A composite material with a wide temperature range and self-healing SiC fiber reinforced multiphase matrix and a preparation method thereof

Abstract

The present application discloses a composite material with a wide temperature range and a self-healing SiC fiber reinforced multiphase matrix and a preparation method thereof, specifically relating to the field of SiC composite materials. It comprises a SiC fiber preform, on which a BN interface phase, a first SiC matrix, and an alternating matrix are sequentially deposited, and a SiAlBCN matrix is ​​coated on the alternating matrix, wherein the alternating matrix comprises a B4C matrix, a BN matrix, and a second SiC matrix deposited in sequence. First, a BN interface phase and a first SiC matrix are deposited in the SiC fiber preform, and then a B4C matrix, a BN matrix, and a second SiC matrix are cyclically deposited. Finally, the deposited composite material is impregnated and cracked to obtain a composite material with a SiC fiber reinforced multiphase matrix. It can have good oxidation resistance in a wide temperature range of 900 to 1500°C.

Description

Technical Field

[0001] The present application relates to the field of SiC composite materials, and in particular to a wide-temperature range self-healing SiC fiber-reinforced multiphase matrix composite material and a preparation method thereof. Background Art

[0002] SiC fiber reinforced SiC ceramic matrix composites (SiC f / SiC composite materials) have a series of excellent properties such as low density, high specific strength, high specific modulus and non-catastrophic fracture, making them a candidate for key thermal structural materials for aircraft engines with a thrust-to-weight ratio of more than 10. However, in the thermal-mechanical-oxygen coupled working environment of aircraft engines, SiC f / SiC faces severe oxidation problems, and its service life is significantly shortened. f / The anti-oxidation property of SiC becomes the key to prolonging its service life and improving the working efficiency of aircraft engines.

[0003] Studies have shown that the introduction of self-healing components into the matrix and the use of the viscous flow of the glass phase generated by the oxidation of the self-healing components can quickly fill cracks and holes, effectively preventing oxygen from further diffusing into the material and preventing oxidation of the interface and fibers, thereby significantly improving the SiC f / SiC's antioxidant properties. Currently, self-healing matrix modified SiC f There have been many studies on SiC. Most of the related studies use a certain self-healing component (B4C or SiBC), which can only improve the oxidation resistance in a narrow temperature range. f The operating temperature range of / SiC is relatively wide, and existing self-healing components cannot improve the antioxidant performance in this temperature range. Summary of the Invention

[0004] The main purpose of this application is to provide a wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material and its preparation method, in order to solve the problem that the existing technology cannot improve the SiC f / SiC's oxidation resistance in a wide operating temperature range.

[0005] To achieve the above-mentioned objectives, the present application provides a composite material of a self-healing SiC fiber reinforced multiphase matrix in a wide temperature range, comprising a SiC fiber preform, on which a BN interface phase, a first SiC matrix, and an alternating matrix are sequentially deposited, and the alternating matrix is ​​coated with a SiAlBCN matrix, wherein the alternating matrix comprises a B4C matrix, a BN matrix, and a second SiC matrix deposited sequentially.

[0006] Optionally, the SiC fiber preform is a three-dimensional structure woven from SiC fibers, with gaps formed between the SiC fibers; the BN interface phase, the first SiC matrix, the alternating matrix, and the SiAlBCN matrix are located in the gaps.

[0007] Optionally, the alternating matrix includes n layers, and 1≤n≤3; the SiC fiber preform is a two-dimensional laminated three-dimensional structure, a two-dimensional semi-structure, or a three-dimensional structure.

[0008] Optionally, the volume fraction of the SiC fiber preform is 35% to 42%, the volume fraction of the BN interface phase is 1% to 4%, the volume fraction of the first SiC matrix is ​​20% to 30%, the volume fraction of the alternating matrix is ​​8% to 27%, the volume fraction of the SiAlBCN matrix is ​​6% to 12%, and the total volume fraction of the above components is 85% to 95%.

[0009] Optionally, in the alternating matrix, the volume fraction of the B4C matrix is ​​3% to 9%, the volume fraction of the BN matrix is ​​2% to 6%, and the volume fraction of the second SiC matrix is ​​3% to 12%.

[0010] To achieve the above object, the present application provides a method for preparing the above-mentioned wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material, comprising: depositing a BN interface phase in a SiC fiber preform to obtain a composite SiC fiber preform; depositing a first SiC matrix in the composite SiC fiber preform to obtain a porous SiC f / SiC composite materials; in porous SiC f The B4C matrix, BN matrix and second SiC matrix are deposited in sequence in the SiC / SiC composite material to obtain SiC f / SiC-B4C-BN composite material; polyborosilazane and aluminum acetylacetonate were dissolved in toluene to obtain a polymer solution; SiC f / SiC-B4C-BN composite material was immersed in polymer solution, and the SiC f / SiC-B4C-BN composite material is cracked to obtain a SiC fiber reinforced multiphase matrix composite material; wherein the reaction conditions during the cracking process are: first heating to 130-160°C, reacting for 2-4 hours, then heating to 270-320°C, curing for 1-3 hours, and then heating to 1000-1200°C and cracking for 1-4 hours.

[0011] Alternatively, SiC f During the preparation of the porous SiC / SiC-B4C-BN composite material, f The B4C matrix, BN matrix and SiC matrix are deposited in a cycle within the / SiC composite material, with the cycle number being 1 to 3.

[0012] Optionally, the BN interface phase is deposited in the SiC fiber preform by the CVI method, and the gaseous precursors used in the deposition process are boron trichloride and ammonia, the flow rate of boron trichloride is 80-250 mL / min, the flow rate of ammonia is 250-500 mL / min, the deposition pressure is 2-5 kPa, the deposition temperature is 850-950°C, and the deposition time is 25-50 h; the first SiC matrix is ​​deposited in the composite SiC fiber preform by the CVI method, and the gaseous precursor used in the deposition process is trichloromethylsilane, the flow rate of trichloromethylsilane is 50-300 mL / min, the deposition pressure is 2-5 kPa, the deposition temperature is 850-1000°C, and the deposition time is 240-360 h.

[0013] Alternatively, in porous SiC f The B4C matrix, BN matrix and SiC matrix are sequentially deposited in the SiC / SiC composite material using the CVI method. In the B4C matrix deposition process, the gaseous precursors used are boron trichloride and methane, the flow rate of boron trichloride is 100-500 mL / min, the flow rate of methane is 80-200 mL / min, the deposition pressure is 2-5 kPa, the deposition temperature is 900-1100 °C, and the deposition time is 20-100 h. In the BN matrix deposition process, the gaseous precursors used are boron trichloride and ammonia. gas, the flow rate of boron trichloride is 100-400mL / min, the flow rate of ammonia is 300-700mL / min, the deposition pressure is 2-5kPa, the deposition temperature is 900-1100℃, and the deposition time is 5-20h; in the deposition process of the second SiC substrate, the gaseous precursor used is trichloromethylsilane, the flow rate of trichloromethylsilane is 50-300mL / min, the deposition pressure is 2-5kPa, the deposition temperature is 900-1100℃, and the deposition time is 30-70h.

[0014] Optionally, during the preparation of the SiC fiber reinforced multiphase matrix composite material, the impregnation and cracking processes are repeated; the mass ratio of toluene, polyborosilazane and aluminum acetylacetonate is (7-12):(6-14):1, and the impregnation time is 0.4-2h.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The present invention discloses a composite material with a wide temperature range self-healing SiC fiber reinforced multiphase matrix, wherein B4C, BN and SiAlBCN can respectively function in their respective effective self-healing temperature ranges; wherein, the B2O3 glass generated by the oxidation of B4C and BN can play a good protective role on the composite material at 900-1000°C; at 1300-1500°C, the SiO2-Al2O3 and aluminosilicate glass generated by the oxidation of SiAlBCN can efficiently perform the self-healing function. At 1000-1300°C, the SiO2-Al2O3 and aluminosilicate high-melting-point glass generated by the oxidation of external SiAlBCN can significantly reduce the volatilization rate of the low-melting-point B2O3 glass generated by the oxidation of internal B4C and BN, thereby improving the antioxidant capacity of the composite material. In summary, the three self-healing components work together to make SiC f / SiC-B4C-BN-SiAlBCN has good oxidation resistance in a wide temperature range of 900~1500℃.

[0017] The present invention discloses a method for preparing a composite material with a wide temperature range self-healing SiC fiber-reinforced multiphase matrix. The method comprises adjusting the number of cyclic deposition times of B4C, BN, and SiC to regulate the deflection and propagation path of matrix cracks, thereby controlling the mechanical properties of the composite material. Different volume fractions of the B4C, BN, and SiAlBCN matrices are set, and different contents of low-melting-point glass and high-melting-point glass generated after oxidation are obtained, thereby controlling the key self-healing temperature range of the composite material to meet customized service requirements. Simultaneously, the number of cyclic deposition times and deposition time are adjusted to ensure that the volume fractions of the B4C and BN matrices reach ideal values ​​and obtain expected values. By controlling the number of PIP (polymerization impregnation pyrolysis) process cycles, a SiAlBCN matrix with a target content is prepared, thereby achieving synergistic improvements in the mechanical properties and antioxidant properties of the composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic flow chart of a method for preparing a wide-temperature-range self-healing SiC fiber-reinforced multiphase matrix composite material of the present application;

[0019] Figure 2 The SiC prepared in Example 1 of this application f Cross-sectional micromorphology photograph of / SiC-B4C-BN-SiAlBCN composite material;

[0020] Figure 3 The SiC prepared in Example 1 of this application f Bending load-displacement curves of / SiC-B4C-BN-SiAlBCN composite materials in the initial state, after oxidation at 900℃ for 10h, after oxidation at 1100℃ for 10h, after oxidation at 1300℃ for 10h, and after oxidation at 1500℃ for 10h;

[0021] Figure 4 The SiC prepared in Example 1 of this application f / SiC-B4C-BN-SiAlBCN composite material and SiC prepared in comparative example f Changes in the flexural strength retention and flexural modulus retention of SiC / SiC composites after oxidation at 900, 1100, 1300 and 1500 °C for 10 h.

[0022] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0024] A first embodiment of the present invention provides a composite material of a self-healing SiC fiber reinforced multiphase matrix in a wide temperature range, comprising a SiC fiber preform, on which a BN interface phase, a first SiC matrix, and an alternating matrix are sequentially deposited, and the alternating matrix is ​​coated with a SiAlBCN matrix, wherein the alternating matrix comprises a B4C matrix, a BN matrix, and a second SiC matrix deposited sequentially.

[0025] The SiC fiber preform is a three-dimensional structure woven from SiC fibers, with gaps between the fibers. The BN interface phase, the first SiC matrix, the alternating matrix, and the SiAlBCN matrix are located within the gaps. The alternating matrix comprises n layers, with 1 ≤ n ≤ 3. The volume fraction of the SiC fiber preform is 35% to 42%, the volume fraction of the BN interface phase is 1% to 4%, and the thickness of the BN interface phase is 60 to 100 nm. The volume fraction of the first SiC matrix is ​​20% to 30%, the volume fraction of the alternating matrix is ​​8% to 27%, and the volume fraction of the SiAlBCN matrix is ​​6% to 12%. Within the alternating matrix, the volume fraction of the B4C matrix is ​​3% to 9%, the volume fraction of the BN matrix is ​​2% to 6%, and the volume fraction of the second SiC matrix is ​​3% to 12%. Since the composite material also contains 5% to 15% of pores (including open and closed pores), the total volume fraction of these components is 85% to 95%.

[0026] The design concept of the SiC fiber reinforced multiphase matrix composite material of the present invention is as follows:

[0027] In order to improve SiC fThe oxidation resistance of SiC / SiC over a wide temperature range of 900-1500°C was investigated experimentally using several feasible self-healing components. The results revealed that the glass phases generated by oxidation of different self-healing components have different melting points, resulting in distinct effective temperature ranges for these glass phases. Specifically, the effective temperature range for B2O3 glass is 450-1000°C, while that for borosilicate glass is 1000-1400°C. The melting points of borosilicate glass vary significantly depending on the ratio of B2O3 to SiO2. Borosilicate glass with a higher B2O3 content is suitable for temperatures between 1000-1200°C, while that with a higher SiO2 content is effective at temperatures between 1200-1400°C. Above 1400°C, the volatilization rate of SiO2 accelerates, necessitating the addition of Al2O3 to enhance its stability. Different self-healing components have different starting oxidation temperatures. Combined with the effective temperature ranges of different glass phases, we can obtain the effective self-healing temperature ranges of different self-healing components: the effective self-healing temperature range of B4C is 600-900℃; the effective self-healing temperature range of BN is 800-1000℃; the effective self-healing temperature range of SiBC is 1000-1200℃; the effective self-healing temperature range of SiAlBCN is 1300-1500℃. Based on the above analysis, in SiC f A variety of self-healing components are introduced into SiC / SiC, and a reasonable order / structure design of different self-healing components is carried out to finally obtain a self-healing SiC fiber reinforced multiphase matrix (i.e. SiC) with a wide temperature range of 900-1500℃. f / SiC-B4C-BN-SiAlBCN) composite material.

[0028] SiC of the present invention f The SiC-B4C-BN-SiAlBCN composite matrix features SiAlBCN on the outside and B4C and BN on the inside. This order and structure allows the high-melting-point SiO2-Al2O3 and aluminosilicate glass, generated by oxidation of the SiAlBCN on the outside, to fully inhibit the volatilization of the low-melting-point B2O3 glass, generated by oxidation of B4C and BN on the inside, enhancing the self-healing effect. The SiC-B4C-BN-SiAlBCN multilayer matrix promotes crack deflection at the interface between the high-modulus matrix phases (SiC, B4C) and the low-modulus matrix phases (BN, SiAlBCN), effectively extending the crack propagation path. This not only improves the toughness of the composite but also extends the oxygen diffusion path, enhancing the composite's oxidation resistance.

[0029] The second embodiment of the present invention provides a method for preparing a composite material having a wide temperature range and self-healing SiC fiber reinforced multiphase matrix, such as Figure 1 As shown, the specific steps include:

[0030] Step S1, depositing a BN interface phase in a SiC fiber preform using a CVI method to obtain a composite SiC fiber preform;

[0031] Among them, the SiC fiber preform can be a two-dimensional (2D) laminated solid structure, a two-dimensional and a half (2.5D) structure, or a three-dimensional (3D) structure. Specifically, the two-dimensional (2D) laminated solid structure SiC fiber preform is obtained by weaving SiC fibers into a two-dimensional fiber cloth and then laminating them. Specifically, a SiC fiber preform is suspended on a sample holder supporting a BN deposition furnace, and boron trichloride, ammonia, diluent gas argon, and catalytic gas hydrogen are introduced simultaneously. The flow rate of boron trichloride is 80-250 mL / min, the flow rate of ammonia is 250-500 mL / min, the flow rate of argon is 200-400 mL / min, and the flow rate of hydrogen is 400-850 mL / min. The pressure in the furnace is maintained at 2-5 kPa, and a BN interface phase is deposited at 850-950° C. for 25-50 h to obtain a composite SiC fiber preform, wherein the thickness of the BN interface phase is 60-100 nm, and the volume fraction of the BN interface phase is 1%-4%.

[0032] Step S2, using CVI method to deposit the first SiC matrix in the composite SiC fiber preform to obtain a porous SiC f / SiC composite materials;

[0033] Specifically, the composite SiC fiber preform is hung on the sample holder of the SiC deposition furnace, and trichloromethylsilane, dilution gas argon and catalytic gas hydrogen are introduced, wherein the flow rate of trichloromethylsilane is 50-300 mL / min, the flow rate of argon is 200-450 mL / min, and the flow rate of hydrogen is 350-650 mL / min; the pressure in the furnace is maintained at 2-5 kPa, the deposition temperature is 850-1000 ° C, and the deposition time is 240-360 h to obtain porous SiC f / SiC composite material; wherein the volume fraction of the first SiC matrix is ​​20-30%.

[0034] In this embodiment, a BN interface phase is deposited in the SiC fiber preform. The BN interface phase is distributed between the SiC fiber preform and the first SiC matrix, and mainly plays the role of alleviating thermal expansion mismatch, modulus mismatch and deflection cracks between the fiber and the matrix. In an oxidizing environment, it has a certain crack healing effect.

[0035] Step S3, in the porous SiC f The B4C matrix, BN matrix, and second SiC matrix are deposited on the surface of the SiC composite material in sequence to obtain SiC f / SiC-B4C-BN composite materials;

[0036] The SiC of this embodiment f In the SiC-B4C-BN composite material, the volume fraction of the B4C matrix is ​​3% to 9%, the volume fraction of the BN matrix is ​​2% to 6%, and the volume fraction of the second SiC matrix is ​​3% to 12%. In order to obtain the above-mentioned target content of B4C, BN and the second SiC matrix, step S3 can be repeated, that is, the CVI method can be used to obtain the porous SiC matrix. f The B4C matrix, BN matrix, and second SiC matrix are sequentially deposited in the SiC / SiC composite material, with the number of cycles being 1 to 3. The specific deposition process is as follows:

[0037] Porous SiC f The / SiC composite material is hung on the supporting frame of the B4C deposition furnace, and boron trichloride, methane, diluent gas argon and catalytic gas hydrogen are introduced. The flow rate of boron trichloride is 100-500mL / min, the flow rate of methane is 80-200mL / min, the flow rate of argon is 300-500mL / min, and the flow rate of hydrogen is 300-700mL / min. The pressure in the furnace is maintained at 2-5kPa, the deposition temperature is 900-1100℃, and the deposition time is 20-100h to obtain porous SiC deposited on a B4C matrix. f / SiC composite materials;

[0038] The porous SiC on the B4C matrix will be deposited f The / SiC composite material is hung on the supporting frame of the BN deposition furnace, and boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen are introduced. The boron trichloride flow rate is 100-400mL / min, the ammonia flow rate is 300-700mL / min, the argon flow rate is 300-500mL / min, and the hydrogen flow rate is 700-1100mL / min. The pressure in the furnace is maintained at 2-5kPa, the deposition temperature is in the range of 900-1000℃, and the deposition time is 5-20h to obtain porous SiC deposited on a B4C-BN matrix. f / SiC composite materials;

[0039] The porous SiC on the B4C-BN matrix will be deposited f / SiC composite material is hung on the supporting frame of SiC deposition furnace, and trichloromethylsilane, diluent gas argon and catalytic gas hydrogen are introduced. The flow rate of trichloromethylsilane is 50-300mL / min, the flow rate of argon is 300-500mL / min, and the flow rate of hydrogen is 200-500mL / min. The pressure in the furnace is maintained at 2-5kPa, the deposition temperature is in the range of 900-1100℃, the deposition time is 30-70h, and SiC f / SiC-B4C-BN composite materials.

[0040] Step S4, dissolving polyborosilazane and aluminum acetylacetonate in toluene to obtain a polymer solution, wherein the mass ratio of toluene, polyborosilazane and aluminum acetylacetonate is (7-12):(6-14):1;

[0041] Step S5, SiC f / SiC-B4C-BN composite material was immersed in polymer solution, and the SiC f / SiC-B4C-BN composite material is cracked to obtain SiC f / SiC-B4C-BN-SiAlBCN composite material.

[0042] In order to obtain the target volume fraction of SiAlBCN matrix, step S5 can be repeated to make the volume fraction of SiAlBCN 6% to 12%. f / SiC-B4C-BN-SiAlBCN composite material, the process is as follows:

[0043] SiC f / SiC-B4C-BN composite material is immersed in polymer solution for 0.4-2h, taken out and placed in alumina crucible, the crucible is placed in a tube furnace, heated to 130-160℃ under nitrogen atmosphere, reacted for 2-4h; then heated to 270-320℃, cured for 1-3h; finally heated to 1000-1200℃, cracked for 2-4h, and obtained SiC f / SiC-B4C-BN-SiAlBCN composite material.

[0044] Example 1

[0045] Step S1: stack 20 sheets of 25 cm × 16 cm two-dimensional plain woven SiC fiber cloth (500 pieces / bundle) and fix them with a graphite clamp to obtain a two-dimensional (2D) SiC fiber preform, wherein the volume fraction of the SiC fiber preform is 38%; hang the SiC fiber preform on a sample rack supporting a BN deposition furnace, and simultaneously introduce boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen, with a boron trichloride flow rate of 200 mL / min, an ammonia flow rate of 400 mL / min, an argon flow rate of 300 mL / min, and a hydrogen flow rate of 750 mL / min. Maintain the furnace pressure at 2 kPa, deposit a BN interface phase at 900°C for 40 hours, and obtain a composite SiC fiber preform, wherein the thickness of the BN interface phase is 80 nm and the volume fraction of the BN interface phase is 3%.

[0046] Step S2: hang the composite SiC fiber preform on the sample rack of the SiC deposition furnace, introduce trichloromethylsilane, diluent gas argon and catalytic gas hydrogen, wherein the flow rate of trichloromethylsilane is 200 mL / min, the flow rate of argon is 300 mL / min, and the flow rate of hydrogen is 500 mL / min; maintain the pressure in the furnace at 2 kPa, the deposition temperature at 900 ° C, and the deposition time for 300 h to obtain porous SiC f / SiC composite material; wherein the volume fraction of the first SiC matrix is ​​25%.

[0047] Step S3, porous SiC f The / SiC composite material was hung on the supporting frame of the B4C deposition furnace, and boron trichloride, methane, diluent gas argon and catalytic gas hydrogen were introduced. The flow rate of boron trichloride was 200mL / min, the flow rate of methane was 100mL / min, the flow rate of argon was 300mL / min, and the flow rate of hydrogen was 400mL / min. The pressure in the furnace was maintained at 2kPa, the deposition temperature was 900℃, and the deposition time was 40h. The porous SiC on the B4C matrix was obtained. f / SiC composite material, wherein the volume fraction of B4C matrix is ​​3%;

[0048] The porous SiC on the B4C matrix will be deposited f The / SiC composite material was suspended on the supporting frame of the BN deposition furnace, and boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen were introduced. The boron trichloride flow rate was 100 mL / min, the ammonia flow rate was 350 mL / min, the argon flow rate was 450 mL / min, and the hydrogen flow rate was 700 mL / min. The pressure in the furnace was maintained at 2 kPa, the deposition temperature was within the range of 950 ° C, and the deposition time was 10 h to obtain porous SiC deposited on a B4C-BN matrix. f / SiC composite material, wherein the volume fraction of BN matrix is ​​2%;

[0049] The porous SiC on the B4C-BN matrix will be deposited f The SiC / SiC composite material was suspended on the supporting frame of the SiC deposition furnace, and trichloromethylsilane, diluent gas argon and catalytic gas hydrogen were introduced. The flow rate of trichloromethylsilane was 200 mL / min, the flow rate of argon was 300 mL / min, and the flow rate of hydrogen was 500 mL / min. The pressure in the furnace was maintained at 2 kPa, the deposition temperature was within the range of 900 °C, the deposition time was 50 h, and the SiC f / SiC-B4C-BN composite material, wherein the volume fraction of the second SiC matrix is ​​4%.

[0050] Step S4, dissolving polyborosilazane and aluminum acetylacetonate in toluene in a mass ratio of 9:1:10 to obtain a polymer solution;

[0051] Step S5, SiC f The SiC / SiC-B4C-BN composite material was vacuum impregnated in the polymer solution for 0.5 hours, and then the composite material was placed in an alumina crucible. The crucible was placed in a tube furnace and heated to 150°C and kept warm in a nitrogen atmosphere for 3 hours; then the temperature was raised to 300°C and kept warm for 2 hours; finally, the temperature was raised to 1000°C and kept warm for 2 hours. After that, the SiAlBCN matrix was successfully obtained in the composite material. By cyclic impregnation and cracking three times, a wide temperature range self-healing SiC / SiC-B4C-BN composite material was finally obtained. f / SiC-B4C-BN-SiAlBCN composite material, wherein the volume fraction of the SiAlBCN matrix is ​​10%.

[0052] The SiC obtained in this embodiment f In the / SiC-B4C-BN-SiAlBCN composite material, the volume fraction of the SiC fiber preform is 38%, the volume fraction of the BN interface phase is 3%, the sum of the volume fractions of the first SiC matrix and the second SiC matrix is ​​29%, the volume fraction of the B4C matrix is ​​3%, the volume fraction of the BN matrix is ​​2%, the volume fraction of the SiAlBCN matrix is ​​10%, and the total porosity of the composite material is 15%.

[0053] Detection of SiC obtained in this embodiment f The cross-sectional micromorphology of the / SiC-B4C-BN-SiAlBCN composite material is shown in the following figure. Figure 2 ab, where Figure 2 b is Figure 2 A partial enlarged view of a, from Figure 2 As can be seen from ab, the self-healing components are primarily distributed in the interbundle region. The CVI B4C is continuous and dense, tightly bonding to the CVI SiC matrix. The CVI BN matrix is ​​distributed between the CVI B4C and CVI SiC matrices. Since the CVI BN modulus lies between that of the CVI B4C and CVI SiC, it effectively mitigates the thermal expansion mismatch between the B4C and SiC matrices, resulting in a strong bond with both matrices. Furthermore, the PIP SiAlBCN contains a small number of pores and cracks, demonstrating good bonding with the CVI SiC.

[0054] Figure 3 SiC f Bending load-displacement curves of SiC-B4C-BN-SiAlBCN composite materials in the initial state, after oxidation at 900℃ for 10h, after oxidation at 1100℃ for 10h, after oxidation at 1300℃ for 10h, and after oxidation at 1500℃ for 10h. As can be seen from the figure, the fracture displacement and fracture load after oxidation are not reduced compared with those before oxidation, indicating that the matrix combination (including order / structure) design of B4C, BN, SiC and SiAlBCN can ensure the fracture of SiC.f The mechanical properties of SiC-B4C-BN-SiAlBCN composite materials do not decrease after oxidation at 900-1500℃ for 10h. f / SiC-B4C-BN-SiAlBCN composite material has excellent oxidation resistance in a wide temperature range.

[0055] Example 2

[0056] Step S1, fix a 25cm×16cm×4cm two-dimensional and a half (2.5D) SiC fiber preform (500 pieces / bundle) with a graphite clamp (fiber volume fraction is 37%); hang the SiC fiber preform on a sample rack supporting a BN deposition furnace, and simultaneously introduce boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen, with a boron trichloride flow rate of 250mL / min, an ammonia flow rate of 450mL / min, an argon flow rate of 300mL / min, and a hydrogen flow rate of 800mL / min. Maintain the furnace pressure at 2kPa, deposit the BN interface phase at 950°C for 50h to obtain a composite SiC fiber preform, wherein the thickness of the BN interface phase is 100nm and the volume fraction of the BN interface phase is 4%.

[0057] Step S2: hang the composite SiC fiber preform on the sample rack of the SiC deposition furnace, introduce trichloromethylsilane, diluent gas argon and catalytic gas hydrogen, wherein the flow rate of trichloromethylsilane is 200 mL / min, the flow rate of argon is 300 mL / min, and the flow rate of hydrogen is 500 mL / min; maintain the pressure in the furnace at 2 kPa, the deposition temperature at 900 ° C, and the deposition time for 270 h to obtain porous SiC f / SiC composite material; wherein the volume fraction of the first SiC matrix is ​​23%.

[0058] Step S3, porous SiC f The / SiC composite material was hung on the supporting frame of the B4C deposition furnace, and boron trichloride, methane, diluent gas argon and catalytic gas hydrogen were introduced. The flow rate of boron trichloride was 300mL / min, the flow rate of methane was 120mL / min, the flow rate of argon was 300mL / min, and the flow rate of hydrogen was 300mL / min. The pressure in the furnace was maintained at 2kPa, the deposition temperature was 950℃, and the deposition time was 30h. The porous SiC on the B4C matrix was obtained. f / SiC composite materials;

[0059] The porous SiC on the B4C matrix will be deposited fThe / SiC composite material was suspended on the supporting frame of the BN deposition furnace, and boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen were introduced. The boron trichloride flow rate was 150mL / min, the ammonia flow rate was 450mL / min, the argon flow rate was 500mL / min, and the hydrogen flow rate was 1000mL / min. The pressure in the furnace was maintained at 2kPa, the deposition temperature was within the range of 950℃, and the deposition time was 10h to obtain porous SiC deposited on a B4C-BN matrix. f / SiC composite materials;

[0060] The porous SiC on the B4C-BN matrix will be deposited f The SiC / SiC composite material was suspended on the supporting frame of the SiC deposition furnace, and trichloromethylsilane, diluent gas argon and catalytic gas hydrogen were introduced. The flow rate of trichloromethylsilane was 200 mL / min, the flow rate of argon was 300 mL / min, and the flow rate of hydrogen was 500 mL / min. The pressure in the furnace was maintained at 2 kPa, the deposition temperature was within the range of 900 °C, the deposition time was 60 h, and the SiC f / SiC-B4C-BN composite materials.

[0061] Step S4, repeat step S4 for 3 times, after the deposition is completed, SiC f In the / SiC-B4C-BN composite material, the volume fraction of the B4C matrix is ​​6%, the volume fraction of the BN matrix is ​​4%, and the volume fraction of the second SiC matrix is ​​12%.

[0062] Step S5, dissolving polyborosilazane and aluminum acetylacetonate in toluene in a mass ratio of 9:1:10 to obtain a polymer solution;

[0063] Step S6, SiC f / SiC-B4C-BN composite material was vacuum impregnated in polymer solution for 0.5 hours, and then the composite material was placed in an alumina crucible, which was placed in a tube furnace and heated to 150 ° C and kept warm in a nitrogen atmosphere for 3 hours; then the temperature was raised to 300 ° C and kept warm for 2 hours; finally, the temperature was raised to 1000 ° C and kept warm for 2 hours to successfully obtain the SiAlBCN matrix in the composite material. By cyclic impregnation and cracking twice, a wide temperature range self-healing SiC f / SiC-B4C-BN-SiAlBCN composite material, wherein the volume fraction of the SiAlBCN matrix is ​​6%.

[0064] The SiC prepared in this example fCompared with the composite material of Example 1, the B4C-BN-SiC matrix in step 3 is deposited three times in a cycle. The multiple introduction of the BN matrix enables the composite material to undergo multiple crack deflections at the B4C / BN and BN / SiC interfaces when the composite material fails, extending the crack propagation path and improving the mechanical properties of the composite material. f The flexural strength of the SiC-B4C-BN-SiAlBCN composite was 450±42 MPa, higher than the composite prepared in Example 1 (365±87 MPa). However, due to the low volume fraction of the SiAlBCN matrix in the composite, the flexural strength retention of the composite after oxidation at 1500°C for 10 h was 91.21%, lower than the 95.88% retention of the composite prepared in Example 1.

[0065] Example 3

[0066] Step S1, fix a 25cm×16cm×4cm three-dimensional four-directional (3D4) SiC fiber preform (500 pieces / bundle) with a graphite clamp, wherein the volume fraction of the SiC fiber preform is 42%; hang the SiC fiber preform on a sample rack supporting a BN deposition furnace, and simultaneously introduce boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen, with a boron trichloride flow rate of 250mL / min, an ammonia flow rate of 450mL / min, an argon flow rate of 300mL / min, and a hydrogen flow rate of 800mL / min. Maintain the pressure in the furnace at 2kPa, deposit a BN interface phase at 950°C for 35h, and obtain a composite SiC fiber preform, wherein the thickness of the BN interface phase is 80nm and the volume fraction of the BN interface phase is 4%.

[0067] Step S2: hang the composite SiC fiber preform on the sample rack of the SiC deposition furnace, introduce trichloromethylsilane, diluent gas argon and catalytic gas hydrogen, wherein the flow rate of trichloromethylsilane is 200 mL / min, the flow rate of argon is 300 mL / min, and the flow rate of hydrogen is 500 mL / min; maintain the pressure in the furnace at 2 kPa, the deposition temperature at 950 ° C, and the deposition time for 200 h to obtain porous SiC f / SiC composite material; wherein the volume fraction of the first SiC matrix is ​​20%.

[0068] Step S3, porous SiC fThe / SiC composite material was hung on the supporting frame of the B4C deposition furnace, and boron trichloride, methane, diluent gas argon and catalytic gas hydrogen were introduced. The flow rate of boron trichloride was 500mL / min, the flow rate of methane was 200mL / min, the flow rate of argon was 400mL / min, and the flow rate of hydrogen was 500mL / min. The pressure in the furnace was maintained at 2kPa, the deposition temperature was 1000℃, and the deposition time was 50h. The porous SiC on the B4C matrix was obtained. f / SiC composite materials;

[0069] The porous SiC on the B4C matrix will be deposited f The / SiC composite material was hung on the supporting frame of the BN deposition furnace, and boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen were introduced. The boron trichloride flow rate was 300mL / min, the ammonia flow rate was 550mL / min, the argon flow rate was 400mL / min, and the hydrogen flow rate was 900mL / min. The pressure in the furnace was maintained at 2kPa, the deposition temperature was 950℃, and the deposition time was 15h to obtain porous SiC deposited on a B4C-BN matrix. f / SiC composite materials;

[0070] The porous SiC on the B4C-BN matrix will be deposited f / SiC composite material was hung on the supporting frame of SiC deposition furnace, and trichloromethylsilane, diluent gas argon and catalytic gas hydrogen were introduced. The flow rate of trichloromethylsilane was 300mL / min, the flow rate of argon was 450mL / min, and the flow rate of hydrogen was 500mL / min. The pressure in the furnace was kept at 2kPa, the deposition temperature was 1000℃, the deposition time was 70h, and the SiC f / SiC-B4C-BN composite materials.

[0071] Step S4, repeat step S4 twice, after the deposition is completed, SiC f In the / SiC-B4C-BN composite material, the volume fraction of the B4C matrix is ​​5%, the volume fraction of the BN matrix is ​​4%, and the volume fraction of the second SiC matrix is ​​10%.

[0072] Step S4, dissolving polyborosilazane and aluminum acetylacetonate in toluene in a mass ratio of 9:1:10 to obtain a polymer solution;

[0073] Step S5, SiC f / SiC-B4C-BN composite material was vacuum impregnated in polymer solution for 0.5 hours, and then the composite material was placed in an alumina crucible, which was placed in a tube furnace and heated to 150 ° C and kept warm in a nitrogen atmosphere for 3 hours; then the temperature was raised to 300 ° C and kept warm for 2 hours; finally, the temperature was raised to 1000 ° C and kept warm for 2 hours to successfully obtain the SiAlBCN matrix in the composite material. By cyclic impregnation and cracking once, a wide temperature range self-healing SiC f / SiC-B4C-BN-SiAlBCN composite material, wherein the volume fraction of the SiAlBCN matrix is ​​5%.

[0074] In this embodiment, SiC f In the / SiC-B4C-BN-SiAlBCN composite material, the volume fraction of the SiC fiber preform is 42%, the volume fraction of the BN interface phase is 4%, the sum of the volume fractions of the first SiC matrix and the second SiC matrix is ​​30%, the volume fraction of the B4C matrix is ​​5%, the volume fraction of the BN matrix is ​​4%, the volume fraction of the SiAlBCN matrix is ​​5%, and the total porosity of the composite material is 10%.

[0075] Compared with Example 2, Example 3 improves the SiC f The volume fraction of reinforcement (fiber) in the SiC-B4C-BN-SiAlBCN composite was increased, and the preform had a three-dimensional woven structure. The flexural strength of the composite was increased to 480±36 MPa. After oxidation at 900°C, 1100°C, 1300°C, and 1500°C for 10 hours, the flexural strength retention rates were 95.86%, 101.36%, 96.65%, and 93.67%, respectively. The composite exhibited excellent self-healing properties at temperatures between 900 and 1500°C.

[0076] Comparative Example

[0077] Step S1: stack 20 sheets of 25 cm × 16 cm two-dimensional plain woven SiC fiber cloth (500 pieces / bundle) and fix them with a graphite clamp to obtain a two-dimensional (2D) SiC fiber preform, wherein the volume fraction of the SiC fiber preform is 38%; hang the SiC fiber preform on a sample rack supporting a BN deposition furnace, and simultaneously introduce boron trichloride, ammonia, diluent gas argon and catalytic gas hydrogen, with a boron trichloride flow rate of 200 mL / min, an ammonia flow rate of 400 mL / min, an argon flow rate of 300 mL / min, and a hydrogen flow rate of 750 mL / min. Maintain the furnace pressure at 2 kPa, deposit a BN interface phase at 900°C for 40 hours, and obtain a composite SiC fiber preform, wherein the thickness of the BN interface phase is 80 nm and the volume fraction of the BN interface phase is 3%.

[0078] Step S2: hang the composite SiC fiber preform on the sample rack of the SiC deposition furnace, introduce trichloromethylsilane, diluent gas argon and catalytic gas hydrogen, wherein the flow rate of trichloromethylsilane is 200 mL / min, the flow rate of argon is 300 mL / min, and the flow rate of hydrogen is 500 mL / min; maintain the pressure in the furnace at 2 kPa, the deposition temperature at 900 ° C, and the deposition time for 600 h to obtain SiC f / SiC composite material; wherein the volume fraction of the SiC matrix is ​​44%.

[0079] The SiC prepared in this comparative example f The total porosity of the / SiC composite material is similar to that of the SiC prepared in Example 1. f The composite material prepared in this comparative example has a similar structure, with a 15% content. However, the composite material matrix prepared in this comparative example does not contain self-healing phases such as B4C, BN and SiAlBCN.

[0080] The two composite materials in this comparative example and Example 1 were oxidized at 900℃, 1100℃, 1300℃ and 1500℃ for 10h, and the flexural strength and flexural modulus after oxidation were tested. The test results of flexural strength are shown in Figure 2. Figure 4 a. The test results of flexural modulus are as follows Figure 4 As shown in Figure 2, the bending strength retention rate and bending modulus retention rate of the two composite materials involved in the comparative example and Example 1 after oxidation at 900℃ and 1100℃ are both greater than 90%, and there is no significant performance degradation after oxidation. When the oxidation temperature is increased to 1300℃ and 1500℃, the SiC prepared in Example 1 f / SiC-B4C-BN-SiAlBCN composites showed excellent strength retention and modulus retention. Especially after oxidation at 1500℃ for 10h, SiC f The strength retention rate and modulus retention rate of the SiC-B4C-BN-SiAlBCN composite material are both higher than 80%. f / SiC composite materials have made significant progress.

[0081] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material, characterized in that: It comprises a SiC fiber preform, on which a BN interface phase, a first SiC matrix, and an alternating matrix are sequentially deposited, and the alternating matrix is ​​coated with a SiAlBCN matrix, wherein the alternating matrix comprises a B4C matrix, a BN matrix, and a second SiC matrix deposited sequentially; The volume fraction of the SiC fiber preform is 35% to 42%, the volume fraction of the BN interface phase is 1% to 4%, the volume fraction of the first SiC matrix is ​​20% to 30%, the volume fraction of the alternating matrix is ​​8% to 27%, the volume fraction of the SiAlBCN matrix is ​​6% to 12%, and the total volume fraction of the above components is 85% to 95%; In the alternating matrix, the volume fraction of the B4C matrix is ​​3% to 9%, the volume fraction of the BN matrix is ​​2% to 6%, and the volume fraction of the second SiC matrix is ​​3% to 12%.

2. The wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material according to claim 1, characterized in that: The SiC fiber preform is a three-dimensional structure woven from SiC fibers, with gaps formed between the SiC fibers; The BN interface phase, the first SiC matrix, the alternating matrix and the SiAlBCN matrix are located in the gap.

3. The wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material according to claim 1, characterized in that: The alternating matrix includes n layers, and 1≤n≤3; the SiC fiber preform is a two-dimensional laminated three-dimensional structure, a two-dimensional semi-structure or a three-dimensional structure.

4. A method for preparing a wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material according to any one of claims 1 to 3, characterized in that: include: Depositing a BN interface phase in a SiC fiber preform to obtain a composite SiC fiber preform; A first SiC matrix is ​​deposited in the composite SiC fiber preform to obtain a porous SiC f / SiC composite materials; In porous SiC f The B4C matrix, BN matrix and second SiC matrix are deposited in sequence in the SiC / SiC composite material to obtain SiC f / SiC-B4C-BN composite materials; dissolving polyborosilazane and aluminum acetylacetonate in toluene to obtain a polymer solution; The SiC f / SiC-B4C-BN composite material is placed in the polymer solution for impregnation, and the impregnated SiC f / SiC-B4C-BN composite material is cracked to obtain a SiC fiber reinforced multiphase matrix composite material; The reaction conditions during the cracking process are as follows: first heating to 130-160°C, reacting for 2-4 hours, then heating to 270-320°C, curing for 1-3 hours, and then heating to 1000-1200°C and cracking for 1-4 hours.

5. The method for preparing a wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material according to claim 4, characterized in that: The SiC f During the preparation of the porous SiC / SiC-B4C-BN composite material, f A B4C matrix, a BN matrix, and a SiC matrix are deposited in a cycle within the / SiC composite material, and the number of cycles is 1 to 3.

6. The method for preparing a wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material according to claim 4, characterized in that: The CVI method was used to deposit the BN interface phase in the SiC fiber preform. The gaseous precursors used in the deposition process were boron trichloride and ammonia. The flow rate of boron trichloride was 80-250 mL / min, the flow rate of ammonia was 250-500 mL / min, the deposition pressure was 2-5 kPa, the deposition temperature was 850-950°C, and the deposition time was 25-50 h. The first SiC matrix is ​​deposited in the composite SiC fiber preform by the CVI method. The gaseous precursor used in the deposition process is trichloromethylsilane, the flow rate of trichloromethylsilane is 50-300 mL / min, the deposition pressure is 2-5 kPa, the deposition temperature is 850-1000° C., and the deposition time is 240-360 h.

7. The method for preparing a wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material according to claim 4, characterized in that: In porous SiC f The B4C matrix, BN matrix, and SiC matrix were sequentially deposited in the SiC / SiC composite material using the CVI method. During the B4C matrix deposition process, the gaseous precursors used were boron trichloride and methane. The flow rate of boron trichloride was 100-500 mL / min, the flow rate of methane was 80-200 mL / min, the deposition pressure was 2-5 kPa, the deposition temperature was 900-1100°C, and the deposition time was 20-100 h. During the BN substrate deposition process, the gaseous precursors used were boron trichloride and ammonia. The flow rate of boron trichloride was 100-400 mL / min, the flow rate of ammonia was 300-700 mL / min, the deposition pressure was 2-5 kPa, the deposition temperature was 900-1100°C, and the deposition time was 5-20 h. During the deposition of the second SiC substrate, the gaseous precursor used is trichloromethylsilane, the flow rate of trichloromethylsilane is 50~300mL / min, the deposition pressure is 2~5kPa, the deposition temperature is 900~1100℃, and the deposition time is 30~70h.

8. The method for preparing a wide temperature range self-healing SiC fiber reinforced multiphase matrix composite material according to claim 4, characterized in that: During the preparation of the SiC fiber reinforced multiphase matrix composite material, the impregnation and cracking processes are repeated; The mass ratio of toluene, polyborosilazane and aluminum acetylacetonate is (7-12): (6-14): 1, and the immersion time is 0.4-2 hours.

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