A ceramic slurry for bonding zirconia ceramics, its preparation method and application

Abstract

This application relates to the field of ceramic materials technology, and more particularly to a ceramic slurry for bonding zirconia ceramics, its preparation method, and its application. The ceramic slurry comprises an inorganic functional phase and an organic carrier; the inorganic functional phase includes modified zirconia powder, a stabilizer, and a low-temperature active sintering aid. The modified zirconia powder is cerium-doped zirconia powder modified with a modifier. This application modifies the zirconia powder using a specific wet ball milling process, improving the slurry's stability and solid content; by introducing borosilicate glass powder, the sintering temperature is lowered to 1150-1250℃, avoiding the adverse effects of high-temperature sintering on the zirconia phase structure. The resulting adhesive layer has a high coefficient of thermal expansion matching with the zirconia matrix, a temperature resistance ≥1000℃, a room temperature shear strength ≥42.5MPa, and high volume resistivity, making it suitable for applications such as solid oxide fuel cells, high-temperature sensors, dental restorations, and aerospace.

Description

Technical Field

[0001] This application relates to the field of ceramic materials technology, specifically to a ceramic slurry for bonding zirconia ceramics and its preparation method, as well as the application of the slurry in the fields of solid oxide fuel cells, high-temperature sensors, dental restorations and aerospace components. Background Technology

[0002] Zirconia (ZrO2) ceramics, with their high melting point, high hardness, excellent wear and corrosion resistance, good biocompatibility, and high-temperature ionic conductivity, are widely used in aerospace, energy (such as solid oxide fuel cells, SOFCs), medical (dental prostheses, artificial joints), and high-temperature sensors. A key technology for manufacturing large, complex-shaped, or highly sealing zirconia ceramic components is the reliable and high-performance connection of multiple simple-shaped components.

[0003] Currently, ceramic component joining mainly relies on metal-based solders (such as Ag-Cu-Ti) or glass-phase bonding agents. However, these technologies have insurmountable drawbacks when applied to zirconia ceramics: 1) Insufficient temperature resistance: The maximum operating temperature of metal brazing filler metal is usually below 600℃, which cannot meet the long-term service requirements of SOFC (operating temperature 800-1000℃) or high-temperature sensors in harsh environments.

[0004] 2) Coefficient of thermal expansion (CTE) mismatch: Metals (such as Ag-Cu alloys) have a CTE of approximately 18-20 × 10⁻⁶. -6 / K) and zirconium oxide (CTE approximately 10⁻¹¹ × 10⁻¹⁰) -6 The CTE of / K) is huge, which will generate huge thermal stress during thermal cycling, leading to joint cracking and failure.

[0005] 3) Loss of insulation: The conductive nature of the solder can compromise the electrical insulation required for zirconia ceramics in certain applications, such as when embedding sensitive elements near the adhesive layer or when sealing electrochemical devices.

[0006] 4) High sintering temperature and poor process compatibility: Although some existing ceramic adhesives have certain temperature resistance, they often require high-temperature sintering above 1400℃, which not only consumes a lot of energy but may also cause undesirable phase transformations or grain coarsening in the zirconia matrix. At the same time, the powder in traditional slurries has poor compatibility with the resin, making it difficult to obtain a stable slurry with high solid content and low viscosity, which affects the density and strength of the adhesive layer.

[0007] Therefore, there is an urgent need to develop a new type of adhesive material and method that can achieve good thermal matching with zirconia ceramic matrix, achieve densification sintering at a lower temperature (≤1250℃), withstand ultra-high temperature, have high insulation and high bonding strength. Summary of the Invention

[0008] This application aims to address the technical problems in the prior art of high-temperature bonding of zirconia ceramics, such as insufficient temperature resistance, mismatch of thermal expansion coefficients, poor insulation, and narrow process window caused by excessively high sintering temperatures. It provides a ceramic slurry for bonding zirconia ceramics, its preparation method, and its application.

[0009] In a first aspect, this application provides a ceramic slurry for bonding zirconia ceramics, employing the following technical solution: A ceramic slurry for bonding zirconia ceramics, the ceramic slurry comprising an inorganic functional phase and an organic carrier; the inorganic functional phase comprising: modified zirconia powder, a stabilizer, and a low-temperature active sintering aid; the modified zirconia powder being cerium-doped zirconia powder modified by the modifier; the low-temperature active sintering aid comprising borosilicate glass powder.

[0010] As a preferred technical solution, the inorganic functional phase, by mass parts, comprises the following raw materials: 70-85 parts modified zirconia powder, 5-15 parts stabilizer, and 10-20 parts low-temperature active sintering aid; the borosilicate glass powder has a softening point of 800-850℃ and a particle size D50 of 1-5μm. The borosilicate glass powder forms a low-viscosity liquid phase at high temperatures, which significantly promotes particle rearrangement and densification, effectively reducing the sintering temperature to 1150-1250℃, avoiding adverse effects on the cerium oxide-doped zirconia ceramic phase structure, and preventing abnormal grain growth.

[0011] As a preferred technical solution, the preparation method of the modified zirconia powder includes the following steps: (a) The dried cerium oxide-doped zirconium oxide powder (D50 particle size 100-500 nm, specific surface area 7-9.5 m²) 2 / g, cerium oxide content 5-6.5wt%), anhydrous ethanol and modifier are added to a ball mill jar and mixed, wherein the mass ratio of cerium oxide-doped zirconium oxide powder, anhydrous ethanol and modifier is 100:(100-300):(0.4-1); the modifier includes any one of methacrylic acid, allyltrimethoxysilane or hexadecanoic acid. (b) Add large grinding balls with a particle size of 10-15 mm and small grinding balls with a particle size of 5-10 mm, so that the mass ratio of cerium oxide-doped zirconium oxide powder: large grinding balls: small grinding balls is 1:(1.5-2.5):(0.8-1.5); (c) Ball milling modification at a speed of 300-600 r / min for 8-12 hours; (d) Dry the ball-milled mixture at 60-80℃, grind it and pass it through a 100-mesh sieve. Take the portion that passes through the sieve to obtain modified zirconia powder.

[0012] This specific wet modification significantly improves the compatibility between zirconia powder and organic carrier, thereby enhancing the solid content, stability, and final adhesion density of the slurry.

[0013] As a preferred technical solution, the stabilizer is yttrium oxide; the low-temperature active sintering aid also includes one or both of copper oxide or titanium oxide, with a mass ratio of 1:(2-5) to borosilicate glass powder. This is used to further reduce the sintering temperature and promote interfacial reactions.

[0014] As a preferred technical solution, the organic carrier, by mass parts, comprises the following raw materials: 8-15 parts polymer binder, 75-88 parts organic solvent, 3-8 parts plasticizer, and 0.5-2 parts dispersant; As a preferred technical solution, the polymer binder is polyvinyl butyral; the organic solvent is one or more of terpineol, butyl carbitol, or anhydrous ethanol; the plasticizer is dibutyl phthalate; and the dispersant is a phosphate ester.

[0015] As a preferred technical solution, the mass ratio of the inorganic functional phase to the organic carrier is (80-90):(10-20).

[0016] Secondly, this application provides a method for preparing a ceramic slurry for bonding zirconia ceramics, using the following technical solution: As a general technical concept, this application also provides a method for preparing the above-mentioned ceramic slurry for bonding zirconia ceramics, comprising the following steps: Step 1: Preparation of modified zirconium oxide powder; Step 2: Preparation of organic carrier: Weigh the polymer binder, organic solvent, plasticizer and dispersant according to the mass ratio, and stir at 50-80℃ until completely dissolved and clear to obtain the organic carrier; Step 3: Preparation of inorganic functional phase: Weigh the modified zirconia powder, stabilizer and low-temperature active sintering aid obtained in Step 1 according to the mass ratio, place them in a ball mill jar for mixing and ball milling. The ball milling speed is 180rpm-250rpm and the ball milling time is 15-20h to obtain the inorganic functional phase. Step 4: Prepare the slurry: Mix the inorganic functional phase obtained in Step 3 and the organic carrier obtained in Step 2 at a mass ratio of (80-90):(10-20), and disperse them evenly through a ball mill to obtain the ceramic slurry.

[0017] Thirdly, this application also provides the application of the ceramic slurry in the bonding of zirconia ceramic components, particularly for the preparation of solid oxide fuel cells, high-temperature sensors, dental restorations or aerospace zirconia ceramic components.

[0018] Fourthly, the present invention provides a method for bonding zirconia ceramics using the ceramic slurry, comprising the following steps: (1) Apply the ceramic slurry to the surface of the zirconia ceramic component to be bonded; (2) Align and fit the ceramic parts coated with slurry, and apply a pressure of 0.1-2 MPa; (3) The bonded components are de-adhesive and sintered; the sintering process is as follows: the temperature is raised to 500-700℃ at a rate of 3-5℃ / min and held for 1-3 hours, and then the temperature is raised to 1150-1250℃ at a rate of 5-10℃ / min and held for 2-4 hours to obtain the bonded zirconia ceramic components.

[0019] As a preferred technical solution, the thickness of the adhesive layer after sintering is 10-150 μm.

[0020] In summary, compared with the prior art, this application includes at least one of the following beneficial technical effects: 1. Low-temperature sintering and phase structure preservation: By introducing borosilicate glass powder as a low-temperature active sintering aid, the sintering window was successfully reduced to 1150-1250℃. This temperature is much lower than the traditional sintering temperature of zirconia ceramics (≥1400℃), effectively avoiding undesirable phase transformations (such as the tetragonal-to-monoclinic phase transformation) and grain coarsening that may occur in cerium oxide-doped zirconia at high temperatures, thus ensuring the excellent mechanical properties of the matrix and the bonding layer.

[0021] 2. Ultra-high temperature service stability: The sintered bonding layer has an all-ceramic structure. After sintering, the borosilicate glass powder forms a stable silicate glass-ceramic composite phase, which can reach a long-term service temperature of over 1000℃, far exceeding that of metal brazing filler metal.

[0022] 3. Excellent thermal compatibility: The main component of the adhesive layer is consistent with that of the substrate (both are zirconium oxide), and the CTE of the substrate can be precisely matched through formulation control (10-11×10). -6 / K), which greatly relieves thermal stress and has excellent resistance to thermal shock and thermal fatigue.

[0023] 4. Excellent electrical insulation: The adhesive layer is an insulating ceramic / glass-ceramic dielectric with high volume resistivity (≥10). 13 (Ω·cm), meeting the requirements for electrical insulation applications.

[0024] 5. High bonding strength and density: Modified zirconia powder, prepared through a specific wet process, exhibits excellent compatibility with organic carriers, enabling the formulation of stable slurries with high solid content (≥83wt%) and low viscosity. Combined with the liquid-phase sintering promoting effect of borosilicate glass powder and the interfacial activation effect of copper oxide / titanium oxide, the adhesive layer is dense (relative density ≥95.4%), with high interfacial bonding strength (room temperature shear strength ≥42.5MPa).

[0025] 6. Wide process window and good compatibility: The viscosity of the paste is adjustable, making it suitable for various precision coating processes such as screen printing and dispensing, and it is easy to achieve automated and mass production. Detailed Implementation

[0026] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this application. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0027] In the following examples and preparation examples, 1 part represents 10g.

[0028] Preparation Example 1: Preparation of Modified Zirconia Powder The preparation method of modified zirconia powder includes the following steps: (a) 1000 parts of dried cerium oxide-doped zirconium oxide powder (D50 particle size 450 nm, specific surface area 8.5 m²) 2 (5.5 wt% cerium oxide) was added to a ball mill jar and mixed with 2000 parts anhydrous ethanol and 6 parts modifier; wherein the modifier was methacrylic acid; (b) Add 2000 parts of large grinding balls with a particle size of 10 mm and 1000 parts of small grinding balls with a particle size of 7 mm; (c) Ball milling modification was carried out at a speed of 500 r / min for 10 hours; (d) The ball-milled mixture is dried at 70°C, ground, and passed through a 100-mesh sieve. The undersize portion is collected to obtain modified zirconia powder.

[0029] Preparation Example 2 Same as in Preparation Example 1, except that the modifier is allyltrimethoxysilane.

[0030] Preparation Example 3 Same as in Preparation Example 1, except that the modifier is hexadecanoic acid. Example 1

[0031] 1) Preparation of ceramic slurry Preparation of organic carrier: Weigh 8 parts of polyvinyl butyral, 88 parts of terpineol, 3 parts of dibutyl phthalate (DBP) and 1 part of phosphate ester and put them into a reactor. Stir in a 50°C water bath for 2 hours until completely dissolved to obtain a clear organic carrier. Preparation of inorganic functional phase: 70 parts of modified zirconia powder, 15 parts of yttrium oxide (D50=0.3μm), 10 parts of borosilicate glass powder (softening point 820℃, D50=2μm), and 5 parts of copper oxide (D50=0.5μm) prepared in Preparation Example 1 were weighed respectively. The weighed inorganic powders were placed in a ball mill jar, and 200 parts of anhydrous ethanol were used as the medium. The ball milling speed was 180 rpm and the ball milling time was 15 h. After drying, the inorganic functional phase was obtained. Slurry preparation: The prepared inorganic functional phase and organic carrier are mixed at a mass ratio of 85:15 and dispersed evenly by ball milling to obtain a uniform and stable ceramic slurry; The slurry was tested and found to have a solid content of 87 wt% and a viscosity of 12,000 mPa·s (25°C, Brookfield viscometer, 10 rpm). No sedimentation or stratification was observed after 30 days of standing at room temperature.

[0032] 2) Adhesion process Coating and bonding: Take two cerium oxide-doped zirconia ceramic sheets (with the same powder composition) measuring 25mm × 10mm × 3mm, and apply the above ceramic slurry to the surfaces to be bonded by screen printing (coating thickness approximately 60μm). Align and bond the two ceramic sheets, applying a constant pressure of 0.5MPa.

[0033] Adhesive removal and sintering: The bonded components are placed in a high-temperature furnace and sintered in an air atmosphere. The heating program is as follows: heat to 500℃ at 3℃ / min and hold for 3 hours to remove the adhesive; then heat to 1250℃ at 5℃ / min and hold for 4 hours for high-temperature sintering; finally cool to room temperature at 3℃ / min to obtain the bonded zirconia ceramic components. Example 2

[0034] 1) Preparation of ceramic slurry Preparation of organic carrier: 15 parts of polyvinyl butyral, 80 parts of terpineol, 3.5 parts of dibutyl phthalate (DBP) and 1.5 parts of phosphate ester were weighed and placed into a reactor. The mixture was stirred in an 80°C water bath for 2 hours until completely dissolved to obtain a clear organic carrier.

[0035] Preparation of inorganic functional phase: 85 parts of modified zirconia powder, 5 parts of yttrium oxide (D50=0.3μm), 7 parts of borosilicate glass powder (softening point 820℃, D50=2μm), and 3 parts of titanium oxide (D50=0.5μm) prepared in Preparation Example 2 were weighed respectively. The weighed inorganic powders were placed in a ball mill jar, and 200 parts of anhydrous ethanol were used as the medium. The ball milling speed was 180 rpm and the ball milling time was 15 h. After drying, the inorganic functional phase was obtained.

[0036] Slurry preparation: The prepared inorganic functional phase and organic carrier were mixed at a mass ratio of 80:20 and dispersed evenly using a ball mill to obtain a uniform and stable ceramic slurry. Testing showed that the slurry had a solid content of 83 wt% and a viscosity of 12,300 mPa·s (25℃, Brookfield viscometer, 10 rpm). No sedimentation or stratification was observed after standing at room temperature for 30 days.

[0037] 2) Adhesion process Coating and bonding: Take two cerium oxide-doped zirconia ceramic sheets (with the same powder composition) measuring 25mm × 10mm × 3mm, and apply the above ceramic slurry to the surfaces to be bonded by screen printing (coating thickness approximately 10μm). Align and bond the two ceramic sheets, applying a constant pressure of 0.1MPa.

[0038] Adhesive removal and sintering: The bonded components are placed in a high-temperature furnace and sintered in an air atmosphere. The heating program is as follows: heat to 700℃ at 5℃ / min and hold for 1 hour to remove the adhesive; then heat to 1200℃ at 10℃ / min and hold for 2 hours for high-temperature sintering; finally, cool to room temperature at 3℃ / min to obtain the bonded zirconia ceramic components. Example 3

[0039] 1) Preparation of ceramic slurry Preparation of organic carrier: 11 parts of polyvinyl butyral, 84 parts of terpineol, 4.5 parts of dibutyl phthalate (DBP), and 0.5 parts of phosphate ester were weighed and placed into a reactor. The mixture was stirred in a 60°C water bath for 2 hours until completely dissolved, yielding a clear organic carrier.

[0040] Preparation of inorganic functional phase: 80 parts of modified zirconia powder, 8 parts of yttrium oxide (D50=0.3μm), and 12 parts of borosilicate glass powder (softening point 820℃, D50=2μm) prepared in Preparation Example 3 were weighed respectively. The weighed inorganic powders were placed in a ball mill jar, and 200 parts of anhydrous ethanol were used as the medium. The ball milling speed was 210 rpm and the ball milling time was 18 h. After drying, the inorganic functional phase was obtained.

[0041] Slurry preparation: The prepared inorganic functional phase and organic carrier were mixed at a mass ratio of 90:10 and dispersed evenly using a ball mill to obtain a uniform and stable ceramic slurry. Testing showed that the slurry had a solid content of 89 wt% and a viscosity of 15,000 mPa·s (25℃, Brookfield viscometer, 10 rpm). No sedimentation or stratification was observed after standing at room temperature for 30 days.

[0042] 2) Adhesion process Coating and bonding: Take two cerium oxide-doped zirconia ceramic sheets (with the same powder composition) measuring 25mm × 10mm × 3mm, and apply the above ceramic slurry to the surfaces to be bonded by screen printing (coating thickness approximately 120μm). Align and bond the two ceramic sheets, applying a constant pressure of 1MPa.

[0043] Adhesive removal and sintering: The bonded components are placed in a high-temperature furnace and sintered in an air atmosphere. The heating program is as follows: heat to 600℃ at 4℃ / min and hold for 2 hours to remove adhesive; then heat to 1150℃ at 7℃ / min and hold for 3 hours for high-temperature sintering; finally cool to room temperature at 3℃ / min to obtain the bonded zirconia ceramic components.

[0044] Comparative Example 1 (Comparison of Metal Brazing Fillers) Commercially available Ag-Cu-Ti active metal solder foil (60μm thick) was used to braze the same cerium oxide-doped zirconia ceramic sheet at 850℃ under vacuum for 15 minutes.

[0045] Comparative Example 2 (Borosilicate Glass Powder) The method is basically the same as in Example 1, except that borosilicate glass powder and CuO are not added to the inorganic functional phase, the content of modified zirconia powder is increased to 95 parts, yttrium oxide is 5 parts, and the high-temperature sintering is 1450°C.

[0046] Comparative Example 3 (using unmodified zirconia powder) The process was essentially the same as in Example 1, except that cerium oxide-doped zirconium oxide powder with the same particle size and specific surface area as in Example 1, but without any modification, was used. The prepared slurry had a solid content of only 72 wt%, and after standing for 24 hours, it showed severe sedimentation and stratification, making it unsuitable for subsequent bonding processes.

[0047] Performance Testing and Evaluation The adhesive joints prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to the following performance tests. Comparative Example 3 was not included in the subsequent tests because it was impossible to prepare an effective adhesive joint.

[0048] Coefficient of thermal expansion (CTE) test: The average CTE of the adhesive layer material (single-fired) was tested using a thermomechanical analyzer (TMA) at room temperature to 800°C, in accordance with ASTM E228.

[0049] Shear strength test: The room temperature shear strength and 800°C shear strength of the bonded joint were tested using a universal testing machine according to ASTM C1469 standard, with a loading rate of 0.5 mm / min. Five samples were tested for each example / comparative example, and the average value was taken.

[0050] High-temperature strength retention rate: Calculate the percentage of shear strength at 800℃ to shear strength at room temperature.

[0051] Thermal cycling test: The bonded joint is subjected to rapid thermal cycling between -50℃ and 800℃ (heating / cooling rate 20℃ / min, holding at each temperature point for 10 minutes). After 50 cycles, its room temperature shear strength retention rate is tested.

[0052] Insulation resistance test: The room temperature volume resistivity was tested on the sandwich structure bonded sample (10mm×10mm×2mm) in accordance with GB / T 5598-2015 standard.

[0053] Adhesive layer density test: The relative density of the adhesive layer material (fired separately) was tested using the Archimedes drainage method.

[0054] X-ray diffraction (XRD) analysis: Phase composition analysis was performed on the zirconia matrix near the adhesive layer to detect the presence of monoclinic phase (m-ZrO2). The test results are shown in Table 1.

[0055] Table 1 Summary of Performance Test Results Analyzing the data in Table 1, we can see that: 1) CTE matching: CTE of Examples 1-3 (10.5×10 -6 / K to 10.7×10 -6 The / K) is highly compatible with the zirconia matrix, far superior to the metal solder of Comparative Example 1 (18.2×10). -6 / K), which is the basis for its excellent resistance to thermal fatigue.

[0056] 2) Low-temperature sintering and phase structure: Examples 1-3 achieved densification sintering (relative density >95%) at 1150-1250℃, while Comparative Example 2 required 1450℃. More importantly, the low-temperature sintering of the examples did not cause undesirable phase transformations in the zirconia matrix (XRD showed a pure tetragonal phase), while the high-temperature sintering of Comparative Example 2 resulted in the formation of a small amount of monoclinic phase, which would impair mechanical properties.

[0057] 3) Mechanical properties: Example 1, due to the optimization of the modifier (methacrylic acid) and the low-temperature active sintering aid (CuO + borosilicate glass), achieved the highest room temperature strength (48.6 MPa) and 800°C strength (25.7 MPa). Comparative Example 2, lacking a liquid-phase sintering aid, had the lowest density and the worst strength.

[0058] 4) Thermal stability: At 800℃, the metal joint of Comparative Example 1 melted. Examples 1-3 still maintained high shear strength. After 50 severe thermal cycles, the strength retention rate of Example 1 was as high as 90.5%, while Comparative Example 1 almost failed due to thermal stress (58.6%), verifying the excellent thermal compatibility and thermal fatigue resistance of the present invention.

[0059] 5) Slurry performance: Examples 1-3 used modified zirconia powder, resulting in slurries with high solid content and excellent stability. Comparative Example 3 used unmodified powder, resulting in slurries with low solid content and easy sedimentation, making them unsuitable for practical bonding.

[0060] 6) Electrical insulation: All ceramic adhesive layers are good insulators, while Comparative Example 1 is conductive.

[0061] The above embodiments are only used to explain the technical solutions of this application and are not intended to limit it. Although the above embodiments have provided specific descriptions of this application, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation methods of this application. Any modifications and equivalent substitutions that do not depart from the spirit and scope of this application should be covered within the protection scope of this application.

Claims

1. A ceramic slurry for bonding zirconia ceramics, characterized in that, The ceramic slurry comprises an inorganic functional phase and an organic carrier; The inorganic functional phase includes: modified zirconium oxide powder, stabilizer, and low-temperature active sintering aid; The low-temperature active sintering aid includes borosilicate glass powder; the mass ratio of the inorganic functional phase to the organic carrier is (80-90):(10-20); the modified zirconium oxide powder is cerium oxide-doped zirconium oxide powder modified by a modifier.

2. The ceramic slurry for bonding zirconia ceramics according to claim 1, characterized in that, The method for preparing the modified zirconium oxide powder includes the following steps: (a) The dried cerium oxide-doped zirconium oxide powder, anhydrous ethanol and modifier are added to a ball mill jar and mixed, wherein the mass ratio of cerium oxide-doped zirconium oxide powder, anhydrous ethanol and modifier is 100:(100-300):(0.4-1); the modifier includes any one of methacrylic acid, allyltrimethoxysilane or hexadecanoic acid. (b) Add large grinding balls with a particle size of 10-15 mm and small grinding balls with a particle size of 5-10 mm, so that the mass ratio of cerium oxide-doped zirconium oxide powder: large grinding balls: small grinding balls is 1:(1.5-2.5):(0.8-1.5); (c) Ball milling modification at a speed of 300-600 r / min for 8-12 hours; (d) Dry the ball-milled mixture at 60-80℃, grind it and pass it through a 100-mesh sieve. Take the portion that passes through the sieve to obtain modified zirconia powder.

3. The ceramic slurry for bonding zirconia ceramics according to claim 1, characterized in that, The inorganic functional phase, by mass parts, includes the following raw materials: 70-85 parts of modified zirconia powder, 5-15 parts of stabilizer, and 10-20 parts of low-temperature active sintering aid. The borosilicate glass powder has a softening point of 800-850℃ and a particle size D50 of 1-5μm.

4. The ceramic slurry for bonding zirconia ceramics according to claim 1, characterized in that, The stabilizer is yttrium oxide; the low-temperature active sintering aid also includes one or two of copper oxide or titanium oxide, and the mass ratio of the copper oxide to the borosilicate glass powder is 1:(2-5).

5. The ceramic slurry for bonding zirconia ceramics according to claim 1, characterized in that, The organic carrier, by mass, comprises the following raw materials: 8-15 parts polymer binder, 75-88 parts organic solvent, 3-8 parts plasticizer, and 0.5-2 parts dispersant.

6. The ceramic slurry for bonding zirconia ceramics according to claim 5, characterized in that, The polymer binder is polyvinyl butyral; the organic solvent is one or more of terpineol, butyl carbitol, or anhydrous ethanol; the plasticizer is dibutyl phthalate; and the dispersant is a phosphate ester.

7. A method for preparing a ceramic slurry for bonding zirconia ceramics according to any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Preparation of modified zirconium oxide powder; Step 2: Preparation of organic carrier: Weigh the polymer binder, organic solvent, plasticizer and dispersant according to the mass ratio, and stir at 50-80℃ until completely dissolved and clear to obtain the organic carrier; Step 3: Preparation of inorganic functional phase: Weigh the modified zirconia powder, stabilizer and low-temperature active sintering aid obtained in Step 1 according to the mass ratio, place them in a ball mill jar for mixing and ball milling. The ball milling speed is 180rpm-250rpm and the ball milling time is 15-20h to obtain the inorganic functional phase. Step 4: Prepare the slurry: Mix the inorganic functional phase obtained in Step 3 and the organic carrier obtained in Step 2 at a certain mass ratio, and disperse them evenly through a ball mill to obtain the ceramic slurry.

8. A method for bonding zirconia ceramics using the ceramic slurry according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Apply the ceramic slurry to the surface of the zirconia ceramic component to be bonded; (2) Align and attach the ceramic parts coated with slurry, and apply a pressure of 0.1-2 MPa; (3) The bonded components are de-adhesive and sintered; the sintering process is as follows: the temperature is raised to 500-700℃ at a rate of 3-5℃ / min and held for 1-3 hours, and then the temperature is raised to 1150-1250℃ at a rate of 5-10℃ / min and held for 2-4 hours to obtain the bonded zirconia ceramic components.

9. The method according to claim 8, characterized in that, The thickness of the adhesive layer after sintering is 10-150 μm.

10. The use of the ceramic slurry according to any one of claims 1-6 or the method according to any one of claims 8-9 in the preparation of solid oxide fuel cells, high-temperature sensors, dental restorations or aerospace zirconia ceramic components.

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