WO2020239149A1

WO2020239149A1 - Method for producing a component from a ceramic fibre-reinforced composite material with a modified sliding or frictional surface

Info

Publication number: WO2020239149A1
Application number: PCT/DE2020/000095
Authority: WO
Inventors: Beate SCHLEIF; Benedikt Albert
Original assignee: MTU Aero Engines AG
Priority date: 2019-05-24
Filing date: 2020-05-18
Publication date: 2020-12-03
Also published as: DE102019207621A1

Abstract

The present invention relates to a component formed from a fibre-reinforced composite material and to a method for producing same. In the fibre-reinforced composite material, fibres (8) consisting of ceramic and/or carbon are embedded in a matrix (9) consisting of ceramic and/or carbon and/or a polymer. The component has a surface which is at least in part designed as a contact face for mechanical contact with a contact partner, and solid lubricant particles (10) are inlaid in the matrix (9) in at least one surface edge region of the component adjacent to the contact face, wherein the solid lubricant particles (10) are intermeshed or dispersed with the matrix and/or the fibres in the microstructure.

Description

METHOD FOR MANUFACTURING A COMPONENT FROM A CERAMIC FIBER COMPOSITE MATERIAL WITH A MODIFIED SLIDING OR FRICTION SURFACE

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 described, for example, in European patent EP 1 999 288 B1 and US patent application US 2018/0187560 A1.

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.

Confirmation copy 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, there may be highly stressed contact surfaces, such as on rotor blades, in particular on rotor blade shrouds or rotor blade-disk contact surfaces, or on the housing surrounding the flow channel or other components that bear against each other.

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.

Accordingly, it is known for example from US Pat. No. 9,238,595 B2 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 an object of the present invention to provide a fiber composite material, in particular a ceramic fiber composite material, its matrix made of ceramic and / or carbon and whose fibers are also made of ceramic and / or carbon, or to provide a carbon fiber-reinforced plastic which is improved in its tribological properties compared to the prior art, with in particular friction and wear on corresponding surfaces being 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, as well as by a component with the features of claim 4. Advantageous configurations are the subject of the dependent claims.

The invention proposes to improve the tribological properties of a fiber composite material, 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 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, incorporate 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 provides lubrication can. The direct incorporation of the solid lubricant particles into 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 area of the component for the introduction of the solid lubricant particles. Furthermore, by dispensing with a coating, there is no risk of the layer flaking off. Accordingly, a corresponding component is preferably uncoated in the area of the contact surface, so it does not have to have a separately and / or subsequently formed, applied or deposited layer in this area. As a result, there is no need for an accompanying layer transition or interface and / or an abrupt transition in the chemical composition.

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, i.e. with different volume proportions, so that concentration gradients, in particular with continuous, in particular monotonous or strictly monotonous, decreasing or increasing concentration, along the surface of the component and / or vertical to the surface of the component can be formed. 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 deposit the matrix from the gas phase, for example 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 made of 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 filtration 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, where 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, especially 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.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings show in a purely schematic manner

Figure 1 is a representation of a component according to the invention, which with two other

Components are in mechanical contact,

FIG. 2 shows a section through a surface edge region of a component according to the invention modified according to the invention, as shown in FIG.

FIG. 3 shows a representation of a fiber structure as a starting material for the production of a component according to the invention,

FIG. 4 shows an illustration of the fiber structure from FIG. 3 after surface areas have been filled with solid lubricant particles to form a component according to the invention and in FIG

FIG. 5 shows a representation of the finished component made from a fiber composite material which has modified surface edge regions.

EXAMPLES

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

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

In the surface edge areas 6 and 7, 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, which are present in the area of the contact surfaces 4, 5 on the surface of the component 1 and there Contribute to an improvement in 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 on the contact surfaces 4 and 5 of the component 1. For example, the solid lubricant particles can be hexagonal boron nitride, which provides lubrication on the contact surfaces 4 and 5 and thus improves the sliding behavior of the contact surfaces 4 and 5.

FIG. 2 shows a section through a surface edge region 6, 7 of the component 1, the fibers 8 on the one hand and the ceramic grains 9 of the ceramic fiber composite material on the other being visible in the sectional view. Solid lubricant particles 10 are embedded in the structure of the ceramic matrix 9 and the fibers 8, so that when the component 1 comes into contact with a sliding or friction partner 2, 3 on the contact surface 4, 5, the solid lubricant particles 10 on the surface get the solid lubricant into the gap between the contact surface 4, 5 of the component 1 and the friction or sliding partner 2, 3. As a result, the tribological behavior or the contact behavior of a correspondingly modified component 1 can be improved.

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

Firstly, a fiber structure 11 is provided, as shown in FIG. 3, which comprises the fibers which are intended to provide the fiber reinforcement in the fiber composite material to be formed. The fiber structure 11 can be provided by a 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 a multitude of cavities and pores includes, in which subsequently the ceramic matrix is formed becomes. 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.

According to the illustration in Figure 4, in the embodiment shown, solid lubricant particles are filled into the surface edge regions 12 and 13 of the fiber structure 1 1, which are adjacent to the contact surfaces 14 and 15, so that during the subsequent production of the matrix these not only the fibers of the fiber structure 1 1, but also the solid lubricant particles present in the surface edge regions 12 and 13.

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

Alternatively, it is also possible to arrange starting materials for the subsequent formation of the matrix in the fiber structure 11 in order, for example, to form the matrix again by a subsequent pyrolysis or chemical reaction with a molten or gaseous infiltrated substance. In this case too, the solid lubricant particles provided in the surface edge regions 12 and 13 are 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 is formed in the free spaces of the fiber structure 11 by means of chemical vapor phase deposition or chemical vapor phase infiltration and the solid lubricant particles provided in the surface edge areas 12 and 13 are included in the matrix will.

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

Although the present invention has been described in detail on the basis of the exemplary embodiments, it is obvious to a 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 are omitted or other types of combinations of features can be realized without departing from the scope of protection of the attached 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.

REFERENCE LIST

1 component

2 friction or sliding partners

3 friction or sliding partners

4 contact area

5 contact area

6 surface edge area

7 surface edge area

8 fibers

9 ceramic grains or ceramic matrix

10 solid lubricant particles

1 1 fiber structure

12 surface edge area

13 Surface edge area 14 contact area

15 contact area

16 surface edge area

17 Surface edge area

18 ceramic fiber composite

Claims

EXPECTATIONS

1 . 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) the fibers made of ceramic and / or carbon is provided, with 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 upper surface edge area (12, 13) of the fiber structure (1 1) so that when the matrix (9 ) the solid lubricant particles (10) are incorporated in the at least one surface edge region of the component adjacent to a surface of the component.

2. The method according to claim 1,

characterized in that

the formation of the matrix (9) is carried out by one or more processes from the group that includes deposition from the gas phase, chemical vapor phase deposition, chemical gas phase infiltration, pyrolysis of polymers, pyrolysis of Si-containing polymers, infiltration processes, melt infiltration processes, Liquid silicon infiltration, which includes liquid polymer infiltration, electrophoresis, slip processes, and sintering processes.

3. The method according to any 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.

4. Component made of a fiber composite material, in particular produced by the method according to one of claims 1 to 3, wherein the fiber composite material fibers (8) made of ceramic and / or carbon in a matrix (9) made of ceramic and / or carbon and / or a Polymer are embedded, 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) are embedded in the matrix (9) in at least one surface edge area (6, 7; 16, 17) of the component adjacent to the contact surface (4, 5; 14, 15), the solid lubricant particles (10) in the structure with the matrix and / or the fibers are interlocked or dispersed.

5. Component according to claim 4,

characterized in that

the solid lubricant particles (10) are firmly held by uneven, three-dimensional interfaces with projections and depressions or undercuts with the surrounding matrix and / or the fibers and / or the component is uncoated in the area of the contact surface (4, 5; 14, 15).

6. Component according to claim 4 or 5,

characterized in that

the solid lubricant particles (10) 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 percentages are held ent

7. component according to 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) along the surface of the component (1).

8. Component according to one of claims 4 to 7,

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.