A high-performance SiC for nuclear applications f / SiC composite material and preparation method thereof

Abstract

The present invention discloses a high performance SiC f / SiC composite material and its preparation method, which relates to the technical field of composite materials. The method includes obtaining a two-dimensional SiC f / Ti‑Si‑C‑O fiber cloth; SiC obtained by RMI process f / Ti3SiC2 interface phase two-dimensional fiber cloth; SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth is immersed in the slurry suspension to obtain SiC f / Ti3SiC2 interface / TiC‑TiO2 fiber cloth; SiC f / Ti3SiC2 interface / TiC‑TiO2 preform; SiC f / Ti3SiC2 interface / TiC-TiO2 preform is embedded in AlSi alloy powder, and liquid phase siliconization is carried out in a vacuum furnace at 1250~1450℃ for 30~60min using RMI process to obtain high performance SiC for nuclear use. f / SiC composite material. The present invention adopts gas phase and liquid phase combined successive siliconization process to solve the current nuclear SiC f / SiC composite materials have poor air tightness and low thermal conductivity, and can further enhance the material's resistance to radiation amorphization and damage tolerance, thereby improving the SiC f / The structural strength of SiC composite materials during reactor service improves the safety margin of reactor design.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to a novel high-performance SiC f / SiC composite material and preparation method thereof. Background Art

[0002] Silicon carbide (SiC) materials have high strength, small neutron absorption cross section, good resistance to radiation damage, excellent high-temperature chemical inertness, low activation, excellent high-temperature strength and structural stability, and have great application prospects in the extreme use environment of reactors. However, the intrinsic brittleness of SiC ceramics limits its practical application as a structural material. In response to this, continuous SiC fiber reinforced SiC composites (SiC f / SiC) makes up for the shortcoming of low toughness of SiC ceramics, while also having excellent high-temperature mechanical properties and chemical inertness. It is considered to be one of the ideal candidate materials for the cladding structure of the next generation of advanced nuclear energy systems.

[0003] Nuclear SiC f / SiC composite material consists of SiC fiber preform, PyC interface phase and SiC matrix. Among them, the SiC fiber preform is obtained by weaving SiC fibers. Then, using propylene (C3H6) as the gas source, the PyC interface phase is deposited in the SiC fiber preform through chemical vapor infiltration (CVI) process. Finally, using trichloromethylsilane (CH3SiCl, MTS) as the gas source, the SiC matrix is ​​further deposited into the preform using CVI process until the sample is completely dense. SiC prepared by CVI process f / SiC composite materials due to the "bottleneck effect" in the CVI process deposition process, that is, when the internal pores of the fiber bundle are not fully deposited and filled densely, the deposition gas channel closes prematurely, resulting in the formation of SiC f There are many pores inside the SiC composite material. Therefore, the SiC prepared by CVI process f / SiC composite materials generally have a porosity of 10%~13%.

[0004] Existing SiC for nuclear applications f / SiC composite materials use PyC interface phase, which is prone to irradiation amorphization during service, resulting in composite material interface failure and SiC f / SiC composite materials have a sharp decline in mechanical properties; existing nuclear SiC f Due to the intrinsic brittleness of the SiC ceramic matrix, SiC composite materials are prone to through-cracks during service, which destroys the airtightness of the material and may cause leakage of radioactive materials. f / SiC composite materials are prepared by CVI process, but due to the "bottleneck effect" of CVI process when depositing SiC matrix, the SiC f There are generally 10 to 13% open pores in the SiC composite material. The presence of internal pores makes the SiC f / SiC composite materials have greatly reduced air tightness and thermal conductivity; existing nuclear SiC f / SiC composite material optimization scheme generally uses CVI process to prepare interface phase and part of SiC matrix to obtain porous SiC with certain mechanical strength f / SiC composite materials, and then combined with reactive melt infiltration (RMI) process or PIP process for densification, while introducing matrix modified phase. However, due to the large differences in intrinsic properties such as density, porosity and crystal growth orientation of ceramic phases prepared by different processes, SiC f There is a large residual stress inside the SiC / SiC composite material, which causes f / SiC composite materials have problems such as reduced load-bearing capacity, internal cracks caused by thermal mismatch, and reduced thermal conductivity during service; the current commercial application of nuclear SiC prepared by CVI process f / SiC composite materials have a long process cycle, high production cost, and are only suitable for the preparation of thin-walled parts.

[0005] At present, the core SiC prepared by chemical vapor infiltration (CVI) process with pyrolytic carbon (PyC) as the interface phase f / SiC composites have poor airtightness, low thermal conductivity, and PyC interface failure under high-dose irradiation. Summary of the Invention

[0006] In view of the shortcomings of the above background technology, the present invention provides a new type of high performance SiC f / SiC composite materials and preparation methods thereof. This method uses magnetron sputtering combined with a vapor phase RMI process to produce a Ti3SiC2 interface phase. Compared with currently reported Ti3SiC2 interface phase preparation processes, the Ti3SiC2 interface phase produced by this process is of higher purity and has good thermal stability, ensuring structural integrity during subsequent matrix preparation.

[0007] The first purpose of the present invention is to provide a new type of high performance SiC f A method for preparing a SiC / SiC composite material, using a single reaction melt infiltration process to sequentially prepare an interface phase and a matrix phase of the composite material, comprises the following steps:

[0008] The two-dimensional SiC fiber was placed in a magnetron sputtering instrument, and a SiC target and a TiO2 target were used for co-sputtering to form a Ti-Si-CO interface layer on the surface of the SiC fiber to obtain a two-dimensional SiC f / Ti-Si-CO fiber cloth;

[0009] Two-dimensional SiC f / Ti-Si-CO fiber cloth was transferred to a porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, and Si powder was placed at the bottom of the graphite crucible. The temperature was raised to 1450~1500℃ and kept for 30~60min to obtain SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth;

[0010] TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are sequentially added to the dextrin solution, and ball milled to obtain a slurry suspension;

[0011] SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth is immersed in the slurry suspension to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth;

[0012] SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth is stacked to form a layered preform, and the layered preform is axially pressed and dried to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body;

[0013] SiC f / Ti3SiC2 interface / TiC-TiO2 green body, in an inert atmosphere or under vacuum conditions, at 1200 ~ 1400 ℃ for 2 ~ 4h, to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform;

[0014] SiC f / Ti3SiC2 interface / TiC-TiO2 preform is embedded in AlSi alloy powder and kept at 1250~1450℃ in a vacuum furnace for 30~60min to obtain Ti3SiC2 modified SiC matrix phase, thus obtaining a new high-performance SiCf / SiC composite material for nuclear use.

[0015] Preferably, the dextrin solution is prepared by adding dextrin at a mass fraction of 0.1 to 1.0 wt.% to distilled water.

[0016] Preferably, the TiC and TiO2 mixed raw material comprises TiC powder and TiO2 powder;

[0017] Wherein, the molar ratio of TiC powder to TiO2 powder is 1:1~3:1;

[0018] The particle diameters of the TiC powder and TiO2 powder are both 5-8 μm.

[0019] Preferably, the TiC powder is replaced with a mixed powder of Ti powder and C powder.

[0020] Preferably, the Y2O3 and Al2O3 mixed reaction aid comprises Y2O3 powder and Al2O3 powder;

[0021] Wherein, the molar ratio of Y2O3 powder to Al2O3 powder is 2:1~1:2;

[0022] The particle diameters of Y2O3 powder and Al2O3 powder are both 10-12 μm.

[0023] Preferably, TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the dextrin solution in sequence, and the mass of the mixed powder is 30 to 50 wt.% of the mass of the solution.

[0024] Preferably, SiC f The time for immersing the two-dimensional fiber cloth with / Ti3SiC2 interface phase in the slurry suspension is 5 to 30 minutes;

[0025] When axial pressure is applied to the layered preform, an axial pressure of 5 to 20 MPa is applied and the pressure is maintained for 5 to 30 minutes; the temperature during drying is 110 to 125° C. and the drying time is 24 to 48 hours.

[0026] Preferably, the AlSi alloy powder is replaced with Si powder, ZrSi alloy powder or YSi alloy powder.

[0027] The second purpose of the present invention is to provide a new type of high performance SiC f / SiC composite materials.

[0028] The third object of the present invention is to provide a high performance SiC f Application of SiC composite materials in nuclear industry.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention provides a new type of high performance SiC f / SiC composite material and preparation method thereof, the present invention adopts RMI process to prepare Ti3SiC2 interface phase and Ti3SiC2 modified SiC matrix, that is, a single RMI process is used to realize the conversion from existing SiC fiber to SiC f Preparation of SiC composite materials, including the preparation of interface phase and matrix. f / SiC composite material interface phase modification, and then another process is selected to prepare the matrix, which ultimately leads to huge residual stress between the components of the composite materials prepared by different processes, affecting the SiC f / The overall performance of SiC composite materials is different. The Ti3SiC2 interface phase is prepared by magnetron sputtering combined with gas phase RMI process. Compared with the currently reported Ti3SiC2 interface phase preparation process, the Ti3SiC2 interface phase prepared by this process has higher purity, controllable thickness, and good thermal stability, which ensures the structural integrity in the subsequent matrix preparation process; the present invention draws on the prepreg process commonly used in resin-based composite materials, and first impregnates the two-dimensional SiC fiber cloth with Ti3SiC2 interface phase into the RMI precursor, and then laminates and shapes the fiber cloth with RMI precursor slurry, and then performs heat treatment and pre-sintering to obtain an RMI preform with a certain structural strength, and finally performs liquid phase siliconization to obtain the final dense SiC f / SiC composite materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention provides a new type of high-performance SiC for nuclear f / SiC composite material preparation process flow chart;

[0032] Figure 2 The dense SiC prepared by the present invention f / Ti3SiC2 interface / physical picture of SiC-Ti3SiC2 composite material;

[0033] Figure 3 New high-performance nuclear SiC prepared by the present invention f / SiC composite microstructure image. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below with reference to specific embodiments and drawings, but the embodiments are not intended to limit the present invention.

[0035] The present invention is aimed at the core SiC prepared by the current chemical vapor infiltration (CVI) process with pyrolytic carbon (PyC) as the interface phase. fThe problems of poor air tightness, low thermal conductivity and failure of PyC interface under high-dose irradiation are solved by using vapor phase siliconization process to prepare Ti3SiC2 interface phase and combining with liquid phase siliconization process to prepare ternary layered ceramic Ti3SiC2 matrix phase to obtain dense SiC f / SiC composite materials. The gas phase and liquid phase combined successive siliconization process can solve the current nuclear SiC f / SiC composite materials have poor air tightness and low thermal conductivity, and can further enhance the material's resistance to radiation amorphization and damage tolerance, thereby improving the SiC f / The structural strength of SiC composite materials during reactor service improves the safety margin of reactor design.

[0036] The purpose of this invention is to change the traditional nuclear SiC f The CVI preparation process of / SiC composite materials adopts RMI process to prepare Ti3SiC2 interface phase by gas phase siliconization and Ti3SiC2 modified SiC matrix by liquid phase siliconization, and finally obtain high density SiC f / SiC composite materials. Among them, the replacement of PyC interface phase by Ti3SiC2 interface phase greatly improves the radiation resistance of the interface phase to amorphous, and the introduction of Ti3SiC2 into the SiC matrix can further improve the SiC f / SiC composite material damage tolerance. At the same time, SiC prepared by RMI process f The increase in density of SiC composite materials has a great effect on the thermal conductivity and air tightness of the materials. In addition, compared with the shortcomings of the traditional CVI process, which has a long cycle and high cost, the SiC prepared by the RMI process f / SiC composite material process equipment is simple, production cycle is short, production cost is low, and can achieve near net size molding for large-sized structural parts. The present invention adopts a single RMI process to realize the preparation of Ti3SiC2 interface phase and Ti3SiC2 modified SiC matrix, which is different from traditional SiC f The process improvement of SiC composite materials is revolutionary. The interface phase prepared by RMI process and the prepared matrix have better thermal adaptability, making SiC f The overall mechanical, radiation resistance and thermal physical properties of the SiC composite material can be greatly improved. Therefore, the present invention is a high-performance SiC composite material for nuclear applications. f The new process for preparing SiC / SiC composite materials has great potential for application in structural materials of future advanced nuclear energy systems.

[0037] The first aspect of the present invention provides a new type of high performance SiC f A method for preparing a SiC / SiC composite material, using a single reaction melt infiltration process to sequentially prepare an interface phase and a matrix phase of the composite material, comprises the following steps:

[0038] The two-dimensional SiC fiber was placed in a magnetron sputtering instrument, and a SiC target and a TiO2 target were used for co-sputtering to form a Ti-Si-CO interface layer on the surface of the SiC fiber to obtain a two-dimensional SiC f / Ti-Si-CO fiber cloth; the Ti-Si-CO interface layer prepared on the fiber surface in this step is the target Ti3SiC2 interface layer precursor, which reacts with Si to form Ti3SiC2 in the subsequent vapor phase siliconization step.

[0039] Two-dimensional SiC f / Ti-Si-CO fiber cloth was transferred to a porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, and Si powder was placed at the bottom of the graphite crucible. The temperature was raised to 1450~1500℃ and kept for 30~60min to obtain SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth; This step is the RMI process gas phase siliconization to obtain SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth, wherein the Si powder placed at the bottom of the crucible evaporates after being heated to a temperature exceeding the melting point of 1410 ℃. The Si vapor diffuses into the two-dimensional SiC fiber cloth through the holes in the graphite plate and reacts with the Ti-Si-CO precursor prepared on the fiber surface in the previous step to generate a Ti3SiC2 interface phase in situ.

[0040] TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction additives are added to the dextrin solution in sequence, and ball milling is performed to obtain a slurry suspension; the TiC and TiO2 mixed powder is the precursor for preparing the SiC-Ti3SiC2 matrix by the RMI process. By making it into a slurry suspension, the pores in and between the fiber bundles are fully filled.

[0041] SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth is immersed in the slurry suspension to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth;

[0042] SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth is stacked to form a layered preform, and the layered preform is axially pressed and dried to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body; the purpose of this step is to stack and shape the two-dimensional fiber cloth to obtain a compact two-dimensional plate.

[0043] SiC f / Ti3SiC2 interface / TiC-TiO2 green body, in an inert atmosphere or under vacuum conditions, at 1200 ~ 1400 ℃ for 2 ~ 4h, to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform; the purpose of this step is to make the plate obtain a certain mechanical strength through heat treatment to ensure that it will not be deformed or damaged during the subsequent RMI siliconization process.

[0044] SiC f / Ti3SiC2 interface / TiC-TiO2 preform is embedded in AlSi alloy powder and kept at 1250~1450℃ for 30~60min in a vacuum furnace to obtain Ti3SiC2 modified SiC matrix phase and dense SiC f / Ti3SiC2 interface / SiC-Ti3SiC2 composite material, that is, a new type of nuclear high-performance SiCf / SiC composite material is obtained. This step adopts RMI process liquid phase siliconization to obtain a new type of nuclear high-performance SiC f / SiC composite materials.

[0045] The dextrin solution is prepared by adding dextrin at a mass fraction of 0.1 to 1.0 wt.% into distilled water.

[0046] The TiC and TiO2 mixed raw material includes TiC powder and TiO2 powder; the molar ratio of TiC powder to TiO2 powder is 1:1~3:1; the particle diameters of the TiC powder and TiO2 powder are both 5-8 μm; the TiC powder is replaced with a mixed powder of Ti powder and C powder.

[0047] The Y2O3 and Al2O3 mixed reaction aid comprises Y2O3 powder and Al2O3 powder; the molar ratio of the Y2O3 powder to the Al2O3 powder is 2:1 to 1:2; and the particle diameters of the Y2O3 powder and the Al2O3 powder are both 10-12 μm.

[0048] TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction additives are added to the dextrin solution in sequence, and the mass of the mixed powder is 30 ~ 50 wt.% of the solution mass.

[0049] SiC f The time for immersing the two-dimensional fiber cloth with the / Ti3SiC2 interface phase in the slurry suspension is 5 to 30 minutes.

[0050] When axial pressure is applied to the layered preform, the axial pressure is 5 to 20 MPa and the pressure is maintained for 5 to 30 minutes.

[0051] The drying temperature is 110~125℃ and the drying time is 24~48h.

[0052] The AlSi alloy powder is replaced with Si powder, ZrSi alloy powder or YSi alloy powder.

[0053] In one embodiment, a high performance SiC core is provided. f / SiC composite material preparation method, see Figure 1 As shown, two-dimensional SiC fiber cloth, SiC target with a purity of 99% and TiO2 target are used, a mixed powder of TiC powder and TiO2 powder with a particle diameter of 5-8 μm and a molar ratio of 3:1 to 1:1 is used as a raw material, a mixed powder of Y2O3 and Al2O3 with a particle diameter of 10-12 μm and a molar ratio of 2:1 to 1:2 is used as a reaction aid, and the mass ratio of the raw material mixed powder to the reaction aid mixed powder is 10:1 to 20:1, and the preparation is carried out according to the following steps:

[0054] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 to 5 μm on the surface of the SiC fiber;

[0055] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1450~1500℃ and kept for 30~60 minutes to prepare SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth;

[0056] Step 3: Add dextrin to distilled water at a mass fraction of 0.1 to 1.0 wt.% and stir thoroughly to obtain a solution;

[0057] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, with the mass of the mixed powder added to the solution being 30 to 50 wt.% of the mass of the solution. The mixture is then placed in a ball mill for 24 to 48 hours to obtain a uniform slurry suspension;

[0058] Step 5: SiC f The two-dimensional fiber cloth with the interface phase of Ti3SiC2 was immersed in the above slurry suspension and taken out after standing for 5 to 30 minutes to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth;

[0059] Step 6: 2D SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth laminate, fixed with flat molds on the upper and lower sides, applied axial pressure of 5 ~ 20 MPa, kept under pressure for 5 ~ 30 minutes, then removed from the press and placed in an oven at 120 ° C for 48 hours to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body;

[0060] Step 7: SiC f / Ti3SiC2 interface / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1200 ~ 1400 ℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform;

[0061] Step 8: SiC f / Ti3SiC2 interface / TiC-TiO2 preform is embedded in AlSi alloy powder and kept at 1200 ~ 1450 ℃ in a vacuum furnace for 30 ~ 60 minutes to obtain dense SiC f / Ti3SiC2 interface / SiC-Ti3SiC2 composite material.

[0062] The TiC powder used as the raw material in step 4 can be replaced by a mixed powder of Ti powder and C powder;

[0063] The AlSi alloy powder used in steps 2 and 8 can be replaced by Si powder or other types of Si-containing alloys, such as ZrSi, YSi alloy, etc.

[0064] The AlSi alloy powder in the present invention is used only to provide Si element, so alloys containing Si element are theoretically possible to use;

[0065] The vacuum furnace used in step 8 to infiltrate AlSi alloy powder in the RMI process can be replaced by a "tube furnace or box furnace used in an airtight and inert atmosphere".

[0066] It can be seen that the present invention uses a single RMI process to prepare a Ti3SiC2 interface phase and a Ti3SiC2 modified SiC matrix. The present invention innovatively selects a TiO2 target and a SiC target to co-sputter on the surface of the SiC fiber to prepare an interface layer prefabricated phase, combines the gas phase RMI process for siliconization, and prepares the Ti3SiC2 interface phase by in-situ reaction; in the RMI preform shaping stage, the present invention selects to use a prepreg process to directly laminate and pressurize the two-dimensional SiC fiber cloth impregnated with a mixed slurry of TiC and TiO2, and then performs heat treatment to give the preform a certain structural strength, thereby ensuring the structural integrity of the composite material in the subsequent RMI process.

[0067] The second aspect of the present invention provides a new type of high performance SiC f / SiC composite materials.

[0068] The third aspect of the present invention provides a high performance SiC f Application of SiC composite materials in nuclear industry.

[0069] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0070] Example 1

[0071] A high-performance SiC for nuclear applications f A new process for preparing / SiC composite materials, the preparation flow chart is as follows Figure 1 As shown, two-dimensional SiC fiber cloth, SiC target with a purity of 99% and TiO2 target were used, a mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as raw materials, a mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as a reaction aid, and the mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0072] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 μm on the surface of the SiC fiber;

[0073] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1450 ℃ and kept for 30 minutes to prepare SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth;

[0074] Step 3: Add dextrin at a mass fraction of 0.5 wt.% into distilled water and stir thoroughly to obtain a solution;

[0075] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0076] Step 5: SiC fThe two-dimensional fiber cloth with Ti3SiC2 interface phase was immersed in the above slurry suspension and taken out after standing for 20 minutes to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth;

[0077] Step 6: 2D SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth laminate, fixed with flat molds on the upper and lower sides, applied axial pressure of 10 MPa, kept the pressure for 5 minutes, removed from the press, and placed in an oven at 120 ° C for 48 hours to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body;

[0078] Step 7: SiC f / Ti3SiC2 interface / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1400℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform;

[0079] Step 8: SiC f / Ti3SiC2 interface / TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1250℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / Ti3SiC2 interface / SiC-Ti3SiC2 composite materials, such as Figure 2 shown.

[0080] Figure 2 The dense SiC prepared in Example 1 f / Ti3SiC2 interface / physical picture of SiC-Ti3SiC2 composite material; Figure 2 (a) and (b) are actual pictures taken from different orientations. As shown in the figure, the sample has a compact structure, a metallic luster on the surface, and the two-dimensional SiC fiber cloth laminate can be clearly seen in the cross section.

[0081] Figure 3 The new high-performance nuclear SiC prepared in Example 1 f / SiC composite material microstructure image. Among them, Figure 3 (a) and (b) Microscopic images of the composite material at different magnifications. Figure 3 It can be seen that the new high-performance nuclear SiC fThe SiC / SiC composite material consists of SiC fibers, Ti3SiC2 interface phase and Ti3SiC2 modified SiC matrix. Under low magnification, it can be seen that the Ti3SiC2 modified SiC matrix introduced by the RMI process has completely filled the large-sized pores in the matrix, which intuitively illustrates that the RMI process adopted in the present invention has achieved a significant improvement in the performance of conventional SiC. f / SiC composite material density improvement.

[0082] Example 2

[0083] A high-performance SiC for nuclear applications f A new process for preparing / SiC composite materials, the preparation flow chart is as follows Figure 1 As shown, two-dimensional SiC fiber cloth, SiC target with a purity of 99% and TiO2 target were used, a mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as raw materials, a mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as a reaction aid, and the mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0084] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 μm on the surface of the SiC fiber;

[0085] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1450 ℃ and kept for 30 minutes to prepare SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth;

[0086] Step 3: Add dextrin at a mass fraction of 0.5 wt.% into distilled water and stir thoroughly to obtain a solution;

[0087] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0088] Step 5: SiC f The two-dimensional fiber cloth with Ti3SiC2 interface phase was immersed in the above slurry suspension and taken out after standing for 20 minutes to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth;

[0089] Step 6: 2D SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth laminate, fixed with flat molds on the upper and lower sides, applied axial pressure of 10 MPa, kept the pressure for 5 minutes, removed from the press, and placed in an oven at 120 ° C for 48 hours to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body;

[0090] Step 7: SiC f / Ti3SiC2 interface / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1400℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform;

[0091] Step 8: SiC f / Ti3SiC2 interface / TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1350℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / Ti3SiC2 interface / SiC-Ti3SiC2 composite material.

[0092] Example 3

[0093] A high-performance SiC for nuclear applications f A new process for preparing / SiC composite materials, the preparation flow chart is as follows Figure 1 As shown, two-dimensional SiC fiber cloth, SiC target with a purity of 99% and TiO2 target were used, a mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as raw materials, a mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as a reaction aid, and the mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0094] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 μm on the surface of the SiC fiber;

[0095] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1450 ℃ and kept for 30 minutes to prepare SiCf / Ti3SiC2 interface phase two-dimensional fiber cloth;

[0096] Step 3: Add dextrin at a mass fraction of 0.5 wt.% into distilled water and stir thoroughly to obtain a solution;

[0097] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0098] Step 5: SiC f The two-dimensional fiber cloth with Ti3SiC2 interface phase was immersed in the above slurry suspension and taken out after standing for 20 minutes to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth;

[0099] Step 6: 2D SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth laminate, fixed with flat molds on the upper and lower sides, applied axial pressure of 10 MPa, kept the pressure for 5 minutes, removed from the press, and placed in an oven at 120 ° C for 48 hours to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body;

[0100] Step 7: SiC f / Ti3SiC2 interface / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1400℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform;

[0101] Step 8: SiC f / Ti3SiC2 interface / TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1450℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / Ti3SiC2 interface / SiC-Ti3SiC2 composite material.

[0102] Example 4

[0103] A high-performance SiC for nuclear applications f A new process for preparing / SiC composite materials, the preparation flow chart is as follows Figure 1As shown, two-dimensional SiC fiber cloth, SiC target with a purity of 99% and TiO2 target were used, a mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as raw materials, a mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as a reaction aid, and the mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0104] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 μm on the surface of the SiC fiber;

[0105] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f The Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1500 °C and kept for 30 minutes to prepare SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth;

[0106] Step 3: Add dextrin at a mass fraction of 0.5 wt.% into distilled water and stir thoroughly to obtain a solution;

[0107] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0108] Step 5: SiC f The two-dimensional fiber cloth with Ti3SiC2 interface phase was immersed in the above slurry suspension and taken out after standing for 20 minutes to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth;

[0109] Step 6: 2D SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth laminate, fixed with flat molds on the upper and lower sides, applied axial pressure of 10 MPa, kept the pressure for 5 minutes, removed from the press, and placed in an oven at 120 ° C for 48 hours to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body;

[0110] Step 7: SiC f / Ti3SiC2 interface / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1400℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform;

[0111] Step 8: SiC f / Ti3SiC2 interface / TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1250℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / Ti3SiC2 interface / SiC-Ti3SiC2 composite material.

[0112] Comparative Example 1

[0113] Two-dimensional SiC fiber cloth was used, and a mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as the raw material. A mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as the reaction aid. The mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0114] Step 1: Place a two-dimensional SiC fiber cloth on a porous graphite plate and place it in a CVI chemical deposition furnace to prepare a PyC interface layer. Deposition is performed at 900°C for 72 hours to obtain a PyC interface layer with a thickness of 0.5 μm on the SiC fiber surface.

[0115] Step 2: Add dextrin at a mass fraction of 0.5 wt.% to distilled water and stir thoroughly to obtain a solution;

[0116] Step 3: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction additives are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0117] Step 4: SiC f The SiC / PyC interface phase two-dimensional fiber cloth was immersed in the above slurry suspension and taken out after standing for 20 minutes to obtain f / PyC interface / TiC-TiO2 fiber cloth;

[0118] Step 5: 2D SiC f / PyC interface / TiC-TiO2 fiber cloth laminate, fixed with a flat mold on the top and bottom, applied axial pressure of 10 MPa, kept the pressure for 5 minutes, removed from the press, and placed in an oven at 120 ° C for 48 hours to obtain SiC f / PyC interface / TiC-TiO2 green body;

[0119] Step 6: SiC f / PyC interface / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1400℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / PyC interface / TiC-TiO2 preform;

[0120] Step 7: SiC f / PyC interface / TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1250℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / PyC interface / SiC-Ti3SiC2 composite material.

[0121] Comparative Example 2

[0122] Two-dimensional SiC fiber cloth was used, and a mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as the raw material. A mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as the reaction aid. The mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0123] Step 1: Place a two-dimensional SiC fiber cloth on a porous graphite plate and place it in a CVI chemical vapor deposition furnace to prepare a PyC interface layer. Deposition is performed at 900°C for 72 hours to obtain a PyC interface layer with a thickness of 0.5 μm on the SiC fiber surface.

[0124] Step 2: SiC f The two-dimensional fiber cloth of the / PyC interface phase was stacked and fixed with a porous graphite flat mold. The SiC matrix was deposited in a CVI chemical vapor deposition furnace at 1000 °C for 360 h to obtain a semi-dense porous SiC f / PyC interface phase / SiC composite material;

[0125] Step 3: Add dextrin at a mass fraction of 0.5 wt.% into distilled water and stir thoroughly to obtain a solution;

[0126] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0127] Step 5: Porous SiC f The sample of the SiC / PyC interface phase / SiC composite material was immersed in the above slurry suspension and taken out after standing for 20 minutes to obtain the SiCf / PyC interface / SiC-TiC-TiO2 composite preform;

[0128] Step 6: SiC f / PyC interface / SiC-TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1250 ℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / PyC interface / SiC-Ti3SiC2 composite material.

[0129] Comparative Example 3

[0130] Use two-dimensional SiC fiber cloth and prepare it according to the following steps:

[0131] Step 1: Place a two-dimensional SiC fiber cloth on a porous graphite plate and place it in a CVI chemical vapor deposition furnace to prepare a PyC interface layer. Deposition is performed at 900°C for 72 hours to obtain a PyC interface layer with a thickness of 0.5 μm on the SiC fiber surface.

[0132] Step 2: SiC f The two-dimensional fiber cloth of the / PyC interface phase was stacked and fixed with a porous graphite flat mold. The SiC matrix was deposited in a CVI chemical vapor deposition furnace at 1000 °C for 1200 h to obtain a dense SiC f / PyC interface phase / SiC composite materials.

[0133] Comparative Example 4

[0134] Two-dimensional SiC fiber cloth, SiC target with a purity of 99%, and TiO2 target were used. A mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as the raw material. A mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as the reaction aid. The mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0135] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 μm on the surface of the SiC fiber;

[0136] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1450 ℃ and kept for 30 minutes to prepare SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth;

[0137] Step 3: SiC f The two-dimensional fiber cloth of the / Ti3SiC2 interface phase was stacked and fixed with a porous graphite flat mold. The SiC matrix was deposited in a CVI chemical vapor deposition furnace at 1000 ° C for 1200 h to obtain a dense SiC f / Ti3SiC2 interface phase / SiC composite material.

[0138] Comparative Example 5

[0139] Two-dimensional SiC fiber cloth, SiC target with a purity of 99%, and TiO2 target were used. A mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as the raw material. A mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as the reaction aid. The mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0140] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 μm on the surface of the SiC fiber;

[0141] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f The Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1400 °C and kept for 30 minutes to prepare a two-dimensional SiC fiber cloth with a TiO2+TiC interface phase.

[0142] Step 3: Add dextrin at a mass fraction of 0.5 wt.% into distilled water and stir thoroughly to obtain a solution;

[0143] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0144] Step 5: Immerse the two-dimensional SiC fiber cloth with the interface phase in the above slurry suspension, let it stand for 20 minutes, and then take it out to obtain a two-dimensional SiC fiber cloth with TiC-TiO2 attached;

[0145] Step 6: The two-dimensional SiC fiber cloth with TiC-TiO2 attached is stacked and fixed with a flat mold on the top and bottom. An axial pressure of 10 MPa is applied. After holding the pressure for 5 minutes, the SiC fiber cloth is taken out from the press and dried in an oven at 120°C for 48 hours to obtain SiC. f / TiO2+TiC interface phase / TiC-TiO2 green body;

[0146] Step 7: SiC f / TiO2+TiC interface phase / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1400℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / TiO2+TiC interface phase / TiC-TiO2 preform;

[0147] Step 8: SiC f / TiO2+TiC interface phase / TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1250℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / TiO2+TiC interface phase / SiC-Ti3SiC2 composite material.

[0148] Comparative Example 6

[0149] Two-dimensional SiC fiber cloth, SiC target with a purity of 99%, and TiO2 target were used. A mixed powder of TiC powder and TiO2 powder with a particle diameter of 5 μm and a molar ratio of 2:1 was used as the raw material. A mixed powder of Y2O3 and Al2O3 with a particle diameter of 10 μm and a molar ratio of 1:1 was used as the reaction aid. The mass ratio of the raw material mixed powder to the reaction aid mixed powder was 20:1. The preparation was carried out according to the following steps:

[0150] Step 1: Place the two-dimensional SiC fiber cloth in a magnetron sputtering instrument and co-sputter using a TiO2 target and a SiC target to prepare a Ti-Si-CO interface layer with a thickness of 0.5 μm on the surface of the SiC fiber;

[0151] Step 2: 2D SiC f / Ti-Si-CO fiber cloth was transferred to the porous graphite plate, and then the two-dimensional SiC f The Ti-Si-CO fiber cloth was placed in a graphite crucible, Si powder was placed at the bottom of the graphite crucible, and the temperature was raised to 1550 °C and kept for 30 minutes to prepare a two-dimensional SiC fiber cloth with a TiSi2+SiC interface phase.

[0152] Step 3: Add dextrin at a mass fraction of 0.5 wt.% into distilled water and stir thoroughly to obtain a solution;

[0153] Step 4: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are added to the above solution in sequence, and the mass of the mixed powder added to the solution is 30 wt.% of the mass of the solution. Then, the mixture is placed in a ball mill for 24 hours to obtain a uniform slurry suspension;

[0154] Step 5: Immerse the two-dimensional SiC fiber cloth with the interface phase in the above slurry suspension, let it stand for 20 minutes, and then take it out to obtain a two-dimensional SiC fiber cloth with TiC-TiO2 attached;

[0155] Step 6: The two-dimensional SiC fiber cloth with TiC-TiO2 attached is stacked and fixed with a flat mold on the top and bottom. An axial pressure of 10 MPa is applied. After holding the pressure for 5 minutes, the SiC fiber cloth is taken out from the press and dried in an oven at 120°C for 48 hours to obtain SiC. f / TiSi2+SiC interface phase / TiC-TiO2 green body;

[0156] Step 7: SiC f / TiSi2+SiC interface phase / TiC-TiO2 green body is placed in a vacuum furnace and heat treated at 1400℃ for 2 hours under inert atmosphere or vacuum conditions to obtain SiC f / TiSi2+SiC interface phase / TiC-TiO2 preform;

[0157] Step 8: SiC f / TiSi2+SiC interface phase / TiC-TiO2 preform was embedded in AlSi alloy powder and kept at 1250℃ in a vacuum furnace for 30 minutes to obtain dense SiC f / TiSi2+SiC interface phase / SiC-Ti3SiC2 composite material.

[0158] In order to illustrate the new high performance SiC f The relevant performances of the preparation method of the SiC composite material are explained in combination with the embodiments and comparative examples.

[0159] It's important to note that differences in microstructural features like grain arrangement and porosity between phases produced using different fabrication processes can lead to differences in thermal expansion coefficients, even for the same material. This difference results in internal stresses, known as residual thermal stresses, that maintain phase equilibrium between phases produced using different fabrication processes after the material is cooled from the fabrication temperature to room temperature. For ceramic-based composites, residual thermal stresses can generate numerous microcracks in the matrix, significantly reducing the material's strength and fracture toughness.

[0160] SiC was prepared by RMI process fThe Ti3SiC2 interface phase and Ti3SiC2 matrix in the Ti3SiC2 / SiC composite material can greatly reduce the residual stress caused by preparing the interface phase and matrix separately using different preparation processes, such as the combination of "CVI process to prepare the interface phase + RMI process to prepare the matrix phase", "RMI process to prepare the interface phase + CVI process to prepare the matrix phase" or "molten salt process to prepare the interface phase + CVI process to prepare the matrix phase", as shown in Table 1.

[0161] Table 1 shows SiC prepared by different processes f Comparison of performance parameters of / SiC composite materials

[0162]

[0163] As can be seen from Table 1, compared with traditional core SiC f / SiC composite material, the new composite material proposed by the present invention has high density and low porosity, and the SiC prepared by CVI process is f / SiC composite material open porosity is reduced from 10-13% to below 3%, further improving the flexural strength of the material; compared with SiC prepared by CVI combined with RMI hybrid preparation process f / SiC composite material, the new composite material prepared by the single RMI process proposed in this invention has higher flexural strength, up to 700 MPa or more, and fracture toughness up to 25 MPa·m 1 / 2 Compared with SiC with PyC interface, TiO2+TiC interface and TiSi2+SiC interface f / SiC composite material, the present invention proposes a new composite material using Ti3SiC2 interface with better fracture toughness.

[0164] The present invention adopts the RMI process to simultaneously prepare the Ti3SiC2 interface phase and the Ti3SiC2 matrix. Compared with the combined process modification methods such as CVI+RMI or CVI+PIP+RMI, the unified interface phase and matrix preparation method can greatly improve the thermal adaptability between the interface phase and the matrix, reduce the residual stress in the composite material, and improve the mechanical strength of the material; the present invention adopts the RMI process to replace the traditional CVI process preparation method, and the process cycle is shortened to one tenth of the traditional CVI process cycle, and the production cost is greatly reduced; the product prepared by the RMI process can achieve near-net size molding, which is suitable for the preparation of large-sized special-shaped composite components.

[0165] The present invention proposes to use Ti3SiC2 interface phase to replace the traditional core SiC fThe PyC interface phase in the Ti3SiC2 / SiC composite material can effectively avoid the amorphization failure of the traditional interface phase during irradiation service, which ultimately leads to a significant attenuation of the mechanical properties of the composite material. The introduction of the Ti3SiC2 interface phase greatly improves the SiC f / SiC composite materials’ radiation resistance and mechanical strength retention during service;

[0166] The present invention proposes that SiC f Ti3SiC2 is used to replace part of the SiC matrix in the matrix of the SiC / SiC composite material. Under the action of the Ti3SiC2 modified matrix, the SiC f The overall fracture toughness of the SiC / SiC composite material is further improved.

[0167] The present invention describes preferred embodiments and their effects. However, those skilled in the art, once informed of the basic inventive concept, may make additional changes and modifications to these embodiments. Therefore, it is intended that the appended claims be interpreted to include the preferred embodiments as well as all changes and modifications that fall within the scope of the invention.

[0168] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-performance SiC for nuclear applications f A method for preparing a SiC composite material, characterized in that: The composite material interface phase and matrix phase are prepared in sequence using a single reaction melt infiltration process, including the following steps: The two-dimensional SiC fiber was placed in a magnetron sputtering instrument, and a SiC target and a TiO2 target were used for co-sputtering to form a Ti-Si-CO interface layer on the surface of the SiC fiber to obtain a two-dimensional SiC f / Ti-Si-CO fiber cloth; Two-dimensional SiC f / Ti-Si-CO fiber cloth was transferred to a porous graphite plate, and then the two-dimensional SiC f / Ti-Si-CO fiber cloth was placed in a graphite crucible, and Si powder was placed at the bottom of the graphite crucible. The temperature was raised to 1450~1500℃ and kept for 30~60min to obtain SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth; TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction aids are sequentially added to the dextrin solution, and ball milled to obtain a slurry suspension; SiC f / Ti3SiC2 interface phase two-dimensional fiber cloth is immersed in the slurry suspension to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth; SiC f / Ti3SiC2 interface / TiC-TiO2 fiber cloth is stacked to form a layered preform, and the layered preform is axially pressed and dried to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 green body; SiC f / Ti3SiC2 interface / TiC-TiO2 green body, in an inert atmosphere or under vacuum conditions, at 1200 ~ 1400 ℃ for 2 ~ 4h, to obtain SiC f / Ti3SiC2 interface / TiC-TiO2 preform; SiC f / Ti3SiC2 interface / TiC-TiO2 preform is embedded in AlSi alloy powder and kept at 1250~1450℃ in a vacuum furnace for 30~60min to obtain Ti3SiC2 modified SiC matrix phase, that is, high performance SiC for nuclear use. f / SiC composite materials.

2. The high-performance SiC for nuclear applications according to claim 1 f A method for preparing a SiC composite material, characterized in that: The dextrin solution is prepared by adding dextrin at a mass fraction of 0.1 to 1.0 wt.% into distilled water.

3. The high-performance SiC for nuclear applications according to claim 1 f A method for preparing a SiC composite material, characterized in that: The TiC and TiO2 mixed raw material includes TiC powder and TiO2 powder; Wherein, the molar ratio of TiC powder to TiO2 powder is 1:1~3:1; The particle diameters of the TiC powder and TiO2 powder are both 5-8 μm.

4. The high-performance SiC for nuclear applications according to claim 3 f A method for preparing a SiC composite material, characterized in that: The TiC powder is replaced with a mixed powder of Ti powder and C powder.

5. The high-performance SiC for nuclear applications according to claim 1 f A method for preparing a SiC composite material, characterized in that: The Y2O3 and Al2O3 mixed reaction aid comprises Y2O3 powder and Al2O3 powder; Wherein, the molar ratio of Y2O3 powder to Al2O3 powder is 2:1~1:2; The particle diameters of Y2O3 powder and Al2O3 powder are both 10-12 μm.

6. The high-performance SiC for nuclear applications according to claim 1 f A method for preparing a SiC composite material, characterized in that: TiC and TiO2 mixed raw materials and Y2O3 and Al2O3 mixed reaction additives are added to the dextrin solution in sequence, and the mass of the mixed powder is 30 to 50 wt.% of the solution mass.

7. The high-performance SiC for nuclear applications according to claim 1 f A method for preparing a SiC composite material, characterized in that: SiC f The time for immersing the two-dimensional fiber cloth with / Ti3SiC2 interface phase in the slurry suspension is 5 to 30 minutes; When axial pressure is applied to the layered preform, an axial pressure of 5 to 20 MPa is applied and the pressure is maintained for 5 to 30 minutes; the temperature during drying is 110 to 125° C. and the drying time is 24 to 48 hours.

8. The high-performance SiC for nuclear applications according to claim 1 f A method for preparing a SiC composite material, characterized in that: The AlSi alloy powder is replaced with Si powder, ZrSi alloy powder or YSi alloy powder.

9. A high-performance SiC for nuclear use obtained by the method according to any one of claims 1 to 8 f / SiC composite materials.

10. A high performance SiC according to claim 9 f Application of SiC composite materials in nuclear industry.

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