Zirconia-based bioceramic material and method for its preparation

Abstract

This invention relates to a zirconia-based bioceramic material based on high-entropy design and its preparation method, wherein the chemical composition of the bioceramic material is Zr. 1‑x (Y 1‑6y Al 2y Mg y Si y Sr 0.5y Ca 0.5y Ti y ) x O 2‑x / 2 Where x and y are molar contents, 0.025

Description

Technical Field

[0001] This invention belongs to the field of bioceramic materials technology, specifically relating to a zirconia-based bioceramic material and its preparation method. Background Technology

[0002] Tetragonal zirconia polycrystalline ceramics are widely used bioceramic materials in the biomedical field, specifically as ceramic matrix materials for human hip joint implants and dental restorations. These ceramic materials possess excellent mechanical properties and biocompatibility. The most widely used is yttrium-doped tetragonal zirconia (Y-TZP, Y₂O₃-stabilized tetragonal ZrO₂ polycrystals). The high strength and toughness of these zirconia ceramics are attributed to stress-induced phase transitions. Although these ceramics have been widely adopted in the biomedical field, they suffer from low-temperature degradation (LTD). Experiments have observed that Y-TZP ceramics spontaneously degrade in performance when exposed to biological or hydrothermal environments; this degradation process is associated with a spontaneous phase transition from tetragonal to monoclinic structure under humid conditions. The degradation mechanism of LTD is not yet fully understood [International Materials Review, vol. 63, pp. 375-406, 2018; Journal of the European Ceramic Society, vol. 38, pp. 3573-3577, 2018]. Currently, there are patents for zirconia ceramics designed based on the high-entropy concept. For example, patent CN 115124339A discloses a multi-element high-entropy doped zirconia-based ceramic material, its preparation method, and its applications. The doping elements in this invention are selected from Ca, Mg, Sr, Sc, Ce, Gd, La, Y, Yb, and Sm. It should be emphasized that one of the raw materials, Sc2O3, is extremely expensive. This ceramic material can be used for extended periods below 1600℃ without undergoing a phase transition and also exhibits excellent properties such as low thermal conductivity, high coefficient of thermal expansion, and high fracture toughness, making it a promising new material for thermal barrier coatings. However, this patent belongs to the field of thermal barrier coatings, does not involve hydrothermal stability research, nor does it involve ceramic surface optimization technology required to improve cell adhesion and growth, and there is no evidence or data to prove that the material can be used in orthopedics, dentistry or biomedicine. Summary of the Invention

[0003] The purpose of this invention is to overcome the defects in the existing technology, utilize the concept of high entropy for material design, and provide a zirconia-based bioceramic material and its preparation method.

[0004] This invention provides a zirconia-based bioceramic material with the following general structural formula:

[0005] Zr 1-x (Y 1-6y Al 2y Mg y Si y Sr 0.5y Ca 0.5y Ti y ) x O 2-x / 2 Equation (1)

[0006] Among them, 0.025 <x<0.075,0.05 ≤y≤ 0.1。

[0007] Furthermore, the zirconium oxide-based bioceramic material has a relative density greater than 99% and an average grain size ≤240nm.

[0008] Furthermore, the zirconia-based bioceramic material has a snowflake-shaped groove pattern on its surface, and a surface roughness Ra≤1.15 μm.

[0009] Furthermore, the zirconia-based bioceramic material has a hardness greater than 14.0 GPa, a biaxial bending strength greater than 800 MPa, and a Weibull modulus greater than 10.

[0010] Furthermore, when the zirconia-based bioceramic material was kept in a hydrothermal reactor at 135°C and 0.2 MPa for 100 hours, XRD analysis showed that no phase transition from a tetragonal structure to a monoclinic structure occurred.

[0011] A second aspect of the present invention provides a method for preparing the above-mentioned zirconia-based bioceramic material, comprising the following steps:

[0012] S1 Ball milling: According to the ratio of formula (1), select nano powders of ZrO2, Y2O3, Al2O3, MgO, SiO2, SrO, CaO and TiO2, and ball mill them to obtain uniformly mixed ceramic powders;

[0013] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0014] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0015] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0016] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material;

[0017] Furthermore, as a preferred embodiment of the present invention, S1 uses a wet ball milling method for mixing materials, and the mass ratio of raw materials, zirconia milling balls and deionized water is as follows: raw materials: zirconia milling balls: deionized water = 1:(1.6~2.0):(0.65~0.80).

[0018] Furthermore, the ball milling speed of S1 is 50 revolutions per minute, and the ball milling time is 8 to 10 hours.

[0019] Furthermore, the binder in S2 is polyvinyl alcohol, and the amount of binder added is 5wt% to 7wt% of the ceramic powder.

[0020] Furthermore, the pressure during the pressing process in S2 is 50–75 MPa.

[0021] Furthermore, the pressure of the cold isostatic pressing in S3 is 180–220 MPa.

[0022] Furthermore, the discharge temperature of S4 is 600℃~800℃, and the heat preservation time is 2~3h.

[0023] Furthermore, S5 employs a two-stage sintering mechanism:

[0024] The first stage involves heating from room temperature to 1500℃ at a rate of 2–5℃ / min, with a holding time of 1 hour at 1500℃.

[0025] The second stage involves cooling from 1500℃ to 1425-1450℃ at a rate of 200℃ / min to 300℃ / min, followed by holding at 1425-1450℃ for 3-5 hours, and then cooling in the furnace to complete the sintering process.

[0026] Furthermore, it also includes the following steps:

[0027] S6 Cleaning and Drying: Place the sintered ceramic from step S5 above into an ethanol solution, ultrasonically clean for 10 minutes to remove oil and contaminants, rinse with ultrapure water, and dry with 50°C hot air or clean air.

[0028] S7 surface chemical etching: The S6 ceramic is placed in a hydrofluoric acid HF solution (concentration 38% ~ 45%) and chemically etched in a temperature range of 25°C to 40°C for 30 to 90 minutes.

[0029] S8 Neutralizing Residual Acid: Take out the etched sample from S7 and transfer it to an ultrasonic cleaning tank filled with pure water. Ultrasonic cleaning is performed 3 times, 5 minutes each time, to remove residual acid and reaction products from the surface. Then, the sample is soaked in sodium bicarbonate (NaHCO3) solution for 5 minutes to further neutralize the residual acid. Ultrasonic cleaning is performed again with pure water 3 times, 5 minutes each time.

[0030] S9 Annealing: The sample treated with S8 was annealed at 1250 degrees Celsius for 60 minutes to obtain the high-entropy zirconia-based bioceramic material of the present invention.

[0031] Research has found that Y doping leads to the formation of oxygen vacancies within the zirconia ceramic lattice, with the specific point defect chemical equation as follows [J Am Ceram Soc. 2022; 105: 1106–1115].

[0032]

[0033] in, Represents Y 3+ Zirconium ions occupy ZrO2 4+ The position, in the crystal structure, shows a monovalent negative charge, O x O This indicates that oxygen occupies the O sites in ZrO2, locally showing electroneutrality, V ·· o represents oxygen vacancies in ZrO2, indicating a divalent positive charge. Studies have found that the low-temperature degradation behavior of Y-TZP ceramics is related to the diffusion of Y element within the zirconia ceramic, and this diffusion is associated with oxygen vacancy diffusion, leading to compositional segregation and low-temperature degradation. This invention, through the design of a high-entropy material system, introduces multiple metal oxides to increase the potential barrier, achieving a 1+1>2 effect. By reducing the diffusion capacity of oxygen vacancies, it improves resistance to LTD (Low-Temperature Degradation). The high-entropy material design system of this invention can enhance the zirconia lattice distortion effect, introduce local stress, and help achieve a non-uniform stress distribution on the ceramic surface. This helps to achieve a snowflake-like groove morphology after acid etching, facilitating cell adhesion and growth. This ensures that the high-entropy zirconia-based ceramic material of this invention maintains good mechanical properties and biocompatibility. Attached Figure Description

[0034] Figure 1 shows the surface morphology of the zirconia-based ceramic material prepared in Example 1 of the present invention after acid etching and annealing, as displayed by scanning electron microscopy (SEM), magnified 1,000 times;

[0035] Figure 2 shows the surface morphology of the zirconia-based ceramic material prepared in Example 1 of the present invention after acid etching and annealing, magnified 50,000 times;

[0036] Figure 3 shows the XRD results of the zirconia-based ceramic material prepared in Example 1 of the present invention after acid etching and annealing, followed by hydrothermal treatment. In the figure, T(101) is the diffraction peak of the tetragonal phase.

[0037] Figure 4 shows the XRD results of the zirconium oxide and ceramic prepared by Comparative Example 1 of the present invention after hydrothermal treatment; in the figure, M(-1 1 1) and M(111) are the diffraction peaks of the monoclinic phase, and T(101) is the diffraction peak of the tetragonal phase.

[0038] Figure 5 shows the surface morphology of the zirconia-based ceramic prepared in Comparative Example 6 of this invention after low-concentration acid etching treatment, as displayed by SEM at 1,000x magnification. Detailed Implementation

[0039] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0040] A high-entropy zirconia-based bioceramic material, Zr 1-x (Y 1-6y Al 2y Mg y Si y Sr 0.5y Ca 0.5y Ti y ) x O 2-x / 2 Where x and y are molar contents, 0.025 <x<0.075, 0.05 ≤y≤ 0.1。

[0041] Ceramics are obtained by direct reaction sintering using nano-oxides as raw materials: ZrO2, Y2O3, Al2O3, MgO, SiO2, SrO, CaO, and TiO2. Unless otherwise specified, the raw materials used in this invention are commercially available products well-known to those skilled in the art.

[0042] The measurement methods for performance characterization in this embodiment are as follows: the density of the ceramic is measured using Archimedes' displacement method; the microstructure and average grain size of the ceramic are observed using scanning electron microscopy (SEM); the strength of the ceramic is measured using the biaxial bending method; the hardness (HV1) is measured using a hardness tester; and the material structure is tested using XRD. For the specific measurement of hydrothermal stability, the ceramic is kept at temperature and pressure in a hydrothermal reactor for a certain period of time. The structure of the material after hydrothermal treatment is tested using XRD, and the ratio Xm of the monoclinic phase after hydrothermal treatment is measured using Garvie's formula [Dental Materials, vol. 26, pp807-820, 2010].

[0043] Xm = [Im(-1 1 1)+Im(111)] / [Im(-1 1 1)+Im(111) + It(101)],

[0044] Where Im and It are the intensities of the corresponding XRD diffraction peaks for monoclinic and tetragonal, respectively, and the numbers in parentheses represent the corresponding Miller indices.

[0045] Example 1

[0046] A high-entropy zirconia-based bioceramic material has the following general structural formula:

[0047] Zr 1-x (Y 1-6y Al 2y Mg y Si y Sr 0.5y Ca 0.5y Ti y ) x O 2-x / 2 x = 0.028, y = 0.1

[0048] The preparation method includes the following steps:

[0049] S1 Ball milling and mixing: The ceramic powder is obtained by ball milling and mixing according to the above composition.

[0050] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0051] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0052] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0053] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

[0054] The S1 process uses wet ball milling for mixing. The mass ratio of raw materials, zirconia grinding balls, and deionized water is as follows: raw materials: zirconia grinding balls: deionized water = 1:1.8:0.7.

[0055] The ball milling speed of S1 is 50 revolutions per minute, and the ball milling time is 8 hours.

[0056] The binder in S2 is polyvinyl alcohol, and the amount of binder added is 6 wt% of the ceramic powder.

[0057] The pressure during the pressing process in S2 is 60 MPa.

[0058] The pressure of the cold isostatic pressing in S3 is 200 MPa.

[0059] The discharge temperature of S4 is 700℃, and the heat preservation time is 2h.

[0060] The S5 adopts a two-stage sintering process: the first stage involves heating from room temperature to 1500℃ at a rate of 5℃ / min, and holding at 1500℃ for 1 hour; the second stage involves cooling from 1500℃ to 1430℃ at a rate of 220℃ / min, holding at 1430℃ for 5 hours, and then cooling with the furnace to end the sintering process.

[0061] The bioceramic material obtained in this embodiment has a relative density of 99.5% and an average grain size of ≤230 nm as measured by scanning electron microscopy. The bioceramic material exhibits excellent performance, with a hardness of 14.3±0.1 GPa, a biaxial flexural strength of 830±20 MPa, and a corresponding Weibull modulus of 12. The bioceramic material provided by this invention demonstrates structural stability. Under hydrothermal conditions, it remained stable for 100 hours in a hydrothermal reactor at 135°C and 0.2 MPa. XRD analysis showed no evidence of a phase transition from a tetragonal to a monoclinic structure. This proves that the material has excellent hydrothermal stability.

[0062] The sintered Y-TZP ceramic was placed in an ethanol + deionized water (1:1) solution and ultrasonically cleaned for 10 minutes to remove oil and contaminants. It was then rinsed with ultrapure water and dried with 50 °C hot air or clean air.

[0063] The prepared ceramic samples were placed in a 40% hydrofluoric acid (HF) solution and chemically etched at 35°C. The samples were completely immersed in the preheated acid solution, ensuring they were separated and not overlapping. The etching time was 65 minutes. After etching, the samples were removed and quickly transferred to an ultrasonic cleaning tank filled with purified water. The samples were ultrasonically cleaned three times, 5 minutes each time, to remove residual acid and reaction products from the surface. Then, the samples were immersed in a 1% NaHCO3 solution for 5 minutes to further neutralize the residual acid. Finally, the samples were ultrasonically cleaned again with purified water three times, 5 minutes each time.

[0064] The acid-etched and cleaned samples were annealed at 1250°C for 60 minutes. Morphology, roughness, strength, and hydrothermal stability were then observed. The sample surface exhibited a snowflake-like groove pattern, with a roughness Ra of 1.15 μm (e.g., ...). Figure 1 , Figure 2 (As shown). Under hydrothermal conditions, the reactor was maintained at 135°C and 0.2 MPa for 100 hours. XRD analysis showed no evidence of a phase transition from tetragonal to monoclinic structure (e.g., ...). Figure 3 (As shown). This proves that the material still has excellent hydrothermal stability. After hydrothermal aging, neither hardness nor strength decreased.

[0065] Example 2

[0066] A high-entropy zirconia-based bioceramic material, Zr 1-x (Y 1-6y Al 2y Mg y Si y Sr 0.5y Ca 0.5y Ti y ) x O 2-x / 2 x=0.070, y=0.05.

[0067] The preparation method includes the following steps:

[0068] S1 Ball milling and mixing: The ceramic powder is obtained by ball milling and mixing according to the above composition.

[0069] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0070] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0071] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0072] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

[0073] The S1 process uses wet ball milling for mixing. The mass ratio of raw material, zirconia milling balls, and deionized water is as follows: raw material: zirconia milling balls: deionized water = 1:1.8:0.7.

[0074] The ball milling speed of S1 is 50 revolutions per minute, and the ball milling time is 8 hours.

[0075] The binder in S2 is polyvinyl alcohol, and the amount of binder added is 6 wt% of the ceramic powder.

[0076] The pressure during the pressing process in S2 is 60 MPa.

[0077] The pressure of the cold isostatic pressing in S3 is 200 MPa.

[0078] The discharge temperature of S4 is 700℃, and the heat preservation time is 2h.

[0079] The S5 employs a two-stage sintering process:

[0080] The first stage involves heating from room temperature to 1500℃ at a rate of ~5℃ / min, with a holding time of 1 hour at 1500℃.

[0081] The second stage involves cooling from 1500℃ to 1450℃ at a rate of 220℃ / min, holding at 1450℃ for 5 hours, and then cooling in the furnace to end the sintering process.

[0082] The bioceramic material obtained in this embodiment has a relative density of 99.6% and an average grain size of ≤220 nm as determined by scanning electron microscopy. The bioceramic material has a hardness of 14.6 ± 0.1 GPa, a biaxial flexural strength of 850 ± 20 MPa, and a Weibull modulus of 12. Under hydrothermal conditions, it was maintained in a hydrothermal reactor at 135°C and 0.2 MPa for 100 hours. XRD analysis showed no evidence of a phase transition from a tetragonal to a monoclinic structure. This demonstrates the material's excellent hydrothermal stability.

[0083] The sintered Y-TZP ceramic was placed in an ethanol + deionized water (1:1) solution and ultrasonically cleaned for 10 minutes to remove oil and contaminants. It was then rinsed with ultrapure water and dried with 50 °C hot air or clean air.

[0084] The prepared ceramic samples were placed in a 42% hydrofluoric acid (HF) solution and chemically etched at 40°C. The samples were completely immersed in the preheated acid solution, ensuring they were separated and not overlapping. The etching time was 60 minutes. After etching, the samples were removed and quickly transferred to an ultrasonic cleaning tank filled with purified water. The samples were ultrasonically cleaned three times, 5 minutes each time, to remove residual acid and reaction products. Then, the samples were soaked in a 1% sodium bicarbonate (NaHCO3) solution for 5 minutes to further neutralize residual acid. Finally, the samples were ultrasonically cleaned again with purified water three times, 5 minutes each time.

[0085] The acid-etched and cleaned samples were annealed at 1250°C for 60 minutes. Morphology, roughness, strength, and hydrothermal stability were then observed. The sample surface exhibited a snowflake-like groove pattern with a surface roughness Ra of 1.27 μm. No decrease in four-point complete strength was observed. Furthermore, the samples were kept in a hydrothermal reactor at 135°C and 0.2 MPa for 100 hours. XRD analysis showed no evidence of a phase transition from a tetragonal to a monoclinic structure. This demonstrates that the material retains excellent hydrothermal stability. Additionally, no decrease in hardness or strength was observed after hydrothermal aging.

[0086] Example 3

[0087] A high-entropy zirconia-based bioceramic material, Zr 1-x (Y 1-6y Al 2y Mg y Si y Sr 0.5y Ca 0.5y Ti y ) x O 2-x / 2 x = 0.030, y = 0.07. The preparation method includes the following steps:

[0088] S1 Ball milling and mixing: The ceramic powder is obtained by ball milling and mixing according to the above composition.

[0089] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0090] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0091] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0092] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

[0093] The S1 process uses wet ball milling for mixing. The mass ratio of raw material, zirconia milling balls, and deionized water is as follows: raw material: zirconia milling balls: deionized water = 1:1.8:0.7.

[0094] The ball milling speed of S1 is 50 revolutions per minute, and the ball milling time is 8 hours.

[0095] The binder in S2 is polyvinyl alcohol, and the amount of binder added is 6 wt% of the ceramic powder.

[0096] The pressure during the pressing process in S2 is 60 MPa.

[0097] The pressure of the cold isostatic pressing in S3 is 200 MPa.

[0098] The discharge temperature of S4 is 700℃, and the heat preservation time is 2h.

[0099] The S5 employs a two-stage sintering process:

[0100] The first stage involves heating from room temperature to 1500℃ at a rate of ~5℃ / min, with a holding time of 1 hour at 1500℃.

[0101] The second stage involves cooling from 1500℃ to 1425℃ at a rate of 220℃ / min, holding at 1425℃ for 5 hours, and then cooling in the furnace to end the sintering process.

[0102] The bioceramic material obtained in this embodiment has a relative density of 99.5% and an average grain size of ≤227 nm as measured by scanning electron microscopy. The bioceramic material exhibits excellent properties, with a hardness of 14.2±0.1 GPa, biaxial flexural strength of 816±20 MPa, and a Weibull modulus of 11. The bioceramic material provided by this invention demonstrates structural stability. Under hydrothermal conditions, it remained stable for 100 hours in a hydrothermal reactor at 135°C and 0.2 MPa. XRD analysis showed no evidence of a phase transition from a tetragonal to a monoclinic structure. This proves that the material has excellent hydrothermal stability.

[0103] The sintered Y-TZP ceramic was placed in an ethanol solution and ultrasonically cleaned for 10 minutes to remove oil and contaminants. It was then rinsed with ultrapure water and dried with hot air at 50 °C or clean air.

[0104] The prepared ceramic samples were placed in a 41% hydrofluoric acid solution and chemically etched at 40°C. The samples were completely immersed in the preheated acid solution, ensuring they were separated and not overlapping. The etching time was 60 minutes. After etching, the samples were removed and quickly transferred to an ultrasonic cleaning tank filled with purified water. The samples were ultrasonically cleaned three times, 5 minutes each time, to remove residual acid and reaction products from the surface. Then, the samples were immersed in a 1% NaHCO3 solution for 5 minutes to further neutralize the residual acid. Finally, the samples were ultrasonically cleaned again with purified water three times, 5 minutes each time.

[0105] The acid-etched and cleaned samples were annealed at 1250°C for 60 minutes. The sample surface exhibited a snowflake-like groove pattern with a roughness Ra of 1.32 μm. The samples were then kept in a hydrothermal reactor at 135°C and 0.2 MPa for 100 hours. XRD analysis showed no evidence of a phase transition from a tetragonal to a monoclinic structure. This demonstrates that the material retains excellent hydrothermal stability. No decrease in hardness or strength was observed after hydrothermal aging.

[0106] Comparative Example 1

[0107] A zirconia bioceramic material, Zr 1-x (Y 1-5y Al y Mg y Si y Sr y Ti y ) x O 2-x / 2

[0108] Where x and y represent molar amounts, x = 0.030, y = 0, and the preparation method specifically includes the following steps:

[0109] S1 Ball milling and mixing: The ceramic powder is obtained by ball milling and mixing according to the above composition.

[0110] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0111] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0112] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0113] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

[0114] The S1 process uses a wet ball milling method for mixing materials. The mass ratio of raw materials, zirconia grinding balls, and deionized water is as follows: raw materials: zirconia grinding balls: deionized water = 1:1.8:0.7. The ball milling speed is 50 revolutions per minute, and the ball milling time is 8 hours.

[0115] The binder in S2 is polyvinyl alcohol, and the amount of binder added is 6 wt% of the ceramic powder. The pressing pressure is 60 MPa.

[0116] The pressure of the cold isostatic pressing in S3 is 200 MPa.

[0117] The discharge temperature of S4 is 700℃, and the heat preservation time is 2h.

[0118] The S5 adopts a two-stage sintering process: the first stage involves heating from room temperature to 1500℃ at a heating rate of ~5℃ / min, and holding at 1500℃ for 1 hour; the second stage involves cooling from 1500℃ to 1425℃ at a cooling rate of 220℃ / min, holding at 1425℃ for 5 hours, and then cooling with the furnace to end the sintering process.

[0119] The ceramic material obtained in the comparative example had an average grain size ≤450 nm as measured by scanning electron microscopy. Its biaxial flexural strength was 520±35 MPa, corresponding to a Weibull modulus of 8. However, this ceramic material was structurally unstable. Under hydrothermal conditions, it was kept in a hydrothermal reactor at 135℃ and 0.2 MPa for 100 hours. XRD analysis showed evidence of a 38% monoclinic phase (Xm=0.38). A significant phase transition from a tetragonal structure to a monoclinic structure occurred (e.g., ...). Figure 4 ).

[0120] Comparative Example 2

[0121] A zirconia bioceramic material, Zr 1-x (Y 1-3y Al y Sr y Ti y ) x O 2-x / 2 Given x = 0.030 and y = 0.1, the preparation process includes the following steps:

[0122] S1 Ball milling and mixing: The ceramic powder is obtained by ball milling and mixing according to the above composition.

[0123] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0124] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0125] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0126] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

[0127] The S1 process uses a wet ball milling method for mixing materials. The mass ratio of raw materials, zirconia grinding balls, and deionized water is as follows: raw materials: zirconia grinding balls: deionized water = 1:1.8:0.7. The ball milling speed is 50 revolutions per minute, and the ball milling time is 8 hours.

[0128] The binder in S2 is polyvinyl alcohol, and the amount of binder added is 6 wt% of the ceramic powder. The pressing pressure is 60 MPa.

[0129] The pressure of the cold isostatic pressing in S3 is 200 MPa.

[0130] The discharge temperature of S4 is 700℃, and the heat preservation time is 2h.

[0131] The S5 employs a two-stage sintering process:

[0132] The first stage involves heating from room temperature to 1500℃ at a rate of ~5℃ / min, with a holding time of 1 hour at 1500℃.

[0133] The second stage involves cooling from 1500℃ to 1425℃ at a rate of 220℃ / min, holding at 1425℃ for 5 hours, and then cooling in the furnace to end the sintering process.

[0134] The bioceramic material obtained in this comparative example has an average grain size ≤420 nm as measured by scanning electron microscopy. Its biaxial flexural strength is 576±35 MPa, corresponding to a Weibull modulus of 8. However, the ceramic material is structurally unstable. Under hydrothermal conditions, after being held in a hydrothermal reactor at 135℃ and 0.2 MPa for 100 hours, XRD analysis revealed the presence of a 30% monoclinic phase (Xm=0.30). A significant phase transition from a tetragonal structure to a monoclinic structure occurred.

[0135] Comparative Example 3

[0136] A zirconia bioceramic material, Zr 1-x (Y 1-3y Al y Mg y Si y ) x O 2-x / 2 Given x = 0.030 and y = 0.07, the preparation process specifically includes the following steps:

[0137] S1 Ball milling and mixing: The ceramic powder is obtained by ball milling and mixing according to the above composition.

[0138] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0139] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0140] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0141] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

[0142] The S1 process uses a wet ball milling method for mixing materials. The mass ratio of raw materials, zirconia grinding balls, and deionized water is as follows: raw materials: zirconia grinding balls: deionized water = 1:1.8:0.7. The ball milling speed is 50 revolutions per minute, and the ball milling time is 8 hours.

[0143] The binder in S2 is polyvinyl alcohol, and the amount of binder added is 6 wt% of the ceramic powder. The pressing pressure is 60 MPa.

[0144] The pressure of the cold isostatic pressing in S3 is 200 MPa.

[0145] The discharge temperature of S4 is 700℃, and the heat preservation time is 2h.

[0146] The S5 process involves a single-stage sintering process: the temperature is raised from room temperature to 1500℃ at a rate of ~5℃ / min, and held at 1500℃ for 6 hours; sintering is then completed by cooling in the furnace.

[0147] The bioceramic material obtained in this comparative example has an average grain size ≤430 nm as determined by scanning electron microscopy. It exhibits a biaxial flexural strength of 565±35 MPa and a Weibull modulus of 9. However, the ceramic material is structurally unstable. Under hydrothermal conditions, after being held in a hydrothermal reactor at 135℃ and 0.2 MPa for 100 hours, XRD analysis revealed a 35% monoclinic phase (Xm=0.35). A significant phase transition from a tetragonal structure to a monoclinic structure was observed.

[0148] Comparative Example 4

[0149] The formulation in Example 1 yields ceramics via a one-step direct reaction sintering method. This method includes the following steps:

[0150] S1 Ball milling and mixing: The ceramic powder is obtained by ball milling and mixing according to the above composition.

[0151] S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body.

[0152] S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank.

[0153] S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment;

[0154] S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

[0155] The S1 process uses a wet ball milling method for mixing materials. The mass ratio of raw materials, zirconia grinding balls, and deionized water is as follows: raw materials: zirconia grinding balls: deionized water = 1:1.8:0.7. The ball milling speed is 50 revolutions per minute, and the ball milling time is 8 hours.

[0156] The binder in S2 is polyvinyl alcohol, and the amount of binder added is 6 wt% of the ceramic powder. The pressing pressure is 60 MPa.

[0157] The pressure of the cold isostatic pressing in S3 is 200 MPa.

[0158] The discharge temperature of S4 is 700℃, and the heat preservation time is 2h.

[0159] The S5 adopts a one-stage sintering method: the temperature is raised from room temperature to 1425℃ at a rate of ~5℃ / min, and held at 1425℃ for 5 hours; sintering is completed by cooling in the furnace.

[0160] The bioceramic material obtained in this comparative example has a relative density of 95%, which does not meet the requirements for use.

[0161] Comparative Example 5

[0162] The ceramic prepared in Example 1 using a two-step method underwent surface modification via prolonged strong acid etching. The sintered ceramic was placed in an ethanol + deionized water (1:1) solution and ultrasonically cleaned for 10 minutes to remove oil and contaminants. It was then rinsed with ultrapure water and dried with hot air at 50 °C or clean air. The prepared ceramic was then placed in a 50% HF solution and chemically etched at 60 °C. The sample was completely immersed in the preheated acid solution, ensuring it was separated and not overlapping. The etching time was 120 minutes. After etching, the sample was removed and quickly transferred to an ultrasonic cleaning tank filled with pure water. It was ultrasonically cleaned three times, 5 minutes each time, to remove residual acid and reaction products. The sample was then soaked in NaHC O3 solution for 5 minutes to neutralize the residual acid. The etched and cleaned sample was then tested for hydrothermal stability and strength. The sample was kept in a hydrothermal reactor at 135 °C and 0.2 MPa for 100 hours under hydrothermal conditions. XRD analysis revealed a 25% monoclinic phase transition (Xm=0.25). Additionally, the biaxial bending strength decreased by 56%.

[0163] Comparative Example 6

[0164] The ceramic prepared in Example 1 using a two-step method underwent surface modification using low-concentration acid etching. The sintered ceramic was placed in an ethanol + deionized water (1:1) solution and ultrasonically cleaned for 10 minutes to remove oil and contaminants. It was then rinsed with ultrapure water and dried with 50°C hot air or clean air. The prepared ceramic was then placed in an HF solution (20% concentration) and chemically etched at 60°C. The sample was completely immersed in the preheated acid solution, keeping the samples separate and not overlapping. The etching time was 120 minutes each time. After etching, the sample was removed and transferred to an ultrasonic cleaning tank filled with pure water, cleaned three times for 5 minutes each time to remove residual acid and reaction products. The sample was then soaked in a NaHCO3 solution for 5 minutes to neutralize the residual acid. The morphology of the acid-etched and cleaned sample was observed using a scanning electron microscope; no snowflake-like groove morphology was observed (e.g., ...). Figure 5 ).

[0165] Example of effect

[0166] Table 1 shows a comparison of the product parameters of Examples 1-3 and Comparative Examples 1-6.

[0167] Table 1 Comparison of parameters between the examples and comparative examples

Claims

1. A zirconia-based bioceramic material, characterized in that, Its general structural formula is: Zr 1-x (Y 1-6y Al 2y Mg y Si y Sr 0.5y Ca 0.5y Ti y ) x O 2-x / 2 , of which 0.025 <x<0.075,0.05 ≤y≤ 0.1。 2. The high-entropy zirconia-based bioceramic material according to claim 1, characterized in that, The high-entropy zirconia-based bioceramic material has a relative density greater than 99% and an average grain size ≤240nm.

3. The zirconia-based bioceramic material according to claim 1, characterized in that, The high-entropy zirconia-based bioceramic material has a snowflake-like groove pattern on its surface, and a surface roughness Ra≤1.15 μm.

4. The zirconia-based bioceramic material according to claim 1, characterized in that, The high-entropy zirconia-based bioceramic material has a hardness greater than 14.0 GPa, a biaxial bending strength greater than 800 MPa, and a Weibull modulus greater than 10.

5. The zirconia-based bioceramic material according to claim 1, characterized in that, The high-entropy zirconia-based bioceramic material was kept in a hydrothermal reactor at 135°C and 0.2 MPa for 100 hours. XRD analysis showed that no phase transition from a tetragonal structure to a monoclinic structure occurred.

6. A method for preparing a zirconia-based bioceramic material according to any one of claims 1-5, comprising the following steps: S1 Ball Milling Mixing: According to the formula, select nanoparticles of ZrO2, Y2O3, Al2O3, MgO, SiO2, SrO, CaO, and TiO2, and ball mill them to obtain uniformly mixed ceramic powder; S2 Granulation and Pressing: Add a binder to the ceramic powder obtained in S1 for granulation, press it into shape, and obtain a green body. S3 Cold Isostatic Pressing Treatment: The green blank obtained in S2 is subjected to cold isostatic pressing to densify it, resulting in a compacted green blank. S4 Plastic Removal Treatment: The compacted green blank obtained in S3 is subjected to plastic removal treatment; S5 sintering: The green body after S4 plastic removal treatment is subjected to reaction sintering to obtain bioceramic material.

7. The method according to claim 6, characterized in that, The S1 material is mixed using a wet ball milling method, with a mass ratio of raw material, zirconia milling balls, and deionized water of 1:(1.6~2.0):(0.65~0.80); the ball milling speed of the S1 is 50 r / min, and the ball milling time is 8~10h.

8. The method according to claim 6, characterized in that, The binder in S2 is polyvinyl alcohol, and the amount of binder added is 5wt% to 7wt% of the ceramic powder. The pressing pressure is 50 to 75 MPa.

9. The method according to claim 6, characterized in that, The pressure of the cold isostatic pressing in S3 is 180-220 MPa.

10. The method according to claim 6, characterized in that, The discharge temperature of S4 is 600℃~800℃, and the heat preservation time is 2~3h.

11. The method according to claim 6, characterized in that, The S5 adopts a two-stage sintering mechanism: the first stage involves heating from room temperature to 1500℃ at a rate of 2-5℃ / min, and holding at 1500℃ for 1 hour; the second stage involves cooling from 1500℃ to 1425-1450℃ at a rate of 200℃ / min-300℃ / min, and then holding at 1425-1450℃ for 3-5 hours, followed by furnace cooling to end the sintering process.

12. The method according to claim 6, characterized in that, It also includes the following surface treatment steps: S6 Cleaning and Drying: Place the sintered ceramic from step S5 above into an ethanol solution, clean it with ultrasound, and then dry it. S7 surface chemical etching: S6 ceramic material is chemically etched by immersing it in a 38%~45% hydrofluoric acid solution; S8 Neutralize residual acid: Take out the etched sample from S7 and transfer it to an ultrasonic cleaning tank filled with pure water. Use ultrasonic cleaning to remove residual acid and reaction products from the surface. Then, immerse the sample in NaHCO3 solution to neutralize the residual acid and clean it again. S9 Annealing: The sample treated with S8 is annealed at 1250℃.

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