High-temperature co-sintered multilayer special-shaped ceramic high-temperature sensor and preparation method thereof

Abstract

The invention is applicable to the technical field of ceramic high-temperature sensors, and provides a high-temperature co-sintered multilayer special-shaped ceramic high-temperature sensor and a preparation method thereof.The ceramic high-temperature sensor sequentially comprises a protective layer, a functional layer, an insulating layer and a supporting layer, and metal electrode networks are printed on the functional layer and the supporting layer; according to the high-temperature co-sintered multilayer special-shaped ceramic high-temperature sensor, zirconium oxide and aluminum oxide are used as matrixes, lanthanum oxide and yttrium oxide are added, the microstructure and performance of ceramic are optimized, the ceramic has higher high-temperature resistance, mechanical strength and stability, the nano Al2O3 is doped with platinum-iridium alloy ink, and the high-temperature co-sintered multilayer special-shaped ceramic high-temperature sensor has the advantages that the high-temperature co-sintered multilayer special-shaped ceramic high-temperature sensor is more stable in performance. The problem of interface failure of metal and ceramic at high temperature is solved, the electrode made of high-temperature-resistant metal ink is printed on the ceramic layer through the 3D printing technology, good binding force and conductivity exist between the electrode and the ceramic layer, and the electrode can stably work in the high-temperature environment.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic high-temperature sensors, and particularly relates to a multi-layered shaped ceramic high-temperature sensor with co-firing at high temperature and a preparation method thereof. Background Art

[0002] Accurate measurement in high-temperature environments is of great significance for fields such as industrial production, aerospace, and energy. When traditional high-temperature sensors work in high-temperature environments, there are problems such as low accuracy, poor stability, and short service life, and it is difficult to meet application scenarios with complex shapes and high-performance requirements. Therefore, it is of great significance to develop a new type of multi-layered shaped ceramic high-temperature sensor. Summary of the Invention

[0003] The present invention provides a multi-layered shaped ceramic high-temperature sensor with co-firing at high temperature, aiming to solve the above problems.

[0004] The present invention is implemented as follows. A multi-layered shaped ceramic high-temperature sensor with co-firing at high temperature sequentially includes a protective layer, a functional layer, an insulating layer, and a support layer. A metal electrode network is printed on the functional layer and the support layer. Both the functional layer and the support layer include the following raw materials by mass percentage: 60 - 75% of alumina, 15 - 25% of zirconia, 5 - 10% of yttrium oxide, 0.5 - 2% of lanthanum oxide, 0.3 - 0.7% of modified quercetin, and 1 - 3% of modified mannitol.

[0005] Preferably, the thickness of the protective layer is 0.05 - 0.1 mm, the thickness of the functional layer is 0.2 - 0.4 mm, the thickness of the insulating layer is 0.1 - 0.2 mm, and the thickness of the support layer is 0.5 - 0.6 mm.

[0006] Preferably, the raw material of the insulating layer is porous alumina, and the protective layer includes the following raw materials by mass percentage: 60 - 65% of zirconia, 25 - 30% of nano silicon carbide, 3 - 5% of yttrium oxide, and 2 - 6% of lanthanum oxide.

[0007] Preferably, the preparation method of the modified quercetin is as follows: Dissolve quercetin in an NH3•H2O buffer solution with pH = 9, add an Al(NO3)3 solution according to a molar ratio of Al 3＋： quercetin = 1:3, heat to 80 - 90 °C and stir for 1 - 2 h to form an Al - quercetin complex, vacuum dry at 70 - 80 °C, pulverize to D50 = 1.2 μm, ultrasonically treat the pulverized Al - quercetin complex and carbon nanotubes in a dimethylformamide solvent (35 - 45 kHz, 1 - 2 h), the mass ratio of carbon nanotubes to quercetin is 1:8 - 12, and obtain the modified quercetin after filtration and vacuum drying.

[0008] First, introduce Al through an aluminum nitrate solution 3＋Ionic chelation sites are formed to form a precursor complex with higher thermal stability, the carbonization temperature is increased, the continuity of the carbon film is improved, and the grain boundary bonding strength is increased. Then, carbon nanotubes are grafted onto the quercetin molecular skeleton through π-π conjugation to improve the mechanical properties of the ceramic layer. The conductivity of the carbon network generated by the subsequent high-temperature pyrolysis of modified quercetin is enhanced. The phenolic hydroxyl groups of quercetin form a hydrogen bond network on the surface of ceramic particles, reducing the activation energy of grain boundary migration. The nano-carbon film generated by the subsequent high-temperature pyrolysis improves the mechanical properties.

[0009] Preferably, the preparation method of the modified mannitol is as follows: Mix mannitol and Al(OH)3 in a mass ratio of 1:0.3 - 0.5, perform eutectic melting treatment at 140 - 145 °C, cool and then crush to D50 = 20 μm. React the crushed particles with epichlorohydrin at a molar ratio of 1:0.1 - 0.3 under alkaline conditions at 60 - 70 °C for 2 - 3 h. Then mix with SiO2 nanospheres and perform melting stirring at 160 °C, cool and crush to D50 = 15 μm. Obtain the modified mannitol according to the mass ratio of mannitol to SiO2 nanospheres of 2 - 4:1.

[0010] A three-dimensional network is formed through cross-linking with epichlorohydrin to control the pore distribution and improve the mechanical properties of the ceramic layer. Honeycomb-like pores are generated during sintering, and the nano-Al2O3 (particle size 30 - 50 nm) generated by thermal decomposition becomes the grain boundary strengthening phase of the ceramic matrix, realizing the synergistic improvement of the strength, toughness and functionality of the ceramic matrix.

[0011] Preferably, the metal ink used for the metal electrode network includes the following raw materials by mass percentage: 40 - 50% of platinum-iridium alloy nanoparticles (particle size 20 - 50 nm), 5 - 10% of nano-Al2O3 particles (particle size 50 - 100 nm), 15 - 20% of ethyl cellulose binder, 20 - 30% of α-terpineol solvent. After ultrasonic dispersion (power 200 - 300 W, time 30 - 40 min), perform ball milling (rotation speed 300 - 400 rpm, time 1 - 2 h) to form a stable suspension. The doping of nano-Al2O3 significantly improves the antioxidant property and interfacial bonding force of the metal ink.

[0012] The present invention also provides a preparation method of the above-mentioned multi-layer special-shaped ceramic high-temperature sensor by high-temperature co-sintering, including the following steps: Prepare ceramic slurry; Form green bodies for each layer; Print and preliminarily cure the metal electrode network on the functional layer and the support layer; Stack and assemble each ceramic layer in sequence to form a green compact; Perform co-sintering to form an integrated multi-layer structure.

[0013] Preferably, the preparation of the ceramic slurry is specifically as follows: Functional layer and support layer slurries: Alumina, zirconia, yttria, and lanthanum oxide are mixed in proportion and ball-milled to D50 = 0.5 μm to obtain ceramic powder; ethanol and trichloroethylene (volume ratio 7:3) are added with a hyperbranched polyimide dispersant (0.5 wt%) to obtain a mixture; the ceramic powder is added to the mixture, ball-milled for 1 - 3 h until uniform, then modified quercetin is added, ball-milled for another 1 h, modified mannitol is added, stirred and mixed at low speed for 30 - 40 min, and stirred under vacuum (-0.1 MPa, 30 min), with the viscosity controlled at 5000 ± 200 mPa·s; Protective layer slurry: Nano silicon carbide is washed with acid (HF:HNO3 = 1:3, 30 - 50 min), then mixed with zirconia, yttria, and lanthanum oxide, and planetary ball-milled for 1 - 3 h (zirconia pot, ethanol medium, 400 rpm).

[0014] Preferably, the green body forming of each layer is specifically as follows: The protective layer is formed by gradient casting, and the nano silicon carbide content continuously changes from 5 - 25% along the thickness direction. The functional layer is formed by casting, dried at 50 °C to form a Y-shaped corrugated structure; the insulating layer is formed by dry pressing; the support layer is formed by molding with a three-dimensional truss mold, with a pressure of 20 - 25 MPa and a holding pressure of 5 - 10 min.

[0015] Preferably, the metal electrode network printing and preliminary curing on the functional layer and support layer are specifically as follows: Using 3D printing technology, a metal electrode pattern is printed. After printing, the printed ceramic layer is placed in an infrared heating device and heated at 100 - 150 °C for 5 - 10 min for preliminary curing. Preferably, the printing speed is 10 - 50 mm / s, the layer height is 0.05 - 0.1 mm, and the nozzle temperature is 40 - 60 °C to ensure uniform deposition and preliminary curing of the metal ink. The micron-level accuracy and complex morphology adaptability are achieved through 3D printing, with higher accuracy compared to traditional screen printing.

[0016] Preferably, the stacking and assembling of each ceramic layer in sequence are specifically as follows: The printed ceramic layers are stacked in the designed order and cold isostatically pressed (CIP, pressure 200 - 250 MPa, time 25 - 35 min) to form a green body.

[0017] Preferably, the co-sintering to form an integrated multi-layer structure is specifically as follows: The stacked green body is placed in a high-temperature sintering furnace, and an Ar-H2 mixed gas (H2 volume fraction 5%) is introduced to prevent metal oxidation. The heating rate is 5 °C / min to 600 °C, held for 1 - 2 h, then continuously heated to 1500 - 1600 °C, held for 1 - 2 h, and the cooling rate is 3 °C / min to room temperature.

[0018] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects: The ceramic material of the high-temperature co-fired multi-shaped ceramic high-temperature sensor provided by the present invention is based on zirconia and alumina, and lanthanum oxide and yttrium oxide are added to optimize the microstructure and properties of the ceramic, making it have higher high-temperature resistance, mechanical strength and stability. By adding modified quercetin, hydrogen bond networks are formed between phenolic hydroxyl groups and the surface of ceramic particles, reducing the activation energy of grain boundary migration, and the nano-carbon film generated by high-temperature pyrolysis improves the mechanical properties. By adding modified mannitol, honeycomb-like pores are generated during sintering, and the nano-Al2O3 generated by thermal decomposition becomes the grain boundary strengthening phase of the ceramic matrix, realizing the synergistic improvement of the strength, toughness and functionality of the ceramic matrix; the nano-Al2O3 doped platinum-iridium alloy ink solves the problem of interface failure between metal and ceramic at high temperatures. Electrodes made of high-temperature resistant metal ink are printed on the ceramic layer through 3D printing technology, and there is good bonding force and conductivity between the electrodes and the ceramic layer, enabling stable operation in high-temperature environments. Brief Description of the Drawings

[0019] Figure 1 It is a flowchart of the preparation method of a high-temperature co-fired multi-shaped ceramic high-temperature sensor provided by the present invention. Detailed Description of the Embodiments

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order.

[0021] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0022] Embodiment 1 An embodiment of the present invention provides a high-temperature co-fired multi-layered special-shaped ceramic high-temperature sensor, which sequentially includes a protective layer, a functional layer, an insulating layer, and a support layer. Preferably, the thickness of the protective layer is 0.1 mm, the thickness of the functional layer is 0.3 mm, the thickness of the insulating layer is 0.1 mm, and the thickness of the support layer is 0.6 mm. A metal electrode network is printed on the functional layer and the support layer. The functional layer and the support layer both include the following raw materials by mass percentage: 60% alumina, 25% zirconia, 10% yttrium oxide, 2% lanthanum oxide, 0.5% modified quercetin, and 2.5% modified mannitol.

[0023] Among them, the raw material of the insulating layer is porous alumina, and the protective layer includes the following raw materials by mass percentage: 60% zirconia, 30% nano silicon carbide, 5% yttrium oxide, and 5% lanthanum oxide.

[0024] Further, the preparation method of the modified quercetin is as follows: Dissolve quercetin in an NH3•H2O buffer solution with pH = 9, add an Al(NO3)3 solution according to the molar ratio of Al 3＋： quercetin = 1:3, heat up to 80 °C and stir for 1 h to form an Al-quercetin complex. Vacuum dry at 70 °C and crush to D50 = 1.2 μm. Ultrasonically treat the crushed Al-quercetin complex and carbon nanotubes in a dimethylformamide solvent (35 kHz, 1 h). The mass ratio of carbon nanotubes to quercetin is 1:8. After filtration, vacuum dry to obtain modified quercetin.

[0025] Furthermore, the preparation method of the modified mannitol is as follows: Mix mannitol and Al(OH)3 according to a mass ratio of 1:0.3, perform a eutectic treatment by melting at 140 °C, cool and crush to D50 = 20 μm. React the crushed particles with epichlorohydrin according to a molar ratio of 1:0.1 under alkaline conditions at 60 °C for 2 h, then mix with SiO2 nanospheres and perform a melting and stirring at 160 °C. After cooling, crush to D50 = 15 μm. According to the mass ratio of mannitol to SiO2 nanospheres of 2:1, obtain modified mannitol.

[0026] In this embodiment, the metal ink used for the metal electrode network includes the following raw materials by mass percentage: 40% platinum-iridium alloy nanoparticles (particle size 20 nm), 5% nano Al2O3 particles (particle size 50 nm), 15% ethyl cellulose binder, 20% α-terpineol solvent. After ultrasonic dispersion (power 200 W, time 30 min), perform ball milling (rotation speed 300 rpm, time 1 h) to form a stable suspension.

[0027] The present invention also provides a preparation method for the above-mentioned high-temperature co-fired multi-layered special-shaped ceramic high-temperature sensor, as Figure 1 shown, including the following steps: 1) Prepare ceramic slurry Functional layer and support layer slurries: Alumina, zirconia, yttria, and lanthanum oxide are mixed in proportion and ball-milled to D50 = 0.5 μm to obtain ceramic powder; ethanol and trichloroethylene (volume ratio 7:3) are added with a hyperbranched polyimide dispersant (0.5 wt%) to obtain a mixture; the ceramic powder is added to the mixture, ball-milled for 1 h until uniform, then modified quercetin is added, ball-milled for another 1 h, modified mannitol is added, stirred at low speed for 30 min, and stirred under vacuum (-0.1 MPa, 30 min), with the viscosity controlled at 4800 mPa·s; Protective layer slurry: Nano silicon carbide is washed with hydrofluoric acid and nitric acid (HF:HNO3 = 1:3, 30 min), then mixed with zirconia, yttria, and lanthanum oxide, and planetary ball-milled for 1 h (zirconia pot, ethanol medium, 400 rpm); 2) Green body forming of each layer The protective layer is formed by gradient casting, and the nano silicon carbide content continuously changes from 5 - 25% along the thickness direction. The functional layer is formed by casting and dried at 50 °C to form a Y-shaped corrugated structure; the insulating layer is formed by dry pressing; the support layer is formed by die pressing, using a three-dimensional truss mold, with a pressure of 20 MPa and a holding pressure of 5 min; 3) Printing and preliminary curing of the metal electrode network on the functional layer and support layer Using 3D printing technology, a metal electrode pattern is printed. After printing, the printed ceramic layer is placed in an infrared heating device and heated at 100 °C for 5 min for preliminary curing. The preferred printing speed is 10 mm / s, the layer height is 0.05 mm, and the nozzle temperature is 40 °C to ensure uniform deposition and preliminary curing of the metal ink; 4) Stacking and assembling each ceramic layer in sequence to form a green body The printed ceramic layers are stacked in the designed order and cold isostatically pressed (CIP, pressure 200 MPa, time 25 min) to form a green body; 5) Co-sintering to form an integrated multi-layer structure The stacked green body is placed in a high-temperature sintering furnace, and an Ar-H2 mixed gas (H2 volume fraction 5%) is introduced to prevent metal oxidation. The heating rate is 5 °C / min to 600 °C, held for 1 h, then continuously heated to 1500 °C, held for 1 h, and the cooling rate is 3 °C / min to room temperature.

[0028] Example 2 An embodiment of the present invention provides a high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor, which sequentially includes a protective layer, a functional layer, an insulating layer, and a support layer. Preferably, the thickness of the protective layer is 0.1 mm, the thickness of the functional layer is 0.3 mm, the thickness of the insulating layer is 0.1 mm, and the thickness of the support layer is 0.6 mm. A metal electrode network is printed on the functional layer and the support layer. The functional layer and the support layer both include the following raw materials by mass percentage: 65% alumina, 23% zirconia, 8% yttrium oxide, 2% lanthanum oxide, 0.5% modified quercetin, and 1.5% modified mannitol.

[0029] Among them, the raw material of the insulating layer is porous alumina. The protective layer includes the following raw materials by mass percentage: 62% zirconia, 28% nano silicon carbide, 4% yttrium oxide, and 6% lanthanum oxide.

[0030] Further, the preparation method of the modified quercetin is as follows: Dissolve quercetin in an NH3•H2O buffer solution with a pH of 9, add an Al(NO3)3 solution according to a molar ratio of Al 3＋： quercetin = 1:3, heat to 80 °C and stir for 1 h to form an Al-quercetin complex. Dry it in vacuum at 70 °C and crush it to D50 = 1.2 μm. Ultrasonically treat the crushed Al-quercetin complex and carbon nanotubes in a dimethylformamide solvent (35 kHz, 1 h). The mass ratio of carbon nanotubes to quercetin is 1:8. After filtration, dry it in vacuum to obtain modified quercetin.

[0031] Furthermore, the preparation method of the modified mannitol is as follows: Mix mannitol and Al(OH)3 according to a mass ratio of 1:0.3, perform a eutectic treatment by melting at 140 °C, cool and crush to D50 = 20 μm. React the crushed particles with epichlorohydrin according to a molar ratio of 1:0.1 under alkaline conditions at 60 °C for 2 h, then mix with SiO2 nanospheres and stir by melting at 160 °C. After cooling, crush to D50 = 15 μm. According to the mass ratio of mannitol to SiO2 nanospheres of 2:1, modified mannitol is obtained.

[0032] In this embodiment, the metal ink used for the metal electrode network includes the following raw materials by mass percentage: 40% platinum-iridium alloy nanoparticles (particle size 20 nm), 5% nano Al2O3 particles (particle size 50 nm), 15% ethyl cellulose binder, 20% α-terpineol solvent. After ultrasonic dispersion (power 200 W, time 30 min), ball milling (rotation speed 300 rpm, time 1 h) is performed to form a stable suspension.

[0033] The present invention also provides a preparation method for the above-mentioned high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor, as Figure 1 shown, including the following steps: 1) Prepare ceramic slurry Functional layer and support layer slurries: Alumina, zirconia, yttria, and lanthanum oxide are mixed in proportion and ball-milled to D50 = 0.5 μm to obtain ceramic powder; Hyperbranched polyimide dispersant (0.5 wt%) is added to ethanol and trichloroethylene (7:3 volume ratio) to obtain a mixture; The ceramic powder is added to the mixture, ball-milled for 1 h until uniform, then modified quercetin is added, and ball-milling is continued for 1 h. Modified mannitol is added, and low-speed stirring and mixing are carried out for 30 min, followed by vacuum stirring (-0.1 MPa, 30 min), and the viscosity is controlled at 4800 mPa·s; Protective layer slurry: Nano silicon carbide is washed with acid (HF:HNO3 = 1:3, 30 min), and then mixed with zirconia, yttria, and lanthanum oxide, and planetary ball-milled for 1 h (zirconia pot, ethanol medium, 400 rpm); 2) Green body forming of each layer The protective layer is formed by gradient casting, and the nano silicon carbide content continuously changes from 5 - 25% along the thickness direction. The functional layer is formed by casting and dried at 50 °C to form a Y-shaped corrugated structure; The insulating layer is formed by dry pressing; The support layer is formed by molding with a three-dimensional truss mold at a pressure of 20 MPa and holding pressure for 5 min; 3) Printing and preliminary curing of the metal electrode network on the functional layer and the support layer Using 3D printing technology, a metal electrode pattern is printed. After printing, the printed ceramic layer is placed in an infrared heating device and heated at 100 °C for 5 min for preliminary curing. The preferred printing speed is 10 mm / s, the layer height is 0.05 mm, and the nozzle temperature is 40 °C to ensure uniform deposition and preliminary curing of the metal ink; 4) Stacking and assembling each ceramic layer in sequence to form a green body The printed ceramic layers are stacked in the designed order and cold isostatically pressed (CIP, pressure 200 MPa, time 25 min) to form a green body; 5) Co-sintering to form an integrated multi-layer structure The stacked green body is placed in a high-temperature sintering furnace, and an Ar-H2 mixed gas (H2 volume fraction 5%) is introduced to prevent metal oxidation. The heating rate is 5 °C / min to 600 °C, held for 1 h, then continued to be heated to 1500 °C, held for 1 h, and the cooling rate is 3 °C / min to room temperature.

[0034] Example 3 An embodiment of the present invention provides a high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor, which sequentially includes a protective layer, a functional layer, an insulating layer, and a support layer. Preferably, the thickness of the protective layer is 0.1 mm, the thickness of the functional layer is 0.3 mm, the thickness of the insulating layer is 0.1 mm, and the thickness of the support layer is 0.6 mm. A metal electrode network is printed on the functional layer and the support layer. The functional layer and the support layer both include the following raw materials by mass percentage: 68% alumina, 22% zirconia, 7% yttrium oxide, 1% lanthanum oxide, 0.3% modified quercetin, and 1.7% modified mannitol.

[0035] Among them, the raw material of the insulating layer is porous alumina. The protective layer includes the following raw materials by mass percentage: 63% zirconia, 28% nano silicon carbide, 4% yttrium oxide, and 5% lanthanum oxide.

[0036] Further, the preparation method of the modified quercetin is as follows: Dissolve quercetin in an NH3•H2O buffer solution with pH = 9, add an Al(NO3)3 solution according to the molar ratio of Al 3＋： quercetin = 1:3, heat up to 85 °C and stir for 1.5 h to form an Al-quercetin complex. Vacuum dry at 75 °C and crush to D50 = 1.2 μm. Ultrasonically treat the crushed Al-quercetin complex and carbon nanotubes in a dimethylformamide solvent (40 kHz, 1.5 h). The mass ratio of carbon nanotubes to quercetin is 1:10. After filtration, vacuum dry to obtain modified quercetin.

[0037] Furthermore, the preparation method of the modified mannitol is as follows: Mix mannitol and Al(OH)3 according to a mass ratio of 1:0.4, perform a eutectic treatment by melting at 142.5 °C, cool and crush to D50 = 20 μm. React the crushed particles with epichlorohydrin according to a molar ratio of 1:0.2 under alkaline conditions at 65 °C for 2.5 h, then mix with SiO2 nanospheres and melt and stir at 160 °C. After cooling, crush to D50 = 15 μm. According to the mass ratio of mannitol to SiO2 nanospheres of 3:1, obtain modified mannitol.

[0038] In this embodiment, the metal ink used for the metal electrode network includes the following raw materials by mass percentage: 45% platinum-iridium alloy nanoparticles (particle size 30 nm), 7.5% nano Al2O3 particles (particle size 70 nm), 17.5% ethyl cellulose binder, and 25% α-terpineol solvent. After ultrasonic dispersion (power 250 W, time 35 min), ball milling (rotation speed 350 rpm, time 1.5 h) is performed to form a stable suspension.

[0039] The present invention also provides a preparation method for the above-mentioned high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor, as Figure 1 shown, including the following steps: 1) Prepare ceramic slurry Functional layer and support layer slurries: Alumina, zirconia, yttria, and lanthanum oxide are mixed in proportion and ball-milled to D50 = 0.5 μm to obtain ceramic powder; hyperbranched polyimide dispersant (0.5 wt%) is added to ethanol and trichloroethylene (7:3 volume ratio) to obtain a mixture; the ceramic powder is added to the mixture, ball-milled for 2 h until uniform, then modified quercetin is added, ball-milled for another 1 h, modified mannitol is added, stirred at low speed for 35 min, and stirred under vacuum (-0.1 MPa, 30 min), with the viscosity controlled at 5000 mPa·s; Protective layer slurry: Nano silicon carbide is washed with acid (HF:HNO3 = 1:3, 40 min), then mixed with zirconia, yttria, and lanthanum oxide, and planetary ball-milled for 2 h (zirconia pot, ethanol medium, 400 rpm); 2) Green body forming of each layer The protective layer is formed by gradient casting, and the nano silicon carbide content continuously changes from 5 - 25% along the thickness direction. The functional layer is formed by casting and dried at 50 °C to form a Y-shaped corrugated structure; the insulating layer is formed by dry pressing; the support layer is formed by molding with a three-dimensional truss mold at a pressure of 23 MPa and holding pressure for 8 min; 3) Printing and preliminary curing of the metal electrode network on the functional layer and support layer Using 3D printing technology, a metal electrode pattern is printed. After printing, the printed ceramic layer is placed in an infrared heating device and heated at 125 °C for 8 min for preliminary curing. The preferred printing speed is 30 mm / s, the layer height is 0.07 mm, and the nozzle temperature is 50 °C to ensure uniform deposition and preliminary curing of the metal ink; 4) Stacking and assembling each ceramic layer in sequence to form a green body The printed ceramic layers are stacked in the designed order and cold isostatically pressed (CIP, pressure 225 MPa, time 30 min) to form a green body; 5) Co-sintering to form an integrated multi-layer structure The stacked green body is placed in a high-temperature sintering furnace, and an Ar-H2 mixed gas (H2 volume fraction 5%) is introduced to prevent metal oxidation. The heating rate is 5 °C / min to 600 °C, held for 1.5 h, then continuously heated to 1550 °C, held for 1.5 h, and the cooling rate is 3 °C / min to room temperature.

[0040] Example 4 An embodiment of the present invention provides a high-temperature co-fired multi-layered special-shaped ceramic high-temperature sensor, which sequentially includes a protective layer, a functional layer, an insulating layer, and a support layer. Preferably, the thickness of the protective layer is 0.1 mm, the thickness of the functional layer is 0.3 mm, the thickness of the insulating layer is 0.1 mm, and the thickness of the support layer is 0.6 mm. A metal electrode network is printed on the functional layer and the support layer. The functional layer and the support layer both include the following raw materials by mass percentage: 72% alumina, 22% zirconia, 3% yttrium oxide, 1% lanthanum oxide, 0.4% modified quercetin, and 1.6% modified mannitol.

[0041] Among them, the raw material of the insulating layer is porous alumina. The protective layer includes the following raw materials by mass percentage: 64% zirconia, 29% nano silicon carbide, 4% yttrium oxide, and 3% lanthanum oxide.

[0042] Further, the preparation method of the modified quercetin is as follows: Dissolve quercetin in an NH3•H2O buffer solution with a pH of 9, add an Al(NO3)3 solution according to a molar ratio of Al 3＋： quercetin = 1:3, heat up to 90 °C and stir for 2 h to form an Al-quercetin complex. Vacuum dry at 80 °C and crush to D50 = 1.2 μm. Ultrasonically treat the crushed Al-quercetin complex and carbon nanotubes in a dimethylformamide solvent (45 kHz, 2 h). The mass ratio of carbon nanotubes to quercetin is 1:12. After filtration, vacuum dry to obtain modified quercetin.

[0043] Furthermore, the preparation method of the modified mannitol is as follows: Mix mannitol and Al(OH)3 according to a mass ratio of 1:0.5, perform a eutectic melting treatment at 145 °C, cool and crush to D50 = 20 μm. React the crushed particles with epichlorohydrin according to a molar ratio of 1:0.3 under alkaline conditions at 70 °C for 3 h, then mix with SiO2 nanospheres and perform a melting and stirring at 160 °C. After cooling, crush to D50 = 15 μm. According to the mass ratio of mannitol to SiO2 nanospheres of 4:1, obtain modified mannitol.

[0044] In this embodiment, the metal ink used for the metal electrode network includes the following raw materials by mass percentage: 50% platinum-iridium alloy nanoparticles (particle size 50 nm), 10% nano Al2O3 particles (particle size 100 nm), 20% ethyl cellulose binder, and 30% α-terpineol solvent. After ultrasonic dispersion (power 300 W, time 40 min), perform ball milling (rotation speed 400 rpm, time 2 h) to form a stable suspension.

[0045] The present invention also provides a preparation method for the above-mentioned high-temperature co-fired multi-layered special-shaped ceramic high-temperature sensor, as Figure 1 shown, including the following steps: 1) Prepare ceramic slurry Functional layer and support layer slurries: Alumina, zirconia, yttria, and lanthanum oxide are mixed in proportion and ball-milled to D50 = 0.5 μm to obtain ceramic powder; ethanol and trichloroethylene (volume ratio 7:3) are added with a hyperbranched polyimide dispersant (0.5 wt%) to obtain a mixture; the ceramic powder is added to the mixture, ball-milled for 3 h until uniform, then modified quercetin is added, ball-milled for another 1 h, modified mannitol is added, stirred at low speed for 40 min, and stirred under vacuum (-0.1 MPa, 30 min), with the viscosity controlled at 5200 mPa·s; Protective layer slurry: Nano silicon carbide is washed with acid (HF:HNO3 = 1:3, 50 min), then mixed with zirconia, yttria, and lanthanum oxide, and planetary ball-milled for 3 h (zirconia pot, ethanol medium, 400 rpm); 2) Green body forming of each layer The protective layer is formed by gradient casting, and the nano silicon carbide content continuously changes from 5 - 25% along the thickness direction. The functional layer is formed by casting and dried at 50 °C to form a Y-shaped corrugated structure; the insulating layer is formed by dry pressing; the support layer is formed by die pressing, using a three-dimensional truss mold, with a pressure of 25 MPa and a holding pressure of 10 min; 3) Printing and preliminary curing of the metal electrode network on the functional layer and support layer Using 3D printing technology, a metal electrode pattern is printed. After printing, the printed ceramic layer is placed in an infrared heating device and heated at 150 °C for 10 min for preliminary curing. The preferred printing speed is 50 mm / s, the layer height is 0.1 mm, and the nozzle temperature is 60 °C to ensure uniform deposition and preliminary curing of the metal ink; 4) Stacking and assembling each ceramic layer in sequence to form a green compact The printed ceramic layers are stacked in the designed order and cold isostatically pressed (CIP, pressure 250 MPa, time 35 min) to form a green compact; 5) Co-sintering to form an integrated multi-layer structure The stacked green compact is placed in a high-temperature sintering furnace, and an Ar-H2 mixed gas (H2 volume fraction 5%) is introduced to prevent metal oxidation. The heating rate is 5 °C / min to 600 °C, held for 2 h, then continuously heated to 1600 °C, held for 2 h, and the cooling rate is 3 °C / min to room temperature.

[0046] Example 5 An embodiment of the present invention provides a high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor, which sequentially includes a protective layer, a functional layer, an insulating layer, and a support layer. Preferably, the thickness of the protective layer is 0.1 mm, the thickness of the functional layer is 0.3 mm, the thickness of the insulating layer is 0.1 mm, and the thickness of the support layer is 0.6 mm. A metal electrode network is printed on the functional layer and the support layer. The functional layer and the support layer both include the following raw materials by mass percentage: 75% alumina, 16% zirconia, 5% yttrium oxide, 2% lanthanum oxide, 0.7% modified quercetin, and 1.3% modified mannitol.

[0047] Among them, the raw material of the insulating layer is porous alumina, and the protective layer includes the following raw materials by mass percentage: 65% zirconia, 30% nano silicon carbide, 3% yttrium oxide, and 2% lanthanum oxide.

[0048] Further, the preparation method of the modified quercetin is as follows: Dissolve quercetin in an NH3•H2O buffer solution with a pH of 9, add an Al(NO3)3 solution according to a molar ratio of Al 3＋： quercetin = 1:3, heat to 90 °C and stir for 2 h to form an Al-quercetin complex. Vacuum dry at 80 °C and crush to D50 = 1.2 μm. Ultrasonically treat the crushed Al-quercetin complex and carbon nanotubes in a dimethylformamide solvent (45 kHz, 2 h). The mass ratio of carbon nanotubes to quercetin is 1:12. After filtration, vacuum dry to obtain modified quercetin.

[0049] Furthermore, the preparation method of the modified mannitol is as follows: Mix mannitol and Al(OH)3 in a mass ratio of 1:0.5, perform a eutectic treatment by melting at 145 °C, cool and crush to D50 = 20 μm. React the crushed particles with epichlorohydrin at a molar ratio of 1:0.3 under alkaline conditions at 70 °C for 3 h, then mix with SiO2 nanospheres and melt and stir at 160 °C. After cooling, crush to D50 = 15 μm. According to the mass ratio of mannitol to SiO2 nanospheres of 4:1, modified mannitol is obtained.

[0050] In this embodiment, the metal ink used for the metal electrode network includes the following raw materials by mass percentage: 50% platinum-iridium alloy nanoparticles (particle size 50 nm), 10% nano Al2O3 particles (particle size 100 nm), 20% ethyl cellulose binder, and 30% α-terpineol solvent. After ultrasonic dispersion (power 300 W, time 40 min), ball milling (rotation speed 400 rpm, time 2 h) is performed to form a stable suspension.

[0051] The present invention also provides a preparation method for the above-mentioned high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor, as Figure 1 shown, including the following steps: 1) Prepare ceramic slurry Functional layer and support layer slurries: Alumina, zirconia, yttria, and lanthanum oxide were mixed in proportion and ball-milled to D50 = 0.5 μm to obtain ceramic powder; ethanol and trichloroethylene (volume ratio 7:3) were added with a hyperbranched polyimide dispersant (0.5 wt%) to obtain a mixture; the ceramic powder was added to the mixture, ball-milled for 1 - 3 h until uniform, then modified quercetin was added, ball-milled for another 1 h, modified mannitol was added, stirred at low speed for 40 min, and vacuum stirred (-0.1 MPa, 30 min), with the viscosity controlled at 5200 mPa·s; Protective layer slurry: The nano silicon carbide was washed with acid (HF:HNO3 = 1:3, 50 min), then mixed with zirconia, yttria, and lanthanum oxide, and planetary ball-milled for 3 h (zirconia pot, ethanol medium, 400 rpm); 2) Green body forming of each layer The protective layer was formed by gradient casting, with the nano silicon carbide content continuously varying from 5 - 25% along the thickness direction. The functional layer was formed by casting, dried at 50 °C to form a Y-shaped corrugated structure; the insulating layer was formed by dry pressing; the support layer was formed by die pressing, using a three-dimensional truss mold, with a pressure of 25 MPa and a holding pressure of 10 min; 3) Printing and preliminary curing of the metal electrode network on the functional layer and support layer Using 3D printing technology, a metal electrode pattern was printed. After printing, the printed ceramic layer was placed in an infrared heating device and heated at 150 °C for 10 min for preliminary curing. The preferred printing speed was 50 mm / s, the layer height was 0.1 mm, and the nozzle temperature was 60 °C to ensure uniform deposition and preliminary curing of the metal ink; 4) Stacking and assembling each ceramic layer in sequence to form a green compact The printed ceramic layers were stacked in the designed order and cold isostatically pressed (CIP, pressure 250 MPa, time 35 min) to form a green compact; 5) Co-sintering to form an integrated multi-layer structure The stacked green compact was placed in a high-temperature sintering furnace, and an Ar-H2 mixed gas (H2 volume fraction 5%) was introduced to prevent metal oxidation. The heating rate was 5 °C / min to 600 °C, held for 2 h, then continued to be heated to 1600 °C, held for 2 h, and the cooling rate was 3 °C / min to room temperature.

[0052] Comparative Example 1: The difference from Example 3 was that it did not contain modified quercetin.

[0053] Comparative Example 2: The difference from Example 3 was that modified quercetin was replaced with ordinary quercetin.

[0054] Comparative Example 3: The difference from Example 3 was that it did not contain modified mannitol.

[0055] Comparative Example 4: The difference from Example 3 is that modified mannitol is replaced with ordinary mannitol.

[0056] Comparative Example 5: The difference from Example 3 is that it does not contain modified quercetin and modified mannitol.

[0057] Comparative Example 6: The difference from Example 3 is that modified quercetin is replaced with ordinary quercetin and modified mannitol is replaced with ordinary mannitol.

[0058] Performance Test I. Performance tests were carried out on the samples of Examples 1-5 and Comparative Examples 1-6, and the flexural strength and thermal shock resistance were tested. The test results are shown in Table 1 below: Table 1 Test Results of Flexural Strength and Thermal Shock Resistance

[0059] It can be seen from the above results that the ceramic high-temperature sensor of the present invention has high flexural strength and good thermal shock resistance. By adding modified quercetin and modified mannitol, the two have a synergistic effect and can further improve the performance.

[0060] II. Performance Test of Metal Ink Composition 1. Conductivity Test Test Method: Four-probe method (ASTM F1529): Measure the resistivity of the sintered metal electrode (at room temperature and 1200 °C).

[0061] High-temperature in-situ resistance drift test: Record the change rate of resistance over time in a constant-temperature environment of 1200 °C.

[0062] Control Group: The metal ink of this application.

[0063] Traditional ink: Pure platinum paste (without Al2O3 doping).

[0064] 2. Interface Bonding Strength Test Test Method: Micro-tensile test (ISO 13779-3): Measure the interface bonding strength between the metal electrode and the ceramic substrate.

[0065] High-temperature shear test (ASTM D1002): Apply shear force at 1200 °C until the interface fails.

[0066] Control Group: The metal ink of this application.

[0067] Traditional process: Screen-printing pure platinum paste.

[0068] 3. High-temperature Oxidation Resistance Test method: Thermogravimetric analysis (TGA): Heat up to 1200 °C in an air atmosphere and record the mass change.

[0069] SEM-EDS analysis: Observe the surface morphology and element distribution of the electrode after high-temperature oxidation.

[0070] The test results are shown in Table 2 below: Table 2 Performance Test Table of Metal Ink Composition

[0071] It can be seen from the above results that the metal ink of the present invention significantly improves the oxidation resistance and interfacial bonding strength of the metal ink through nano-Al2O3 doping. Compared with the traditional screen printing technology, the core indicators such as conductivity and stability are improved by 3-5 times, meeting the sensing requirements in extreme environments.

[0072] It should be noted that for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict, make combinations, additions, deletions, or other adjustments to the features in the embodiments of the present invention according to the situation without creative efforts, so as to obtain different technical solutions that are essentially not divorced from the concept of the present invention, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. A multilayer special-shaped ceramic high-temperature sensor with co-firing at high temperature, characterized in that It includes a protective layer, a functional layer, an insulating layer and a supporting layer in sequence, wherein a metal electrode network is printed on the functional layer and the supporting layer, and the functional layer and the supporting layer both include the following raw materials in percentage by mass: 60-75% aluminum oxide, 15-25% zirconium oxide, 5-10% yttrium oxide, 0.5-2% lanthanum oxide, 0.3-0.7% modified quercetin, and 1-3% modified mannitol.

2. The high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor according to claim 1, wherein The raw material of the insulating layer is porous aluminum oxide, and the protective layer includes the following raw materials in percentage by mass: 60-65% zirconium oxide, 25-30% nano silicon carbide, 3-5% yttrium oxide, and 2-6% lanthanum oxide.

3. The high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor according to claim 1, characterized in that The preparation method of the modified quercetin is as follows: Dissolve quercetin in an NH3•H2O buffer solution with a pH of 9, and add an Al(NO3)3 solution in a molar ratio of Al 3＋： quercetin = 1:3, heat to 80 - 90 °C and stir for 1 - 2 h to form an Al-quercetin complex. Vacuum dry at 70 - 80 °C and pulverize to D50 = 1.2 μm. Ultrasonically treat the pulverized Al-quercetin complex and carbon nanotubes in a dimethylformamide solvent. The mass ratio of carbon nanotubes to quercetin is 1:8 - 12. After filtration, vacuum dry to obtain modified quercetin.

4. The high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor according to claim 1, wherein The preparation method of the modified mannitol is as follows: Mannitol and Al(OH)3 are mixed in a mass ratio of 1:0.3-0.5, subjected to melt eutectic treatment at 140-145°C, and then pulverized to D50=20μm after cooling. The pulverized particles are reacted with epichlorohydrin in a molar ratio of 1:0.1-0.3 under alkaline conditions at 60-70°C for 2-3h, then mixed with SiO2 nanospheres, melt-stirred at 160°C, and then pulverized to D50=15μm after cooling. The mass ratio of mannitol to SiO2 nanospheres is 2-4:1 to obtain modified mannitol.

5. The high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor according to claim 1, characterized in that, The metal ink used in the metal electrode network includes the following raw materials in percentage by mass: 40-50% of platinum-iridium alloy nanoparticles, 5-10% of nano-Al2O3 particles, 15-20% of ethyl cellulose binder, and 20-30% of α-terpineol solvent are ultrasonically dispersed and then ball-milled to form a stable suspension.

6. The preparation method of the high-temperature co-sintered multi-layer special-shaped ceramic high-temperature sensor according to any one of claims 1-5, characterized in that, The steps include: preparing a ceramic slurry; Each layer of green body is formed; Printing and preliminary curing of metal electrode networks on functional layers and support layers; The ceramic layers are stacked and assembled in sequence to form a green body; Co-sintering is performed to form an integrated multi-layer structure.

7. The preparation method of the high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor according to claim 6, characterized in that, The preparation of ceramic slurry is specifically as follows: Functional layer and support layer slurry: Alumina, zirconium oxide, yttrium oxide and lanthanum oxide are mixed in proportion and ball-milled to D50=0.5μm to obtain ceramic powder; hyperbranched polyimide dispersant is added to ethanol and trichloroethylene to obtain a mixture; ceramic powder is added to the mixture and ball-milled for 1-3h until uniform, then modified quercetin is added, ball-milling is continued for 1h, modified mannitol is added, and mixing is carried out at a low speed for 30-40min, and vacuum stirring is carried out; Protective layer slurry: acid-wash the nano-silicon carbide, then mix it with zirconium oxide, yttrium oxide and lanthanum oxide, and planetary ball mill for 1-3 hours.

8. The preparation method of the high-temperature co-fired multi-layer special-shaped ceramic high-temperature sensor according to claim 6, characterized in that, The green body forming of each layer is specifically as follows: The protective layer is formed by gradient tape casting, and the nano-silicon carbide content changes continuously from 5-25% along the thickness direction. The functional layer is formed by tape casting and dried at 50°C to form a Y-shaped corrugated structure. The insulating layer is formed by dry pressing. The support layer is formed by compression molding, using a three-dimensional truss mold, with a pressure of 20-25MPa and holding pressure for 5-10min.

9. The preparation method of the multi-layer special-shaped ceramic high-temperature sensor by high-temperature co-sintering according to claim 6, characterized in that The printing and preliminary curing of the metal electrode network on the functional layer and the support layer are specifically as follows: The metal electrode pattern is printed using 3D printing technology. After printing is completed, the printed ceramic layer is placed in an infrared heating device and heated at 100-150°C for 5-10 minutes for preliminary curing.

10. The preparation method of the multi-layer special-shaped ceramic high-temperature sensor by high-temperature co-sintering according to claim 6, characterized in that, The co-sintering to form an integrated multi-layer structure is specifically as follows: Put the laminated green body into a high-temperature sintering furnace, introduce an Ar-H2 mixed gas, raise the temperature at a rate of 5 °C / min to 600 °C, hold for 1-2 h, continue to raise the temperature to 1500-1600 °C, hold for 1-2 h, and cool at a rate of 3 °C / min to room temperature.

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