DE102019207621A1 - PROCESS FOR PRODUCING A COMPONENT FROM A CERAMIC FIBER COMPOSITE MATERIAL WITH A MODIFIED SLIDING OR FRICTION SURFACE - Google Patents

Abstract

The present invention relates to a component made of a fiber composite material and a method for producing the same, wherein in the fiber composite material fibers (8) made of ceramic and / or carbon are embedded in a matrix (9) made of ceramic and / or carbon and / or a polymer and wherein the component has a surface, of which at least a part is designed as a contact surface for mechanical contact with a contact partner, and wherein solid lubricant particles (10) are embedded in at least one surface edge region of the component adjacent to the contact surface in the matrix (9), the Solid lubricant particles (10) are interlocked or dispersed in the structure with the matrix and / or the fibers.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a component made of a ceramic fiber composite material and a method for producing the same, wherein in the fiber composite material fibers made of ceramic and / or carbon are embedded in a matrix made of ceramic and / or carbon.

STATE OF THE ART

Fiber composite materials such as carbon fiber reinforced plastic (CFRP) and ceramic fiber composite materials, which are also referred to as Ceramic Matrix Composites CMC, are used in many areas of technology due to their excellent mechanical properties.

Ceramic fiber composite materials, which should also include those made of carbon in addition to ceramic materials for forming the matrix and / or fibers, are used, among other things, in high-temperature applications in aircraft or aircraft engine construction due to their good high temperature and corrosion resistance. Processes for the efficient production of ceramic fiber composite materials which are as dense as possible and which can be used in gas turbines or aircraft engines are for example in the European patent EP 1 999 288 B1 and the US patent application US 2018/0187560 A1 described.

In addition, carbon fiber-reinforced plastics are also used, in which carbon fibers are embedded in a matrix made of a polymer or synthetic resin.

However, components made of fiber composite materials often have to be provided with protective layers if the fiber composite materials are subject to high wear in the event of mechanical contact with other components or if they would cause this in adjacent components. For example, in fluid flow machines, such as gas turbines or aircraft engines, highly stressed contact surfaces can exist, such as on moving blade, in particular on moving blade shrouds or moving blade - disk - contact surfaces, or on the housing surrounding the flow channel or other components that rest against one another.

Protective layers can, however, flake off in the event of cyclical thermal stress or thermal shock stress, so that the protective effect is lost and the flaked particles can also cause damage to the corresponding machines or engines. For permanent and reliable use of fiber composite materials, the functionality of the components made from them must be ensured over a wide temperature range. In addition, excessive wear must be avoided, which would severely limit the service life of the relevant components.

It is corresponding, for example, from the US patent US 9 238 595 B2 known to smooth the surface of ceramic fiber composite materials in order to reduce the frictional resistance.

In the European patent application EP 2 535 182 A1 it is proposed to perforate an outer fabric layer in a component with several fabric layers and to introduce a lubricating filler material into the punched-out areas. However, such a manufacturing process is complex due to the additional manufacturing steps and the filler material can easily break out of the punched-out recesses.

DISCLOSURE OF THE INVENTION

OBJECT OF THE INVENTION

It is therefore the object of the present invention to provide a fiber composite material, in particular a ceramic fiber composite material, the matrix of which is made of ceramic and / or carbon and the fibers of which are also made of ceramic and / or carbon, or a carbon fiber-reinforced plastic that has tribological properties compared to the prior art the technology is improved, in particular friction and wear on corresponding surfaces are permanently reduced. In addition, such a fiber composite material should be able to be produced efficiently and have a long service life.

TECHNICAL SOLUTION

This object is achieved by a method for producing a component from a fiber composite material, which comprises the features of claim 1, and by a component having the features of claim 4. Advantageous configurations are the subject matter of the dependent claims.

In order to improve the tribological properties of a fiber composite material, the invention proposes, directly during the production of the fiber composite material in the matrix of ceramic and / or carbon and / or a polymer, in which the fibers of the fiber composite material are embedded, additionally at least in corresponding surface edge areas of the material to be produced Components that can come into mechanical contact, e.g. friction or sliding contact, with contact partners, such as friction or sliding partners, store solid lubricant particles so that the solid lubricant is present on the corresponding contact surfaces of a component formed from the modified fiber composite material and can provide lubrication. The direct embedding of the solid lubricant particles in the structure with the matrix and the fibers ensures a secure and solid arrangement of the solid lubricant particles and thus a reliable and permanent supply of the solid lubricant to the contact surfaces of the correspondingly manufactured component. In addition, the production is simplified compared to the prior art, since no additional production steps have to be carried out to apply an additional protective layer or to prepare an edge region of the component for the introduction of the solid lubricant particles. Furthermore, dispensing with a coating means that there is no risk of the layer flaking off.

The solid lubricant particles are introduced before and / or simultaneously with the arrangement of the matrix material in a fiber structure, e.g. by infiltration, the fibers provided for reinforcing the fiber composite material with the fiber structure. A corresponding fiber structure can be provided, for example, as a fiber fabric, fiber braid, fiber knitted fabric or the like.

The solid lubricant particles can be incorporated in the fiber structure limited to the surface edge areas in which mechanical contact, e.g. in the form of frictional or sliding contact is to be expected. Correspondingly, a locally limited formation of surface edge regions with the solid lubricant particles can be realized.

The solid lubricant particles can be provided in the corresponding surface edge areas in different concentrations, that is to say with different volume proportions, so that concentration gradients can be formed along the surface of the component and / or vertical to the surface of the component. For example, the volume fraction of the solid lubricant particles in the structure in the surface edge areas can increase from an inner area to the surface.

The formation of the matrix can be realized by different methods. The introduction of the solid lubricant particles into the corresponding surface edge areas can be adapted to the selected method for forming the matrix around the fibers or in the cavities and openings of the fiber structure.

For example it is possible to carry out the deposition of the matrix from the gas phase, e.g. by chemical vapor phase deposition or chemical gas phase infiltration, in which case the solid lubricant particles can already be arranged in the fiber structure, for example from a fiber structure made of fibers bonded with resin.

Polymers for subsequent pyrolysis, for example silicon-containing polymers, can also be provided in the fiber structure, with the solid lubricant particles additionally being arranged in the surface edge areas in which the material is to be modified according to the invention.

Also in other infiltration processes, such as liquid infiltration, e.g. liquid polymer infiltration or infiltration via slurry or melt infiltration processes, such as liquid silicon infiltration or the like, the solid lubricant particles can already be provided in the fiber structure, with additional components for chemical reaction with the infiltrated substance to form the matrix.

Further methods for forming the matrix, in particular a ceramic matrix, are electrophoresis or sintering processes, in which the solid lubricant particles can also already be provided in the fiber structure in order to be embedded in the forming matrix.

By embedding the solid lubricant particles in the structure of a matrix made of ceramic and / or carbon and / or an organic matrix, in particular a polymer, and fibers made of ceramic and / or carbon, the solid lubricant particles are firmly embedded in the surface of the component, whereby e.g. uneven, three-dimensional interfaces between the solid lubricant particles and the grains of the matrix and / or the fibers, in particular with protrusions and depressions or undercuts, and the dispersion in the matrix cause the solid lubricant particles to be firmly integrated in the structure.

The solid lubricant particles introduced can be of different types and are only intended to provide the lubricant appropriate for the intended tribological properties. For example, boron nitride, in particular amorphous boron nitride or hexagonal boron nitride, metal oxides such as molybdenum oxide or tungsten oxide, and chalcogens or graphite can be used for this purpose.

Figure list

• 1 eine Darstellung eines erfindungsgemäßen Bauteils, welches mit zwei anderen Bauteilen in mechanischem Kontakt ist,
• 2 einen Schnitt durch einen erfindungsgemäß modifizierten Oberflächenrandbereich eines erfindungsgemäßen Bauteils, wie es in 1 dargestellt ist,
• 3 eine Darstellung eines Fasergebildes als Ausgangsmaterial für die Herstellung eines erfindungsgemäßen Bauteils,
• 4 eine Darstellung des Fasergebildes aus 3 nach Befüllen von Oberflächenrandbereichen mit Festschmierstoffpartikeln zur Ausbildung eines erfindungsgemäßen Bauteils und in
• 5 eine Darstellung des fertig gestellten Bauteils aus einem Faserverbundwerkstoff, das modifizierte Oberflächenrandbereiche aufweist.

The accompanying drawings show in a purely schematic manner

• 1 a representation of a component according to the invention which is in mechanical contact with two other components,
• 2 a section through an inventive modified surface edge region of a component according to the invention, as shown in FIG 1 is shown
• 3 a representation of a fiber structure as a starting material for the production of a component according to the invention,
• 4th a representation of the fiber structure 3 after filling surface edge areas with solid lubricant particles to form a component according to the invention and in
• 5 a representation of the finished component made of a fiber composite material that has modified surface edge areas.

EXAMPLES

Further advantages, characteristics and features of the present invention will become apparent in the following detailed description of the exemplary embodiments. However, the invention is not restricted to these exemplary embodiments.

The 1 shows part of a component according to the invention 1 , which is formed from a ceramic fiber composite material and with two further friction or sliding partners 2 and 3 is in frictional or sliding contact. The component has accordingly 1 a first contact surface 4th that are in contact with the first friction or sliding partner 2 is, and a second contact surface 5 those in contact with the second friction or sliding partner 3 is. Adjacent to the contact surfaces 4th , 5 are surface edge areas 6th and 7th in the component 1 formed from one opposite the remaining areas of the component 1 modified material.

In the surface edge areas 6th and 7th the ceramic fiber composite material is modified in such a way that solid lubricant particles are embedded in the structure consisting of the ceramic particles forming the matrix and the fibers in the area of the contact surfaces 4th , 5 on the surface of the component 1 exist and there to improve the tribological behavior, that is to say the friction or sliding behavior between the friction or sliding partners 2 and 3 and the component 1 at the contact surfaces 4th and 5 of the component 1 contribute. For example, the solid lubricant particles can be hexagonal boron nitride, which lubricates the contact surfaces 4th and 5 and thus an improvement in the sliding behavior of the contact surfaces 4th and 5 causes.

The 2 shows a section through a surface edge area 6th , 7th of the component 1 , with the fibers in the sectional view 8th and on the other hand the ceramic grains 9 of the ceramic fiber composite material can be seen. In the structure of the ceramic matrix 9 and the fibers 8th are solid lubricant particles 10 stored so that when the component comes into contact 1 at the contact surface 4th , 5 with a sliding or friction partner 2 , 3 the solid lubricant particles 10 the solid lubricant on the surface in the gap between the contact surface 4th , 5 of the component 1 and the friction or sliding partner 2 , 3 submit. This enables the tribological behavior or the contact behavior of a correspondingly modified component 1 be improved.

The 3 to 5 show different stages in an embodiment of the production of a fiber composite material with modified surface edge regions according to the invention.

First is a fiber structure 11 provided as in 3 shown, which comprises the fibers that are to provide the fiber reinforcement in the fiber composite material to be formed. The fiber structure 11 can be provided by a woven fabric or some other fiber arrangement, such as a braid or knitted fabric, in which the fibers are preferably glued to one another via a resin, the fiber structure not being a dense structure but rather comprising a multitude of cavities and pores in which the following the ceramic matrix is formed. The fibers themselves can also be made of ceramic, carbon for the present description of the invention falling under the term of ceramic. Correspondingly, the fiber structure can consist of a large number of carbon fibers and / or ceramic fibers, such as SiC fibers, for example, around which a matrix of ceramic and / or carbon and / or a polymer is formed.

As shown in 4th are in the embodiment shown in the surface edge areas 12 and 13 of the fiber structure 11 that are adjacent to the contact surfaces 14th and 15th are filled with solid lubricant particles, so that during the subsequent production of the matrix these not only the fibers of the fiber structure 11 encloses, but also those in the surface edge areas 12 and 13 present solid lubricant particles.

In addition to the solid lubricant particles, which are only found in the surface edge areas 12 , 13 are provided, further substances, such as ceramic particles, in the fiber structure can be provided in the entire fiber structure 11 be arranged to for example, to form the ceramic matrix from the ceramic particles by a sintering process, the in the surface edge areas 12 and 13 additionally provided solid lubricant particles are embedded in the ceramic matrix.

Alternatively, it is also possible to use starting materials for the subsequent formation of the matrix in the fiber structure 11 to be arranged in order to form the matrix again, for example by a subsequent pyrolysis or chemical reaction with a molten or gaseous infiltrated substance. In this case too, those in the surface edge areas 12 and 13 provided solid lubricant particles embedded in the corresponding matrix.

The same applies to a possible deposition of the ceramic material via the vapor phase, in which the ceramic material in the free spaces of the fiber structure by means of chemical vapor phase deposition or chemical vapor phase infiltration 11 is formed and that in the surface edge areas 12 and 13 provided solid lubricant particles are included in the matrix.

The 5 shows a correspondingly finished component made of a ceramic fiber composite material 18th which surface edge areas 16 and 17th with solid lubricant particles embedded in the ceramic matrix and / or the fibers, which improve the sliding behavior and / or the wear in the contact surfaces 14th and 15th reduce significantly.

Although the present invention has been described in detail on the basis of the exemplary embodiments, it is obvious to the person skilled in the art that the invention is not limited to these exemplary embodiments, but rather that modifications are possible in such a way that individual features can be omitted or other types of combinations of features can be implemented without departing from the scope of protection of the appended claims. In particular, the present disclosure includes all combinations of the individual features shown in the various exemplary embodiments, so that individual features that are only described in connection with one exemplary embodiment can also be used in other exemplary embodiments or combinations of individual features that are not explicitly shown.

List of reference symbols

1

Component

2

Friction or sliding partner

3

Friction or sliding partner

4th

Contact area

5

Contact area

6

Surface edge area

7th

Surface edge area

8th

Fibers

9

Ceramic grains or ceramic matrix

10

Solid lubricant particles

11

Fiber structures

12

Surface edge area

13

Surface edge area

14th

Contact area

15th

Contact area

16

Surface edge area

17th

Surface edge area

18th

ceramic fiber composite

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1999288 B1 [0003]
• US 2018/0187560 A1 [0003]
• US 9238595 B2 [0007]
• EP 2535182 A1 [0008]

Claims (8)

Process for the production of components made of fiber composite materials, in which fibers (8) made of ceramic and / or carbon are embedded in a matrix (9) made of ceramic and / or carbon and / or a polymer, with at least one fiber structure (11) made of the fibers made of ceramic and / or carbon, the matrix material or starting material for matrix material being arranged in and / or on the fiber structure so that the matrix can be formed from the matrix material or the starting material so that the fibers (8) of the fiber structure in the matrix (9) are embedded, characterized in that before and / or simultaneously with the arrangement of the matrix material or the starting material for the matrix, solid lubricant particles (10) are arranged in or on at least one surface edge area (12, 13) of the fiber structure (11) so that when the matrix (9) is formed, the solid lubricant particles (10) in the at least one surface edge region cal of the component are embedded adjacent to a surface of the component. Procedure according to Claim 1 , characterized in that the formation of the matrix (9) is carried out by one or more processes from the group consisting of the deposition from the gas phase, the chemical vapor phase deposition, the chemical gas phase infiltration, the pyrolysis of polymers, the pyrolysis of Si-containing polymers , Infiltration method, melt infiltration method, liquid silicon infiltration which includes liquid polymer infiltration, electrophoresis, slip method, and sintering method. Method according to one of the preceding claims, characterized in that the solid lubricant particles (10) are selected from the group comprising boron nitride, amorphous boron nitride, hexagonal boron nitride, graphite, chalcogens, metal oxides, molybdenum oxide and tungsten oxide. Component made of a fiber composite material, in particular produced by the method according to one of the Claims 1 to 3 , wherein in the fiber composite material fibers (8) made of ceramic and / or carbon are embedded in a matrix (9) made of ceramic and / or carbon and / or a polymer, the component (1) having a surface of which at least a part is designed as a contact surface (4,5; 14,15) for mechanical contact with a contact partner (2,3), characterized in that solid lubricant particles (10) in at least one surface edge area (6,7; 16,17) of the component adjoin the contact surface (4,5; 14,15) are embedded in the matrix (9), the solid lubricant particles (10) being interlocked or dispersed in the structure with the matrix and / or the fibers. Component after Claim 4 , characterized in that the solid lubricant particles (10) are firmly held with the surrounding matrix and / or the fibers by uneven, three-dimensional interfaces with projections and depressions or undercuts. Component after Claim 4 or 5 , characterized in that the solid lubricant particles (10) are contained in the surface edge area (6,7; 16,17) of the component (1) over the surface edge area (6,7; 16,17) with different volume proportions Component after Claim 6 , characterized in that a gradient of the volume fraction of the solid lubricant particles (10) with increasing volume fraction of the solid lubricant particles (10) in the matrix (9) in the direction of the surface and / or a gradient of the volume fraction of the solid lubricant particles (10) in the matrix (9) is present along the surface of the component (1). Component according to one of the Claims 4 to 7th , characterized in that the solid lubricant particles (10) are selected from the group comprising boron nitride, amorphous boron nitride, hexagonal boron nitride, graphite, chalcogens, metal oxides, molybdenum oxide and tungsten oxide.

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