Method for producing a ceramic bearing component, ceramic bearing component, and hybrid bearing having such a component

Abstract

Disclosed is a method for producing a ceramic bearing component (1), wherein the method comprises the following steps: providing (S1) the ceramic bearing component (2), which has a naturally occurring oxide layer (4) with a first thickness (d1); and at least partially modifying (S2, S3, S4, S5) the naturally occurring oxide layer (4) on the surface of the ceramic component (1) and / or of the ceramic material.

Description

[0001] Description

[0002] Manufacturing method of a ceramic bearing component, ceramic bearing component and hybrid bearing comprising such a component

[0003] Technical area

[0004] The present invention relates to a manufacturing method of a ceramic bearing component according to the preamble of patent claim 1. Furthermore, the present invention relates to a ceramic bearing component and a hybrid bearing with a ceramic bearing component.

[0005] Technical background

[0006] Bearings are generally known for enabling relative rotational movement between two components. A distinction is made between plain bearings, in which the two relatively moving parts are in direct contact, and rolling bearings, in which rolling elements are arranged between an inner and outer ring. Both plain bearings and rolling bearings incorporate lubrication to reduce frictional resistance between the moving parts of the bearings.

[0007] Under harsh operating conditions, such as higher loads combined with higher temperatures, thinner lubricant films, and / or inadequate lubrication conditions, the components of a bearing can suffer surface-initiated fatigue, known as micropitting, which can further lead to denting, surface-initiated chipping, and seizure. Under such harsh conditions, it may be necessary to use a so-called hybrid bearing, in which at least one component is made of a ceramic. For example, in a hybrid rolling bearing, at least one rolling element, or even all of the rolling elements, can be made of a ceramic, while the bearing ring or bearing raceways are made of steel.

[0008] In particular, ceramic bearing components often exhibit greater hardness and / or a higher modulus of elasticity than steel bearing components. Furthermore, they can also exhibit lower density and thus be lighter than steel components, which, for example, allows a higher speed limit to be achieved in the case of a hybrid rolling bearing. Furthermore, ceramic bearing components can exhibit greater wear resistance, improved grease life, and / or lower bearing temperatures. Additionally, steel-ceramic contact can be advantageous from a tribological perspective. A further advantage of ceramic components is that they are electrically insulating. Therefore, hybrid bearings are often used in very demanding environments, such as in applications with reduced lubrication conditions and / or in high-speed and / or high-temperature applications.

[0009] In order to further reduce friction losses and / or damage to the components of a bearing, such as the sliding surfaces of a plain bearing and / or the raceways of the rolling bearing and / or the rolling elements, it is desirable to optimize the surface properties of the ceramic components of a hybrid bearing.

[0010] It is therefore an object of the present invention to provide a manufacturing method of a ceramic bearing component in order to optimize the surface properties of the ceramic components of a hybrid bearing.

[0011] Summary of the invention

[0012] This object is achieved by a manufacturing method of a ceramic bearing component according to patent claim 1.

[0013] A manufacturing process for a ceramic bearing component is proposed below. The process comprises the following steps:

[0014] Providing the bearing component from a ceramic material having a naturally occurring oxide layer with a first thickness, and at least partially modifying the naturally occurring oxide layer on the surface of the ceramic bearing component and / or the ceramic material.

[0015] The ceramic component can, in particular, be a rolling element. For example, the ceramic component can be a ball, a tapered roller, a cylindrical roller, a needle roller, a spherical roller, or the like. Furthermore, a ceramic rolling element can be solid or hollow. Furthermore, the ceramic component can be a sliding surface for an inner ring and / or an outer ring for a plain bearing. Alternatively or additionally, the ceramic component can form a raceway on which the rolling elements can roll. For example, the ceramic component can be an inner ring or an outer ring of a rolling bearing.

[0016] The ceramic component can be formed, in particular, from silicon nitride (SiSn). Alternatively, the ceramic component can be formed from aluminum oxide (Al2O3), zirconium oxide (ZrO, ZrO?), and / or silicon carbide. For example, zirconium oxide can have a thermal expansion comparable to steel, so that it can be used, in particular, for bearing rings. In particular, the ceramic material can form a ceramic base matrix in which further elements can be embedded. The further elements can be, for example, metals such as aluminum, tungsten, titanium, iron, yttrium, zirconium, cerium, magnesium, or the like. Furthermore, carbon, oxygen, and / or silicon and / or combinations of the aforementioned can also be embedded in the ceramic base matrix. In particular, the ceramic material and / or the ceramic base matrix can comprise only a single ceramic base material.Furthermore, the single ceramic base material may contain unavoidable impurities.

[0017] Furthermore, the ceramic component can be manufactured using a known process. For example, the ceramic component can be densified and / or manufactured in a gas-pressure sintering furnace (GPS) and / or by hot isostatic pressing (HIP).

[0018] Ceramics, such as silicon nitride, form an oxide layer on their surface through interaction with air and / or water, which is present, for example, in the atmosphere. The thickness and composition of the oxide layer depends on numerous influencing factors during the production and storage of the ceramic rolling elements, such as temperature, humidity, and grinding media. Since this oxide layer is located on the surface of the ceramic component, it can also influence the properties of the ceramic component, such as its running characteristics and / or interaction with other substances, such as the lubricant.

[0019] In order to optimize the surface properties of the ceramic bearing component, in particular the naturally occurring oxide layer is at least partially modified. When modifying the naturally occurring oxide layer on the surface of the ceramic component, for example, the thickness of the naturally occurring oxide layer can be changed. In particular, the oxide layer can be enlarged or reduced. A chemical composition of the oxide layer and / or a layer on the surface of the ceramic component can also be changed. Furthermore, the oxide layer can be modified on the entire surface of the ceramic component, i.e. globally, and / or in at least one section of the surface of the ceramic component, i.e. locally. For example, the surface of the ceramic component can be modified point by point and / or in strips and / or according to a predetermined pattern.Furthermore, in a case where the surface is first subjected to a first modification and then to a second modification, the first modification may be global and the second modification local, or the first modification may be local and the second modification global, or both modifications may be global, or both modifications may be local. Furthermore, if both modifications are local, they may be performed on the same sections and / or on different sections.

[0020] By modifying the naturally occurring oxide layer, the interaction between a lubricant and the ceramic component can be advantageously altered. For example, the wetting properties of the surface of the ceramic bearing component can be improved and / or adjusted. Surface roughness can also be modified. Furthermore, the at least partially modified surface can also reduce friction losses and / or increase maintenance intervals for a hybrid bearing, thereby further reducing costs.

[0021] According to a preferred embodiment, the modification comprises treating the ceramic component with heat. The heat treatment can be carried out in a furnace in a gas, for example in air, and / or in a liquid, for example in a bath, but also with radiation, for example with a laser. In particular, the heat treatment can be carried out in an arbitrarily adjustable atmosphere and / or in a solution bath and / or in a salt bath that has been heated, for example, to the melting point of the salt, but also under vacuum. Advantageously, the heat treatment can be carried out below a crystallization temperature of the ceramic material. The term crystallization temperature is understood in particular to mean a temperature at which crystal growth begins.

[0022] After heat treatment, the ceramic component can have an oxide layer with a second thickness on its surface. For example, the second thickness can be greater than the first thickness. In other words, the thickness of the oxide layer can be modified by heat treatment. In addition, the chemical composition of the oxide layer can also be changed by heat treatment. For example, heat treatment can facilitate the gradual transition from the ceramic matrix, for example, made of silicon nitride (SiSn4), via a nitrogen-poor oxy-nitride layer (SiN x O y ) to silicon dioxide (SiO?) on the surface.

[0023] The treatment of the ceramic component with heat can, in particular, comprise heating the ceramic component to a first predetermined temperature for a predetermined first period of time. Advantageously, the first predetermined temperature can be below a crystallization temperature of the ceramic material. Furthermore, the treatment of the ceramic component with heat can comprise cooling the heated component to a predetermined second temperature over a second predetermined period of time. For example, the ceramic component can be cooled to room temperature. Alternatively, the ceramic component can also be slowly cooled down to several temperatures over a predetermined period of time in order to prevent stress cracks in the ceramic component. Advantageously, a heat treatment can influence residual stress in the ceramic component.

[0024] Furthermore, modifying the naturally occurring oxide layer and / or the ceramic material can comprise implanting ions and / or exchanging ions. The implantation of ions can be carried out, for example, by treating the ceramic component with ions over its entire surface, whereby the ceramic component can be exposed, for example, to a salt bath and / or a solution, and / or by irradiating the ceramic component with at least one ion beam and / or a plasma. For example, the ion beam can be scanned over the ceramic component. Furthermore, the treatment of the ceramic component with at least one ion beam and / or a plasma can be carried out below a crystallization temperature.

[0025] Alternatively, a sputtering process can be used. This can, for example, remove unwanted deposits of other chemical elements in the naturally occurring oxide layer. This makes it possible to obtain an oxide layer that is as free as possible from unwanted chemical elements. Furthermore, by implanting and / or exchanging ions, ions can be specifically exchanged and / or introduced into the oxide layer and / or the ceramic material in order to modify the chemical composition of the oxide layer and / or the ceramic material.

[0026] For example, the oxide layer and / or the ceramic material can have regions in which the material of the oxide layer and / or the ceramic material is present in a glass phase. A glass phase can, in particular, comprise elements and / or molecules that act as network formers and elements and / or molecules that act as network additives. Preferably, ion exchange can occur in the glass phase regions. In particular, ions can be exchanged with the network formers and / or the network additives. Furthermore, the implantation of ions and / or the exchange of ions can also occur before and / or after and / or during a heat treatment of the ceramic component.

[0027] According to a further embodiment, modifying the naturally occurring oxide layer can comprise irradiating the ceramic component with light. In particular, the light can be a laser beam. For example, interaction with the light can trigger a chemical reaction in the oxide layer and / or specifically ionize certain chemical elements. In particular, a light beam and / or laser beam can be used to locally modify the oxide layer. For example, the oxide layer can be locally heated and / or locally chemically altered by light. Ultraviolet light, i.e., light with a wavelength of less than 400 nm, preferably between 100 nm and 380 nm, and / or infrared light, i.e., light with a wavelength of greater than 780 nm, preferably between 800 nm and 10 pm, can be used.

[0028] Preferably, the modification may include etching the ceramic component. Etching may be performed, for example, with an acid. An inorganic acid may be used as the acid. For example, hydrofluoric acid (HF), hydrochloric acid (HCl), and / or nitric acid (HNO3) may be used. Furthermore, an organic acid may be used for etching. For example, acetic acid (CH3COOH) may be used.

[0029] Furthermore, an inorganic and / or organic base can be used to etch the ceramic bearing component. For example, potassium hydroxide (KOH), sodium carbonate, and / or amines can be used. Alternatively or additionally, plasma etching can be used to modify the naturally occurring oxide layer.

[0030] Depending on the ceramic material and the acid used, a transition of the ceramic material into a glass phase or amorphization can also be achieved. Furthermore, it is possible to achieve chemical activation of the layers through acid treatment. Activation is understood in particular to mean that the oxide layer and / or the ceramic material are prepared for specific reactions by converting the oxide layer and / or the ceramic material into an intermediate compound suitable for the specific reaction.

[0031] Preferably, modifying the naturally occurring oxide layer can comprise at least partially removing the naturally occurring oxide layer of the ceramic component. For example, at least partially removing the naturally occurring oxide layer of the ceramic component can be done with at least one acid and / or with a plasma. In particular, the oxide layer can be at least partially removed by etching. However, it is also possible to completely remove the oxide layer so that the ceramic material of the component, i.e. the base matrix, is freely accessible. In particular, hydrofluoric acid (HF) can be suitable for completely removing the oxide layer on a silicon nitride base matrix. Alternatively or additionally, the oxide layer can be cleaned and / or removed mechanically and / or thermally.In particular, a combination can also be used, for example, combining chemical modification with mechanical removal.

[0032] To prevent the oxide layer from re-forming after removal, the oxide layer can be removed in a vacuum and / or in an environment enriched with a medium that does not react with the base matrix of the ceramic component. For example, the oxide layer can be removed in a protective atmosphere, which includes, for example, a noble gas and / or a shielding gas. Additionally or alternatively, the ceramic component can be coated after removal of the oxide layer to prevent the oxide layer from re-forming.

[0033] Furthermore, after etching the ceramic component, the etched ceramic component can be treated with at least one chemical or with another chemical or with several chemicals. This can, for example, provide a surface of the ceramic component with a predetermined chemical composition. This predetermined chemical composition can, for example, improve the wetting properties of the surface and / or enable better interaction with a lubricant. Furthermore, other surface properties, such as hardness, of the ceramic component can also be modified using the at least one additional chemical.Preferably, a heat treatment can also be carried out during the etching of the ceramic component and / or after the etching of the ceramic component and / or during the treatment of the ceramic component with at least one further chemical and / or after the treatment of the ceramic component with at least one further chemical.

[0034] According to a further embodiment, the modification comprises activating at least a portion of the naturally occurring oxide layer and / or the ceramic material, such that the at least a portion of the naturally occurring oxide layer and / or the ceramic material is converted into a suitable intermediate compound for at least one specific reaction. For example, the activation of at least a portion of the naturally occurring oxide layer and / or the ceramic material can be achieved by plasma, in particular by nitrogen plasma, oxygen plasma, and / or hydrocarbon plasma, by electromagnetic radiation, in particular by ultraviolet and / or infrared light, by chemical modification, by removal of the naturally occurring oxide layer, and / or mechanically, in particular by pressure.

[0035] Preferably, modifying the naturally occurring oxide layer comprises functionalizing at least part of the naturally occurring oxide layer and / or the ceramic material, such that at least part of the naturally occurring oxide layer and / or the ceramic material has at least one chemical compound with at least one predetermined functional group. In particular, the functional group can be selected such that the ceramic component and / or a surface of the ceramic material has a desired function and / or desired chemical and / or physical material property. The term “functionalization” can be understood as adapting the chemical composition at least on one surface of the ceramic component. In particular, a chemical composition of the outermost atomic and / or molecular layer orLayers are changed so that the ceramic component and / or a surface of the ceramic material has a desired function and / or desired chemical and / or physical material property.

[0036] The specified functional group can be attached, for example, at an interface, within the interface, and / or beneath the interface. The interface can be, for example, the surface of the ceramic material, the surface of the naturally occurring oxide layer, or a transition layer between the ceramic material and the oxide layer. For example, during functionalization, a selected chemical compound can be bonded to the atoms or molecules of the surface. Furthermore, during functionalization, the chemical composition of the surface can be adjusted to a depth of up to 200 μm.

[0037] Furthermore, the functional group can be an elemental ligand, preferably fluorine, hydrogen, oxygen, and / or nitrogen. Furthermore, the functional group can be selected from the group of salts, in particular from the group of soaps. In particular, a soap can be understood as a salt of a fatty acid, wherein the corresponding soap comprises a metal and an organic radical (R*). For example, the functional group can be calcium soap (Ca-R*), lithium soap (Li-R*), aluminum soap (Al-R*), etc. Furthermore, the salts and soaps can be present in an aqueous solution. Advantageously, a functional group selected from the group of salts and / or the group of soaps can improve the interaction between polar elements and compounds, for example, water, and nonpolar elements and compounds, for example, oils and / or fats, which can be present, for example, in lubricants.

[0038] According to a further preferred embodiment, the functional group is a solid lubricant. For example, the functional group can be boron nitride (BN) and / or molybdenum sulfide (MOS2). Furthermore, the functional group can be selected from at least one of the following: silanes, complexes, alcohols, micelles, hydrocarbons, in particular aliphatic hydrocarbons, and / or chlorinated hydrocarbons.

[0039] According to a further aspect, a ceramic bearing component is proposed, wherein the ceramic component has a naturally occurring oxide layer with a first thickness on its surface. The ceramic component is manufactured according to the above-mentioned manufacturing method. In particular, the ceramic component can be formed from silicon nitride. According to yet another aspect, a hybrid bearing with at least one ceramic bearing component described above is proposed.

[0040] Further advantages and advantageous embodiments are set forth in the description, the drawings, and the claims. In particular, the combinations of features set forth in the description and the drawings are purely exemplary, so the features may also be present individually or in other combinations.

[0041] Short character description

[0042] The invention will be described in more detail below with reference to exemplary embodiments illustrated in the drawings. The exemplary embodiments and the combinations shown in the exemplary embodiments are purely exemplary and are not intended to define the scope of the invention. This scope is defined solely by the appended claims.

[0043] Shown are: Fig. 1: a schematic representation of a manufacturing method of a ceramic bearing component according to a first embodiment,

[0044] Fig. 2: a schematic representation of a manufacturing method of a ceramic bearing component according to a second embodiment,

[0045] Fig. 3: a schematic representation of a manufacturing method of a ceramic bearing component according to a third embodiment, and

[0046] Fig. 4: a hybrid bearing with at least one ceramic component that is manufactured according to one of the processes shown in Fig. 1 - 3.

[0047] Detailed description of the invention

[0048] In the following, identical or functionally equivalent elements are identified by the same reference symbols.

[0049] Fig. 1 shows a schematic representation of a manufacturing method of a ceramic bearing component 1 according to a first embodiment, wherein only a section of the ceramic component 1 is shown. The ceramic component 1 (Fig. 4) can in particular be a rolling element, such as a ball, a tapered roller, a cylindrical roller, a needle roller, a spherical roller, or the like. Furthermore, the component 1 is formed from a ceramic material 2, such as silicon nitride (SiSn).

[0050] The method comprises step S1, in which the ceramic bearing component 1 is provided with a naturally occurring oxide layer 4 having a first thickness d1. Silicon nitride forms an oxide layer 4 on its surface 6 through interaction with the air and / or water present, for example, in the atmosphere. The thickness of the formed oxide layer 4 can depend on various factors, such as temperature, air humidity, etc. This oxide layer 4 forms the surface 6 of the ceramic component 1, so that it also significantly influences the surface properties of the ceramic component 1, such as the running properties and / or interaction with other substances, such as the lubricant.

[0051] In order to optimize the surface properties of the ceramic bearing component 1, in the embodiment shown in Fig. 1, the naturally occurring oxide layer 4 on the surface 6 of the ceramic component is treated with heat 8 in a further method step S2. For example, the ceramic component 1 can be heated in a furnace (not shown) in a gas, for example in air, and / or in a liquid, for example in a bath, but also with radiation, for example with a laser. After the heat treatment, the oxide layer 4 on the surface 6 of the ceramic component 1 can have grown by a second thickness d?. In other words, a thickness of the oxide layer 4 can be modified by the heat treatment. In the method shown in Fig. 1, the ceramic component 1 is heated to a first predetermined temperature for a first period of time. For example, the component 1 is heated to 400°C for 30 minutes.It is then slowly cooled at room temperature.

[0052] Fig. 2 shows a schematic representation of a manufacturing method for a ceramic bearing component 1 according to a second embodiment, wherein Fig. 2 also only shows a section of the ceramic component 1. For example, the method shown in Fig. 2 can be used alone to manufacture the ceramic component 1. It is also conceivable that the method shown in Fig. 2 is applied to the ceramic component 1 following the method shown in Fig. 1.

[0053] In the embodiment of the method shown in Fig. 2, in a step S3, the naturally occurring oxide layer 4 of the ceramic component 1 is etched with an acid 10. In particular, the oxide layer 4 can thereby be at least partially removed, so that the ceramic material 2 of the component 1 is freely accessible. The acid can be, for example, hydrofluoric acid (HF), hydrochloric acid (HCl), nitric acid (HN03), and / or acetic acid (CH3COOH), etc. Optionally, the etching can be assisted by a heat treatment 8. Furthermore, it is also conceivable to use several acids simultaneously and / or sequentially for etching. Alternatively, a plasma treatment and / or bases can also be used to remove the oxide layer.

[0054] To prevent the oxide layer 4 from forming again after removal of the oxide layer 4, the removal S3 of the oxide layer 4 can take place in a vacuum and / or in an environment enriched with a medium that does not react with the base matrix 4 of the ceramic component 1. For example, the removal S3 of the oxide layer 4 can take place in a protective atmosphere comprising, for example, a noble gas and / or a protective gas. Additionally or alternatively, the ceramic component 1 can be coated after removal of the oxide layer 4 to prevent the oxide layer 4 from forming again.

[0055] In particular, depending on the method used to remove the oxide layer 4, after the acid treatment S3, the ceramic component 1 can have an activated surface 6', which can subsequently be chemically modified particularly easily. In particular, removing the oxide layer 4 with an acid can lead to an activated surface 6'. Additionally or alternatively, the activation of at least part of the naturally occurring oxide layer 4 and / or the ceramic material 2 can be carried out by plasma, in particular by nitrogen plasma, oxygen plasma and / or hydrocarbon plasma, by electromagnetic radiation, in particular by ultraviolet and / or infrared light, by chemical modification, and / or mechanically, in particular by pressure.

[0056] Alternatively or additionally, after etching S3 of the ceramic component 1 with the acid, a treatment S4 of the etched and / or activated surface 6, 6' of the ceramic component 1' can be carried out with a further chemical 12. This allows the surface 6, 6' of the ceramic component to be provided with a layer 14 having a predetermined chemical composition that differs from the ceramic material 2. This predetermined chemical composition can, for example, improve a wetting property of the surface and / or enable better interaction with a lubricant and / or change a chemical and / or physical material property. Optionally, the treatment with the further chemical 12 can be supported by a heat treatment 8.

[0057] Depending on the requirements of the ceramic component 1, the activated surface 6' can be functionalized by subsequent treatment with the additional chemical 12, wherein the chemical composition is changed at least on the surface 6, 6' of the ceramic component 1. In particular, the additional chemical 12 can comprise at least one chemical compound that interacts with the elements and / or molecules of the surface 6, 6' of the ceramic component 1 such that at least one predetermined functional group is bonded to the ceramic component 1 and / or the surface 6, 6' of the ceramic material 2, such that the ceramic component 1 subsequently exhibits a desired function and / or desired chemical and / or physical material property. This predetermined chemical composition can, for example, improve a wetting property of the surface and / or enable better interaction with a lubricant.

[0058] The specified functional group can be attached, for example, at an interface, within the interface, and / or beneath the interface. The interface can be, for example, the surface 6' of the ceramic material 2, the surface 6 of the naturally occurring oxide layer 4, or a transition layer between the ceramic material 2 and the oxide layer 4. Furthermore, during functionalization, the chemical composition of the surface can be adjusted to a depth of up to 200 μm.

[0059] The additional chemical 12, which contains the functional group and / or a precursor for the functional group, can be a gas, a liquid, and / or a solid. Furthermore, the additional chemical 12 can be applied locally and / or globally to the ceramic component 1. For example, the additional chemical 12 can be applied only to selected areas of the ceramic component 1 and / or the ceramic component can be completely immersed in the additional chemical 12. Of course, multiple chemicals can also be applied consecutively and / or simultaneously to achieve a desired functionalization.

[0060] Furthermore, the functional group can be an elemental ligand, preferably fluorine, hydrogen, oxygen, and / or nitrogen. Furthermore, the functional group can be selected from the group of salts, in particular from the group of soaps. Furthermore, the functional group can be a solid lubricant, such as boron nitride (BN) and / or molybdenum sulfide (MOS2). Furthermore, the functional group can be selected from the group of silanes, complexes, alcohols, micelles, hydrocarbons, in particular aliphatic hydrocarbons, and / or chlorinated hydrocarbons.

[0061] Furthermore, the further chemical 12 can make it possible to modify the naturally occurring oxide layer 4 and / or the ceramic material 2 in such a way that the implantation of ions and / or the exchange of ions in the naturally occurring oxide layer 4 and / or the ceramic material 2 is enabled. The implantation of ions can be carried out, for example, by a surface treatment of the ceramic component 1 with ions, wherein the ceramic component 1 can be exposed, for example, to a salt bath and / or a solution. Alternatively or additionally, the ceramic component 1 can be irradiated with at least one ion beam and / or a plasma (see Fig. 3).

[0062] Fig. 3 shows a schematic representation of a manufacturing method for a ceramic bearing component 1 according to a third embodiment, wherein Fig. 3 also only shows a section of the ceramic component 1. For example, the method shown in Fig. 3 can be used alone to manufacture the ceramic component 1. It is also conceivable that the method shown in Fig. 3 is applied to the ceramic component 1 following the method shown in Fig. 1 and / or following the method shown in Fig. 2.

[0063] In the embodiment of the method shown in Fig. 3, the naturally occurring oxide layer 4 is modified by irradiating (S5) the ceramic component. The component 1 can be irradiated, for example, using a plasma 16. By irradiating with a plasma 16, for example, an undesired accumulation of other chemical elements in the naturally occurring oxide layer 4 can be removed. This makes it possible to obtain an oxide layer that is as free as possible from undesired chemical elements. Alternatively or additionally, the naturally occurring oxide layer 4 can be irradiated with an ion beam. This can, for example, allow ions to be implanted and / or exchanged in the oxide layer 4 in order to modify a chemical composition of the oxide layer 4.Alternatively or additionally, a sputtering process can be used and / or the naturally occurring oxide layer can be irradiated with light, for example with a laser beam. For example, an interaction with the light can trigger a chemical reaction in the oxide layer and / or specifically ionize certain chemical elements. In particular, a light beam and / or laser beam can be used to achieve local modification of the oxide layer. For example, the oxide layer can be locally heated and / or locally chemically modified by light. Ultraviolet light, i.e., light with a wavelength of less than 400 nm, preferably between 100 nm and 380 nm, and / or infrared light, i.e., light with a wavelength of greater than 780 nm, preferably between 800 nm and 10 pm, can be used. Fig. 4 shows a hybrid bearing 18.The hybrid bearing comprises an inner ring 20, an outer ring 22 and a plurality of ceramic rolling elements 24 formed from silicon nitride and manufactured by at least one of the processes shown in Figs. 1-3.

[0064] In summary, in order to optimize the surface properties of the ceramic bearing component 1, the naturally occurring oxide layer 4 in particular can be modified. For example, the thickness of the naturally occurring oxide layer 4 can be changed and / or a chemical composition of the oxide layer 4 and / or a layer on the surface 6 of the ceramic component 1 can be changed. By modifying the naturally occurring oxide layer 4, the interaction between a lubricant and the ceramic component can advantageously be changed. For example, a wetting property of the surface of the ceramic bearing component 1 can be adjusted. Furthermore, a surface roughness of the ceramic component can be changed globally and / or locally.Furthermore, the modified surface can also reduce friction losses and / or increase maintenance intervals for a hybrid bearing, which can further reduce costs.

[0065] List of reference symbols

[0066] 1 component

[0067] 2 ceramic material

[0068] 4 Oxide layer

[0069] 6 Surface

[0070] 8 Heat

[0071] 10 Acid

[0072] 12 more chemicals

[0073] 14 shift

[0074] 16 ion beam

[0075] 18 hybrid bearings

[0076] 20 inner ring

[0077] 22 Outer ring

[0078] 24 rolling elements

[0079] S1-S5 Process steps di, d2 Thickness

Claims

Patent claims 1. Manufacturing method of a ceramic bearing component (1), the method comprising the following steps: Providing (Sl) the bearing component (1) from a ceramic material with a naturally occurring oxide layer (4) with a first thickness (di), at least partially modifying (S2, S3, S4, S5) the naturally occurring oxide layer (4) on the surface of the ceramic bearing component (1) and / or the ceramic material.

2. The method according to claim 1, wherein the modifying comprises treating (S2) the ceramic component (1) with heat (8).

3. Method according to one of the preceding claims, wherein the modifying comprises an implantation of ions and / or an ion exchange.

4. Method according to one of the preceding claims, wherein the modifying comprises at least a partial removal (S3) of the naturally occurring oxide layer (4) of the ceramic component (1).

5. The method according to claim 4, wherein the at least partial removal (S3) of the naturally occurring oxide layer (4) of the ceramic component (1) is carried out with at least one acid (10) and / or with a plasma.

6. The method according to any one of the preceding claims, wherein the modifying comprises activating at least a portion of the naturally occurring oxide layer and / or the ceramic material such that at least a portion of the naturally occurring oxide layer and / or the ceramic material is converted into an intermediate compound suitable for at least one specific reaction.

7. The method according to claim 6, wherein the activation of at least a part of the naturally occurring oxide layer and / or the ceramic material is carried out by plasma, in particular by nitrogen plasma, oxygen plasma and / or hydrocarbon plasma, by electromagnetic radiation, in particular by ultraviolet and / or infrared light, by chemical modification, by removal of the naturally occurring oxide layer and / or mechanically.

8. The method according to any one of the preceding claims, wherein modifying the naturally occurring oxide layer comprises functionalizing at least a portion of the naturally occurring oxide layer and / or the ceramic material such that the at least a portion of the naturally occurring oxide layer and / or the ceramic material comprises at least one chemical compound having at least one predetermined functional group.

9. The process according to claim 8, wherein the functional group is an elemental ligand, preferably fluorine, hydrogen, oxygen and / or nitrogen.

10. The method according to claim 8 or 9, wherein the functional group is selected from the group of salts, in particular from the group of soaps.

11. The method according to any one of claims 8 to 10, wherein the functional group is a solid lubricant, in particular boron nitride and / or molybdenum sulfide.

12. The method according to any one of claims 8 to 11, wherein the functional group is selected from at least one of the following: Silanes, complexes, alcohols, micelles, hydrocarbons, especially aliphatic hydrocarbons, and / or chlorinated hydrocarbons.

13. Ceramic bearing component (1), wherein the bearing component (1) comprises a ceramic material and has on its surface (6) a naturally occurring oxide layer (4) with a first thickness (di), and wherein the ceramic bearing component (1) is produced by the method according to one of the preceding claims.

14. Ceramic bearing component (1) according to claim 11, wherein the ceramic material is silicon nitride.

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