Bonding method for ceramic matrix composite material connection

Abstract

The invention discloses a bonding method for connecting ceramic matrix composites, which comprises the following steps: acquiring a main component and a connecting component in a weight ratio of (80-85): (5-8), and uniformly mixing the main component and the connecting component to obtain an adhesive; cleaning the to-be-bonded surface of the ceramic-based composite material, smearing the adhesive on the to-be-bonded surface, and bonding; and hot-pressing curing treatment is carried out twice after bonding is completed. The main components and the connecting components are used for preparing the adhesive and connecting the ceramic-based composite material, and meanwhile, the two-time hot-pressing curing process is performed, so that the connecting strength of the ceramic-based composite material component is higher, the construction difficulty is reduced, and the cost is saved.

Description

Technical Field

[0001] This application relates to the technical field of ceramic matrix composite material processing, and specifically relates to an adhesive bonding method for connecting ceramic matrix composite materials. Background Art

[0002] Ceramic matrix composites (CMCs) are a class of composite materials composed of a ceramic matrix and various fibers. The ceramic matrix can be a high-temperature structural ceramic such as silicon nitride or silicon carbide, which has high temperature resistance, high strength and stiffness, relatively light weight, and corrosion resistance. Currently, aerospace vehicles generally serve in high-temperature vibration environments, and some ceramic matrix composite components are prone to loosening, leading to dangerous accidents.

[0003] Therefore, it is necessary to study an adhesive bonding method for connecting ceramic matrix composite materials to improve the shear strength and adhesive strength between components. Summary of the Invention

[0004] The purpose of the present invention is to provide an adhesive bonding method for connecting ceramic matrix composite materials, which improves the shear strength and adhesive strength between components and solves the problem of loosening of components in the prior art.

[0005] To solve the above technical problems, the present invention adopts the following solutions:

[0006] An adhesive bonding method for connecting ceramic matrix composite materials includes the following steps:

[0007] Step 1: Obtain a main component and a connecting component with a weight ratio of 80 - 85:5 - 8, and mix the main component and the connecting component evenly to obtain an adhesive;

[0008] The main component is composed of phenolic resin, acetone, absolute ethanol, and phthalic anhydride;

[0009] The connecting component is a Ni-based binder;

[0010] Step 2: Clean the surface to be bonded of the ceramic matrix composite material, apply the adhesive to the surface to be bonded, and then perform bonding;

[0011] Step 3: After bonding, perform two hot pressing and curing treatments.

[0012] In this application, the ceramic matrix composite material to be bonded is prepared by the CVI or PIP method to obtain two planar components of the ceramic matrix composite material. The main component mainly composed of phenolic resin and the Ni-based binder are mixed in a certain proportion to form a resin adhesive. The phenolic resin can provide adhesive performance under high-temperature conditions, and the Ni-based binder is used to enhance the adhesion strength between ceramic matrix composite materials. At the same time, two hot pressing and curing treatment processes are adopted to finally enhance the tensile strength and shear strength after bonding.

[0013] Further, in the main component, the mass percentages of phenolic resin, acetone, absolute ethanol, and phthalic anhydride are 60% - 80%, 1% - 5%, 10% - 30%, and 5% - 9% respectively.

[0014] Further, the weight ratio of the main component to the connecting component is 80:5.

[0015] Further, the Ni-based binder contains one or more elements of chromium, titanium, cobalt, tungsten, and molybdenum.

[0016] Further, when preparing the adhesive, first stir acetone, absolute ethanol, and phthalic acid evenly, then add phenolic resin and mix for 2 - 8 min at 500 r / min; add the Ni-based binder and mix for 1 - 5 min at 600 r / min.

[0017] Further, after grinding and cleaning the bonding surface of the ceramic matrix composite material, wipe the bonding surface with absolute ethanol.

[0018] Further, the thickness of the adhesive applied on the bonding surface is 0.05 mm - 0.1 mm.

[0019] Further, place the bonded ceramic matrix composite material in a autoclave for two hot pressing and curing processes, with a total heat preservation time of 3 - 5 h.

[0020] Further, for the first hot pressing and curing, heat up to 600 °C at a rate of 10 °C / min and keep the temperature for 1 - 2 h.

[0021] Further, for the second hot pressing and curing, heat up to 800 °C at a rate of 5 °C / min and keep the temperature for 2 - 3 h.

[0022] The beneficial effects of the present invention are as follows: The bonding method of the ceramic matrix composite material of the present invention uses the main component and the connecting component to prepare the adhesive, bond the ceramic matrix composite material, and at the same time, through two hot pressing and curing processes, it can withstand temperatures up to 800 °C - 1000 °C, and makes the connection strength of the ceramic matrix composite material component higher, reduces the construction difficulty, and saves costs. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the bonding process of the bonding method of the present invention. Detailed Embodiments

[0024] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, 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 described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0025] Unless otherwise specifically stated, the relative arrangements, numerical expressions and values of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0026] Meanwhile, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship.

[0027] In addition, for the sake of clarity and conciseness, the descriptions of well-known structures, functions and configurations may be omitted. Those of ordinary skill in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of the present disclosure.

[0028] The techniques, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said techniques, methods and devices should be regarded as part of the authorization specification.

[0029] In all the examples shown and discussed here, any specific value should be construed as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0030] Embodiment 1

[0031] An adhesive bonding method for connecting ceramic matrix composites, referring to Figure 1 , includes the following steps:

[0032] (1) Obtain the main components composed of phenolic resin, acetone, absolute ethanol and phthalic anhydride according to the weight ratio of 80:5, and a Ni-based binder containing one or more elements of chromium, titanium, cobalt, tungsten and molybdenum. The mass percentages of phenolic resin, acetone, absolute ethanol and phthalic anhydride are 70%, 3%, 20% and 7% respectively.

[0033] (11) First, put acetone, absolute ethanol and phthalic acid into a blender and stir evenly, then add phenolic resin and mix for 5 min at 500 r / min; add the Ni-based binder and mix for 3 min at 600 r / min. After mixing, obtain the adhesive for standby.

[0034] Store the adhesive at -18°C for no more than 15 days.

[0035] (2) Grind two pieces of ceramic matrix composites with the specifications of 40 cm × 20 cm × 3 cm respectively. Gently grind them with 1000 - mesh sandpaper, and then wipe and clean the surface to be bonded with anhydrous ethanol. After that, evenly apply the adhesive on the surface to be bonded of one of the ceramic matrix composites, with the adhesive thickness being 0.1 mm. Align the surfaces to be bonded of the two pieces of ceramic matrix composites and then bond them. During the gluing process, use a clamp or other pressure - applying devices to improve the bonding effect of the surfaces to be bonded.

[0036] (3) Place the bonded ceramic matrix composites in an autoclave, heat them up to 600 °C at a rate of 10 °C / min, and keep them at this temperature for 2 h for the first hot - pressing curing; then heat them up to 800 °C at a rate of 5 °C / min and keep them at this temperature for 3 h for the second hot - pressing curing. Place them in the air and let them cool naturally. Clean the excess overflowing adhesive to complete the bonding of the ceramic matrix composites, and conduct tensile tests and shear tests. The results are: the tensile strength is 55 MPa, and the shear strength is 48 MPa.

[0037] Example 2

[0038] A bonding method for connecting ceramic matrix composites, comprising the following steps:

[0039] (1) Obtain the main components composed of phenolic resin, acetone, anhydrous ethanol and phthalic anhydride according to the weight ratio of 85:8, and a Ni - based binder containing one or more elements of chromium, titanium, cobalt, tungsten, and molybdenum. Among them, the mass percentages of phenolic resin, acetone, anhydrous ethanol and phthalic anhydride are 80%, 5%, 10%, and 5% respectively.

[0040] (11) First, put acetone, anhydrous ethanol and phthalic acid into a blender and stir evenly, then add phenolic resin and mix for 7 min at 500 r / min; add the Ni - based binder and mix for 5 min at 600 r / min. After mixing, obtain the adhesive for standby use.

[0041] Store the adhesive at - 18 °C, and the storage time does not exceed 15 days.

[0042] (2) Grind two pieces of ceramic matrix composites with the specifications of 40 cm × 20 cm × 3 cm respectively. Gently grind them with 1000 - mesh sandpaper, and then wipe and clean the surface to be bonded with anhydrous ethanol. After that, evenly apply the adhesive on the surface to be bonded of one of the ceramic matrix composites, with the adhesive thickness being 0.8 mm. Align the surfaces to be bonded of the two pieces of ceramic matrix composites and then bond them. During the gluing process, use a clamp or other pressure - applying devices to improve the bonding effect of the surfaces to be bonded.

[0043] (3) Place the bonded ceramic matrix composite material in an autoclave, heat it up to 600 °C at a rate of 10 °C / min, and keep it at this temperature for 1 h for the first hot pressing and curing; then heat it up to 800 °C at a rate of 5 °C / min and keep it at this temperature for 2 h for the second hot pressing and curing. Place it in the air and let it cool naturally. Clean the excess overflowing adhesive to complete the bonding of the ceramic matrix composite material, and conduct tensile tests and shear tests. The results are as follows: the tensile strength is 53 MPa, and the shear strength is 45 MPa.

[0044] Example 3

[0045] An adhesive bonding method for connecting ceramic matrix composite materials, comprising the following steps:

[0046] (1) Obtain the main components composed of phenolic resin, acetone, absolute ethanol and phthalic anhydride according to the weight ratio of 85:5, and a Ni-based binder containing one or more elements of chromium, titanium, cobalt, tungsten, and molybdenum. The mass percentages of phenolic resin, acetone, absolute ethanol and phthalic anhydride are 60%, 5%, 30% and 5% respectively.

[0047] (11) First, put acetone, absolute ethanol and phthalic acid into a blender and stir evenly, then add phenolic resin and mix for 5 min at 500 r / min; add the Ni-based binder and mix for 3 min at 600 r / min. After mixing, the adhesive is obtained and ready for use.

[0048] Store the adhesive at -18 °C for no more than 15 days.

[0049] (2) Grind two pieces of ceramic matrix composite materials with specifications of 60 cm × 20 cm × 3 cm respectively. Gently grind them with 1000-mesh sandpaper, and then wipe and clean the surface to be bonded with absolute ethanol. Then evenly apply the adhesive on the surface to be bonded of one of the ceramic matrix composite materials, with a coating thickness of 0.1 mm. Align the surfaces to be bonded of the two pieces of ceramic matrix composite materials and then bond them. During the coating process, use a clamp or other pressure-applying devices to improve the bonding effect of the surface to be bonded.

[0050] (3) Place the bonded ceramic matrix composite material in an autoclave, heat it up to 600 °C at a rate of 10 °C / min, and keep it at this temperature for 1.5 h for the first hot pressing and curing; then heat it up to 800 °C at a rate of 5 °C / min and keep it at this temperature for 2.5 h for the second hot pressing and curing. Place it in the air and let it cool naturally. Clean the excess overflowing adhesive to complete the bonding of the ceramic matrix composite material, and conduct tensile tests and shear tests. The results are as follows: the tensile strength is 50 MPa, and the shear strength is 45 MPa.

[0051] Comparative example

[0052] This comparative example is basically the same as Example 1, except that a single hot pressing and curing treatment is used, heating up to 600 °C at a rate of 10 °C / min, holding for 2 h for a single hot pressing and curing, and the measured tensile strength is 36 MPa and the shear strength is 29 MPa.

[0053] The above are only the preferred embodiments of the present invention, and do not impose any formal restrictions on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A bonding method for connecting ceramic matrix composite materials, characterized in that: The following steps are involved: Step 1, obtaining a main component and a connecting component in a weight ratio of 80-85:5-8, and mixing the main component and the connecting component to obtain an adhesive; The main component is composed of phenolic resin, acetone, anhydrous ethanol and phthalic anhydride; The connecting component is a Ni-based connecting agent; Step 2: Clean the surface of the ceramic matrix composite material to be bonded, apply adhesive to the surface to be bonded, and then bond; Step 3: After bonding is completed, perform two hot pressing curing processes.

2. A bonding method for connecting ceramic matrix composite materials according to claim 1, characterized in that: In the main component, the mass percentages of phenolic resin, acetone, anhydrous ethanol and phthalic anhydride are 60% to 80%, 1% to 5%, 10% to 30% and 5% to 9% respectively.

3. A bonding method for connecting ceramic matrix composite materials according to claim 2, characterized in that: The weight ratio of the main component to the connecting component is 80:

5.

4. A bonding method for connecting ceramic matrix composite materials according to claim 2, characterized in that: The Ni-based connector contains one or more elements of chromium, titanium, cobalt, tungsten and molybdenum.

5. A bonding method for connecting ceramic matrix composite materials according to claim 2, characterized in that: When preparing the adhesive, first stir acetone, anhydrous ethanol and phthalic acid evenly, then add phenolic resin, mix for 2 to 8 minutes at 500 r / min; add Ni-based connector, mix for 1 to 5 minutes at 600 r / min.

6. A bonding method for connecting ceramic matrix composite materials according to claim 2, characterized in that: After the surface to be bonded of the ceramic-based composite material is polished and cleaned, the surface to be bonded is wiped with anhydrous ethanol.

7. A bonding method for connecting ceramic matrix composite materials according to claim 2, characterized in that: The thickness of the glue coating on the surface to be bonded is 0.05mm to 0.1mm.

8. A bonding method for connecting ceramic matrix composite materials according to claim 2, characterized in that: The bonded ceramic matrix composite material is placed in an autoclave for two hot pressing curings, with a total heat preservation time of 3 to 5 hours.

9. A bonding method for connecting ceramic matrix composite materials according to claim 8, characterized in that: The first hot pressing curing was carried out by heating the temperature to 600°C at a rate of 10°C / min and keeping the temperature for 1 to 2 hours.

10. A bonding method for connecting ceramic matrix composite materials according to claim 8, characterized in that: The second hot pressing curing is heated to 800°C at a rate of 5°C / min and kept at this temperature for 2 to 3 hours.

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