High-toughness corrosion-resistant ceramic and preparation method thereof

Abstract

The invention discloses high-toughness corrosion-resistant ceramic and a preparation method thereof. The high-toughness corrosion-resistant ceramic comprises the following raw materials in percentage by mass: 70-80% of a matrix layer; 10%-15% of a transition layer; 5%-20% of a functional surface layer; the invention relates to the technical field of ceramic preparation. According to the high-toughness corrosion-resistant ceramic and the preparation method thereof, yttrium-erbium co-stable zirconium oxide, boron nitride coating branched silicon carbide nanowires and dendritic aluminum oxynitride crystals are adopted to construct a three-dimensional toughening network, the fracture toughness and bending strength are improved, interface bonding is strengthened through copper-nickel alloy and sulfur-based modified graphene quantum dots, the porosity is reduced, and the high-toughness corrosion-resistant ceramic is prepared. The high toughness and long-acting corrosion resistance guarantee of the ceramic is realized by combining the physical barrier of titanium diboride and the self-repairing capability of the liquid metal microcapsule, and the thermal shock resistance of the ceramic is effectively improved by forming pores in PVP microspheres, providing a stress release channel and optimizing stress distribution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ceramic preparation, in particular to a high-toughness corrosion-resistant ceramic and a preparation method thereof. BACKGROUND

[0002] Industrial ceramics refer to ceramic products applied in various industries, such as building and sanitary ceramics, chemical ceramics, chemical porcelain, electrical porcelain, refractory materials and special ceramics. Corrosion-resistant ceramics can be applied in harsh industrial environments. With the increasing requirements for materials, single performance cannot meet the high-quality industrial requirements.

[0003] Traditional corrosion-resistant ceramics are mainly based on zirconia-based ceramics. Although the zirconia-based ceramics are toughened by phase transformation, the grain boundaries are easily corroded in a strong acid and halogen ion environment, and the annual corrosion rate is as high as 0.1-0.3 mm. Although the corrosion-resistant ceramics added with a TiB2 coating and a polymer composite coating can improve the chemical resistance, the fracture toughness is low, the bonding strength with the matrix is insufficient, brittle peeling easily occurs, and it is difficult to find cracks in traditional ceramics in time, which is not conducive to the judgment of the health status of the ceramic. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a high-toughness corrosion-resistant ceramic and a preparation method thereof, which solves the problems that the toughness and corrosion resistance of traditional ceramics are difficult to balance, the interlayer bonding force is weak, it is difficult to find cracks in time, and it is not conducive to the judgment of the health status of the ceramic.

[0005] To achieve the above object, the present application is realized by the following technical scheme: a high-toughness corrosion-resistant ceramic, the raw materials of which include, by mass percentage:

[0006] The base layer includes, by mass percentage: yttrium-erbium co-stable zirconia 91%-93%, boron nitride coating branched silicon carbide nanowire 5%-8%, and dendritic aluminum oxynitride crystal 1%-2%.

[0007] The transition layer includes, by mass percentage: copper-nickel alloy 88%-90% and sulfur-based modified graphene quantum dots 10%-12%.

[0008] The functional surface layer includes, by mass percentage: titanium diboride 85%-88% and liquid metal microcapsules 12%-15%.

[0009] The present application is further provided as follows: the preparation method of the yttrium-erbium co-stable zirconia includes:

[0010] Mixing diyttrium trioxide and di-erbium trioxide at a molar ratio of 2:1 as a co-stabilizer;

[0011] Yttrium and erbium co-stabilized zirconia is obtained by mixing zirconia and a stabilizer in a mass ratio of 94.5:5.5, and then treating the mixture in a 10-kW radio frequency plasma for 30 min in an argon-oxygen mixed atmosphere at a volume ratio of 4:1.

[0012] The application further provides a preparation method of the boron nitride coated branched silicon carbide nanowire.

[0013] The 20-nm-diameter silicon carbide nanowire is placed in a fluidized bed reactor, and boron chloride and ammonia gas are mixed in a molar ratio of 1:3 to react at 850 DEG C for 1 h to in-situ grow boron nitride branches on the surface of the silicon carbide nanowire, so that the boron nitride coated branched silicon carbide nanowire is obtained, and the length of the branch is 100-200 nm.

[0014] The application further provides a preparation method of the dendritic aluminum oxynitride crystal.

[0015] The aluminum oxide and ammonium fluoride are placed in a sintering furnace, heated to 1300 DEG C in a nitrogen atmosphere, and reacted for 2 h, then the oxygen-nitrogen mixed gas with a volume ratio of 1:9 is switched, heated to 1500 DEG C, and reacted for 1 h to obtain the dendritic aluminum oxynitride crystal.

[0016] The application further provides that the copper powder and the nickel powder in the copper-nickel alloy are prepared by high-energy ball milling at 400 rpm for 10 h, and the atomic ratio of the copper powder to the nickel powder is 7:3.

[0017] The application further provides a preparation method of the sulfur-modified graphene quantum dot, which comprises the following steps: soaking graphene oxide in a mixed solution of concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1, and then hydrothermally reacting at 180 DEG C for 12 h.

[0018] The application further provides a preparation method of the liquid metal microcapsule.

[0019] Gallium, indium and tin are weighed in a mass ratio of 68.5:21.5:10, the gallium is heated to be melted, the indium and the tin are added, and the liquid alloy is obtained by magnetically stirring at 300 rpm for 30 min and defoaming at 0.1 Pa for 10 min.

[0020] The liquid alloy and ethanol are mixed in a volume ratio of 1:10, ultrasonic dispersion is performed at 40 kHz and 500 W for 10 min, a mixed solution of tetraethyl orthosilicate, ethanol, water and ammonia water in a volume ratio of 1:4:2:0.2 is added dropwise, magnetic stirring is performed at 200 rpm for 6 h, centrifugal separation is performed at 8000 rpm for 10 min, ethanol washing is performed three times, vacuum drying is performed at 60 DEG C for 4 h, then the liquid alloy is transferred into a 0.5 mol / L zirconium oxychloride solution, ammonia water is used to adjust the pH value to 9, and reaction is performed at 60 DEG C for 1 h.

[0021] After calcination in an argon atmosphere at 600 DEG C for 3h, immerse in 5wt% 3-aminopropyltrimethoxysilane ethanol solution, react at 60 DEG C for 2h, obtain liquid metal microcapsule.

[0022] The application further discloses a preparation method of the high-toughness corrosion-resistant ceramic.

[0023] S1, disperse yttrium-erbium co-stabilized zirconia, boron nitride coating branched silicon carbide nanowires and dendritic aluminum oxynitride crystals in a mixed solution of ethanol and polyethylene glycol with a volume ratio of 7:3 to obtain a base slurry, the solid-liquid mass ratio of the base slurry is 1:0.6, and the base layer is prepared in a 1T strong magnetic field; the boron nitride coating branched silicon carbide nanowires are vertically arranged by the strong magnetic field, and the crack bridging efficiency is improved;

[0024] S2, immediately cover the surface of the base layer with PVP microspheres with a diameter of 50 microns after casting, and the coverage rate is 15%;

[0025] S3, disperse copper-nickel alloy and sulfur-based modified graphene quantum dots in a mixed solution of deionized water and glycerol with a volume ratio of 4:1 to obtain a transition slurry, the solid-liquid mass ratio of the transition slurry is 1:1.5, the transition slurry is cast on the surface of the base layer after the base layer is dried to obtain a transition layer;

[0026] S4, disperse titanium diboride and liquid metal microcapsules in a mixed solvent of N-methyl pyrrolidone and silica sol with a mass ratio of 8:2 to obtain a functional surface layer slurry, the solid-liquid mass ratio of the functional surface layer slurry is 1:2.2, the functional surface layer slurry is cast on the surface of the transition layer after the transition layer is dried to obtain a functional surface layer, and then cold isostatic pressing is performed at 10 MPa for 10 min;

[0027] S5, in a 20 MPa environment, 100 V·cm -1 The electric field intensity, the temperature is raised to 1200 DEG C at a rate of 200 DEG C / s in an argon atmosphere, after holding for 60 s, the temperature is lowered to 1000 DEG C at a rate of 20 DEG C / min in a pulse furnace, the temperature is raised to 1550 DEG C at a rate of 10 DEG C / min in a 40 MPa environment in a mixed gas atmosphere of argon and hydrogen with a volume ratio of 1:9, the pulse current is 500 A, then the power is cut off, the temperature is lowered to 800 DEG C at a rate of 25 DEG C / s, the atmosphere is switched to an argon atmosphere, and the temperature is lowered to 300 DEG C at a rate of 5 DEG C / min, and then the furnace is cooled.

[0028] The yttrium-erbium co-stabilized zirconia is subjected to radio frequency plasma activation treatment to realize co-doping of yttrium ions and erbium ions, and to refine grains to improve the phase change toughening efficiency;

[0029] The boron nitride branches in the boron nitride coating branched silicon carbide nanowires form crack deflection anchor points to increase the crack propagation path;

[0030] AlN branch structure in dendritic aluminum oxynitride crystals absorbs fracture energy, and improves bending strength;

[0031] The copper-nickel alloy is atomically mixed by high-energy ball milling, and forms a metallurgical bond with the matrix layer, thereby improving the shear strength;

[0032] The sulfydryl functional group in the sulfydryl-modified graphene quantum dot forms a chemical bond with the ceramic surface, thereby reducing the interface resistance, and the graphene quantum dot fills the micropores, thereby reducing the porosity of the transition layer;

[0033] The gallium-indium-tin alloy can melt and flow at the crack, realize micron-level self-repairing, and control the release through the ethyl silicate coating layer, thereby prolonging the service life.

[0034] The application provides a high-toughness corrosion-resistant ceramic and a preparation method thereof.

[0035] (1) The three-dimensional toughening network is constructed by adopting yttrium-erbium co-stable zirconium oxide, boron nitride coating branched silicon carbide nanowires and dendritic aluminum oxynitride crystals, the fracture toughness and bending strength are improved, the interface bonding is strengthened by the copper-nickel alloy and the sulfydryl-modified graphene quantum dot, and the porosity is reduced, the physical barrier of titanium diboride and the self-repairing ability of the liquid metal microcapsule are combined, and the high toughness and long-acting corrosion-resistant guarantee of the ceramic are realized.

[0036] (2) The matrix layer is prepared by strong magnetic field casting, the directional toughening effect of the ceramic is improved, the isotropic mechanical properties of the matrix layer are ensured, the pulse current sintering is used to inhibit the grain growth by rapid heating, the density is improved, and the problem of abnormal grain growth in traditional sintering is avoided, the stress release channel is provided by the PVP microspheres, the stress distribution is optimized, and the thermal shock stability of the ceramic is effectively improved. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0038] The technical solutions of the embodiments of the application are provided as follows:

[0039] Embodiment 1

[0040] A preparation method of high-toughness corrosion-resistant ceramic, which comprises a substrate layer, a transition layer and a functional surface layer from bottom to top; the three layers of raw materials are as follows in terms of mass percentage: substrate layer: 70%; transition layer: 10%; and functional surface layer: 20%; the preparation method of the high-toughness corrosion-resistant ceramic specifically comprises the following steps:

[0041] S1, substrate layer preparation: the substrate layer raw material comprises, in terms of mass percentage: yttrium-erbium co-stable zirconium oxide: 91%, boron nitride coating branched silicon carbide nanowire: 8%, and dendritic aluminum oxynitride crystal: 1%.

[0042] S11, yttrium-erbium co-stable zirconium oxide preparation: yttrium oxide and erbium oxide are compounded as a co-stabilizer in a molar ratio of 2:1, and zirconium oxide and the co-stabilizer are mixed in a mass ratio of 94.5:5.5, then subjected to 10kW radio frequency plasma activation treatment in an argon-oxygen mixed atmosphere with a volume ratio of 4:1 for 30min to obtain yttrium-erbium co-stable zirconium oxide;

[0043] S12, boron nitride coating branched silicon carbide nanowire preparation: 20nm diameter silicon carbide nanowires are placed in a fluidized bed reactor, and a mixed gas of boron chloride and ammonia in a molar ratio of 1:3 is used to react at 850℃ for 1h to obtain boron nitride coating branched silicon carbide nanowires;

[0044] S13, dendritic aluminum oxynitride crystal preparation: aluminum oxide and ammonium fluoride in a mass ratio of 97:3 are placed in a sintering furnace, heated to 1300℃ in a nitrogen atmosphere, and reacted for 2h, then the mixed gas of oxygen and nitrogen in a volume ratio of 1:9 is switched, heated to 1500℃, and reacted for 1h to obtain dendritic aluminum oxynitride crystals;

[0045] S14, substrate layer preparation: yttrium-erbium co-stable zirconium oxide, boron nitride coating branched silicon carbide nanowires and dendritic aluminum oxynitride crystals are dispersed in a mixed solution of ethanol and polyethylene glycol in a volume ratio of 7:3 to obtain a substrate slurry, and the substrate slurry has a solid-liquid mass ratio of 1:0.6, and then a substrate layer is prepared by tape casting in a 1T strong magnetic field.

[0046] S2, stress channel layout: immediately cover the surface of the substrate layer with PVP microspheres with a diameter of 50μm after tape casting, and the coverage rate is 15%.

[0047] S3, transition layer preparation: the transition layer raw material comprises, in terms of mass percentage: copper-nickel alloy: 88%, and sulfur-based modified graphene quantum dots: 12%.

[0048] S31, copper-nickel alloy preparation: copper powder and nickel powder in an atomic ratio of 7:3 are subjected to high-energy ball milling at 400rpm for 10h to obtain a copper-nickel alloy;

[0049] S32, Sulfur-modified graphene quantum dot preparation: graphene oxide was immersed in a mixed solution of concentrated sulfuric acid and concentrated nitric acid with a volume ratio of 3:1, and hydrothermal reaction was carried out at 180°C for 12h to obtain sulfur-modified graphene quantum dots;

[0050] S33, Preparation of transition layer: copper-nickel alloy and sulfur-modified graphene quantum dots were dispersed in a mixed solution of deionized water and glycerol with a volume ratio of 4:1 to obtain a transition slurry. The solid-liquid mass ratio of the transition slurry was 1:1.5. After drying the base layer, the transition slurry was cast on the surface of the base layer to obtain the transition layer.

[0051] S4, Functional surface layer preparation: the functional surface layer raw material includes titanium diboride 85% and liquid metal microcapsule 15% by mass percentage.

[0052] S41, Liquid metal microcapsule preparation: gallium, indium and tin were weighed according to the mass ratio of 68.5:21.5:10. After gallium was heated to melt, indium and tin were added. The liquid alloy was obtained by magnetic stirring at 300 rpm for 30 min, defoaming for 10 min in a vacuum environment of 0.1 Pa, mixing the liquid alloy with ethanol at a volume ratio of 1:10, ultrasonic dispersion for 10 min at 40 kHz and 500 W, adding a mixed solution of tetraethyl orthosilicate, ethanol, water and ammonia water with a volume ratio of 1:4:2:0.2, magnetic stirring at 200 rpm for 6 h, centrifugal separation at 8000 rpm for 10 min, ethanol washing for three times, vacuum drying at 60°C for 4 h, then transferring to a 0.5 mol / L zirconium oxychloride solution, adjusting pH to 9 with ammonia water, reacting at 60°C for 1 h, then calcining at 600°C in an argon atmosphere for 3 h, and then immersing in a 5wt% 3-aminopropyltrimethoxysilane ethanol solution and reacting at 60°C for 2 h to obtain the liquid metal microcapsule.

[0053] S42, Preparation of functional surface layer: titanium diboride and liquid metal microcapsule were dispersed in a mixed solvent of N-methyl pyrrolidone and silica sol with a mass ratio of 8:2 to obtain a functional surface layer slurry. The solid-liquid mass ratio of the functional surface layer slurry was 1:2.2. After drying the transition layer, the functional surface layer slurry was cast on the surface of the transition layer to obtain the functional surface layer, and then cold isostatic pressing at 10 MPa for 10 min.

[0054] S5, Sintering and forming: under the environment of 20 MPa, 100 V·cm -1Electric field intensity, argon atmosphere, 200℃ / s rate to 1200℃, 60s, transferred to pulse furnace, 20℃ / min rate to 1000℃, 40MPa environment, argon and hydrogen mixed atmosphere in volume ratio of 1:9, 10℃ / min rate to 1550℃, 5min, pulse current: 500A, then cut off the power, 25℃ / s rate to 800℃, switch to argon atmosphere, 5℃ / min to 300℃, then furnace cooling.

[0055] The mass percentage of raw materials in this embodiment is shown in Table 1:

[0056] Table 1

[0057] Example 2

[0058] The difference between this embodiment and Example 1 is:

[0059] The mass percentage of raw materials in this embodiment is shown in Table 2:

[0060] Table 2

[0061] Example 3

[0062] The difference between this embodiment and Example 1 is:

[0063] The mass percentage of raw materials in this embodiment is shown in Table 3:

[0064] Table 3

[0065] Simulation experiment

[0066] The traditional ZrO2 ceramic is taken as Comparative Example 1, and the pearl structure Al2O3-ZrO2 proposed in the paper DOI: 10.1002 / adma.202108267 is taken as Comparative Example 2. The mechanical properties, corrosion resistance and intelligent response, and thermal shock and fatigue performance of the present application are tested and compared. The mechanical properties are indicated by fracture toughness, bending strength and Vickers hardness. The fracture toughness is obtained by SENB method according to ASTM C1421-18 standard, the bending strength is obtained by three-point bending test according to ISO 14704:2016 standard, and the Vickers hardness is obtained by applying a load of 1kgf according to ISO 14705:2016 standard. The test results are shown in Table 4:

[0067] Table 4

[0068] The corrosion resistance and intelligent response test takes the acid corrosion rate, salt spray corrosion life, self-repairing efficiency and crack early warning response time as indexes, the acid corrosion rate is tested by immersion weight loss method according to the ISO 17718 standard, the salt spray corrosion life is obtained by neutral salt spray test according to the GB / T10125-2021 standard, the self-repairing efficiency is observed in situ by a laser confocal microscope, the crack early warning response time is recorded by a high-speed camera, and the test results are shown in Table 5:

[0069] Table 5

[0070] The thermal shock and fatigue performance takes the thermal shock critical temperature difference and cyclic fatigue life as indexes, wherein the thermal shock critical temperature difference is obtained by water quenching according to the ASTM C1525-18 standard, and the cyclic fatigue life is obtained by four-point bending fatigue test at 300MPa according to the ISO 13124:2011 standard, and the test results are shown in Table 6:

[0071] Table 6

[0072] In the water quenching test, the ceramic of the present application has no crack after 50 cycles, while the ceramic of the comparative example 2 has crack after 10 cycles.

[0073] In summary, it can be seen that the present application not only realizes the synergistic optimization of high toughness and corrosion resistance, but also has good thermal shock stability, can find cracks in the matrix layer in time, provides reliable guarantee for long-term safe use of the ceramic, and through the self-repairing ability of the liquid metal microcapsule, provides reliable guarantee for high toughness and long-term corrosion resistance of the ceramic, and is suitable for use in extreme scenes such as nuclear power and deep sea.

[0074] Although the embodiments of the present application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A high-toughness corrosion-resistant ceramic, characterized by, The raw materials include, by mass percentage: The base layer: 70% to 80%, the raw materials of the base layer include, by mass percentage: yttrium-erbium co-stable zirconium oxide: 91% to 93%, boron nitride coating branched silicon carbide nanowires: 5% to 8%, dendritic aluminum oxynitride crystals: 1% to 2%; The transition layer: 10% to 15%, the raw materials of the transition layer include, by mass percentage: copper-nickel alloy: 88% to 90%, sulfur-based modified graphene quantum dots: 10% to 12%; The functional surface layer: 5% to 20%, the raw materials of the functional surface layer include, by mass percentage: titanium diboride 85% to 88%, liquid metal microcapsules: 12% to 15%.

2. The corrosion resistant ceramic of claim 1, wherein, The preparation method of the yttrium-erbium co-stable zirconium oxide includes: Mixing yttrium trioxide and erbium trioxide at a molar ratio of 2:1 as a co-stabilizing agent; Mixing zirconium oxide and the co-stabilizing agent at a mass ratio of 94.5:5.5, then treating with 10kW radio frequency plasma activation for 30min in a mixed atmosphere of argon and oxygen at a volume ratio of 4:1 to obtain yttrium-erbium co-stable zirconium oxide.

3. The corrosion resistant ceramic of claim 1, wherein, The preparation method of the boron nitride coating branched silicon carbide nanowires includes: Placing 20nm diameter silicon carbide nanowires in a fluidized bed reactor, reacting with a mixed gas of boron chloride and ammonia at a molar ratio of 1:3 at 850℃ for 1h to obtain boron nitride coating branched silicon carbide nanowires.

4. The corrosion resistant ceramic of claim 1, wherein, The preparation method of the dendritic aluminum oxynitride crystals includes: Placing aluminum trioxide and ammonium fluoride at a mass ratio of 97:3 in a sintering furnace, heating to 1300℃ in a nitrogen atmosphere, switching to a mixed gas of oxygen and nitrogen at a volume ratio of 1:9 after reacting for 2h, heating to 1500℃, reacting for 1h to obtain dendritic aluminum oxynitride crystals.

5. The corrosion resistant ceramic of claim 1, wherein, The copper-nickel alloy has an atomic ratio of copper powder to nickel powder of 7:3, which is prepared by high-energy ball milling at 400rpm for 10h.

6. The corrosion resistant ceramic of claim 1, wherein, The preparation method of the sulfur-based modified graphene quantum dots is: soaking graphene oxide in a mixed solution of concentrated sulfuric acid and concentrated nitric acid at a volume ratio of 3:1, then hydrothermal reaction at 180℃ for 12h to obtain.

7. The corrosion resistant ceramic of claim 1, wherein, The preparation method of the liquid metal microcapsules includes: Measuring gallium, indium and tin at a mass ratio of 68.5:21.5:10, heating gallium to melt, then adding indium and tin, stirring at 300rpm for 30min, defoaming at 0.1Pa vacuum environment for 10min to obtain a liquid alloy; Mixing the liquid alloy with ethanol at a volume ratio of 1:10, ultrasonic dispersion at 40kHz and 500W for 10min, dropping a mixed solution of tetraethyl orthosilicate, ethanol, water and ammonia water at a volume ratio of 1:4:2:0.2, stirring at 200rpm for 6h, centrifugal separation at 8000rpm for 10min, washing with ethanol three times, vacuum drying at 60℃ for 4h, then transferring to a 0.5mol / L zirconium oxychloride solution, adjusting pH to 9 with ammonia water, reacting at 60℃ for 1h; Calcining at 600℃ in an argon atmosphere for 3h, then soaking in a 5wt% 3-aminopropyltrimethoxysilane ethanol solution, reacting at 60℃ for 2h to obtain liquid metal microcapsules.

8. A high toughness corrosion resistant ceramic according to any one of claims 1 to 7, wherein, The preparation method specifically includes the following steps: S1, yttrium erbium co-stable zirconia, boron nitride coating branched silicon carbide nanowires and dendritic aluminum oxynitride crystals are dispersed in a mixed solution of ethanol and polyethylene glycol with a volume ratio of 7:3 to obtain a matrix slurry, the solid-liquid mass ratio of the matrix slurry is 1:0.6, and the matrix layer is prepared by tape casting in a 1T strong magnetic field; S2, immediately after tape casting, PVP microspheres with a diameter of 50μm are covered on the surface of the matrix layer, and the coverage rate is 15%; S3, copper-nickel alloy and sulfur-based modified graphene quantum dots are dispersed in a mixed solution of deionized water and glycerol with a volume ratio of 4:1 to obtain a transition slurry, the solid-liquid mass ratio of the transition slurry is 1:1.5, and after the matrix layer is dried, the transition slurry is tape cast on the surface of the matrix layer to obtain a transition layer; S4, titanium diboride and liquid metal microcapsules are dispersed in a mixed solvent of N-methyl pyrrolidone and silica sol with a mass ratio of 8:2 to obtain a functional surface layer slurry, the solid-liquid mass ratio of the functional surface layer slurry is 1:2.2, and after the transition layer is dried, the functional surface layer slurry is tape cast on the surface of the transition layer to obtain a functional surface layer, and then cold isostatic pressing at 10MPa for 10min. S5, in 20 MPa environment, 100 V·cm -1 electric field intensity, under argon atmosphere, with a rate of 200 ℃ / s to 1200 ℃, after holding for 60 s, transferred to pulse furnace, with a rate of 20 ℃ / min to 1000 ℃, in 40 MPa environment, under the mixed atmosphere of argon and hydrogen with a volume ratio of 1:9, with a rate of 10 ℃ / min to 1550 ℃, holding for 5 min, pulse current: 500 A, then cut off the power, with a rate of 25 ℃ / s to 800 ℃, switched to argon atmosphere, with a rate of 5 ℃ / min to 300 ℃, then furnace cooling.

Images