High-density zta ceramic and preparation method thereof

Abstract

This invention provides a high-density ZTA ceramic and its preparation method, comprising: oxide powder and composite organic additives. The oxide powder comprises the following components by weight percentage: submicron alumina powder: 78-82 wt%; nano-zirconia powder: 18-22 wt%; sintering aid: 0.3-0.8 wt%. The composite organic additive comprises the following components: poly(2-methyl-2-oxetane), poly(3,3,3-trifluoropropylmethylsiloxane), 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and perfluorooctylsulfonamide ethanol. The composite organic additive accounts for 2.5 wt% of the total mass of the oxide powder. This method improves the density of the sintered ZTA ceramic, reduces the porosity of the sintered ZTA ceramic, and improves the hardness and three-point flexural strength of the ceramic.

Description

Technical Field

[0001] This invention relates to the field of ZTA ceramic technology, specifically to a high-density ZTA ceramic and its preparation method. Background Technology

[0002] In the field of ceramic materials science, zirconia-toughened alumina (ZTA) ceramics have become a focal material in many high-end applications due to their superior mechanical properties, excellent wear resistance, and high toughness. However, traditional ZTA ceramic preparation processes still face a series of inherent challenges, limiting their application potential in a wider range of fields.

[0003] ZTA ceramics face challenges in their preparation, including poor dispersibility, poor uniformity of green body pressing, and high surface energy. Poor dispersibility leads to uneven distribution of ceramic particles within the green body, forming agglomerates. These agglomerates easily become sources of porosity and stress concentration during sintering, severely impairing the ceramic's density and mechanical properties. Poor green body pressing uniformity results in uneven density distribution within the green body, similarly promoting the formation of porosity and cracks, further reducing the ceramic's reliability and service life. The high surface energy of ZTA ceramics makes them prone to surface defects and porosity during debinding and sintering. These defects not only affect the ceramic's appearance but also reduce its mechanical properties and reliability.

[0004] In the debinding and sintering process of ZTA ceramics, traditional debinding and sintering steps also present numerous problems. Specifically, in the debinding stage, the rapid decomposition characteristics of traditional single organic additives often lead to uneven stress distribution within the ceramic body, easily resulting in defects such as cracking and large pores. These defects not only affect the appearance quality of the ceramics but, more importantly, reduce their mechanical properties and density. In the sintering stage, traditional processes typically require prolonged high-temperature holding to ensure sufficient bonding and densification between ceramic particles. However, excessively high sintering temperatures and excessively long holding times not only increase energy consumption but may also lead to abnormal grain growth, resulting in defects such as large grains and large voids, thereby reducing the mechanical properties of the ceramics. Furthermore, the cleanliness and activity of the ceramic particle surface also have a significant impact on the sintering process. Traditional cleaning methods often fail to completely remove impurities and oxide layers from the particle surface, thus affecting the bonding strength between particles and the density of sintering.

[0005] In summary, these factors make it difficult for ZTA ceramics to achieve ideal performance levels in key areas such as density, hardness, and high flexural strength.

[0006] The above background information is provided only to assist in understanding the inventive concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application, nor does it necessarily provide technical teaching. In the absence of clear evidence that the above information was disclosed before the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes a high-density ZTA ceramic and its preparation method, which improves the density of the sintered ZTA ceramic, reduces the porosity of the sintered ZTA ceramic, and improves the ceramic's hardness and three-point bending strength, among other properties.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] This invention provides a high-density ZTA ceramic, comprising: oxide powder and composite organic additives, wherein the oxide powder comprises the following components by weight percentage:

[0010] Submicron alumina powder: 78–82 wt%;

[0011] Nano-zirconia powder: 18–22 wt%;

[0012] Sintering aid: 0.3–0.8 wt%;

[0013] The composite organic additive comprises the following components: poly(2-methyl-2-oxetane), poly(3,3,3-trifluoropropylmethylsiloxane), 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and perfluorooctylsulfonamide ethanol.

[0014] The composite organic additive accounts for 2.5 wt% of the total mass of the oxide powder.

[0015] This invention proposes a high-density ZTA ceramic and its preparation method, which improves the density of the sintered ZTA ceramic, reduces the porosity of the sintered ZTA ceramic, and improves the hardness and three-point bending strength of the ceramic.

[0016] As a preferred technical solution, the weight ratio of the poly(2-methyl-2-oxetane), the poly(3,3,3-trifluoropropylmethylsiloxane), the 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and the perfluorooctylsulfonamide ethanol is 7:5:6:2.

[0017] As a preferred technical solution, the average particle size of the submicron alumina powder is 590nm to 610nm.

[0018] As a preferred technical solution, the purity of the submicron alumina powder is ≥99.99%.

[0019] As a preferred technical solution, the average particle size of the nano-zirconia powder is 75-85 nm.

[0020] As a preferred technical solution, the nano-zirconia powder is composed of zirconium oxide and yttrium oxide, wherein the content of yttrium oxide is 3 mol%.

[0021] As a preferred technical solution, the sintering aid comprises the following components by weight percentage:

[0022] Magnesium oxide 0.1–0.3 wt%;

[0023] Yttrium oxide 0.2–0.5 wt%.

[0024] This invention also provides a method for preparing high-density ZTA ceramics, comprising the following steps:

[0025] S1 weighs and mixes the pre-mixed oxide powder and composite organic additives according to the component ratio, and adds supercritical carbon dioxide as a dispersion medium to obtain a mixture;

[0026] S2 ball mills the mixture, and the slurry after ball milling is then supercritically dried to produce granules.

[0027] S3 sieves the dried particles to obtain ZTA ceramic material.

[0028] As a preferred technical solution, in step S2, ball milling is carried out in a supercritical fluid-assisted ball mill, the ball milling media is nano-zirconia balls, the weight ratio of ball milling media to mixture is 5:1, the ball milling pressure is 22-28 MPa, the ball milling temperature is 27-43℃, the ball milling speed is 350-450 rpm, the ball milling time is 7-9 hours, the supercritical drying pressure is 18-22 MPa, and the supercritical drying temperature is 48-52℃.

[0029] As a preferred technical solution, the following steps are also included:

[0030] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 280-320 MPa and a holding time of 8-12 minutes;

[0031] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the formed ZTA ceramic, resulting in multi-stage debinding of ZTA ceramic.

[0032] S6 high-temperature sintering involves sintering ZTA ceramics after multi-stage degreasing by gradually increasing the temperature from 600℃ to 1650℃, with an argon protective atmosphere during the high-temperature sintering process.

[0033] The present invention provides a high-density ZTA ceramic and its preparation method, which have the following beneficial effects:

[0034] It improves the density of sintered ZTA ceramics, reduces the porosity of sintered ZTA ceramics, and improves the hardness and three-point bending strength of ceramics. Attached Figure Description

[0035] Figure 1 SEM image of the high-density ZTA ceramic prepared by the method provided in Example 1;

[0036] Figure 2 SEM image of ZTA ceramics prepared by the method provided in Comparative Example 3. Detailed Implementation

[0037] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0038] This invention provides a high-density ZTA ceramic, comprising: oxide powder and composite organic additives, wherein the oxide powder comprises the following components by weight percentage:

[0039] Submicron alumina powder: 78–82 wt%;

[0040] Nano-zirconia powder: 18–22 wt%;

[0041] Sintering aid: 0.3–0.8 wt%;

[0042] The composite organic additive comprises the following components: poly(2-methyl-2-oxetane), poly(3,3,3-trifluoropropylmethylsiloxane), 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and perfluorooctylsulfonamide ethanol.

[0043] The composite organic additive accounts for 2.5 wt% of the total mass of the oxide powder.

[0044] This invention provides a high-density ZTA ceramic and its preparation method, which improves the density of the sintered ZTA ceramic, reduces the porosity of the sintered ZTA ceramic, and improves the hardness and three-point bending strength of the ceramic.

[0045] Preferably, the weight ratio of the poly(2-methyl-2-oxetane), the poly(3,3,3-trifluoropropylmethylsiloxane), the 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and the perfluorooctylsulfonamide ethanol is 7:5:6:2.

[0046] Preferably, the average particle size of the submicron alumina powder is 590 nm to 610 nm.

[0047] Preferably, the purity of the submicron alumina powder is ≥99.99%.

[0048] Preferably, the average particle size of the nano-zirconia powder is 75-85 nm.

[0049] Preferably, the nano-zirconia powder is composed of zirconium oxide and yttrium oxide, wherein the yttrium oxide content is 3 mol%.

[0050] Preferably, the sintering aid comprises the following components by weight percentage:

[0051] Magnesium oxide 0.1–0.3 wt%;

[0052] Yttrium oxide 0.2–0.5 wt%.

[0053] This invention also provides a method for preparing high-density ZTA ceramics, comprising the following steps:

[0054] S1 weighs and mixes the pre-mixed oxide powder and composite organic additives according to the component ratio, and adds supercritical carbon dioxide as a dispersion medium to obtain a mixture;

[0055] S2 ball mills the mixture, and the slurry after ball milling is then supercritically dried to produce granules.

[0056] S3 sieves the dried particles to obtain ZTA ceramic material.

[0057] Preferably, in step S2, ball milling is carried out in a supercritical fluid-assisted ball mill, the ball milling media is nano-zirconia balls, the weight ratio of the ball milling media to the mixture is 5:1, the ball milling pressure is 22-28 MPa, the ball milling temperature is 27-43°C, the ball milling speed is 350-450 rpm, the ball milling time is 7-9 hours, the supercritical drying pressure is 18-22 MPa, and the supercritical drying temperature is 48-52°C.

[0058] Preferably, the mesh size of the sieve in step S3 is 400 mesh;

[0059] Preferably, the method further includes the following steps:

[0060] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 280-320 MPa and a holding time of 8-12 minutes;

[0061] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the molded ZTA ceramic, resulting in multi-stage debinding of the ZTA ceramic. The specific steps include:

[0062] The S501 is heated from room temperature to 200°C, with a holding time of 2 hours and a heating rate of 0.5°C / min.

[0063] S502 is heated from 200℃ to 400℃, with a holding time of 3 hours and a heating rate of 0.3℃ / min.

[0064] S503 is heated from 400℃ to 600℃, held at that temperature for 2 hours, and the heating rate is 0.5℃ / min;

[0065] S6 high-temperature sintering involves sintering the ZTA ceramic after multi-stage debinding by gradually increasing the temperature from 600℃ to 1650℃. The specific steps include:

[0066] S601 is heated from 600℃ to 1200℃, with a holding time of 0.5 hours and a heating rate of 5℃ / min.

[0067] S602 is heated from 1200℃ to 1500℃, with a holding time of 2 hours and a heating rate of 3℃ / min;

[0068] The S603 was heated from 1500℃ to 1650℃, with a holding time of 1 hour and a heating rate of 2℃ / min.

[0069] The high-temperature sintering is performed using a hot-press sintering furnace, and the atmosphere during the high-temperature sintering process is an argon protective atmosphere with a purity of ≥99.999% and a flow rate of 3L / min.

[0070] The preparation of supercritical carbon dioxide in step S1 includes the following steps:

[0071] S101 Raw material preparation: Use high-purity carbon dioxide gas or liquid carbon dioxide;

[0072] S102 Pressurization: Compressing carbon dioxide to a pressure exceeding its critical pressure, which is typically accomplished by a high-pressure pump or compressor;

[0073] S103 Heating: Heating pressurized carbon dioxide to above its critical temperature, which can be achieved by a heat exchanger or heating device;

[0074] S104 stability: Maintaining temperature and pressure above the critical point allows carbon dioxide to reach a supercritical state;

[0075] S105 Adjustment: Depending on the specific application requirements, the critical temperature and critical pressure may need to be further adjusted to obtain supercritical carbon dioxide.

[0076] The critical temperature (Tc) of the supercritical carbon dioxide is 31.1℃ (304.25K), and the critical pressure (Pc) is 7.38MPa (73.8bar). When both the temperature and pressure of carbon dioxide exceed these critical values, it enters the supercritical state. In this state, carbon dioxide exhibits mixing characteristics of liquid and gas, and possesses unique physicochemical properties.

[0077] Using supercritical carbon dioxide as the dispersion medium in step S1 has the following advantages:

[0078] a) High diffusivity: It can quickly penetrate between powder particles;

[0079] b) Low surface tension: helps to uniformly disperse powders and organic additives;

[0080] c) Adjustability: Its solubility and density can be adjusted by changing temperature and pressure;

[0081] d) Environmentally friendly: non-toxic, non-flammable, and easy to recycle after use;

[0082] e) Low viscosity: facilitates uniform mixing and dispersion;

[0083] f) No residue: Completely vaporized after decompression, leaving no residue.

[0084] By using supercritical carbon dioxide as a dispersion medium, the mixing effect of ceramic powder and organic additives can be significantly improved, thereby enhancing the quality and performance of the final ceramic product.

[0085] Example 1

[0086] This invention provides a method for preparing high-density ZTA ceramics, comprising the following steps:

[0087] S1 adds 81.7 wt% submicron alumina powder, 18 wt% nano-zirconia powder, 0.1 wt% magnesium oxide and 0.2 wt% yttrium oxide to obtain a well-proportioned oxide powder.

[0088] S2 is prepared by adding the poly(2-methyl-2-oxetane), the poly(3,3,3-trifluoropropylmethylsiloxane), the 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and the perfluorooctylsulfonamide ethanol in a weight ratio of 7:5:6:2 to obtain a composite organic additive.

[0089] S3 weighs 100g of the pre-mixed oxide powder and 2.5g of the composite organic additive and mixes them together. Then, supercritical carbon dioxide is added as a dispersion medium to obtain a mixture.

[0090] S2 ball mills the mixture, wherein the milling media is nano-zirconia balls, the weight ratio of the milling media to the mixture is 5:1, the milling pressure is 25 MPa, the milling temperature is 40℃, the milling speed is 400 rpm, and the milling time is 8 hours. The slurry after milling is then supercritically dried to form particles, wherein the supercritical drying pressure is 20 MPa and the supercritical drying temperature is 50℃.

[0091] S3. The dried particles are passed through a 400-mesh sieve to obtain ZTA ceramic material;

[0092] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 300MPa and a holding time of 10min.

[0093] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the molded ZTA ceramic, resulting in multi-stage debinding of the ZTA ceramic. The specific steps include:

[0094] The S501 is heated from room temperature to 200°C, with a holding time of 2 hours and a heating rate of 0.5°C / min.

[0095] S502 is heated from 200℃ to 400℃, with a holding time of 3 hours and a heating rate of 0.3℃ / min.

[0096] S503 is heated from 400℃ to 600℃, held at that temperature for 2 hours, and the heating rate is 0.5℃ / min;

[0097] S6 high-temperature sintering involves sintering the ZTA ceramic after multi-stage debinding by gradually increasing the temperature from 600℃ to 1650℃. The specific steps include:

[0098] S601 is heated from 600℃ to 1200℃, with a holding time of 0.5 hours and a heating rate of 5℃ / min.

[0099] S602 is heated from 1200℃ to 1500℃, with a holding time of 2 hours and a heating rate of 3℃ / min;

[0100] The S603 was heated from 1500℃ to 1650℃, with a holding time of 1 hour and a heating rate of 2℃ / min.

[0101] The high-temperature sintering is performed using a hot-press sintering furnace, and the atmosphere during the high-temperature sintering process is an argon protective atmosphere with a purity of ≥99.999% and a flow rate of 3L / min.

[0102] This invention also provides high-density ZTA ceramics, such as Figure 1 As shown, the high-density ZTA ceramic was prepared according to the preparation method described above.

[0103] Comparative Example 1

[0104] Comparative Example 1 provides a method for preparing ZTA ceramics, comprising the following steps:

[0105] S1 adds 81.7 wt% submicron alumina powder, 18 wt% nano-zirconia powder, 0.1 wt% magnesium oxide and 0.2 wt% yttrium oxide to obtain a well-proportioned oxide powder.

[0106] S2 weighs 100g of the prepared oxide powder and 2.5g of a mixture of conventional dispersant and low-hydroxyl content PVB resin, mixes them, and adds supercritical carbon dioxide as a dispersion medium to obtain a mixture. The weight ratio of conventional dispersant to low-hydroxyl content PVB resin in the triethyl phosphate and low-hydroxyl content PVB resin mixture is 1:1. The conventional dispersant is composed of triethyl phosphate, castor oil and trioleic acid glyceride, wherein the weight ratio of triethyl phosphate, castor oil and trioleic acid glyceride is 1:1:1.

[0107] S2 ball mills the mixture, wherein the milling media is nano-zirconia balls, the weight ratio of the milling media to the mixture is 5:1, the milling pressure is 25 MPa, the milling temperature is 40℃, the milling speed is 400 rpm, and the milling time is 8 hours. The slurry after milling is then supercritically dried to form particles, wherein the supercritical drying pressure is 20 MPa and the supercritical drying temperature is 50℃.

[0108] S3. The dried particles are passed through a 400-mesh sieve to obtain ZTA ceramic material;

[0109] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 300MPa and a holding time of 10min.

[0110] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the molded ZTA ceramic, resulting in multi-stage debinding of the ZTA ceramic. The specific steps include:

[0111] The S501 is heated from room temperature to 200°C, with a holding time of 2 hours and a heating rate of 0.5°C / min.

[0112] S502 is heated from 200℃ to 400℃, with a holding time of 3 hours and a heating rate of 0.3℃ / min.

[0113] S503 is heated from 400℃ to 600℃, held at that temperature for 2 hours, and the heating rate is 0.5℃ / min;

[0114] S6 high-temperature sintering involves sintering the ZTA ceramic after multi-stage debinding by gradually increasing the temperature from 600℃ to 1650℃. The specific steps include:

[0115] S601 is heated from 600℃ to 1200℃, with a holding time of 0.5 hours and a heating rate of 5℃ / min.

[0116] S602 is heated from 1200℃ to 1500℃, with a holding time of 2 hours and a heating rate of 3℃ / min;

[0117] The S603 was heated from 1500℃ to 1650℃, with a holding time of 1 hour and a heating rate of 2℃ / min.

[0118] The high-temperature sintering is performed using a hot-press sintering furnace, and the atmosphere during the high-temperature sintering process is an argon protective atmosphere with a purity of ≥99.999% and a flow rate of 3L / min.

[0119] Comparative Example 1 also provides ZTA ceramics, which are prepared according to the ZTA ceramics preparation method described above.

[0120] Comparative Example 2

[0121] Comparative Example 2 provides a method for preparing ZTA ceramics, comprising the following steps:

[0122] S1 adds 81.7 wt% submicron alumina powder, 18 wt% nano-zirconia powder, 0.1 wt% magnesium oxide and 0.2 wt% yttrium oxide to obtain a well-proportioned oxide powder.

[0123] S2 is prepared by adding the poly(3,3,3-trifluoropropylmethylsiloxane), the 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and the perfluorooctylsulfonamide ethanol in a weight ratio of 5:6:2 to obtain a composite organic additive.

[0124] S3 weighs 100g of the pre-mixed oxide powder and 2.5g of the composite organic additive and mixes them together. Supercritical carbon dioxide is added as a dispersion medium to obtain the mixture.

[0125] S2 ball mills the mixture, wherein the milling media is nano-zirconia balls, the weight ratio of the milling media to the mixture is 5:1, the milling pressure is 25 MPa, the milling temperature is 40℃, the milling speed is 400 rpm, and the milling time is 8 hours. The slurry after milling is then supercritically dried to form particles, wherein the supercritical drying pressure is 20 MPa and the supercritical drying temperature is 50℃.

[0126] S3. The dried particles are passed through a 400-mesh sieve to obtain ZTA ceramic material;

[0127] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 300MPa and a holding time of 10min.

[0128] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the molded ZTA ceramic, resulting in multi-stage debinding of the ZTA ceramic. The specific steps include:

[0129] The S501 is heated from room temperature to 200°C, with a holding time of 2 hours and a heating rate of 0.5°C / min.

[0130] S502 is heated from 200℃ to 400℃, with a holding time of 3 hours and a heating rate of 0.3℃ / min.

[0131] S503 is heated from 400℃ to 600℃, held at that temperature for 2 hours, and the heating rate is 0.5℃ / min;

[0132] S6 high-temperature sintering involves sintering the ZTA ceramic after multi-stage debinding by gradually increasing the temperature from 600℃ to 1650℃. The specific steps include:

[0133] S601 is heated from 600℃ to 1200℃, with a holding time of 0.5 hours and a heating rate of 5℃ / min.

[0134] S602 is heated from 1200℃ to 1500℃, with a holding time of 2 hours and a heating rate of 3℃ / min;

[0135] The S603 was heated from 1500℃ to 1650℃, with a holding time of 1 hour and a heating rate of 2℃ / min.

[0136] The high-temperature sintering is performed using a hot-press sintering furnace, and the atmosphere during the high-temperature sintering process is an argon protective atmosphere with a purity of ≥99.999% and a flow rate of 3L / min.

[0137] Comparative Example 2 also provides ZTA ceramics, which are prepared according to the ZTA ceramics preparation method described above.

[0138] Comparative Example 3

[0139] Comparative Example 3 provides a method for preparing ZTA ceramics, comprising the following steps:

[0140] S1 adds 81.7 wt% submicron alumina powder, 18 wt% nano-zirconia powder, 0.1 wt% magnesium oxide and 0.2 wt% yttrium oxide to obtain a well-proportioned oxide powder.

[0141] S2 is prepared by adding the poly(2-methyl-2-oxetane), the 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and the perfluorooctylsulfonamide ethanol in a weight ratio of 7:6:2 to obtain a composite organic additive.

[0142] S3 weighs 100g of the pre-mixed oxide powder and 2.5g of the composite organic additive and mixes them together. Then, supercritical carbon dioxide is added as a dispersion medium to obtain a mixture.

[0143] S2 ball mills the mixture, wherein the milling media is nano-zirconia balls, the weight ratio of the milling media to the mixture is 5:1, the milling pressure is 25 MPa, the milling temperature is 40℃, the milling speed is 400 rpm, and the milling time is 8 hours. The slurry after milling is then supercritically dried to form particles, wherein the supercritical drying pressure is 20 MPa and the supercritical drying temperature is 50℃.

[0144] S3. The dried particles are passed through a 400-mesh sieve to obtain ZTA ceramic material;

[0145] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 300MPa and a holding time of 10min.

[0146] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the molded ZTA ceramic, resulting in multi-stage debinding of the ZTA ceramic. The specific steps include:

[0147] The S501 is heated from room temperature to 200°C, with a holding time of 2 hours and a heating rate of 0.5°C / min.

[0148] S502 is heated from 200℃ to 400℃, with a holding time of 3 hours and a heating rate of 0.3℃ / min.

[0149] S503 is heated from 400℃ to 600℃, held at that temperature for 2 hours, and the heating rate is 0.5℃ / min;

[0150] S6 high-temperature sintering involves sintering the ZTA ceramic after multi-stage debinding by gradually increasing the temperature from 600℃ to 1650℃. The specific steps include:

[0151] S601 is heated from 600℃ to 1200℃, with a holding time of 0.5 hours and a heating rate of 5℃ / min.

[0152] S602 is heated from 1200℃ to 1500℃, with a holding time of 2 hours and a heating rate of 3℃ / min;

[0153] The S603 was heated from 1500℃ to 1650℃, with a holding time of 1 hour and a heating rate of 2℃ / min.

[0154] The high-temperature sintering is performed using a hot-press sintering furnace, and the atmosphere during the high-temperature sintering process is an argon protective atmosphere with a purity of ≥99.999% and a flow rate of 3L / min.

[0155] Comparative Example 3 also offers ZTA ceramics, such as Figure 2 As shown, ZTA ceramics were prepared according to the preparation method described above.

[0156] Comparative Example 4

[0157] Comparative Example 4 provides a method for preparing ZTA ceramics, comprising the following steps:

[0158] S1 adds 81.7 wt% submicron alumina powder, 18 wt% nano-zirconia powder, 0.1 wt% magnesium oxide and 0.2 wt% yttrium oxide to obtain a well-proportioned oxide powder.

[0159] S2 is prepared by adding the poly(2-methyl-2-oxetane), the poly(3,3,3-trifluoropropylmethylsiloxane), and the perfluorooctylsulfonamide ethanol in a weight ratio of 7:5:2 to obtain a composite organic additive.

[0160] S3 weighs 100g of the pre-mixed oxide powder and 2.5g of the composite organic additive and mixes them together. Then, supercritical carbon dioxide is added as a dispersion medium to obtain a mixture.

[0161] S2 ball mills the mixture, wherein the milling media is nano-zirconia balls, the weight ratio of the milling media to the mixture is 5:1, the milling pressure is 25 MPa, the milling temperature is 40℃, the milling speed is 400 rpm, and the milling time is 8 hours. The slurry after milling is then supercritically dried to form particles, wherein the supercritical drying pressure is 20 MPa and the supercritical drying temperature is 50℃.

[0162] S3. The dried particles are passed through a 400-mesh sieve to obtain ZTA ceramic material;

[0163] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 300MPa and a holding time of 10min.

[0164] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the molded ZTA ceramic, resulting in multi-stage debinding of the ZTA ceramic. The specific steps include:

[0165] The S501 is heated from room temperature to 200°C, with a holding time of 2 hours and a heating rate of 0.5°C / min.

[0166] S502 is heated from 200℃ to 400℃, with a holding time of 3 hours and a heating rate of 0.3℃ / min.

[0167] S503 is heated from 400℃ to 600℃, held at that temperature for 2 hours, and the heating rate is 0.5℃ / min;

[0168] S6 high-temperature sintering involves sintering the ZTA ceramic after multi-stage debinding by gradually increasing the temperature from 600℃ to 1650℃. The specific steps include:

[0169] S601 is heated from 600℃ to 1200℃, with a holding time of 0.5 hours and a heating rate of 5℃ / min.

[0170] S602 is heated from 1200℃ to 1500℃, with a holding time of 2 hours and a heating rate of 3℃ / min;

[0171] The S603 was heated from 1500℃ to 1650℃, with a holding time of 1 hour and a heating rate of 2℃ / min.

[0172] The high-temperature sintering is performed using a hot-press sintering furnace, and the atmosphere during the high-temperature sintering process is an argon protective atmosphere with a purity of ≥99.999% and a flow rate of 3L / min.

[0173] Comparative Example 4 also provides ZTA ceramics, which were prepared according to the ZTA ceramics preparation method described above.

[0174] Comparative Example 5

[0175] Comparative Example 5 provides a method for preparing ZTA ceramics, comprising the following steps:

[0176] S1 adds 81.7 wt% submicron alumina powder, 18 wt% nano-zirconia powder, 0.1 wt% magnesium oxide and 0.2 wt% yttrium oxide to obtain a well-proportioned oxide powder.

[0177] S2 is prepared by adding the poly(2-methyl-2-oxetane), the poly(3,3,3-trifluoropropylmethylsiloxane), and the 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) in a weight ratio of 7:5:6 to obtain a composite organic additive.

[0178] S3 weighs 100g of the pre-mixed oxide powder and 2.5g of the composite organic additive and mixes them together. Then, supercritical carbon dioxide is added as a dispersion medium to obtain a mixture.

[0179] S2 ball mills the mixture, wherein the milling media is nano-zirconia balls, the weight ratio of the milling media to the mixture is 5:1, the milling pressure is 25 MPa, the milling temperature is 40℃, the milling speed is 400 rpm, and the milling time is 8 hours. The slurry after milling is then supercritically dried to form particles, wherein the supercritical drying pressure is 20 MPa and the supercritical drying temperature is 50℃.

[0180] S3. The dried particles are passed through a 400-mesh sieve to obtain ZTA ceramic material;

[0181] S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 300MPa and a holding time of 10min.

[0182] S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the molded ZTA ceramic, resulting in multi-stage debinding of the ZTA ceramic. The specific steps include:

[0183] The S501 is heated from room temperature to 200°C, with a holding time of 2 hours and a heating rate of 0.5°C / min.

[0184] S502 is heated from 200℃ to 400℃, with a holding time of 3 hours and a heating rate of 0.3℃ / min.

[0185] S503 is heated from 400℃ to 600℃, held at that temperature for 2 hours, and the heating rate is 0.5℃ / min;

[0186] S6 high-temperature sintering involves sintering the ZTA ceramic after multi-stage debinding by gradually increasing the temperature from 600℃ to 1650℃. The specific steps include:

[0187] S601 is heated from 600℃ to 1200℃, with a holding time of 0.5 hours and a heating rate of 5℃ / min.

[0188] S602 is heated from 1200℃ to 1500℃, with a holding time of 2 hours and a heating rate of 3℃ / min;

[0189] The S603 was heated from 1500℃ to 1650℃, with a holding time of 1 hour and a heating rate of 2℃ / min.

[0190] The high-temperature sintering is performed using a hot-press sintering furnace, and the atmosphere during the high-temperature sintering process is an argon protective atmosphere with a purity of ≥99.999% and a flow rate of 3L / min.

[0191] Comparative Example 5 also provides ZTA ceramics, which were prepared according to the ZTA ceramics preparation method described above.

[0192] Experimental methods for testing experimental data

[0193] The ZTA ceramic products prepared in Examples 1 and Comparative Examples 1-5 were tested using a Mitutoyo micro Vickers hardness tester. The testing method for measuring the Vickers hardness of the ZTA ceramic products is as follows:

[0194] 1. Sample preparation:

[0195] a) Grind the ZTA ceramic sample into a 2*10mm block using metallographic grinding;

[0196] b) Polish the sample surface to ensure it is flat and smooth, without obvious scratches or defects;

[0197] c) Clean the sample surface to remove all contaminants and debris;

[0198] 2. Sample placement:

[0199] a) Place the sample on the test stage of the hardness tester and adjust the loading force to 5 kgf;

[0200] b) Adjust the sample position to ensure that the test surface is perpendicular to the indenter;

[0201] 3. Perform the test:

[0202] a) Start the test program;

[0203] b) The indenter descends automatically and leaves an indentation on the sample surface;

[0204] 4. Measure the indentation:

[0205] a) Observe the indentation using the optical system of a hardness tester;

[0206] b) Measure the diagonal length of the indentation and confirm it in the software;

[0207] 5. Read the hardness value:

[0208] Automatically calculates and displays hardness values;

[0209] 6. Repeat the above steps 5 times to obtain 5 sets of hardness values, and calculate the average value to obtain the Vickers hardness data of ZTA ceramic products, as shown in Table 1 below.

[0210] The testing methods for measuring the three-point flexural strength of the ZTA ceramic products prepared in Example 1 and Comparative Examples 1-5 are as follows:

[0211] 1. Sample preparation:

[0212] a) Prepare a cylindrical sample with dimensions of 1.6 mm x 10 mm;

[0213] b) Ensure the sample surface is smooth and free of obvious defects or cracks;

[0214] c) Measure and record the precise dimensions of each sample;

[0215] 2. Equipment preparation:

[0216] a) Use a universal testing machine;

[0217] b) Install the 3-point bending test fixture, including two lower support rollers and one upper loading roller;

[0218] c) Calibrate the equipment to ensure loading accuracy;

[0219] 3. Test parameter settings:

[0220] a) Set the span to 8mm;

[0221] b) Set the loading rate to 0.5 mm / min;

[0222] c) Set the data acquisition frequency;

[0223] 4. Sample placement:

[0224] a) Place the sample on the lower support roller, ensuring it is centered;

[0225] b) Adjust the upper loading roller to make it contact the sample surface but without applying an initial load;

[0226] 5. Perform the test:

[0227] a) Start the test program;

[0228] b) The equipment begins to load at a constant rate;

[0229] c) Continuously record load and displacement data;

[0230] d) The test will automatically stop if the sample breaks;

[0231] 6. Data Collection:

[0232] Data was read directly from the device to obtain the 3-point flexural strength data of ZTA ceramic products, as shown in Table 1 below.

[0233] The porosity of the ZTA ceramic products prepared in Examples 1 and Comparative Examples 1-5 was measured using the density method as follows:

[0234] 1. Sample preparation:

[0235] a) Prepare cylindrical ceramic samples;

[0236] b) Clean the sample surface to remove all contaminants and debris;

[0237] c) Dry the sample in an oven at approximately 105°C until constant weight;

[0238] 2. Determination of theoretical density:

[0239] The theoretical density is calculated based on the proportions of the composite material.

[0240] 3. Volume measurement (geometric method):

[0241] a) Measure the dimensions of the sample using precision calipers;

[0242] b) Calculate the geometric volume of the sample;

[0243] 4. Quality Measurement:

[0244] a) Measure the mass (m1) of the dried sample using a precision balance;

[0245] 5. Immersion method for measuring volume (Archimedes' principle):

[0246] a) Prepare pure water;

[0247] b) Measure the density (ρl) of the immersion solution;

[0248] c) Immerse the sample in the soaking solution, ensuring it is completely submerged;

[0249] d) Measure the mass (m2) of the submerged sample;

[0250] e) After quickly wiping away the surface moisture, measure the mass (m3) of the wet sample;

[0251] 6. Calculate:

[0252] a) Apparent density (ρa) = m1 / (m3-m2)*ρl;

[0253] b) Bulk density (ρb) = m1 / V (geometric volume);

[0254] c) Open porosity (Po) = (m3-m1) / (m3-m2)*100%;

[0255] d) Closed porosity (Pc) = (1 - ρa / ρt) * 100% - Po, where ρt is the theoretical density;

[0256] e) Total porosity (Pt) = Po + Pc = (1 - ρb / ρt) * 100%

[0257] 7. Repeated measures:

[0258] Test 30 samples, repeat steps 3-6, calculate the average value, and obtain the porosity of ZTA ceramic products, as shown in Table 1 below.

[0259] The experimental data of the ZTA ceramic products prepared in Example 1 and Comparative Examples 1-5 are shown in Table 1 below.

[0260] Grain measurement methods:

[0261] The testing methods for measuring grain size are as follows:

[0262] 1. Sample preparation:

[0263] a) Grind and polish the sample to obtain a smooth and flat surface;

[0264] b) Perform chemical or thermal etching to expose the grain boundaries, typically at 1400°C for 2 hours.

[0265] c) Clean the sample surface to remove all contaminants and debris;

[0266] 2. SEM observation:

[0267] Multiple microstructure images were taken in different regions of the sample using a scanning electron microscope (SEM).

[0268] 3. Grain size measurement:

[0269] Select a region within a certain area, use measurement software to measure the size of all grains within that region, and calculate the average value of the grains.

[0270] Table 1. Experimental data of ZTA ceramic products prepared in Example 1 and Comparative Examples 1-5.

[0271] name Vickers hardness (HV) 3-point flexural strength (MPa) Porosity (%) Example 1 2100 1350 0.4 Comparative Example 1 1700 880 4 Comparative Example 2 1750 920 3.2 Comparative Example 3 1790 980 2.8 Comparative Example 4 1820 1130 2.3 Comparative Example 5 1910 1160 1.8

[0272] From Table 1, we can observe that the ZTA ceramic product prepared in Example 1 contains a composite organic additive consisting of poly(2-methyl-2-oxetane), poly(3,3,3-trifluoropropylmethylsiloxane), 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and perfluorooctylsulfonamide ethanol. This results in the ZTA ceramic product prepared in Example 1 having a Vickers hardness of 2100 HV, a three-point flexural strength of 1350 MPa, and a porosity of 0.4%. In contrast, the ZTA ceramic product prepared in Comparative Example 1 does not contain the composite organic additive, resulting in a decrease in the Vickers hardness to 1700 HV and a lower three-point flexural strength. The strength decreased to 880 MPa, and the Vickers hardness and flexural strength decreased significantly. The hardness and three-point bending strength of the ceramic were poor. The porosity of the ceramic product increased to 4%, which was quite significant. The density of the ceramic product was poor. Compared with Comparative Examples 2-5, the ZTA ceramic products prepared in Example 1 did not contain a certain component of the composite organic additive, which led to a decrease in the Vickers hardness and three-point bending strength of the ZTA ceramic products to varying degrees. However, the decrease in Vickers hardness and three-point bending strength was smaller than that of the ZTA ceramic products provided in Comparative Document 1. The porosity of the ZTA ceramic products increased to varying degrees, but the increase was smaller than that of the ZTA ceramic products provided in Comparative Document 1.

[0273] This is because the poly(2-methyl-2-oxetane) (PMOB) and perfluorooctylsulfonamide ethanol (PFOSEA) in this application can synergistically adsorb onto the surface of nano-ceramic powder, forming an adsorption layer. This adsorption layer alters the surface properties of the powder particles, reduces surface energy, and decreases the interaction forces between particles, thereby effectively preventing agglomeration. Furthermore, the relatively long molecular chains of poly(2-methyl-2-oxetane) (PMOB) and perfluorooctylsulfonamide ethanol (PFOSEA) create a three-dimensional spatial barrier after synergistic adsorption onto the powder surface. This barrier effectively prevents powder particles from approaching and contacting each other, further preventing agglomeration. The functional groups in the (2-methyl-2-oxetane) (PMOB) and perfluorooctylsulfonamide ethanol (PFOSEA) molecules are complementary, allowing them to work together on the ceramic powder surface to form a more stable and uniform adsorption layer. For example, the hydroxyl and carboxyl groups in (2-methyl-2-oxetane) (PMOB) can form hydrogen bonds or electrostatic interactions with the polar regions on the surface of ceramic powder, while the sulfonamide and ethanol groups in perfluorooctylsulfonamide ethanol (PFOSEA) can further consolidate this adsorption layer through hydrogen bonds and electrostatic interactions. During adsorption, the molecular chains of (2-methyl-2-oxetane) (PMOB) and perfluorooctylsulfonamide ethanol (PFOSEA) intertwine and entangle, forming a dense organic film. This film tightly coats the surface of the nano-ceramic powder, preventing direct contact and agglomeration between particles. Simultaneously, the intertwining and entanglement of the molecular chains enhances the mechanical strength and stability of the adsorption layer. The sulfonamide and ethanol groups in perfluorooctylsulfonamide ethanol (PFOSEA) have a certain steric hindrance effect, preventing other molecules or particles from approaching the ceramic powder surface. This steric hindrance effect not only helps to enhance the stability and protective performance of the adsorption layer, but also reduces the friction and collision between particles, thereby improving the dispersibility and flowability of ceramic powder. Therefore, the synergistic effect of (2-methyl-2-oxetane) (PMOB) and perfluorooctyl sulfonamide ethanol (PFOSEA) can effectively disperse nano-ceramic powder, prevent agglomeration, and thus achieve more uniform and dense filling during the molding process, ultimately reducing the initial porosity.

[0274] Poly(3,3,3-trifluoropropylmethylsiloxane) (PTFPMS) and 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA) both contain fluorine atoms and have good lubrication properties. During the adsorption process, the molecular chains of PTFPMS and TFBMA may intertwine and entangle, forming a more stable and dense lubricating film on the surface of powder particles, reducing friction between particles and improving the flowability of the powder. This lubrication effect helps the powder to fill the mold more evenly during the pressing process and reduces local stress concentration. These two additives can significantly reduce the surface energy of powder particles, further reducing the attraction between particles. This helps the particles to rearrange and slide more easily during the pressing process, thereby achieving more uniform compaction. Therefore, the synergistic effect of poly(3,3,3-trifluoropropylmethylsiloxane) (PTFPMS) and 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA) significantly improves the pressing performance of the powder, resulting in a more uniform density distribution in the green body and effectively reducing the formation of large pores.

[0275] Poly(2-methyl-2-oxetane) (PMOB) and 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA) undergo thermal decomposition during heating. This decomposition typically begins with the lower molecular weight components and gradually progresses towards the higher molecular weight components. During decomposition, various gaseous products are released, such as CO2 and H2O. During molding, poly(2-methyl-2-oxetane) (PMOB) and 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA) are typically evenly distributed between ceramic particles. This uniform distribution ensures that the formation of micropores is also uniform during the multi-stage debinding process. As the temperature rises, poly(2-methyl-2-oxetane) (PMOB) and 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA) begin to decompose, generating gases. These gases form tiny bubbles inside the ceramic body. As more gases are generated, these bubbles gradually grow and interconnect, forming a microporous network. Poly(2-methyl-2-oxetane) (PMOB) and 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA)... 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA) typically has different decomposition temperatures, leading to a multi-stage decomposition process. This multi-stage decomposition helps form micropores of different sizes, increasing the complexity and connectivity of the microporous network. As organic matter decomposes, tiny capillary channels are formed between ceramic particles. These channels can further promote the discharge of liquid decomposition products through capillary action. During debinding, a pressure gradient is formed inside and outside the green body. This gradient helps push decomposition products from the inside to the outside, promoting the formation and connectivity of micropores. During debinding, poly(2-methyl-2-oxetane) (PMOB) and 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate) (TFBMA) work synergistically to decompose and form a uniform microporous network. These micropores facilitate the subsequent discharge of gases and also provide channels for material transport, thereby achieving more uniform densification during sintering.

[0276] Poly(3,3,3-trifluoropropylmethylsiloxane) (PTFPMS) decomposes during high-temperature sintering to form SiO2. This SiO2 not only fills the tiny voids between ceramic particles, reducing porosity, but it also forms a liquid phase at lower temperatures, accelerating mass transport and promoting particle bonding. The formation of the SiO2 liquid phase not only accelerates mass transport but also promotes particle rearrangement and densification. During sintering, the liquid phase fills the voids between particles and promotes mass diffusion and migration through capillary action.

[0277] The fluorine-containing gases released by perfluorooctyl sulfonamide ethanol (PFOSEA) clean the surface of ceramic particles. The fluorine-containing gases (such as HF and CF4) released by the decomposition of PFOSEA have strong chemical reactivity, effectively cleaning the surface of ceramic particles, removing surface impurities and oxide layers, thereby improving the bonding strength between particles. The cleaning effect also increases the surface activity of the ceramic particles, making them more susceptible to chemical reactions with other particles or additives, thus promoting the sintering process. The cleaned ceramic particle surface has higher activity, which contributes to particle bonding and densification. Simultaneously, the release of fluorine-containing gases may also form tiny channels between particles, which can serve as pathways for mass transport, accelerating mass migration and diffusion during the sintering process.

[0278] The synergistic effect of poly(3,3,3-trifluoropropylmethylsiloxane) (PTFPMS) and perfluorooctylsulfonamide ethanol (PFOSEA) increases the contact area between ceramic particles. This is because the formation of the SiO2 liquid phase fills the voids between particles, while the cleaning effect of PFOSEA removes impurities and oxide layers from the particle surface, resulting in tighter particle contact. The fluorine-containing gases released by both the SiO2 liquid phase and PFOSEA accelerate mass transport and diffusion processes. The SiO2 liquid phase promotes mass migration and diffusion through capillary action, while the fluorine-containing gases clean the particle surface and increase surface activity, further promoting diffusion. The synergistic effect of PTFPMS and PFOSEA also reduces the surface energy of the system. The formation of SiO2 and the presence of the liquid phase reduce porosity and increase the density of the ceramic, thereby lowering the surface energy of the system. Meanwhile, the cleaning effect of perfluorooctyl sulfonamide ethanol (PFOSEA) can also remove impurities and oxide layers from the particle surface, further reducing the surface energy. This reduction in surface energy helps promote densification during the sintering process; therefore, the synergistic effect of poly(3,3,3-trifluoropropylmethylsiloxane) (PTFPMS) and perfluorooctyl sulfonamide ethanol (PFOSEA) not only increases the contact area between particles and accelerates the diffusion process, but also reduces the surface energy of the system, promoting densification.

[0279] The composite organic additive decomposes at different temperatures, achieving multi-stage degreasing and avoiding the cracking and large pore formation that may be caused by the rapid decomposition of traditional single organic additives. The decomposition products of the composite organic additive (such as SiO2) can be used as sintering aids in the sintering process, reducing the sintering temperature, refining the grains, and making it less likely to produce large grains and large voids. SiO2 and Al2O3 can form a low-melting-point eutectic phase at high temperatures. The presence of this liquid phase lowers the overall sintering temperature of the system, increases the mass transport rate, accelerates the densification process, promotes particle rearrangement, and fills micropores. This eutectic phase helps form a more uniform fine-grained structure, further improving the mechanical properties of the ceramic. Specifically, the presence of SiO2 at grain boundaries increases the grain boundary diffusion rate and promotes mass transport, which helps accelerate neck growth—the expansion of the intergranular connection region—thus enhancing the density of the ceramic. SiO2 particles can form pinning points at grain boundaries, inhibiting grain boundary migration, limiting grain growth, promoting the formation of a uniform fine-grained structure, and preventing abnormal grain growth. This uniform fine-grained structure helps improve the hardness and flexural strength of the ceramic. SiO2 can lower grain boundary energy, reducing the driving force for grain growth, promoting a more stable fine-grained structure, accelerating the closure process of pores, and preventing the formation and retention of large voids.

[0280] like Figure 1 As shown, the ZTA ceramic prepared in Example 1 is essentially free of pores, especially large pores, which are not visible. This reduces the porosity of the sintered ZTA ceramic and increases its density. Figure 2 As shown, the ZTA ceramic prepared in Comparative Example 3 does not contain the poly(3,3,3-trifluoropropylmethylsiloxane) component in the composite organic additive. The ZTA ceramic has more basic pores and more macropores. This is because, compared with the ZTA ceramic prepared in Example 1, Comparative Example 3 does not contain the poly(3,3,3-trifluoropropylmethylsiloxane) component in the composite organic additive. The poly(3,3,3-trifluoropropylmethylsiloxane) (PTFPMS) in the ZTA ceramic provided in Example 1 decomposes at high temperature to form SiO2. This SiO2 can not only fill the tiny gaps between ceramic particles and reduce porosity, but it can also form a liquid phase at a lower temperature, accelerating mass transport and promoting the bonding between ceramic particles. The formation of the SiO2 liquid phase not only helps to accelerate mass transport, but also promotes the rearrangement and densification of ceramic particles. During sintering, the liquid phase fills the voids between particles and promotes the diffusion and migration of matter through capillary action, reducing the porosity of the sintered ZTA ceramic and increasing its density. Figure 1As shown, the average particle size of the high-density ZTA ceramic in Example 1 is 0.8 μm, while the average particle size of the ZTA ceramic prepared in Comparative Example 3 is 1.03 μm. The particle size of the ZTA ceramic prepared by the method in Example 1 is reduced. Smaller particle size helps the particles to pack tightly together, thereby increasing the density of the material. When the particle size of the ZTA ceramic provided in Example 1 decreases, the interfacial area between the particles increases accordingly. A larger interfacial area means more grain boundaries and shorter diffusion paths, which helps to improve the Vickers hardness of the ZTA ceramic. When the particle size of the ZTA ceramic provided in Example 1 decreases, the interfacial area between the particles increases, which helps to disperse and transfer stress. A larger interfacial area can provide more stress transfer paths, thereby reducing the stress concentration of the material during bending and improving the three-point bending strength of the ZTA ceramic.

[0281] It is understood that this invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by this invention. Furthermore, under the teachings of this invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this invention. Therefore, this invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of this invention.

Claims

1. A high-density ZTA ceramic, characterized in that, include: Oxide powder and composite organic additives, wherein the oxide powder comprises the following components by weight percentage: Submicron alumina powder: 78–82 wt%; Nano-zirconia powder: 18–22 wt%; Sintering aid: 0.3–0.8 wt%; The composite organic additive comprises the following components: poly(2-methyl-2-oxetane), poly(3,3,3-trifluoropropylmethylsiloxane), 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and perfluorooctylsulfonamide ethanol. The composite organic additive accounts for 2.5 wt% of the total mass of the oxide powder.

2. The high-density ZTA ceramic according to claim 1, characterized in that, The weight ratio of the poly(2-methyl-2-oxetane), the poly(3,3,3-trifluoropropylmethylsiloxane), the 2,2,3,3-tetrafluoro-1,4-butanediol bis(2-methacrylate), and the perfluorooctylsulfonamide ethanol is 7:5:6:

2.

3. The high-density ZTA ceramic according to claim 1, characterized in that, The average particle size of the submicron alumina powder is 590 nm to 610 nm.

4. The high-density ZTA ceramic according to claim 1, characterized in that, The purity of the submicron alumina powder is ≥99.99%.

5. The high-density ZTA ceramic according to claim 1, characterized in that, The average particle size of the nano-zirconia powder is 75–85 nm.

6. The high-density ZTA ceramic according to claim 1, characterized in that, The nano-zirconia powder is composed of zirconium oxide and yttrium oxide, wherein the content of yttrium oxide is 3 mol%.

7. The high-density ZTA ceramic according to claim 1, characterized in that, The sintering aid comprises the following components by weight percentage: Magnesium oxide 0.1–0.3 wt%; Yttrium oxide 0.2–0.5 wt%.

8. A method for preparing high-density ZTA ceramic, characterized in that, The preparation of high-density ZTA ceramics as described in any one of claims 1-7 comprises the following steps: S1 weighs and mixes the pre-mixed oxide powder and composite organic additives according to the component ratio, and adds supercritical carbon dioxide as a dispersion medium to obtain a mixture; S2 ball mills the mixture, and the slurry after ball milling is then supercritically dried to produce granules. S3 sieves the dried particles to obtain ZTA ceramic material.

9. The method for preparing high-density ZTA ceramic according to claim 8, characterized in that, In step S2, ball milling is carried out in a supercritical fluid-assisted ball mill. The ball milling media is nano-zirconia balls, the weight ratio of the ball milling media to the mixture is 5:1, the ball milling pressure is 22-28 MPa, the ball milling temperature is 27-43℃, the ball milling speed is 350-450 rpm, the ball milling time is 7-9 hours, the supercritical drying pressure is 18-22 MPa, and the supercritical drying temperature is 48-52℃.

10. The method for preparing high-density ZTA ceramic according to claim 8, characterized in that, It also includes the following steps: S4 uses cold isostatic pressing to form ZTA ceramic materials, with a forming pressure of 280-320 MPa and a holding time of 8-12 minutes; S5 multi-stage debinding involves gradually increasing the temperature from room temperature to 600℃ to perform multi-stage debinding on the formed ZTA ceramic, resulting in multi-stage debinding of ZTA ceramic. S6 high-temperature sintering involves sintering ZTA ceramics after multi-stage degreasing by gradually increasing the temperature from 600℃ to 1650℃, with an argon protective atmosphere during the high-temperature sintering process.

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