method, particularly by using powder-metallurgic produced TiAl-targets, coatings with low roughness could be deposited. The measured Ra-values lie in the range between 0.1 and 0.2 µm and thus moved in the same range like comparably produced CrN-coatings. Further smoothening of the coatings was obtained by using a magnetic field generating device consisting of two opposite-poled magnet systems, which is designed in such a way that the component B1 of the result ir. magnetic field that is perpendicular to the surface, revealed mostly constant small values over a large section of the surface, or even zero. The values of the perpendicular magnetic component B1 were thereby set lesser than 30, preferably lesser than 20, ideally lesser than 10 gauss. The Ra-values of the thus deposited (AlyCr1-y) X-coatings lay in the range of 0.5 and 0.15 µm. The magnetic field was generated with the help of two opposite- poled coils arranged co-axially behind the targets. Furthermore, while depositing (AlxCr1-x) X-coatings, also other good-conducting, nitride or even metallic adhesive coatings can be used, or for certain applications one can also do away with such an adhesive coatings. For achieving particularly high productivity, an AlCWAICrN-adhesive coating can be applied instead of TiN-adhesive coating, whereby it is possible to provide all arc sources of a coating plant with AlCr-targets and increase the coating rates. Similarly, depositing of gradient coating with increasing Al-content towards the surface is possible, if two target types with different Al/Cr-ratios are used; or starting with a Cr- and/or CrN-adhesive coating by continuous or step-wise regulation of the corresponding target performances of a coating chamber equipped with Cr- as well as AlCr-target, a change in coating composition can be achieved. Mainly for an industrial application for such coating systems, there is the possibility to adjust the process parameters mainly over the entire coating sequence and hence over the entire coating thickness in a reproducible manner. Minor fluctuations in the composition, as effected by the substrate movement on a single or multiple-rotating substrate carrier, can be used in addition to a nano structuring formed partly or over the entire coating thickness, i.e. laminating in nano- or micrometer range. Process-technically, if unalloyed chromium and aluminium targets are used, a rougher structured hard coating is deposited, than in case of using alloyed AlCr- targets. The known processes as per the state-of-the-art technology are less suitable for this, in which the vaporisation process of at least one component is difficult to control or is discontinuous, because one cannot achieve a reproducible coating quality. Of course it is also possible to produce such coatings on other vacuum coating plants or even through sputtering processes, whereby however, the lower ionisation of the process gas in sputtering processes can be compensated if required by known measure like special adhesive coating, additional ionisation etc., in order to attain a comparable coating adhesion. Basically, with such Cr1-xAlxN coatings with cubic structure very different work-pieces can be coated. The example for these are cutting tools like millers, hob cutters, ball-end millers, planar millers and profile millers, as well as drills, thread-borers, broaching tools, reamers and reversible cutting plates for turning and milling machining or deforming tools like punches, dies, draw-rings, ejecting cores or thread-formers. Even injection moulding tools, e.g. for metallic injection moulding alloys, synthetic resins or thermoplastic synthetic substances, particularly injection moulding tools that are used for producing synthetic moulded parts or data carriers like CDs, DVDs and others, can be protected with such coatings. A further area of application would be structural components that have a high requirement of wear resistance, sometimes coupled with high resistance oxidation. Examples from the pump and engine industry are sealing rings, pistons, punches, sprocket wheels and valve drives like cup-tappets and tipping levers, or needles for injection nozzles, compressor shafts, pump spindles, or many components that have one or more gear elements. Furthermore, on account of the basically similar behaviour of (AlyCr1-y) X coatings, even in improvement of the wear and tear behaviour can be expected, if in the following coating systems the target composition and coating parameters are selected in such a way, that a cubic coating structure is attained. (AlyCr1-y) X coatings, whereby we have X = N, C, B, CN, BN, CBN, NO, CBO, BO, CNO, BNO, CBNO, preferably however N or CN and 0.2 = Y = 0.7, preferably 0.40 = Y =0.68. Thus (Al66 Cr34) NO coatings with different N/O-ratio were deposited and their coating properties were tested. The coating parameters were selected similarly as mentioned above. The total pressure was set between 1 to 5 Pa for an oxygen flow between 20 and 60 sccm (rest nitrogen); the substrate voltage was set between -40 to -150 V, the temperature to 450° C and the source power was set at a current of 140 A at 3.5 KW. This yielded coatings with an O/N-ratio of approx. 0.2 and 0.6 and 0.2. In various milling tests one could see that the coatings were superimposed with low oxygen content. The results were significantly better than those attained for tool edge life with traditional TiN or TiCN. On account of the improved anti-friction properties of the above (AlyCr1-y) X coatings, as compared to known TiAIN-coatings, from the ecological and economic points of view one obtained an interesting possibility in the operation of tools, particularly cutting tools and deforming tools, in that one can either do away with lubricants or use only minimum lubricant quantities. Under the economic aspect it should be taken into account that the costs for cooling lubricants, particularly in cutting tools, could be significantly higher than for the tool itself. There is a further possibility of improving the anti-friction properties of a coating system containing an (AlyCr1-y) X coating as per the invention, if a sliding layer is additionally applied as outer layer. It is thereby advantageous if the sliding layer has a lower hardness than the (AlyCr1-y) X coating and also has inflow property. The sliding coating system could thereby be made up of at least one metal or one carbide of a metal and dispersed carbon, MeC/C, whereby the metal is a metal of the group IVb, Vb and/or VIb and/or silicium. Ideally suited for this, is particularly a WC/C-cover coating with a hardness that can be adjusted between 1000 and 1500 HV, which then reveals excellent inflow properties. Even CrC/C-coatings show a similar behaviour, however with a somewhat higher friction coefficient. In deep hole borers coated in this manner, after producing one to three bore holes, an excellent inflow smoothening of the chipping surfaces could be determined, which till now could be achieved only by cumbersome mechanical machining. Such properties are also particularly interesting for the structural component applications with sliding, friction or rolling loads, especially with lacking lubrication or dry-run, or if simultaneously an uncoated counter-body has to be supported. Further possibilities for formation of a final sliding coating are metal-free diamond-like carbon coatings, or MoSx-, WSX- or titanium-containing MoSx- or MoWx-coatings. The sliding layer can be applied, as already mentioned, directly on the (AlyCr1-y) X coating or after applying further adhesive coating, which could be designed as metallic, nitride, carbide, carbonitride or even as gradient coating with continuous transition between (AlyCr1-y) X- and sliding layer, in order to achieve a good adhesion of the coating combination. For example, WC/C- or CrC/C-coatings can be produced after applying a sputtered or arc-ed Cr- or Ti-adhesive coating by sputtering WC-targets under addition of a carbon- containing gas. The share of carbon-containing gas is increased with time, in order to attain a larger share of free carbon in the coating layer. Further advantageous applications for different (AlyCr1-y) X hard-coated tools are described below with examples of applications for different cutting operations. Example 1: Milling of structural steel Tool: Shank mill for hard metal Diameter D = 8 mm, no of teeth z = 3 Material: Structural steel Ck 45,DIN1.1191 Milling parameters: Cutting velocity vc = 200/400 m/min. Thrust velocity vf = 2388/4776 mm/min. Radial gripping width ae = 0.5 mm Axial gripping width ap = 10 mm Cooling: emulsion 5% Process: down-cut milling Wear criteria: free surface wear VB = 0.12 mm Example 1 shows a comparison of the tool edge life of coated HM-millers, which were tested for different cutting parameters. It becomes thereby very clear that in comparison to the industrially used coating systems so far, like TiCN and TiAIN, the mentioned AlCrN-coatings have higher tool edge lives. It is further clear from the result that with increasing Al-content there is an improvement in the tool edge life behaviour (compare with experiment no. 3, 5, 6), as long as cubic Bl-structure is retained as shown in example 1. This is primarily on account of improved oxidation resistance and hardness (see table 1) that can be determined with increasing Al- content. Particularly in the area of dry machining and high-velocity machining (e.g. vc = 400 m/min.), the very good oxidation resistance of the AlCrN-coating plays a role. Furthermore, it can also be determined in this test that on reversing the crystal lattice from VI to V4 structure, the wear behaviour gets worse (compare with experiment 3 and 4). Example 2: Milling of austenitic steel Tool: Shank miller for hard metal Diameter D = 8 mm, no of teeth z = 3 Material: austenitic steel X 6 CrNiMoTi 17 12 2, DIN 1.4571 Milling parameters: Cutting velocity vc = 240 m/min. Tooth thrust fz = 0.08 mm Radial gripping width ae = 0.5 mm Axial gripping width ap = 10 mm Cooling: emulsion 5% Process: down-cut milling Wear criteria: free surface wear VB = 0.1 mm Example 2 shows a comparison of tool edge lives of coated HM-millers. Here also, similarly with the AlCrN-coating an improvement in wear could be achieved as compared to industrially used hard substance coatings. The tool edge life improvement for AlCrN could be achieved, on the one hand, by means of a not yet proved slight inclination of the second alloy element Cr to the material lubrication, as compared to Ti in TiAIN-coatings, and on the other hand, on account of the good wear resistance of the AlCrN-coatings (A, B, D) as per the invention as one can see in table 1, with simultaneous high hardness. Example 3: Milling of hardened tool Tool: Ball-end miller for hard metal Diameter D = 10 mm, no of teeth z = 3 Material: K 340 (62 HRC) corresponding to C 1.1%, Ai 0.9%, Mn 0.4%, Cr 8.3%, Mo 2.1%, Mo 2.1%, V 0.5%. Milling parameters: Cutting velocity vc = 0 - 20 m/min. Tooth thrust fz = 0.1 mm Radial gripping width ae = 0.2 mm Axial gripping width ap = 0.2 mm Cooling: dry Process: down-cut milling and conventional milling, finishing Wear criteria: free surface wear VB = 0.3 mm Example 3 and Example 4 show an improved withstanding path of the AlCrN-coatings as compared to the industrially used TiAIN-coatings. AlCrN is suitable also particularly for dry milling which requires high specifications with respect to oxidation resistance and wear resistance. Example 5: Boring in tool steel Tool: borer HSS (S 6-5-2), diameter D = 6 mm Material: tool steel X 210 Cr 12, DIN 1.2080 (230 HB) Boring parameters: Gutting velocity vc = 35 m/min. Thrust f= 0.12 mm Bore hole depth z = 15 mm, bottom hole Cooling: emulsion 5% Wear criteria: torque switch-off (corresponds to a corner wear of > 0.3 mm) Example 6 shows a comparison of the standardized no of holes of HSS-boring over the layer thickness with AlyCr1-y N/AlCr1-y CN coatings having different Al content. Layers were produced with the parameters corresponding to table 2. There one can see that with increasing aluminium content there is an increase in withstanding time up to nearly 70% share of the aluminium in the metal content. On further increasing and hence depositing of the coating with hexagonal crystal structure, the performance/capacity however drops significantly. In the range between 41.5 and 69.5 % Al (experiment 15, 17), one could see a clear performance increase for this application as compared to the state-of-the-art technology (experiment 18). Example 6. Deep hole boring 5 x D in Ck45 Tool: borer of hard metal, diameter D == 6.8 mm Material: construction steel 1.1191 (Ck 45) Boring parameters: Cutting velocity vc = 120 m/min. Thrust f= 0.2 mm Bore hole depth z = 34 mm, bottom hole Cooling: emulsion 5% Wear criteria: corner wear VB = 03 mm. Example 6 shows an improved withstanding path of the AlCrN-coating as compared to the industrially used TiAIN-coatings for a boring application. Here the improved abrasive wear resistance of the AlCrN-coating as per the invention plays a role. Additionally, as in the case of experiment no.20, coated borers were provided with a WC- carbon sliding coating after applying a Cr-adhesive layer, whereby under otherwise same testing conditions, one could achieve a clearly improved withstanding time. Toque measurements carried out simultaneously revealed a clearly lower torque than without slidifig coating. One could also determine a better surface quality of the bored holes and till shortly before ending the withstanding time, there was no colouring due to excessive temperature load. Example 7: Thread-boring 2 x D in austenitic steel Tool: thread-borer HSS, thread dimension M 8 Material: austenitic steel 1.4571 (X6 Cr Ni Mo Ti 17/12/2) Cutting parameters: Cutting velocity vc = 3 m/min Thread depth: 2 x D Thread type: sack hole No of threads: 64 Cooling: emulsion 5% Wear criteria: torch flow over thread number, optical wear assessment after 64 threads. Explanation for (1) + satisfactory wear behaviour during thread-boring ++ good wear behaviour during thread-boring +++ very good wear behaviour during thread-boring In all AlCrN-coatings one can achieve a reduction in average maximum cutting moment as compared to the state-of-the-art technology (TiCN). On account of the very good wear resistance of the higher aluminium-containing coatings, one further gets improved wear behaviour as compared to TiCN. However, in this example, probably on account of the adhesive inclination of the aluminium that leads to material lubrication and then to coating dissolutions, the coating from experiment no. 23 shows a better wear picture than no. 22. Thread borers coated as in experiment no. 22 and 23 were additionally provided with a Ti-containing MoS2-coating after applying a AlCr-adhesive layer with a WC/carbon- sliding layer, or after applying a Ti-adhesive layer, whereby similarly under otherwise same testing conditions, one could achieve an improvement in withstanding time and a better surface quality of the machined material. Example 8: Hob miller on Cr-Mo steel Tool: hob cutter Material: DIN S 6-7-7-10 (ASP 60) Diameter D = 80 mm, length L = 240 mm, modulus m = 1.5 25 chip grooves Gripping angle a = 20° Reference profile 2, no of teeth 50, passage width 25 mm Material: Cr-Mo steel DIN 34 CrMo 4 Cutting parameters: Cutting velocity vc = 260 m/min. Thrust: 2 mm/U No of pieces: 300 Cooling: dry cutting, compressed air for removing the chips In the experiments 25 to 30 several hob millers made of powder-metallurgic high- velocity steel (HSS) were tested with different coating systems in dry cut. With the tools coated as per the invention (experiment 29 and 30) one could achieve significant improvements with respect to the known TiCN or TiAIN-coated millers. It can also be similarly identified that AlCrN-coatings with low (no. 28) or too high Al-content offer a slight protection against wear if a hexagonal crystal structure (no. 27) is present. Even the following example numbers 31 to 33 show the clear superiority of AlCrN- coating as per the invention with cubic crystal lattice, especially stoichiometric nitrogen share and an Al-content of 66%. Hob millers made of PM HSS or hard metal were thereby tested in dry as well as in emulsion-lubricated cutting. Experiment no. 31: Hob milling Tool: PM HSS Diameter D = 80 mm, length L = 240 mm Material: 16 Mn Cr 5 Cutting velocity: 180 m/min, dry (Alo.42Tio.5s) N, Balinit NANO: 1809 pcs. (Al0 63Ti0.37) N, Balinit X.CEED 2985 pcs. (Al0.66Cr0.34) N: 5370 pcs. Experiment no. 32: Hob milling Tool: hard metal (HM) Diameter D = 60 mm, length L = 245 mm Modulus: 1.5 Gripping angle A = 20° Material: 42 CrMo 4 Cutting velocity: 350 m/min., dry (Alo.41Tio.59) N, Balinit X.TREME: 1722 pcs. (Al0.63T10.37) N, Balinit X.CEED: 2791 pcs. (Alo.66Cr0.34) N: >3400 pcs. Experiment no. 33. Hob milling Tool: PM HSS Modulus: 2.5 Material: 16 Mn Cr5 Cutting velocity: 140 m/min., emulsion TICN, Balinit B: 1406 pcs. (Al0.42Ti0.58) N, Balinit NANO: 1331 pcs. (Al0..66Cr0.34) N, 1969 pcs. Further experiments, not mentioned here in details, yielded a very good tool edge life duration even at higher cutting velocity ranges up to vc = 450 m/min. Even the tool edge lives of coated hard metal rolling millers could be significantly increased in wet machining as well as in dry machining. Example 9. Rough milling of tool steel Material: shank mill HSS Diameter D = 10 mm, no of teeth z = 4 Material: tool steel X 40 CrMoV 5 1, DIN 152344 (36 HRC) Milling parameters: Cutting velocity vc = 60 m/min. Tooth thrust f2 = 0.05 mm Radial gripping width ae = 3 mm Axial gripping width a, = 5 mm Cooling: emulsion 5% Process: down=cut milling, roughing Wear criteria: free surface wear VB = 0.1 mm HS adhesive layer of TiN Pulse pulsed bias Example 10: External turning of hardened steel Tool: lathe cutter with soldered CBN-insert Material: case hardened steel 16 MnTr 5, DIN 1.7131 (49 - 62 HRC) Turning parameters: hard-soft machining with interrupted cut and partly thin wall thickness Cooling: dry Wear criteria: No. of pieces till reaching a free surface wear of VB = 0.1 mm Similar results were also achieved with powder-metallurgically produced cermet consisting of a TiN, TiC or a Ti (CN)-phase to which in individual cases molybdenum and/or tantalum was added. As binder phase, Ni or Ni/Co was used. Example 11: Thread-forming in galvanized plate Experiment no. 43: Tool: HSS M9 thread-former Material: DC 01 corresponding to DIN 1.0330, St 12 ZE Core hole diameter: 8.34 mm Cutting parameter: 55 m/sec. Cutting rotation speed: 2000 rotations/min. Rotation speed reverse: 3600 rotations/min. Lubrication: S26 CA TiN: 3200 threads TiCN: 3200 threads TiAIN: 3500 threads (Alo.66 Cro.34) N: 8800 threads Experiments with coated CBN (cubic boron nitride) or cermet tools: reversible cutting plates made of different CBN-sintering materials with a CBN-content between 30 - 99% by volume, rest being binding agents, were coated on one side with known TiAIN- coatings according to experiment 8 and on the other side with AlCrN-coatings as per the invention according to experiment 3, 5 and 6. However, on account of the non- conducting character of CBN-sintering material, for the etching and coating process pulsed substrate bias was applied in the medium frequency range, preferably in a frequency range of 20 to 250 KHz. For materials with a CBN-content up to 90%, a binding agent powder was used, which consists of at least one of the elements of the following group: nitride, carbide, boride and oxide of Ti-, V- or Cr-group, i.e. IVa-, Va- and Vla-elements as well as aluminium or Al- compounds. For materials with a CBN-content up to 95% a binding agent powder was used, which consists of titanium nitride and at least one of the elements of the following group: cobalt, nickel, tungsten carbide, aluminium or an aluminium compound. For materials with a CBN-content greater than 90%, also a binding agent powder was used which consists of titanium nitride and at least one of the elements of the following group: boride or boron nitride of alkali metals or mineral alkali metals. In subsequently conducted turning and milling experiments, in most cases one could find a clearly improved wear behaviour as compared to TiAIN-coatings. Similar was the case in a particularly cumbersome external turning experiment, in which only a partially hardened shaft of complex geometry was machined in interrupted cut. Example 12: Hot forging Tool: forging basin 4 St, 220 x 43 x 30 mm, Bohler W360, hardness 54 HRC, 4 tools simultaneously in grip Material: round material of diameter 22 mm, material 42 CrMo4 Process: temperature of work-piece before deformation 1050° C pressing force 57 t/per basin Cooling: molicote + graphite HS adhesive coating of TiN Example 13: Hot flanging Tool: HM flow drill of diameter 10 mm Work-piece: 1.0338 Process: the tool is pressed against the work-piece with a rotation speed of approx. 2800 rpm, 3000 N. Due to the kinetic energy the work-piece becomes red hot, i.e. is brought to approx. 1000° C and deformed. HS adhesive coating of TiN Example 14: Punching Tool: 1.2379, oblong punch 20 mm x 10 mm Work-piece: TRIP 700, 1.2 mm thickness Process: shear cutting, cutting gap 10%, 500 strokes/min., cutting force 20 kN We Claim: 1. Work piece coated with a system of film layers comprising at least one film composed of (AlyCr1-y)X, where X = N,C,B,CN, BN, CBN, NO, CO, BO, CNO, BNO or CBNO and 0.66 with the composition within (AlyCr1-y)X film being either essentially constant or varying over the thickness of the (AlyCr1-y) X film continually or in steps, said (AlyCr1-y)X film having a cubic crystal structure and said work piece constituting one of the following tools: a milling tool, (spherical-head) ball nose mill, planar or profiling cutter, a clearing tool, reamer, (indexable tip) insert for turning and milling, a die or an injection mold. 2. Tool as claimed in claim 1, wherein the tool is a forming tool of an upper die, a bottom swage, a drawing die, an ejector core; or a thread former. 3. Tool as claimed in claim 1, wherein the tool is an injection- molding tool for producing a molded plastic part or a data storage medium. 4. Tool as claimed in claim 1, wherein the tool features a CBN or Cermet base unit or that the tool is a CBN or Cermet (indexable tip) insert. 5. Process comprising the steps of machining a material with a tool recited in claim 1, wherein said machining used said tool is performed without the addition of lubricants or cooling agents. 6. Process as claimed in claim 5, wherein the tool is a hard-metal or HSS hob (cutter) and the cutting speed is 60 to 450 m/min. 7. Process as claimed in claim 5, wherein the tool is an end-milling (spherical-head) ball-nose-mill or a roughing cutter. 8. Work piece coated with a system of film layers comprising at least one film composed of (AlyCr1-y) X, where X = N, C, B, CN, BN, CBN, NO, CO, BO, CNO, BNO or CBNO and 0.66 with the composition within said (AlyCr1-y) X film being either essentially constant or varying over the thickness of the (AlyCr1-y) X film continually or in steps, said (AlyCr1-y) X film having a cubic crystal structure and said work piece constituting a machine component. 9. Machine component as claimed in claim 8 wherein said component is a sealing washer, a gear, a piston, a part of a valve drive or a needle for an injection nozzle, or that it is toothed. 10. Work piece as claimed in one of the claims 1-4, wherein a rate of wear of the (AlyCr1-y) X film is less than or equal to 1.5 m3m-1N- I10-15. 11. Work piece as claimed in one of the claims 1-4, wherein a Vickers pyramid hardness of the (AlyCr1-y) X film is 2300 to 3100. 12. Work piece as claimed in one of claims 1-4, wherein a layer structure of the (AlyCr1-y) X film is microcrystalline with an average grain size of 20 to 120 nm. 13. Work piece as claimed in one of claims 1-4, wherein bonding layer is applied between the work piece and the (AlyCr1-y) X film. 14. Work piece as claimed in claim 13, wherein said bonding layer encompasses at least one of the metals of group IV, V or subgroup VI, or aluminum. 15. Work piece as claimed in claim 13, wherein said bonding layer includes at least one nitride, carbide or carbonitride of one or several metal of subgroup IV, V or VI. 16. Work piece as claimed in claim 13, wherein at least one (AlyCr1-y) X film is additionally coated with a slip layer. 17. Work piece as claimed in claim 16, wherein said slip layer encompasses a carbide of at least one metal with dispersed carbon, MeC/C wherein Me is selected from among group IVb, Vb and Vib metals and silicon, a diamond-like carbon layer, a Si- or metallic diamond-like carbon layer, a MoSx, a WSX or a titanium- containing MoSx or MoWx layer. 18. PVD process for depositing at least one (AlyCr1-y) X film on a work piece, where X = N, C, B, CN, BN, CBN, NO, Ca, BO, CNO, BNO, CBNO and 0.66 installing at least one work piece in a vacuum coating system with at least one AlxzCr1-z target, where 0.25 the addition of a nitrogen-, carbon-, boron-, or oxygen-containing reactive gas and applying on the work piece of a substrate voltage of between -3 and -150V, as an arc or sputtering source, wherein the constituent composition within the said at least one (AlyCr1-y) x film is either essentially constant or varies either continuously or in steps over the thickness of the film said at least one (AlyCr1-y) X film having a cubic crystal structure, and said work piece being selected from among the work pieces recited in either of claims 1 or 8. 19. PVD process as claimed in claim 18, wherein X = N and the reactive gas is nitrogen or oxygen. 20. PVD process as claimed in claims 18 or 19, wherein the substrate voltage is pulsed. 21. PVD process as claimed in claims 18 or 19, wherein the AlxzCr1-z target is a power-metallurgically produced target. 22. PVD process as claimed in claim 21, wherein the target is produced by cold-pressing starting material in powder form with repeated subsequent reshaping, at temperatures under 660°C, densification by fluxing and cold fusion, arid transformation into its final state with a theoretical density at about 96 to 100%. Work piece coated with a system of film layers comprising at least one film composed of (AlyCr1-y)X, where X = N,C,B,CN, BN, CBN, NO, CO, BO, CNO, BNO or CBNO and 0.66 (AlyCr1-y)X film being either essentially constant or varying over the thickness of the (AlyCr1-y)X film continually or in steps, said (AlyCr1-y)X film having a cubic crystal structure and said work piece constituting one of the following tools: a milling tool, (spherical-head) ball nose mill, planar or profiling cutter, a clearing tool, reamer, (indexable tip) insert for turning and milling, a die or an injection mold.

Documents:

2348-KOLNP-2005-(28-09-2012)-CORRESPONDENCE.pdf

2348-KOLNP-2005-ASSIGNMENT.pdf

2348-KOLNP-2005-CORRESPONDENCE 1.1.pdf

2348-KOLNP-2005-CORRESPONDENCE.pdf

2348-KOLNP-2005-FORM 16.pdf

2348-KOLNP-2005-FORM-27.pdf

2348-kolnp-2005-granted-abstract.pdf

2348-kolnp-2005-granted-claims.pdf

2348-kolnp-2005-granted-correspondence.pdf

2348-kolnp-2005-granted-description (complete).pdf

2348-kolnp-2005-granted-drawings.pdf

2348-kolnp-2005-granted-examination report.pdf

2348-kolnp-2005-granted-form 1.pdf

2348-kolnp-2005-granted-form 18.pdf

2348-kolnp-2005-granted-form 2.pdf

2348-kolnp-2005-granted-form 26.pdf

2348-kolnp-2005-granted-form 3.pdf

2348-kolnp-2005-granted-form 5.pdf

2348-kolnp-2005-granted-letter patent.pdf

2348-kolnp-2005-granted-reply to examination report.pdf

2348-kolnp-2005-granted-specification.pdf

2348-KOLNP-2005-OTHERS PATENT DOCUMENTS.pdf