Seal coating material and preparation method thereof
By introducing microcapsules and a Si-Al-O shell onto the YSZ matrix, the problem of easy cracking and peeling of the sealing coating at high temperatures was solved, and the thermal shock resistance of the coating and the stability of the sealing gap were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-18
- Publication Date
- 2026-03-31
AI Technical Summary
Existing sealing coating materials are prone to cracking and peeling under long-term high temperature and thermal cycling, making it difficult to maintain a stable sealing gap over a long period of time. Furthermore, the composite phase is prone to aggregation, leading to uneven structure and stress concentration, which affects thermal shock performance.
Microcapsules are introduced into the YSZ matrix and uniformly dispersed in the form of core-shell particles. The shell softening and core slow release achieve directional filling and buffering of microcracks and pores. A Si-Al-O shell is introduced as a transition interface to adjust the coefficient of thermal expansion. Combined with aluminum nitride and silicon nitride, the thermal conductivity and structural stability are improved.
It improves the coating's thermal shock resistance, reduces the risk of cracking and peeling, ensures stable high-temperature contact wear, and maintains a stable sealing gap over a long period.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of coating materials technology, and in particular to a sealing coating material and its preparation method. Background Technology
[0002] Sealing coatings are functional coatings applied to the inner walls of rotors or casings in high-temperature rotating machinery such as gas turbines and aero engines. Their primary purpose is not to bear high loads or provide thermal insulation, but rather to form a controllable, wear-resistant, and airtight sealing layer between the rotor blade tips and the casing. During initial installation and operation, the rotor blade tips slightly abrade the sealing coating, creating a near-fitting clearance between the coating surface and the blade tips. This significantly reduces working fluid leakage and improves the efficiency of the compressor and turbine stages.
[0003] CN116770214A discloses a high-temperature resistant, self-lubricating, and low-friction sealing coating material and its preparation method, comprising the following preparation steps: S1, NiCoCrAlY alloy powder is sprayed onto the surface of an alloy substrate using plasma spraying, supersonic flame spraying, laser cladding equipment, or arc cladding equipment to form a Ni-based bonding layer; S2, 8YSZ powder is prepared onto the surface of the Ni-based bonding layer using laminar plasma spraying or electron beam physical vapor deposition technology to form a first ceramic coating; S3, a first co-doped zirconium oxide system formed by LZO, LCO, and GZO in a mass ratio of 1:1:1, or a second co-doped zirconium oxide system formed by a first co-doped zirconium oxide system in a mass ratio of 10:3:7, MoS2, and CaF2 is prepared on the surface of the first ceramic coating using laminar plasma spraying or electron beam physical vapor deposition technology to form a second ceramic coating. The sealing coating obtained thereby possesses high-temperature resistance, self-lubrication, and low-friction properties. However, it has significant technical deficiencies in terms of thermal shock resistance life, structural stability, controllable wear, and long-term sealing gap maintenance. Summary of the Invention
[0004] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a sealing coating material and its preparation method that has improved thermal shock resistance, reduced risk of cracking and peeling, more stable high-temperature contact wear, and easier long-term stability of sealing gap.
[0005] Traditional single YSZ sealing coatings are prone to sintering and densification under long-term high temperature and thermal cycling, resulting in increased rigidity and thermal expansion mismatch with the substrate, easy cracking and peeling, and difficulty in maintaining a stable sealing gap over a long period of time. At the same time, when composite phases or glass phases are directly incorporated, local aggregation and uneven structure are likely to occur, resulting in stress concentration and decreased thermal shock performance. The release and timing of the functional phase are also difficult to control.
[0006] To achieve the above objectives, the present invention provides a method for preparing a sealing coating material, characterized by comprising the following steps: Mix 80-90g of YSZ precursor powder and 10-20g of composite particles evenly for 30-40 minutes, add to 150-200mL of water, add 1-3g of binder, 0.1-1g of dispersant, and 1-3g of pore-forming agent, add zirconia balls as grinding media (ball-to-material mass ratio of about 2-3:1), ball mill at 200-300 rpm for 2-6 hours, and then spray dry with a nozzle diameter of 0.7-1 mm, a feed pressure of 0.8-1.5MPa, an inlet air temperature of 150-230℃, and an outlet air temperature of 80-130℃ to obtain particles; heat the particles at room temperature to 1000-1300℃ at 3-5℃ / min for 0.5-2 hours, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 25-35µm, D90≤60µm.
[0007] The adhesive is at least one of polyvinyl alcohol, polyethylene glycol, and hydroxypropyl methylcellulose; The dispersant is at least one of sodium hexametaphosphate, ammonium polyacrylate, or sodium polyacrylate; The pore-forming agent is at least one of soluble starch and microcrystalline cellulose; The method for preparing the composite particles is as follows: 61-63g BaCO3 and 36-38g ZrO2 are added to 100-200mL of water and mixed evenly. 0.1-1g of dispersant and 1-5g of binder are added, and the pH is adjusted to 8-9. Zirconia balls are added as grinding media, with a ball-to-particle mass ratio of (2-3):1. The mixture is ball-milled at 100-300rpm for 4-12h to obtain a slurry. The slurry is then spray-dried at an inlet air temperature of 150-220℃ and an outlet air temperature of 80-120℃ to obtain pre-formed particles. The pre-formed particles are then heated to 600-800℃ at a rate of 3-5℃ / min at room temperature for 1-2h to obtain the composite particles.
[0008] The preparation method of the YSZ precursor powder is as follows: 220-230g of ZrOCl2•8H2O and 45-48g of Y(NO3)3•6H2O are added to 600-800mL of water and mixed evenly. The mixture is heated to 40-60℃, and 10-25wt% ammonia water is added while stirring at 500-800rpm. The pH is adjusted to 8-10 and stirred for 30-60min to obtain a mixture. The mixture is stirred at 40-60℃ for 1-4h and allowed to stand for aging for 4-24h. It is dried at 100-150℃ for 8-24h, and then calcined at 900-1100℃ for 1-4h at a rate of 3-5℃ / min to obtain the YSZ precursor powder.
[0009] This invention introduces composite particles to ensure uniform distribution of the composite phase in the sprayed powder and final coating. It also achieves directional filling and buffering of microcracks and pores through shell softening and core slow release. On the one hand, it maintains the high-temperature stability and mechanical support of the YSZ skeleton; on the other hand, it improves the coating's airtightness, sealing retention, and thermal shock reliability. This effectively reduces the risk of coating sintering densification, cracking, peeling, and leakage failure under long-term high-temperature service conditions.
[0010] Building upon the above, microcapsules are introduced and uniformly dispersed on the YSZ matrix in the form of core-shell particles. The microcapsule particle size is controllable and the morphology is regular, reducing the agglomeration and local enrichment of the Ba-Zr phase in the coating, thereby mitigating the resulting microstructure inhomogeneity and stress concentration. The Si-Al-O shell, as the transition interface between the Ba-Zr core and YSZ, exhibits thermal expansion and softening behavior that falls between the two, thus improving the coating's thermal shock resistance, reducing the risk of cracking and peeling, stabilizing high-temperature contact wear, and making it easier to maintain a stable sealing gap over the long term.
[0011] Preferably, a method for preparing a sealing coating material includes the following steps: Mix 80-90g of YSZ precursor powder and 10-20g of microcapsules evenly for 30-40 minutes, add to 150-200mL of water, add 1-3g of binder, 0.1-1g of dispersant, and 1-3g of pore-forming agent, add zirconia balls as grinding media (ball-to-material mass ratio of about 2-3:1), ball mill at 200-300 rpm for 2-6 hours, and then spray dry with a nozzle diameter of 0.7-1 mm, a feed pressure of 0.8-1.5MPa, an inlet air temperature of 150-230℃, and an outlet air temperature of 80-130℃ to obtain granules; heat the granules at room temperature to 1000-1300℃ at 3-5℃ / min for 0.5-2 hours, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 25-35µm, D90≤60µm.
[0012] The method for preparing the microcapsules is as follows: S1. Add 61-63g BaCO3 and 36-38g ZrO2 to 100-200mL of water and mix well. Add 0.1-1g dispersant and 1-5g binder, adjust the pH to 8-9, and add zirconia balls as grinding media. The ball-to-material mass ratio is (2-3):1. Ball mill at 100-300rpm for 4-12h to obtain a slurry. Spray dry the slurry with an inlet air temperature of 150-220℃ and an outlet air temperature of 80-120℃ to obtain pre-formed particles. Heat the pre-formed particles at room temperature to 600-800℃ at a rate of 3-5℃ / min for 1-2h to obtain composite particles. S2. Add 25-30g of tetraethyl orthosilicate to 30-50mL of anhydrous ethanol and mix thoroughly to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 200-300mL of water and mix thoroughly, then add 12-16g of Al(NO3)3•9H2O and mix thoroughly. Adjust the pH to 2-4 and age at 30-40℃ for 0.5-2h to obtain a sol; add the composite particles to the sol and stir thoroughly. Ultrasonicate at 100-200W for 10-30min, adjust the pH to 2.5-4.0, and treat at 30-40℃ for 2-12h to obtain the precursor; S3. Dry the precursor at 80-120℃ for 8-24h, then heat it at room temperature to 800-1000℃ at 2-5℃ / min for 0.5-2h to obtain microcapsules.
[0013] As a Sr source, aluminum nitride participates in the formation of an Sr-containing aluminosilicate shell, which is used to adjust the shell's coefficient of thermal expansion and viscosity-temperature characteristics. This allows the shell to exhibit more suitable softening and viscous flow behavior in the near-service temperature range, facilitating the slow filling and passivation of microcracks and pores during thermal cycling. The introduction of aluminum nitride into the composite core improves the thermal conductivity of the core region and forms a dispersed reinforcing phase, helping to alleviate temperature gradients and localized overheating within the coating. This enhances the structural stability of the microcapsules under thermo-mechanical coupling, thereby further improving the thermal shock lifetime and long-term sealing performance of the sealing coating.
[0014] Preferably, the microcapsules are prepared by: S1. Add 61-63g BaCO3, 36-38g ZrO2, and 1-3g nitride filler to 100-200mL of water and mix evenly. Add 0.1-1g dispersant and 1-5g binder, adjust the pH to 8-9, and add zirconia balls as grinding media. The ball-to-material mass ratio is (2-3):1. Ball mill at 100-300rpm for 4-12h to obtain a slurry. Spray dry the slurry at an inlet air temperature of 150-220℃ and an outlet air temperature of 80-120℃ to obtain pre-formed particles. Heat the pre-formed particles at room temperature to 600-800℃ at a rate of 3-5℃ / min for 1-2h to obtain composite particles. S2. Add 25-30g of tetraethyl orthosilicate to 30-50mL of anhydrous ethanol and mix thoroughly to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 200-300mL of water and mix thoroughly, then add 12-16g of Al(NO3)3•9H2O and 3-8g of soluble strontium salt and mix thoroughly. Adjust the pH to 2-4 and age at 30-40℃ for 0.5-2h to obtain a sol; add the composite particles to the sol and stir thoroughly, sonicate at 100-200W for 10-30min, adjust the pH to 2.5-4.0, and treat at 30-40℃ for 2-12h to obtain the precursor; S3. Dry the precursor at 80-120℃ for 8-24h, then heat it at room temperature to 800-1000℃ at 2-5℃ / min for 0.5-2h to obtain microcapsules.
[0015] The nitride filler is at least one of aluminum nitride and silicon nitride; preferably, the nitride filler is a mixture of aluminum nitride and silicon nitride in a mass ratio of 1:1 to 3:1.
[0016] The soluble strontium salt mentioned above is Sr(NO3)2; Aluminum nitride provides high thermal conductivity, helping to distribute heat evenly and reduce thermal stress accumulation; silicon nitride improves the high-temperature strength and toughness of the coating, effectively inhibiting crack propagation. The Al2O3 and SiO2 glass phases generated by oxidation modulate the coating's coefficient of thermal expansion and viscosity-temperature characteristics, optimizing thermal stability and further enhancing the coating's thermal shock life and sealing capability.
[0017] The present invention also provides a sealing coating material, which is prepared by the above method.
[0018] The beneficial effects of this invention are as follows: This invention introduces microcapsules onto a YSZ matrix, which are uniformly dispersed in the YSZ matrix as core-shell particles. The microcapsule particle size is controllable and the morphology is regular, reducing the agglomeration and local enrichment of Ba-Zr cores in the coating, thus mitigating the resulting uneven structure and stress concentration. Simultaneously, the shell layer, as the transition interface between the Ba-Zr core and the YSZ matrix, exhibits thermal expansion and softening behavior intermediate between the two, thereby improving the coating's thermal shock resistance, reducing the risk of cracking and peeling, ensuring more stable high-temperature contact wear, and making it easier to maintain a stable sealing gap over the long term. Detailed Implementation
[0019] The endpoints and any values of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.
[0020] Polyvinyl alcohol, model: polyvinyl alcohol PVA-1788, product number: P815723, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Microcrystalline cellulose, product number: M909921, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. ZrO2, product number: Z820679, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Aluminum nitride, product number: A800790, purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Silicon nitride, product number: S106137, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Boron nitride, product number: B887052, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.
[0021] Other raw materials not mentioned are all common raw materials. The above content is only for the purpose of illustrating the present invention and should not be construed as a strict limitation of the present invention. Those skilled in the art can directly purchase the same / similar raw materials from the market or prepare them themselves.
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0023] Example 1 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300 rpm for 4h, and then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0024] The microcapsules are prepared by: S1. Add 62.7g BaCO3 and 37.3g ZrO2 to 150mL of water and mix well. Add 1g sodium hexametaphosphate and 5g polyvinyl alcohol, adjust the pH to 8.5, and add zirconia balls as grinding media. The ball-to-material mass ratio is 3:1. Ball mill at 200rpm for 8 hours to obtain a slurry. Spray dry the slurry with a nozzle diameter of 0.8 mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. Heat the pre-formed particles to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0025] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0026] Example 2 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of composite particles evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-particle mass ratio of approximately 2.5:1). Ball mill at 300 rpm for 4h, and then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain particles. Treat the particles at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0027] The composite particles are prepared as follows: 62.7g BaCO3 and 37.3g ZrO2 are added to 150mL of water and mixed evenly. 1g sodium hexametaphosphate and 5g polyvinyl alcohol are added, and the pH is adjusted to 8.5. Zirconia balls are added as grinding media, with a ball-to-particle mass ratio of 3:1. The mixture is ball-milled at 200rpm for 8 hours to obtain a slurry. The slurry is then spray-dried with a nozzle diameter of 0.8mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. The pre-formed particles are then heated to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles.
[0028] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0029] Example 3 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of composite particles evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-particle mass ratio of approximately 2.5:1). Ball mill at 300 rpm for 4h, and then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain particles. Treat the particles at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0030] The composite particles are prepared as follows: 28g of tetraethyl orthosilicate is added to 40mL of anhydrous ethanol and mixed evenly to obtain a tetraethyl orthosilicate solution; the tetraethyl orthosilicate solution is added to 250mL of water and mixed evenly, then 15g of Al(NO3)3•9H2O is added and mixed evenly, the pH is adjusted to 3, and the mixture is aged at 35℃ for 1h to obtain a sol; the sol is treated at 35℃ for 6h to obtain a precursor; the precursor is dried at 100℃ for 12h, and then heated to 900℃ at 3℃ / min for 1h at room temperature to obtain composite particles.
[0031] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0032] Example 4 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300rpm for 4h, and then spray dry with a nozzle diameter of 0.8mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0033] The microcapsules are prepared by: S1. Add 62.7g BaCO3, 37.3g ZrO2, and 2g aluminum nitride to 150mL of water and mix well. Add 1g sodium hexametaphosphate and 5g polyvinyl alcohol, adjust the pH to 8.5, and add zirconia balls as grinding media. The ball-to-material mass ratio is 3:1. Ball mill at 200rpm for 8 hours to obtain a slurry. Spray dry the slurry with a nozzle diameter of 0.8 mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. Heat the pre-formed particles to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and 5g of Sr(NO3)2 and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0034] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0035] Example 5 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300 rpm for 4h, and then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0036] The microcapsules are prepared by: S1. Add 62.7g BaCO3, 37.3g ZrO2, and 2g aluminum nitride to 150mL of water and mix well. Add 1g sodium hexametaphosphate and 5g polyvinyl alcohol, adjust the pH to 8.5, and add zirconia balls as grinding media. The ball-to-material mass ratio is 3:1. Ball mill at 200rpm for 8 hours to obtain a slurry. Spray dry the slurry with a nozzle diameter of 0.8 mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. Heat the pre-formed particles to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0037] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0038] Example 6 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300 rpm for 4h, and then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0039] The microcapsules are prepared by: S1. Add 62.7g BaCO3 and 37.3g ZrO2 to 150mL of water and mix well. Add 1g sodium hexametaphosphate and 5g polyvinyl alcohol, adjust the pH to 8.5, and add zirconia balls as grinding media. The ball-to-material mass ratio is 3:1. Ball mill at 200rpm for 8 hours to obtain a slurry. Spray dry the slurry with a nozzle diameter of 0.8 mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. Heat the pre-formed particles to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and 5g of Sr(NO3)2 and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0040] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0041] Example 7 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300rpm for 4h, and then spray dry with a nozzle diameter of 0.8mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0042] The microcapsules are prepared by: S1. 62.7g BaCO3, 37.3g ZrO2, and 2g nitride filler were added to 150mL of water and mixed evenly. 1g sodium hexametaphosphate and 5g polyvinyl alcohol were added to adjust the pH to 8.5. Zirconia balls were added as grinding media, with a ball-to-material mass ratio of 3:1. The mixture was ball-milled at 200rpm for 8 hours to obtain a slurry. The slurry was then spray-dried using a 0.8mm nozzle with an inlet air temperature of 180℃ and an outlet air temperature of 95℃ to obtain pre-formed particles. The pre-formed particles were then heated to 700℃ at a rate of 5℃ / min for 2 hours at room temperature to obtain composite particles. The nitride filler was composed of aluminum nitride and silicon nitride mixed in a mass ratio of 1:1. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and 5g of Sr(NO3)2 and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0043] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0044] Example 8 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300rpm for 4h, and then spray dry with a nozzle diameter of 0.8mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0045] The microcapsules are prepared by: S1. Add 62.7g BaCO3, 37.3g ZrO2, and 2g silicon nitride to 150mL of water and mix well. Add 1g sodium hexametaphosphate and 5g polyvinyl alcohol, adjust the pH to 8.5, and add zirconia balls as grinding media. The ball-to-material mass ratio is 3:1. Ball mill at 200rpm for 8 hours to obtain a slurry. Spray dry the slurry with a nozzle diameter of 0.8 mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. Heat the pre-formed particles to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and 5g of Sr(NO3)2 and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0046] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0047] Example 9 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300 rpm for 4h, and then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0048] The microcapsules are prepared by: S1. 62.7g BaCO3, 37.3g ZrO2, and 2g nitride filler were added to 150mL of water and mixed evenly. 1g sodium hexametaphosphate and 5g polyvinyl alcohol were added to adjust the pH to 8.5. Zirconia balls were added as grinding media, with a ball-to-material mass ratio of 3:1. The mixture was ball-milled at 200rpm for 8 hours to obtain a slurry. The slurry was then spray-dried using a 0.8mm nozzle with an inlet air temperature of 180℃ and an outlet air temperature of 95℃ to obtain pre-formed particles. The pre-formed particles were then heated to 700℃ at a rate of 5℃ / min for 2 hours at room temperature to obtain composite particles. The nitride filler was composed of aluminum nitride and silicon nitride mixed in a mass ratio of 1:1. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0049] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0050] Example 10 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300 rpm for 4h, and then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0051] The microcapsules are prepared by: S1. Add 62.7g BaCO3, 37.3g ZrO2, and 2g silicon nitride to 150mL of water and mix well. Add 1g sodium hexametaphosphate and 5g polyvinyl alcohol, adjust the pH to 8.5, and add zirconia balls as grinding media. The ball-to-material mass ratio is 3:1. Ball mill at 200rpm for 8 hours to obtain a slurry. Spray dry the slurry with a nozzle diameter of 0.8 mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. Heat the pre-formed particles to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0052] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0053] Example 11 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300rpm for 4h, and then spray dry with a nozzle diameter of 0.8mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0054] The microcapsules are prepared by: S1. 62.7g BaCO3, 37.3g ZrO2, and 2g nitride filler were added to 150mL of water and mixed evenly. 1g sodium hexametaphosphate and 5g polyvinyl alcohol were added, and the pH was adjusted to 8.5. Zirconia balls were added as grinding media, with a ball-to-material mass ratio of 3:1. The mixture was ball-milled at 200rpm for 8 hours to obtain a slurry. The slurry was then spray-dried using a 0.8mm nozzle with an inlet air temperature of 180℃ and an outlet air temperature of 95℃ to obtain pre-formed particles. The pre-formed particles were then heated to 700℃ at a rate of 5℃ / min for 2 hours at room temperature to obtain composite particles. The nitride filler was composed of aluminum nitride and boron nitride mixed in a mass ratio of 1:1. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and 5g of Sr(NO3)2 and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0055] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0056] Example 12 A method for preparing a sealing coating material includes the following steps: Mix 85g of YSZ precursor powder and 15g of microcapsules evenly for 30min, add 180mL of water, 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose, and add zirconia balls as grinding media (ball-to-material mass ratio of approximately 2.5:1). Ball mill at 300rpm for 4h, and then spray dry with a nozzle diameter of 0.8mm, a feed pressure of 1MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature at 1100℃ for 1h by heating at 5℃ / min, cool to room temperature, pulverize and sieve, and control the particle size distribution: D50 = 30µm, D90≤60µm.
[0057] The microcapsules are prepared by: S1. Add 62.7g BaCO3, 37.3g ZrO2, and 2g boron nitride to 150mL of water and mix well. Add 1g sodium hexametaphosphate and 5g polyvinyl alcohol, adjust the pH to 8.5, and add zirconia balls as grinding media. The ball-to-material mass ratio is 3:1. Ball mill at 200rpm for 8 hours to obtain a slurry. Spray dry the slurry with a nozzle diameter of 0.8 mm, an inlet air temperature of 180℃, and an outlet air temperature of 95℃ to obtain pre-formed particles. Heat the pre-formed particles to 700℃ at a rate of 5℃ / min at room temperature for 2 hours to obtain composite particles. S2. Add 28g of tetraethyl orthosilicate to 40mL of anhydrous ethanol and mix well to obtain a tetraethyl orthosilicate solution; add the tetraethyl orthosilicate solution to 250mL of water and mix well, then add 15g of Al(NO3)3•9H2O and 5g of Sr(NO3)2 and mix well, adjust the pH to 3, and age at 35℃ for 1h to obtain a sol; add the composite particles to the sol and stir well, sonicate at 200W for 20min, adjust the pH to 3.5, and treat at 35℃ for 6h to obtain the precursor; S3. The precursor was dried at 100℃ for 12 hours, and then heated to 900℃ at 3℃ / min for 1 hour at room temperature to obtain microcapsules.
[0058] The preparation method of the YSZ precursor powder is as follows: 225g ZrOCl2•8H2O and 46g Y(NO3)3•6H2O are added to 700mL of water and mixed evenly. The mixture is heated to 50℃, and 20wt% ammonia water is added while stirring at 600rpm. The pH is adjusted to 9 and stirred for 45min to obtain a mixture. The mixture is stirred at 50℃ for 2h and allowed to stand for aging for 12h. It is then dried at 120℃ for 16h and calcined at 1000℃ for 2h at a rate of 4℃ / min to obtain the YSZ precursor powder.
[0059] Comparative Example 1 A method for preparing a sealing coating material includes the following steps: Add 85g of YSZ precursor powder to 180mL of water, along with 2g of polyvinyl alcohol, 0.5g of sodium hexametaphosphate, and 2g of microcrystalline cellulose. Add zirconia balls as grinding media (ball-to-powder mass ratio approximately 2.5:1). Ball mill at 300 rpm for 4 hours, then spray dry with a nozzle diameter of 0.8 mm, a feed pressure of 1 MPa, an inlet air temperature of 190℃, and an outlet air temperature of 100℃ to obtain granules. Treat the granules at room temperature by heating to 1100℃ at 5℃ / min for 1 hour, then cool to room temperature, pulverize, and sieve to control the particle size distribution: D50 = 30µm, D90≤60µm.
[0060] Test Example 1 The sealing coatings prepared in the examples and comparative examples were sprayed onto the outer circular surface of the nickel-based alloy substrate, with a coating thickness of approximately 1.5 mm. Each coating was held at 1100℃ for 1 h, and after stress release, it was cooled to room temperature in the furnace. The samples were placed in a box furnace and heated from room temperature to 650℃, held for 30 min, and then immediately immersed in room temperature water to cool to below approximately 50℃, which was recorded as one thermal shock cycle. The above heating and water cooling process was repeated until the coating showed obvious peeling. After every 10 cycles, the samples were removed, and the surface condition of the coating was inspected with the naked eye and a magnifying glass. The presence of through cracks, local bulges, and peeling was recorded. The number of cycles in which obvious coating peeling first occurred was taken as the thermal shock failure life, and the percentage of peeling area after 40 cycles was also recorded.
[0061] Table 1 Test results of thermal shock resistance Test Example 2 Sealing coatings prepared in the examples and comparative examples were sprayed onto the outer circular surface of a nickel-based alloy substrate, with a coating thickness of approximately 1.5 mm. Each coating was held at 1100℃ for 1 h, and after stress release, it was cooled to room temperature in the furnace. A nickel-based alloy pin was selected as the mating part, with its end face ground and polished, and the contact surface diameter was 6 mm. Test temperature: 820℃ (the test started after heating and holding in the furnace for 30 min); load: 20 N; linear velocity: 0.3 m / s; test time: 30 min, corresponding to a sliding distance of approximately 540 m; the friction coefficient-time curve was recorded in real time during the test, and the wear volume of the coating was measured after the test.
[0062] Table 2 Test results of wear resistance Comparative Example 1, consisting of a single YSZ sealing layer, exhibits high structural rigidity and significant thermal expansion mismatch, making it prone to through-cracks and spalling. It also shows the lowest number of thermal shock spalling events and the largest spalling area, along with the highest high-temperature friction coefficient and wear rate. Example 1, through microencapsulation, uniformly embeds a composite phase into the YSZ framework, forming a soft-hard gradient and controlled viscous flow, significantly delaying crack propagation and reducing the friction coefficient and wear rate. Examples 2 and 3, by adding a composite phase and a glassy phase to the coating, respectively, mitigate local modulus and expansion behavior, reduce stress concentration, and show some improvement in thermal shock events and wear indicators compared to Comparative Example 1. However, due to the mechanical mixing of the composite phase, agglomeration and interfacial mismatch remain prominent, limiting performance improvement. Examples 4-6, based on this, incorporate aluminum nitride and introduce a Sr-containing shell layer, further improving thermal conductivity and expansion matching, resulting in the highest thermal shock lifetime, the smallest spalling area, and improved high-temperature friction and wear indicators. Example 7, which incorporates both aluminum nitride and silicon nitride, exhibits significantly superior performance compared to Examples 4 and 8. This is likely because aluminum nitride provides high thermal conductivity, aiding in uniform heat distribution and reducing thermal stress accumulation; while silicon nitride enhances the high-temperature strength and toughness of the coating, effectively suppressing crack propagation. The Al₂O₃ and SiO₂ glass phases generated by oxidation modulate the coating's coefficient of thermal expansion and viscosity-temperature characteristics, optimizing thermal stability and further improving the coating's thermal shock lifetime and sealing capability.
[0063] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.
Claims
1. A method of making a seal coat material, characterized by, The preparation method comprises the following steps: uniformly mixing YSZ precursor powder and particles, adding water, a binder, a dispersant and a pore-forming agent, uniformly mixing and then performing ball milling treatment, and then performing spray drying to obtain particles; calcining, crushing and sieving the particles to obtain a seal coating material. The particles are composite particles and / or microcapsules.
2. The method of claim 1, wherein the seal coat material is prepared by the steps of: The preparation method of the microcapsules is: tetraethyl orthosilicate solution is obtained; the tetraethyl orthosilicate solution is added into water, uniformly mixed, and then Al(NO3)3·9H2O is added and uniformly mixed, the pH is adjusted, aging is performed, and a sol is obtained; the composite particles are added into the sol, stirred uniformly, ultrasonic treatment is performed, and the pH is adjusted to obtain a precursor; the precursor is dried, and then calcined to obtain microcapsules.
3. The method for preparing the sealing coating material as described in claim 1, characterized in that, The preparation method of the composite particles is: BaCO3 and ZrO2 are added into water, uniformly mixed, a dispersant and a binder are added, the pH is adjusted, and ball milling treatment is performed to obtain slurry; the slurry is subjected to spray drying to obtain pre-prepared particles; the pre-prepared particles are calcined to obtain composite particles.
4. The method for preparing the sealing coating material as described in claim 1, characterized in that, The preparation method of the YSZ precursor powder is: ZrOCl2·8H2O and Y(NO3)3·6H2O are added into water, uniformly mixed, heated, and the pH is adjusted to obtain a mixture; the mixture is aged, dried and calcined to obtain YSZ precursor powder.
5. The method for preparing the sealing coating material as described in claim 1, characterized in that, The binder is at least one of polyvinyl alcohol, polyethylene glycol and hydroxypropyl methyl cellulose.
6. The preparation method of the seal coating material according to claim 1, wherein The dispersant is at least one of sodium hexametaphosphate, ammonium polyacrylate or sodium polyacrylate.
7. The preparation method of the seal coating material according to claim 1, wherein The pore-forming agent is at least one of soluble starch and microcrystalline cellulose.
8. The method of claim 3, wherein the seal coat material is prepared by the steps of: The preparation method of the composite particles further comprises nitride fillers.
9. A seal coat material, characterized by, The seal coating material is prepared by the preparation method according to any one of claims 1-8.
10. The seal coating material according to claim 9, which is used for sealing and fitting between a high-temperature rotating part such as a gas turbine or an aero-engine and a shell after being formed into a coating by thermal spraying.