Process for coating implant and implant having ceramic multi-layer coating

Abstract

To provide a process to coat an implant which circumvents or at least mitigates detriments as described.SOLUTION: The invention relates to a process for coating an implant comprising the step of depositing a ceramic multi-layer coating on a surface of the implant via pulsed magnetron sputtering. Further, the invention refers to an implant having a ceramic multi-layer coating.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a process for coating an implant and to an implant having a ceramic multi-layer coating. [Background technology]

[0002] Applying hard, wear-resistant, and oxidation-reducing multilayer coatings to implants, especially those with concave geometries, is a challenging process. Such coatings typically require extensive post-coat polishing steps to meet surface finish requirements, especially for coating thicknesses of less than 50 nm.

[0003] It is known to apply multilayer coatings using cathodic arc deposition processes. However, this process often results in defects such as pinholes or droplets on the coated surface. Extensive post-polishing of such surfaces is required, which is inherently difficult, especially for concave geometries, where certain Food and Drug Administration (FDA) standards must be considered. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the foregoing, the object underlying the present invention is therefore to make available a process for coating implants which avoids or at least reduces the drawbacks as explained above. Furthermore, it is an object of the present invention to provide an implant with a ceramic multilayer coating. [Means for solving the problem]

[0005] This object is achieved by a process according to independent claim 1 and an implant according to independent claim 13. Preferred embodiments are defined in the dependent claims and in the description of the invention. The subject matter and wording of all claims, respectively, are incorporated herein by express reference.

[0006] According to a first aspect, the present invention relates to a process for coating an implant, in particular a medical or surgical implant, comprising: - depositing or applying a ceramic multilayer coating to the surface of the implant via, i.e. with the aid of, pulsed magnetron sputtering. The present invention relates to a process including:

[0007] The term "ceramic multilayer coating" as used in accordance with the present invention refers to a multilayer coating, i.e. a coating comprising or consisting of two or more layers, preferably 2, 3, 4, 5, 6, 7 or 8 layers, more preferably 7 or 8 layers, at least some, preferably all, of the layers of the coating comprising or consisting of ceramic materials, in particular hard ceramic materials, in particular as detailed in the following description.

[0008] The present invention is based, inter alia, on the surprising discovery that the drawbacks known from the prior art can be adequately overcome by depositing a ceramic multilayer coating on the surface of an implant. In particular, it has been found that pulsed magnetron sputtering results in fewer droplets, pinholes, and porosity than standard cathodic arc deposition, thus resulting in a smoother surface exhibiting higher wear resistance and a lower coefficient of friction, which is particularly advantageous for implants with sliding or articular-sliding surfaces. Thus, surface and coating defects can be advantageously reduced, and the need for extensive post-coat polishing can be reduced. Furthermore, the useful life of the implant can be advantageously extended.

[0009] In contrast to arc evaporation, pulsed magnetron sputtering, particularly pulsed DC magnetron sputtering and high-power pulsed magnetron sputtering, utilizes a relatively high cathode voltage to accelerate inert and / or reactive gas ions toward the sputter target, causing the ejection of target material (ions, atoms, etc.). On the other hand, arc evaporation uses a high target current to melt a small amount of target material that is subsequently evaporated. Both deposition techniques utilize commercially available physical vapor deposition (PVD) coating systems consisting of a stainless steel vacuum chamber, equipped with a heater, a cooling water system, a pumping system allowing a base pressure of <5 mPa, a rotating substrate table connected to a bias power supply, and a cathode on which the pure target material, particularly a metal target, is mounted. In contrast to arc evaporation, the target and / or bias voltages supplied for pulsed magnetron sputtering are preferably voltages with frequencies between 10 Hz and 900 MHz, making the technique suitable for coating poor conductors. For further details on pulsed DC magnetron sputtering and high-power impulse magnetron sputtering, reference is made to the following descriptions.

[0010] Pulsed magnetron sputtering largely utilizes the basic principles of magnetron sputter deposition, a relatively violent atomic-scale process typically performed in a diode plasma system known as a magnetron. On each magnetron, a target source, e.g., a pure metal, is bombarded with ions of a sputtering gas, e.g., argon and / or nitrogen. When struck by the gas ions, target atoms and / or ions are ejected and directed toward a substrate, forming a thin film composed of the sputtered target species.

[0011] To perform magnetron sputtering, a permanent magnet structure can be placed behind the target, which serves as the deposition source. Plasma confinement above the target surface can also be achieved by placing a permanent magnet structure behind the target surface. Magnets are used to confine electrons in the plasma, resulting in higher plasma density and thereby lowering discharge impedance, resulting in a significantly higher current, lower voltage discharge. The resulting magnetic field creates a closed-loop annular path that acts as an electron trap, reshaping the trajectories of secondary electrons emitted from the target into cycloidal orbits, significantly increasing the probability of ionization of the sputtering gas within the confinement zone. Inert and / or reactive gases, such as argon and / or nitrogen, are used as sputtering gases to achieve the desired coating composition: metallic coatings when argon is used alone, and stoichiometric ceramic coatings when a mixture of nitrogen and argon is used. Inert gases, such as argon, do not react with the target material or combine with reactive process gases, but they provide ions to increase the sputtering yield and therefore the deposition rate. To deposit metal nitrides, such as metal oxide nitrides, as ceramic materials, nitrogen is used to provide nitrogen ions. Here, nitrogen is ionized primarily by electron bombardment in the gas phase, and then reacts with metal targets or metal particles in the gas phase, depositing a ceramic film on the substrate.

[0012] Typically, pulsed magnetron sputtering is carried out using a deposition chamber as described above, which additionally includes at least one pulsed power supply connected to at least one magnetron (cathode).

[0013] In principle, pulsed magnetron sputtering according to the present invention can be carried out as pulsed DC (direct current) magnetron sputtering, RF (radio frequency) magnetron sputtering, MF (medium frequency) magnetron sputtering, high power impulse magnetron sputtering, or a combination thereof.

[0014] In one embodiment of the present invention, pulsed magnetron sputtering is performed as pulsed DC (direct current) magnetron sputtering. Pulsed DC (direct current) magnetron sputtering is based on the addition of a reverse voltage pulse to a normal DC waveform. This pulse, particularly provided by a pulse controller, doubles the sputtering of films, particularly dielectric films, that accumulate on the target surface when implemented at a sufficiently high frequency to effectively exploit the mobility difference between ions and electrons in the plasma, effectively eliminating target poisoning and arcing. In particular, each magnetron target alternately functions as an anode and a cathode in a pulse cycle, providing process stability over very long periods at high deposition rates. The magnetron can be operated in an asymmetric bipolar mode with a pulse repetition frequency, for example, in the range of 10 kHz to 300 kHz. Sputtering occurs from the target during a negative voltage pulse, and target surface discharge occurs during a subsequent positive voltage pulse (typically 10% of the nominal "on" voltage).

[0015] In a further embodiment of the invention, pulsed magnetron sputtering is carried out as high-power impulse magnetron sputtering. High-power impulse magnetron sputtering (HIPIMS or HiPIMS), also known as high-power pulsed magnetron sputtering (HPPMS), is a physical vapor deposition process of thin films based on magnetron sputter deposition. HIPIMS operates at significantly lower frequencies than DC magnetron sputtering, in particular in the order of 10 Hz to 10 kHz, especially in the order of 10 Hz to <10 kHz, and at low duty cycles (on / off time ratios) of <10%, in short pulses (impulses) of tens of microseconds, in particular kW cm. -2HIPIMS utilizes extremely high power densities, on the order of 10 W cm. The distinctive feature of HIPIMS is the high degree of ionization of the sputtered material and the resulting high molecular gas dissociation rate, which increases the density of the deposited film. The degree of ionization and dissociation increases with the peak cathode power. The limit is determined by the transition of the discharge from the glow discharge phase to the arc discharge phase. Typically, the peak power and duty cycle are much higher than those of conventional sputtering (1-10 W cm). -2 ) is chosen to maintain an average cathode power similar to

[0016] HIPIMS plasma has a discharge current density of several A cm -2 The discharge is produced by a glow discharge that can reach 100 volts, with the discharge voltage maintained at several hundred volts. The discharge is uniformly distributed over the surface of the cathode (target), but above a certain threshold current density, it becomes concentrated in a narrow ionized zone that moves along a path known as the target erosion "racetrack."

[0017] HIPIMS is particularly useful for detecting high fractions of target material ions, especially in the 10 13 ions cm -3This generates a high-density plasma on the order of 1000 keV. The primary ionization mechanism is electron bombardment, which is balanced by plasma emission due to charge exchange, diffusion, and flare. The ionization rate depends on the plasma density. The degree of ionization of the target vapor strongly depends on the peak current density of the discharge. At high current densities, sputtered ions with a charge state of 2+ or higher—up to 5+ for vanadium—can be generated. The emergence of target ions with a charge state higher than 1+ involves a potential secondary electron emission process, with an emission coefficient higher than the kinetic secondary electron emission seen in conventional glow discharges. The establishment of secondary electron emission can increase the discharge current. HIPIMS is typically operated in a short-pulse (impulse) mode with a low duty cycle to avoid overheating the target and other system components. During every pulse, the discharge goes through several stages: electrical breakdown, gas plasma, target material plasma, and steady state, which can be reached when the target material plasma is dense enough to effectively dominate the gas plasma.

[0018] The on-off cycle is preferably on the order of milliseconds. Because the duty cycle is low (preferably <10%), a relatively low average cathode power (preferably 1-20 kW) can be maintained. The target can cool during the "off time" to maintain process stability.

[0019] The discharge that sustains HIPIMS is a relatively high-current glow discharge, which can be transient or quasi-steady. Each pulse sustains the glow discharge for a critical duration, after which it transitions to an arc discharge. If the pulse length is kept below the critical duration, the discharge will operate stably indefinitely.

[0020] In a further embodiment of the present invention, in pulse magnetron sputtering, 2 to 30kW / cm 2 , especially 0.01kW / cm 2 to 0.5kW / cm 2 , preferably 0.01 kW / cm2 to 0.1kW / cm 2 or 0.1 kW / cm 2 to 30kW / cm 2 , especially 0.1kW / cm 2 to 10kW / cm 2 , preferably 0.1 kW / cm 2 to 5kW / cm 2 Preferably, when the pulse magnetron sputtering is carried out as high power impulse magnetron sputtering, pulses having a peak power density of 0.1 kW / cm are generated. 2 to 30kW / cm 2 , especially 0.1kW / cm 2 to 10kW / cm 2 , preferably 0.1 kW / cm 2 to 5kW / cm 2 A pulse having a peak power density of

[0021] Furthermore, in pulse magnetron sputtering, 0.01A / cm 2 to 3A / cm 2 , especially 0.5A / cm 2 to 1A / cm 2 A pulse having a peak current density of

[0022] In a further embodiment of the invention, pulses having a frequency of 10 Hz to 300 kHz, in particular 20 Hz to 300 kHz, in particular 10 kHz to 300 kHz, preferably 10 kHz to 100 kHz, or pulses having a frequency of 10 Hz to 10 kHz or 10 Hz to <10 kHz, in particular 20 Hz to 10 kHz or 20 Hz to <10 kHz, preferably 40 Hz to 1000 Hz, are generated in pulse magnetron sputtering. Preferably, when pulse magnetron sputtering is carried out as high-power impulse magnetron sputtering, pulses having a frequency of 10 Hz to 10 kHz or 10 Hz to <10 kHz, in particular 20 Hz to 10 kHz or 20 Hz to <10 kHz, preferably 40 Hz to 1000 Hz are generated.

[0023] In a further embodiment of the invention, in pulse magnetron sputtering, pulses having a voltage of 200V to 800V, preferably 300V to 700V, are generated.

[0024] In a further embodiment of the invention, in pulsed magnetron sputtering, preferably high power impulse magnetron sputtering, pulses are generated having a duration of 10 μs to 200 μs, preferably 40 μs to 150 μs.

[0025] Furthermore, the ceramic multilayer coating may be deposited on the surface of the implant at a temperature of 120°C to 400°C, preferably 250°C to 400°C.

[0026] Furthermore, the ceramic multilayer coating is applied to the surface of the implant. -3 mbar to 10 -2 mbar, preferably 2 × 10 -3 mbar to 7×10 -3 It can be deposited under a pressure of 1000 mbar.

[0027] In a further embodiment of the present invention, a ceramic material selected from the group consisting of chromium nitride, chromium carbonitride, zirconium chromium nitride, zirconium nitride, and a combination of at least two of the aforementioned ceramic materials is sputtered and deposited layer by layer on the surface of the implant by pulsed magnetron sputtering to produce a ceramic multilayer coating. The aforementioned ceramic materials have the particular advantage of being biocompatible.

[0028] In a further embodiment of the present invention, a material, particularly a metal material, preferably zirconium, or a metal-containing material, particularly a metal nitride, preferably zirconium nitride, or a metal oxide, particularly zirconium oxide, is sputtered in the presence of oxygen, particularly molecular oxygen (dioxygen, O) and / or nitrogen, particularly molecular nitrogen (dinitrogen, N), to form an oxide or oxynitride layer, particularly a metal oxide or metal oxynitride layer, preferably an outer oxide or outer oxynitride layer, particularly an outer metal oxide or outer metal oxynitride layer, of a ceramic multilayer coating. Preferably, the metal oxide layer is a zirconium oxide layer, particularly the outer zirconium oxide layer, of a ceramic multilayer coating. The metal oxynitride layer is a zirconium oxynitride layer, particularly the outer zirconium oxynitride layer, of a ceramic multilayer coating. The oxide layer may have an oxide gradient or a discontinuous oxygen content.

[0029] The addition of an oxide or oxynitride layer, particularly a metal oxide or metal oxynitride layer, as an outer layer of a ceramic multilayer coating advantageously stabilizes the oxidation rate of the ceramic multilayer coating. Even more advantageously, the addition of an oxide or oxynitride layer does not impair any of the properties of the ceramic multilayer coating, but has beneficial aspects such as reducing discoloration due to oxidation of the outer layer of the ceramic multilayer coating and / or reducing wear of the ceramic multilayer coating.

[0030] The term "oxide layer" as used in accordance with the present invention refers to a layer that comprises or consists of an oxide.

[0031] The term "oxynitride layer" as used in accordance with the present invention refers to a layer that includes or consists of an oxynitride.

[0032] The term "metal oxide layer" as used in accordance with the present invention refers to a layer comprising or consisting of a metal oxide.

[0033] The term "metal oxynitride layer" as used in accordance with the present invention refers to a layer that includes or consists of a metal oxynitride.

[0034] The term "zirconium oxide layer" as used in accordance with the present invention refers to a layer comprising or consisting of zirconium oxide.

[0035] The term "zirconium oxynitride layer" as used in accordance with the present invention refers to a layer that includes or consists of zirconium oxynitride.

[0036] The term "outer oxide layer" as used in accordance with the present invention refers to the oxide layer of the ceramic multi-layer coating that separates the ceramic multi-layer coating from its surroundings.

[0037] The term "outer oxynitride layer" as used in accordance with the present invention refers to the oxynitride layer of the ceramic multi-layer coating that separates the ceramic multi-layer coating from its surroundings.

[0038] The term "outer metal oxide layer" as used in accordance with the present invention refers to the metal oxide layer of the ceramic multilayer coating that separates the ceramic multilayer coating from its surroundings. Accordingly, the term "outer zirconium oxide layer" as used in accordance with the present invention refers to the zirconium oxide layer of the ceramic multilayer coating that separates the ceramic multilayer coating from its surroundings.

[0039] The term "outer metal oxynitride layer" as used in accordance with the present invention refers to a metal oxynitride layer of a ceramic multi-layer coating that separates the ceramic multi-layer coating from its surroundings. Accordingly, the term "outer zirconium oxynitride layer" as used in accordance with the present invention refers to a zirconium oxynitride layer of a ceramic multi-layer coating that separates the ceramic multi-layer coating from its surroundings.

[0040] By applying an outer metal oxide or metal oxynitride layer, the oxidation rate of the surface of the implant can be advantageously stabilized. Thus, the service life of the implant can be further extended. Furthermore, the release of metal ions, and therefore the coefficient of friction of the surface of the implant, can be (additionally) reduced.

[0041] In a further embodiment of the invention, in pulsed magnetron sputtering, the following layer is deposited on the surface of the implant: a) a chromium nitride layer, b) a chromium carbonitride layer; c) a chromium nitride layer; d) a chromium carbonitride layer; e) a chromium nitride layer; f) a zirconium chromium nitride layer, and g) Zirconium nitride layer are deposited in particular directly or indirectly, preferably directly, on top of one another, preferably in the order a) to g), to produce a ceramic multilayer coating.

[0042] The term "chromium nitride layer" as used in accordance with the present invention refers to a layer that comprises or consists of chromium nitride.

[0043] The term "chromium carbonitride layer" as used in accordance with the present invention refers to a layer comprising or consisting of chromium carbonitride.

[0044] The term "zirconium chromium nitride layer" as used in accordance with the present invention refers to a layer comprising or consisting of zirconium chromium nitride.

[0045] The term "zirconium nitride layer" as used in accordance with the present invention refers to a layer comprising or consisting of zirconium nitride.

[0046] In a further embodiment of the invention, in pulsed magnetron sputtering, the following layer is deposited on the surface of the implant: a) a chromium nitride layer, b) a chromium carbonitride layer; c) a chromium nitride layer; d) a chromium carbonitride layer; e) a chromium nitride layer; f) a zirconium chromium nitride layer; g) a zirconium nitride layer, and h) an oxide or oxynitride layer, in particular a metal oxide layer, preferably a zirconium oxide layer, or a metal oxynitride layer, preferably a zirconium oxynitride layer are deposited in particular directly or indirectly, preferably directly, on top of one another, preferably in the order a) to h), to produce a ceramic multilayer coating.

[0047] The advantages of the present invention are particularly evident in the two preceding embodiments.

[0048] In a further embodiment of the invention, the surface of the implant is or comprises a concave surface. Alternatively, or in combination, the surface of the implant is or comprises a convex and / or flat surface.

[0049] In a further embodiment of the invention, the surface of the implant is or comprises a joint sliding or gliding surface, in particular the surface of an artificial glenoid cavity such as a prosthetic acetabular cup, a prosthetic acetabular liner, a femoral component or a shoulder joint prosthesis. Alternatively, the surface of the implant may be the inner surface of a head bore.

[0050] In a further embodiment of the invention, the implant is a joint implant (articular surface implant), in particular selected from the group consisting of tibial implants, femoral implants, knee joint implants, hip joint implants, ankle joint implants, shoulder joint implants, mandibular joint implants, elbow joint implants, finger joint implants and spinal joint implants, or components thereof. In particular, the component may be in the form of an artificial glenoid cavity. More preferably, the component is a component of a hip joint implant, in particular an artificial acetabular cup or an artificial acetabular liner.

[0051] According to a second aspect, the present invention refers to an implant having a ceramic multilayer coating, the implant being produced or being producible according to the process according to the first aspect of the invention and / or the ceramic multilayer coating comprising an oxide or oxynitride layer, in particular a metal oxide or metal oxynitride layer, as an outer layer.

[0052] Preferably, the metal oxide layer is a zirconium oxide layer.

[0053] Particularly preferably, the metal oxynitride layer has the formula ZrO, in particular where 1-x=y and x<1. y N x The zirconium oxynitride layer has the following structure:

[0054] In a further embodiment of the present invention, an oxide or oxynitride layer, in particular a metal oxide or metal oxynitride layer, in particular directly or indirectly, preferably directly, forms the zirconium nitride layer of the ceramic multilayer coating.

[0055] In a further embodiment of the present invention, the ceramic multilayer coating comprises the following layers: a) a chromium nitride layer, b) a chromium carbonitride layer; c) a chromium nitride layer; d) a chromium carbonitride layer; e) a chromium nitride layer; f) a zirconium chromium nitride layer; g) a zirconium nitride layer, and h) an oxide or oxynitride layer, in particular a metal oxide layer, preferably a zirconium oxide layer, or a metal oxynitride layer, preferably a zirconium oxynitride layer Preferably, the composition comprises or consists of the following in the order a) to h):

[0056] In principle, the chromium nitride layer a) may be layered directly or indirectly on the surface of the implant, preferably the chromium nitride layer a) is layered directly on the surface of the implant.

[0057] Furthermore, layers a) to h) may be arranged directly or indirectly, preferably directly, on top of one another.

[0058] More preferably, the ceramic multilayer coating has a thickness, measured in particular according to ISO 26423 and / or ISO 1463, of 2 μm to 10 μm, preferably 3.5 μm to 6 μm.

[0059] More preferably, the ceramic multilayer coating has an average surface roughness of <0.04 μm, in particular 0.01 μm to 0.03 μm, measured in particular according to ISO 21920-2 and / or ISO 21920-3.

[0060] More preferably, the ceramic multilayer coating has an HRC (Rockwell C scale) adhesion of ISO Class 1 or higher, in particular measured according to ISO 26443.

[0061] With regard to further features and advantages of the implant according to the second aspect of the invention, reference is made in general to the features and advantages mentioned under the first aspect of the invention, where applicable.

[0062] Further features and advantages of the invention will become apparent from the following examples in conjunction with the subject matter of the dependent claims. The individual features may be realized alone or in combination in a plurality of embodiments of the invention. The preferred embodiments are merely illustrative and serve for a better understanding of the invention and should not be understood as limiting the invention in any way.

[0063] For a better understanding of the disclosed subject matter, some figures are attached which show, purely by way of non-limiting example, practical cases of embodiments of the invention.

[0064] The figure presents the following: [Brief explanation of the drawings]

[0065] [Figure 1a] FIG. 1 shows a detailed SEM image of the surface of a zirconium nitride multilayer coating applied via a PVD (physical vapor deposition) process. [Figure 1b] Figure 1 shows a detailed SEM image of the surface of a zirconium nitride multilayer coating applied via high-power impulse magnetron sputtering, which clearly shows that pulsed magnetron sputtering produces a smoother surface with fewer visible defects. [Figure 2] FIG. 1 shows, in schematic form, an enlarged detailed representation of an implant 1 coated with a ceramic multilayer coating 10. DETAILED DESCRIPTION OF THE INVENTION

[0066] The ceramic multilayer coating 10 is deposited on the surface 2 of the implant 1 via pulsed magnetron sputtering, in particular pulsed DC (direct current) magnetron sputtering or high power impulse magnetron sputtering.

[0067] The ceramic multilayer coating 10 includes or consists of eight layers 10a-10h. The surface 2 of the implant 2 is directly coated with a first chromium nitride layer 10a. The first chromium nitride layer 10a is directly coated with a first chromium carbonitride layer 10b. The first chromium carbonitride layer 10b is directly coated with a second chromium nitride layer 10c. The second chromium nitride layer 10c is directly coated with a second chromium carbonitride layer 10d. The second chromium carbonitride layer 10d is directly coated with a third chromium nitride layer 10e. The third chromium nitride layer 10e is directly coated with a chromium zirconium nitride layer 10f. The chromium zirconium nitride layer 10f is directly coated with a zirconium nitride layer 10g. The zirconium nitride layer 10g is directly coated with the zirconium oxynitride layer 10h.

[0068] For further features and advantages of the implant 1, the ceramic multilayer coating 10 and pulsed magnetron sputtering, in particular pulsed DC magnetron sputtering or high power impulse magnetron sputtering, reference is made to the features and advantages mentioned in the general description where applicable. [Explanation of symbols]

[0069] 1. Implants 2 surface 10 Ceramic multilayer coating 10a~10h layer

Claims

1. 1. A process for coating an implant, comprising: - depositing a ceramic multilayer coating on the surface of said implant via pulsed magnetron sputtering; A process involving:

2. 2. The process of claim 1, wherein the pulsed magnetron sputtering is performed as pulsed DC magnetron sputtering.

3. 2. The process of claim 1, wherein the pulse magnetron sputtering is performed as high-power impulse magnetron sputtering.

4. In the pulse magnetron sputtering, 0.01 kW / cm ２ to 30 kW / cm ２ , especially 0.01 kW / cm ２ to 0.5 kW / cm ２ , preferably 0.01 kW / cm ２ to 0.1 kW / cm ２ 4. The process according to claim 1, wherein pulses are generated having a peak power density of

5. 5. The process according to claim 1, wherein in the pulsed magnetron sputtering, pulses are generated having a frequency of 10 Hz to 300 kHz, in particular 10 kHz to 300 kHz, preferably 10 kHz to 100 kHz.

6. 6. A process according to any one of claims 1 to 5, characterized in that in the pulse magnetron sputtering pulses are generated having a voltage of 200V to 800V, preferably 300V to 700V.

7. 7. A process according to any one of claims 1 to 6, characterized in that in the pulsed magnetron sputtering pulses are generated having a duration of 10 μs to 200 μs, preferably 40 μs to 150 μs.

8. 8. The process according to claim 1, wherein in the pulsed magnetron sputtering, a ceramic material selected from the group consisting of chromium nitride, chromium carbonitride, zirconium chromium nitride, zirconium nitride, and a combination of at least two of the above ceramic materials is sputtered and deposited layer by layer on the surface of the implant to produce the ceramic multilayer coating.

9. 9. The process according to claim 1, further characterized in that in the pulse magnetron sputtering, a material, in particular a metallic material, preferably zirconium, or a metal-containing material, in particular a metal nitride, preferably zirconium nitride, is sputtered in the presence of oxygen and / or nitrogen to form an outer oxide or outer oxynitride layer, in particular an outer metal oxide or outer metal oxynitride layer, of the ceramic multilayer coating.

10. In the pulsed magnetron sputtering, the following layers are deposited on the surface of the implant: a) a chromium nitride layer; b) a chromium carbonitride layer; c) a chromium nitride layer; d) a chromium carbonitride layer; e) a chromium nitride layer; f) a zirconium chromium nitride layer; g) a zirconium nitride layer, and optionally h) an oxide or oxynitride layer, in particular a metal oxide layer, preferably a zirconium oxide layer, or a metal oxynitride layer, preferably a zirconium oxynitride layer; are deposited, in particular directly on top of each other, preferably in the order a) to g) or optionally in the order a) to h), to produce the ceramic multilayer coating.

11. 11. The process according to any one of claims 1 to 10, characterized in that the surface of the implant is a concave surface and / or a joint-sliding surface.

12. 12. The process according to any one of claims 1 to 11, characterized in that the implant is a joint implant, in particular selected from the group consisting of tibial implants, femoral implants, knee joint implants, hip joint implants, ankle joint implants, shoulder joint implants, mandibular joint implants, elbow joint implants, finger joint implants and spinal joint implants, or components thereof.

13. 13. An implant having a ceramic multilayer coating, characterized in that the implant is produced or is producible according to a process according to any one of claims 1 to 12 and / or the ceramic multilayer coating comprises as an outer layer an oxide or oxynitride layer, in particular a metal oxide layer, preferably a zirconium oxide layer, or a metal oxynitride layer, preferably a zirconium oxynitride layer.

14. 14. The implant according to claim 13, characterized in that the oxide or oxynitride layer, in particular a metal oxide or metal oxynitride layer, in particular directly forms the zirconium nitride layer of the ceramic multilayer coating.

15. The ceramic multilayer coating comprises the following layers: a) a chromium nitride layer; b) a chromium carbonitride layer; c) a chromium nitride layer; d) a chromium carbonitride layer; e) a chromium nitride layer; f) a zirconium chromium nitride layer; g) a zirconium nitride layer, and h) said oxide layer or oxynitride layer, in particular a metal oxide layer, preferably a zirconium oxide layer, or a metal oxynitride layer, preferably a zirconium oxynitride layer; 15. An implant according to claim 13 or 14, characterized in that it comprises or consists of, preferably in the order a) to h).

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