Connecting method of ceramic matrix composite material

Abstract

The invention relates to the technical field of composite materials, in particular to a connecting method of a ceramic matrix composite material. The embodiment of the invention provides a connecting method for ceramic matrix composites. The connecting method comprises the steps that punching machining is conducted on connecting parts of different to-be-connected composites; coating the connecting part with slurry to obtain a slurry layer; wherein the slurry comprises silicon-containing powder; a high-temperature binder is smeared on the slurry layer; wherein the high-temperature binder comprises phenolic resin; connecting the connecting parts of the different to-be-connected composite materials, and penetrating through the machining holes of the different connecting parts through fixing pieces; and the connected to-be-connected composite materials are subjected to curing treatment and high-temperature treatment in sequence. The embodiment of the invention provides a connecting method of a ceramic-based composite material. The connecting method can improve the connecting effect of the ceramic-based composite material.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and particularly relates to a connection method for ceramic matrix composites. Background Art

[0002] Ceramic matrix composites have excellent high-temperature mechanical properties, as well as excellent properties such as oxidation resistance, ablation resistance, thermal shock resistance, and corrosion resistance, and are widely used as thermal structure materials in the aerospace field. Due to limitations in preform technology, forming process technology, etc., it is difficult and costly to directly complete ceramic matrix composite components with large overall dimensions and complex structures. For large-size and complex-structure ceramic matrix composites, the functions of the overall components need to be realized through the connection of different split components. Therefore, connection is essential in the development process of components, and the connection performance directly affects the performance of the components. It can be said that connection has become the key technology restricting its application. Summary of the Invention

[0003] An embodiment of the present invention provides a connection method for ceramic matrix composites, which can improve the connection effect of ceramic matrix composites.

[0004] An embodiment of the present invention provides a connection method for ceramic matrix composites, including:

[0005] Performing drilling on the connection parts of different composite materials to be connected;

[0006] Applying a slurry to the connection part to obtain a slurry layer; wherein, the slurry includes silicon-containing powder;

[0007] Applying a high-temperature binder on the slurry layer; wherein, the high-temperature binder includes phenolic resin;

[0008] Connecting the connection parts of different composite materials to be connected, and passing a fixing member through the processing holes of different connection parts;

[0009] Performing curing treatment and high-temperature treatment on the connected composite materials to be connected in sequence.

[0010] In a possible design, the silicon-containing powder includes silicon dioxide powder.

[0011] In a possible design, the particle size of the silicon-containing powder is 0.5 - 2 μm.

[0012] In a possible design, the slurry further includes epoxy resin, and the mass ratio of the epoxy resin to the silicon-containing powder is 1:(1 - 3).

[0013] In a possible design, the coating thickness of the high-temperature binder on the slurry layer is 0.1 - 0.2 mm.

[0014] In a possible design, the processing temperature of the high-temperature treatment is 1350 - 1650 °C, the processing time is 2 - 4 h, and the processing environment is an argon atmosphere.

[0015] In a possible design, the fixing member and the composite material to be connected are made of the same material.

[0016] In a possible design, after the high-temperature treatment, it further includes:

[0017] Performing matrix densification treatment on the connected composite material.

[0018] In a possible design, the high-temperature binder further includes silicon carbide powder and boron carbide powder, and the phenolic resin includes boron phenolic resin.

[0019] In a possible design, the curing method is as follows:

[0020] Curing is first carried out at 100 - 120 °C for 1 - 4 h, and then at 150 - 200 °C for 1 - 4 h.

[0021] The present invention has at least the following beneficial effects compared with the prior art:

[0022] In this embodiment, the cooperation between the processing hole and the fixing member can mechanically connect different composite materials to be connected, and the high-temperature binder can bond different composite materials to be connected. More importantly, through high-temperature treatment in this application, silicon carbide nanowires can be obtained on the adhesive layer formed by the high-temperature binder. Specifically, during the high-temperature treatment, the phenolic resin will decompose to generate carbon and gas. After the gas escapes, cracks and holes are left. The silicon-containing powder evenly distributed in the slurry layer provides silicon elements, and silicon carbide nanowires are generated in the cracks and holes. These nanowires will grow through the interior of the high-temperature adhesive, thereby improving the microstructure of the adhesive layer after high-temperature treatment, reducing microcracks, and improving the bonding performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a flowchart of a connection method provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In the description of the embodiments of the present invention, unless otherwise clearly defined or limited, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "plurality" means two or more; the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] In the description of this specification, it should be understood that the orientation terms such as "upper" and "lower" described in the embodiments of the present invention are described from the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element.

[0028] As Figure 1 shown, the embodiments of the present invention provide a connection method for ceramic matrix composites, including:

[0029] Performing drilling on the connection parts of different composite materials to be connected;

[0030] Applying a slurry to the connection parts to obtain a slurry layer; wherein, the slurry includes silicon-containing powder;

[0031] Applying a high-temperature binder on the slurry layer; wherein, the high-temperature binder includes phenolic resin;

[0032] Connecting the connection parts of different composite materials to be connected, and passing a fixing member through the processing holes of different connection parts;

[0033] Performing curing treatment and high-temperature treatment on the connected composite materials to be connected in sequence.

[0034] In this embodiment, the cooperation between the processing hole and the fixing member can mechanically connect different composite materials to be joined, and the high-temperature binder can bond different composite materials to be joined. More importantly, through high-temperature treatment in this application, silicon carbide nanowires can be obtained on the adhesive layer formed by the high-temperature binder. Specifically, during the high-temperature treatment process, phenolic resin decomposes to generate carbon and gas. After the gas escapes, cracks and holes are left. The silicon-containing powder evenly distributed in the slurry layer provides silicon elements, and silicon carbide nanowires are generated in the cracks and holes. These nanowires will grow through the interior of the high-temperature adhesive, thereby improving the microstructure of the adhesive layer after high-temperature treatment, reducing microcracks, and enhancing the bonding performance.

[0035] In this embodiment, a CVI / PIP composite process is used to prepare a ceramic matrix composite component until the density of the composite material ≥ 1.65 g / cm 3 ; The ceramic matrix composite uses a structural carbon fiber preform such as needling, stitching, or fine braid piercing. The CVI process is used for carbon matrix densification, and polycarbosilane, zirconium-based ceramic precursor, hafnium-based ceramic precursor, etc. are used to prepare the ceramic matrix by the PIP process, that is, the composite material to be joined.

[0036] The processing of punching holes includes the processing of threaded holes, and the aperture range of the threaded holes is M3 mm to M15 mm. The fixing member can be a ceramic matrix composite screw; the screw size is preferably M3 mm to M15 mm.

[0037] Before coating the slurry, clean the surface of the joint surface, screw holes, and screws with cotton cloth dipped in ethanol for no less than 3 times. The number of times of slurry brushing is 1 to 2 times.

[0038] In some embodiments of the present invention, the silicon-containing powder includes silicon dioxide powder.

[0039] In this embodiment, the silicon dioxide powder reacts with the carbon obtained from the decomposition of phenolic resin, and silicon monoxide gas enters the cracks or holes, nucleates inside the cracks or holes, and silicon carbide nanowires are obtained.

[0040] In some embodiments of the present invention, the particle size of the silicon-containing powder is 0.5 to 2 μm.

[0041] In this embodiment, the silicon-containing powder affects the generation of silicon carbide nanowires. If its particle size is lower than 0.5 μm, the particles are prone to agglomeration and difficult to disperse evenly. If its particle size is higher than 2 μm, the particle size is too large, making it difficult to provide silicon for the carbon in the cracks and holes to generate silicon carbide, and it will also affect the interfacial bonding strength between the slurry layer and the high-temperature binder layer due to the large particle size.

[0042] In some embodiments of the present invention, the slurry further includes epoxy resin, and the mass ratio of epoxy resin to silicon-containing powder is 1:(1 - 3).

[0043] In this embodiment, if there is too much silicon-containing powder, cracking is likely to occur. If there is too little silicon-containing powder, insufficient silicon carbide can be formed in the interface and cracks.

[0044] In some embodiments of the present invention, the coating thickness of the high-temperature binder on the slurry layer is 0.1 - 0.2 mm.

[0045] In this embodiment, if the coating thickness is too low, it is difficult to achieve a good bonding effect. If the coating thickness is too high, it is difficult for the gas during high-temperature treatment to escape, which affects the generation of silicon carbide nanowires.

[0046] In some embodiments of the present invention, the treatment temperature for high-temperature treatment is 1350 - 1650 °C, the treatment time is 2 - 4 h, and the treatment environment is an argon atmosphere.

[0047] In this embodiment, if the high-temperature treatment temperature is too low, not enough SiC nanowires can be obtained after treatment, and high bonding performance cannot be achieved. If the high-temperature treatment temperature is too high, the comprehensive performance of the component is reduced. The bonding performance of the final interface is best when the high-temperature treatment temperature is between 1350 °C and 1600 °C. When the high-temperature treatment temperature is selected between 1350 °C and 1600 °C, its influence on the bonding performance of the final connection sample is small and can be ignored in engineering practice. The entire high-temperature treatment process time is not less than 2 - 4 h. If the time is too short, more microcracks are likely to occur inside the high-temperature binder. If the high-temperature treatment time is too long, the diameter of the nanowires becomes larger, affecting its toughening effect.

[0048] In some embodiments of the present invention, the fixing member and the composite material to be connected are made of the same material.

[0049] In some embodiments of the present invention, after high-temperature treatment, it further includes:

[0050] Performing matrix densification treatment on the connected composite material.

[0051] In some embodiments of the present invention, the high-temperature binder further includes silicon carbide powder and boron carbide powder, and the phenolic resin includes boron phenolic resin. Boron element and silicon carbide can increase the high-temperature resistance of the high-temperature binder.

[0052] Continue to use the PIP process for matrix densification of the ceramic matrix composite connection component, and the PIP process is ≥3 times.

[0053] The ceramic matrix composite connection component is subjected to ≥3 times of PIP process post-densification. The precursor used is liquid polycarbosilane, the pyrolysis temperature is 1000 °C - 1400 °C, and the holding time is 1 h - 4 h.

[0054] After the late densification of the PIP process, the pores and microcracks of the high-temperature adhesive on the joint surface are filled with the SiC matrix, and finally a dense adhesive layer is formed, obtaining high adhesive performance.

[0055] In some embodiments of the present invention, the curing method is as follows:

[0056] Cure at 100-120°C for 1-4h first, and then cure at 150-200°C for 1-4h.

[0057] In order to more clearly illustrate the technical solutions and advantages of the present invention, the following will be described in detail through several embodiments.

[0058] Example 1

[0059] ① Use a carbon fiber flat preform with a needle-punched structure, and prepare a ceramic matrix composite flat plate by the CVI / PIP composite process until the density of the flat plate is 1.65 g / cm 3 ; ② Process a ceramic matrix composite flat sample with dimensions of 30 mm × 25 mm × 10 mm; ③ Clean the joint surface with a cotton cloth dipped in ethanol, and clean it 3 times; ④ Prepare a silica / epoxy resin slurry with a silica particle size of 1 μm and a mass ratio of silica:epoxy resin of 1:2; ⑤ Apply 1 layer of silica / epoxy resin slurry on the joint surface of the ceramic matrix composite; ⑥ Prepare a high-temperature adhesive with a mass ratio of boron phenolic resin:SiC powder:B4C powder of 1:1.5:1.5 and an appropriate amount of ethanol solvent; ⑦ Uniformly apply the high-temperature adhesive on the joint surface after applying the silica / epoxy resin slurry until the thickness is 0.15 mm. The two joint surfaces overlap, and the overlap surface size is 25 mm × 25 mm. Clamp it with a clamping tooling, let it stand for 2 h and then put it into an oven for curing. Cure at 110°C for 2 h and at 180°C for 2 h; ⑨ Perform high-temperature treatment in an Ar atmosphere in a high-temperature treatment furnace at a high-temperature treatment temperature of 1500°C for 2 h; ⑩ Perform 3 times of late densification of the PIP process using a liquid polycarbosilane precursor, with a cracking temperature of 1200°C and a holding time of 2 h. According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", use an electronic universal testing machine to test the normal-temperature compressive shear strength of the joint sample, and the single compressive shear strength is 31 MPa.

[0060] Example 2

[0061] Example 2 is basically the same as Example 1, except that the particle size of the silica powder is 0.5 μm.

[0062] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", use an electronic universal testing machine to test the normal-temperature compressive shear strength of the joint sample, and the single compressive shear strength is 22 MPa.

[0063] Example 3

[0064] Example 3 is basically the same as Example 1, except that the particle size of the silica powder is 2 μm.

[0065] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connection sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 34 MPa.

[0066] Example 4

[0067] Example 4 is basically the same as Example 1, except that the coating thickness of the high-temperature binder is 0.1 mm.

[0068] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connection sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 28 MPa.

[0069] Example 5

[0070] Example 5 is basically the same as Example 1, except that the coating thickness of the high-temperature binder is 0.2 mm.

[0071] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connection sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 27 MPa.

[0072] Example 6

[0073] Example 6 is basically the same as Example 1, except that the temperature of the high-temperature treatment is 1350 °C.

[0074] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connection sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 29 MPa.

[0075] Example 7

[0076] Example 7 is basically the same as Example 1, except that the temperature of the high-temperature treatment is 1650 °C.

[0077] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connection sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 30 MPa.

[0078] Example 8

[0079] Example 8 is basically the same as Example 1, except that the time of the high-temperature treatment is 4 h.

[0080] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connecting sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 29 MPa.

[0081] Comparative Example 1

[0082] Comparative Example 1 was basically the same as Example 1, except that the slurry layer including silica was not applied.

[0083] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connecting sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 4 MPa.

[0084] Comparative Example 2

[0085] Comparative Example 2 was basically the same as Example 1, except that the temperature of the high-temperature treatment was 1200 °C.

[0086] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connecting sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 5 MPa.

[0087] Comparative Example 3

[0088] Comparative Example 3 was basically the same as Example 1, except that the temperature of the high-temperature treatment was 1800 °C.

[0089] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connecting sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 1 MPa.

[0090] Comparative Example 4

[0091] Comparative Example 4 was basically the same as Example 1, except that the coating thickness of the high-temperature binder layer was 0.07 mm.

[0092] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", the compressive shear strength of the connecting sample at room temperature was tested using an electronic universal testing machine, and the single compressive shear strength was 10 MPa.

[0093] Comparative Example 5

[0094] It was basically the same as Example 1, except that the coating thickness of the high-temperature binder layer was 0.3 mm.

[0095] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", an electronic universal testing machine was used to test the compressive shear strength of the connection samples at room temperature, and the single compressive shear strength was 8 MPa.

[0096] Comparative Example 6

[0097] Comparative Example 6 was basically the same as Example 1, except that the particle size of the silica powder was 0.2 μm.

[0098] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", an electronic universal testing machine was used to test the compressive shear strength of the connection samples at room temperature, and the single compressive shear strength was 4 MPa.

[0099] Comparative Example 7

[0100] Comparative Example 7 was basically the same as Example 1, except that the particle size of the silica powder was 0.3 μm.

[0101] According to QJ1634A-96 "Test Method for Compressive Shear Strength of Adhesives", an electronic universal testing machine was used to test the compressive shear strength of the connection samples at room temperature, and the single compressive shear strength was 4 MPa.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for connecting ceramic matrix composite materials, characterized in that: include: Punching the connection parts of different composite materials to be connected; Applying slurry on the connection part to obtain a slurry layer; wherein the slurry includes silicon-containing powder; Applying a high temperature adhesive on the slurry layer; wherein the high temperature adhesive comprises a phenolic resin; Connecting the connecting parts of different composite materials to be connected, and using fixing members to pass through the processed holes of different connecting parts; The composite materials to be connected are sequentially subjected to curing treatment and high temperature treatment.

2. The connection method according to claim 1, characterized in that: The silicon-containing powder includes silicon dioxide powder.

3. The connection method according to claim 1, characterized in that: The particle size of the silicon-containing powder is 0.5 to 2 μm.

4. The connection method according to claim 1, characterized in that: The slurry further comprises epoxy resin, and the mass ratio of the epoxy resin to the silicon-containing powder is 1:(1-3).

5. The connection method according to claim 1, characterized in that: The coating thickness of the high temperature adhesive on the slurry layer is 0.1-0.2 mm.

6. The connection method according to claim 1, characterized in that: The high temperature treatment has a treatment temperature of 1350-1650° C., a treatment time of 2-4 hours, and an argon atmosphere.

7. The connection method according to claim 1, characterized in that: The fixing member and the composite material to be connected are made of the same material.

8. The connection method according to claim 1, characterized in that: After high temperature treatment, it also includes: The connected composite materials are subjected to matrix densification treatment.

9. The connection method according to claim 1, characterized in that: The high temperature binder also includes silicon carbide powder and boron carbide powder, and the phenolic resin includes boron phenolic resin.

10. The connection method according to claim 1, characterized in that: The curing method is as follows: Curing is first performed at 100-120°C for 1-4 hours, and then at 150-200°C for 1-4 hours.

Images