Method for preparing glass infiltrated zirconia bioceramic material by low temperature introduction and application thereof

Abstract

The application discloses a method for preparing glass-infiltrated zirconia bioceramic material by a low-temperature introduction method and application, and belongs to the technical field of glass-infiltrated bioceramic materials. The method comprises the following steps: first, preparing pyrolytic carbon-coated glass-infiltrated particles, then uniformly doping the particles into zirconia ceramic powder, spraying and dry-pressing forming to obtain a green body, and finally, sequentially performing oxygen-free pre-sintering and low-oxygen infiltration on the green body to prepare the glass-infiltrated zirconia bioceramic material. The preparation process is simple, the cost is low, and the large-scale production can be realized. The pyrolytic carbon realizes the preparation of the ceramic framework with connected pores in the pre-sintering process, and the controllable introduction of the glass-infiltrated phase is realized through powder doping, thereby avoiding the technical problem of incomplete pore infiltration caused by traditional high-temperature infiltration, and providing a reliable technical path for preparing personalized and customized bioceramic implants.

Description

Technical Field

[0001] This invention relates to the field of glass-infiltrated bioceramic materials technology, specifically to a method and application for preparing glass-infiltrated zirconia bioceramic materials using a low-temperature introduction method. Background Technology

[0002] Zirconia ceramics (mainly tetragonal zirconia) have become an important structural ceramic material in the biomedical field due to their excellent mechanical properties, good chemical stability, and excellent biocompatibility. They are widely used in load-bearing implant components such as dental prostheses (all-ceramic crowns, bridge abutments), artificial hip joint heads, and bone fixation screws. With their metal-like strength and near-natural tooth translucency, they meet the needs of modern minimally invasive restorations and long-term service.

[0003] However, the inherent brittleness of zirconia ceramics remains a fatal flaw. Although stress-induced phase transformation (TEV) toughening mechanisms can inhibit crack propagation, in humid physiological environments, the tetragonal phase (t-ZrO2) is prone to low-temperature aging degradation (LTD), i.e., spontaneous surface transformation to the monoclinic phase (m-ZrO2), accompanied by volume expansion (approximately 3%-5%) and microcrack initiation, leading to strength degradation or even sudden fracture during long-term service. Furthermore, conventional sintering temperatures (≥1400℃) are too high, easily causing abnormal grain growth and weakening the TEV toughening effect; subsequent hard processing (such as grinding and polishing) introduces a surface damage layer and residual compressive stress, further reducing component reliability. Even more challenging is that complex-shaped implants (such as thin-walled crowns or porous bone scaffolds) are difficult to obtain a uniform, dense body through isostatic pressing or dry pressing; sintering shrinkage anisotropy often leads to dimensional distortion, significantly increasing post-processing costs and scrap rates.

[0004] To overcome the aforementioned challenges, researchers introduced glass infiltration technology, which involves infiltrating a low-melting-point glass phase (such as silicate or borate systems) into a pre-sintered porous zirconia framework. The glass melt is then driven by capillary forces to fill the pores, achieving near-net-shape forming and densification. This process lowers the overall sintering temperature and utilizes the matching thermal expansion coefficients of glass and zirconia to suppress phase transformation and mitigate interfacial thermal stress. The infiltrated composite material combines the high hardness of ceramics with the toughness of glass. Furthermore, the glass phase can seal surface pores, resisting LTD erosion. It has already been used to manufacture inlays, veneers, and customized bone implants, demonstrating promising clinical prospects.

[0005] However, existing high-temperature infiltration technology still has significant limitations. First, to ensure a sufficiently low viscosity of the glass melt for complete infiltration, a high infiltration temperature is often required. This, in turn, leads to continued grain growth in the zirconia matrix, weakening the grain refinement strengthening effect. Furthermore, at high temperatures, the glass-zirconia interface reacts to form brittle phases such as zircon (ZrSiO4), severely degrading fracture toughness (by 20%-30%). Second, prolonged holding at high temperatures promotes glass phase crystallization. The precipitated crystals thermally mismatch with the matrix, generating microcracks. Simultaneously, the residual glass phase introduces tensile residual stress during cooling due to differences in shrinkage rates, causing a decrease in flexural strength instead of an increase. Third, the wettability of the molten glass to the framework is greatly affected by the pore size distribution. Necked or closed-pore areas often cannot fully penetrate, leading to local voids and density inhomogeneities, which become fatigue crack initiation points. These degradations in mechanical properties severely limit its application in core load-bearing components. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention aims to provide a method and application for preparing glass-infiltrated zirconia bioceramic materials using a low-temperature infiltration method, thereby resolving the issue of insufficient mechanical properties in existing high-temperature infiltration techniques for preparing glass-infiltrated zirconia bioceramic materials.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A first aspect of the present invention provides a method for preparing glass-infiltrated zirconia bioceramic materials by a low-temperature introduction method, comprising the following steps: S1. Preparation of glass micro powder: First, SiO2, La2O3, ZrO2, Al2O3 and CeO2 are used as raw materials and melted at high temperature to obtain glass fragments. Then, they are ball-milled and sieved to obtain glass powder. S2. Preparation of pyrolytic carbon-coated glass permeable particles: The glass micropowder obtained in S1 was subjected to surface layered pyrolytic carbon deposition to obtain pyrolytic carbon-coated glass permeable particles; S3. Preparation of the green body: Zirconia matrix, dispersant, binder and S2-derived pyrolytic carbon-coated glass permeable particles are mixed evenly in a dispersion medium to obtain a mixed slurry. The mixed slurry is then spray-granulated to obtain a composite dry-pressed powder. Finally, the composite dry-pressed powder is dry-pressed and dried to obtain a green body. S4, oxygen-free pre-sintering: The green blank obtained from S3 was sintered under a protective atmosphere to obtain a pre-sintered green body. S5, Low oxygen permeability: The pre-sintered green body obtained by S4 was sintered in a mixed atmosphere of Ar and O2 to obtain glass-infiltrated zirconia bioceramic material.

[0008] The beneficial effects of this invention are as follows: This invention proposes a low-temperature sintering and infiltration integrated process: pyrolytic carbon-coated glass particles are uniformly doped into zirconia ceramic powder, and pre-sintering is first performed in an oxygen-free atmosphere. The pyrolytic carbon acts as a temporary pore-forming agent to prevent the glass phase from sintering with the zirconia ceramic phase, forming a ceramic skeleton with interconnected pores. Subsequently, a controllable oxidizing atmosphere is introduced, and the pyrolytic carbon is gradually oxidized to release CO2 gas through a gradient heating process. At the same time, the in-situ released glass liquid phase uniformly wets and fills the micropores distributed in the skeleton, achieving simultaneous infiltration and densification. This successfully solves the problem of insufficient mechanical properties when preparing glass-infiltrated zirconia bioceramic materials using existing high-temperature infiltration technology.

[0009] Furthermore, the mass ratio of SiO2, La2O3, ZrO2, Al2O3 and CeO2 in S1 is (25-38):(10-25):(5-18):(15-25):(0-5).

[0010] Furthermore, the carbon source for pyrolytic carbon deposition in S2 is at least one of methane, ethanol, and propane, the deposition heating rate is 5-10℃ / min, the deposition temperature is 900-1000℃, and the deposition time is 1-3 h.

[0011] Furthermore, in S3, the zirconium oxide matrix is ​​3Y-PSZ powder with a particle size of 30-80 nm; the amount of pyrolytic carbon-coated glass permeable particles added is 5 wt%-20 wt% of the mass of 3Y-PSZ powder; the dispersant is ammonium polyacrylate, and the amount added is 0.1 wt%-2 wt% of the total mass of pyrolytic carbon-coated glass permeable particles and 3Y-PSZ powder; the binder is polyvinyl alcohol, and the amount added is 2 wt%-8 wt% of the total mass of pyrolytic carbon-coated glass permeable particles and 3Y-PSZ powder.

[0012] Furthermore, the mixed slurry in S3 is mixed uniformly by ultrasonic dispersion, with an ultrasonic dispersion power of 400-600 W and a time of 8-12 h.

[0013] Furthermore, the inlet temperature of the spray granulation in S3 is 140-160℃, and the outlet temperature is 75-115℃.

[0014] Furthermore, the dry pressing conditions in S3 are as follows: first, increase the pressure to 40-70 MPa and hold for 3-5 min; then increase to 80-140 MPa and hold for 8-12 min; finally, increase to 190-210 MPa and hold for 15-18 min.

[0015] Furthermore, the drying process in S3 is carried out at a temperature of 80-120℃ for 2-4 hours.

[0016] The beneficial effects of adopting the above-mentioned further technical solutions are as follows: the present invention eliminates internal stress in the green blank and improves the strength of the green blank through drying treatment.

[0017] Furthermore, the protective atmosphere in S4 is argon gas with a flow rate of 360-480 mL / h; the sintering conditions are as follows: first, heat to 240-320℃ at a rate of 0.3-1.2℃ / min and hold for 3-5 h, then heat to 1200-1250℃ at a rate of 1-3℃ / min and hold for 16-28 h, and finally cool to room temperature at a rate of 3-5℃ / min.

[0018] The beneficial effects of adopting the above-mentioned further technical solutions are as follows: In the oxygen-free pre-sintering stage, the pyrolytic carbon layer exists stably and does not oxidize, effectively isolating the glass particles from direct contact with the zirconia matrix, ensuring the sintering of zirconia while avoiding early softening and adhesion of the glass phase; at the same time, the occupation and pinning effects of pyrolytic carbon significantly inhibit the migration of zirconia grain boundaries, effectively strengthening the three-dimensionally connected zirconia ceramic skeleton.

[0019] Furthermore, the total flow rate of the Ar and O2 mixture in S5 is 120-360 mL / h, and the flow rate ratio of argon to oxygen is (14-23):1; the sintering conditions are as follows: first, heat to 850-950℃ at a rate of 3-5℃ / min and hold for 3-8 h, then heat to 1250-1350℃ at a rate of 2-4℃ / min and hold for 8-12 h, and finally cool to room temperature at a rate of 3-5℃ / min.

[0020] The beneficial effects of adopting the above-mentioned further technical solution are as follows: In the low-oxygen permeation stage, the present invention first raises the temperature to a lower temperature at a certain heating rate and holds it at that temperature for an appropriate time, allowing the pyrolytic carbon to slowly oxidize under controllable low-oxygen conditions, uniformly releasing CO2 gas, and avoiding concentrated heat release that could cause cracking of the green body or local overheating; then, the temperature is further raised to a higher temperature at a certain rate and held for several hours. In this second temperature zone, the pyrolytic carbon is completely exhausted, and the glass liquid phase released in situ, driven by capillary force, rapidly and uniformly permeates along the interconnected micropore channels formed by S3, filling the micropores distributed throughout the entire zirconia framework, thus achieving the simultaneous completion of glass permeation and ceramic densification.

[0021] In a second aspect, the present invention provides a glass-infiltrated zirconia bioceramic material, which is prepared by the method described above.

[0022] A third aspect of the present invention provides the application of the above-described glass-infiltrated zirconia bioceramic material in the preparation of medical implant components.

[0023] The present invention has the following beneficial effects: 1. The preparation process is simple, feasible, and low-cost, enabling large-scale production. This invention employs traditional wet mixing, spray granulation, and dry pressing processes, with highly versatile equipment. By utilizing the "in-situ release" strategy of pyrolytic carbon-coated glass particles, the traditional "high-temperature infiltration" process is transformed into a "low-oxygen in-situ infiltration" process, greatly simplifying the operation steps and reducing the difficulty, thus possessing excellent prospects for industrial-scale production.

[0024] 2. Significantly improved mechanical properties of the material. This invention introduces a glassy permeable phase at low temperature, avoiding the problem of incomplete permeation through pores caused by traditional high-temperature permeation. The prepared composite material, while ensuring sufficient glassy phase introduction, exhibits a 49.1% increase in biaxial bending strength compared to traditional processes, significantly improving mechanical properties.

[0025] 3. Achieving controllable introduction of the glass phase content and realizing high-precision near-net-shape forming of complex shapes. This invention achieves controllable introduction of the glass-permeable phase through powder doping, avoiding the problem of insufficient product reliability caused by uneven permeation in traditional processes, thereby improving product precision and providing a reliable technical path for the preparation of personalized, customized high-end bioceramic implants. Attached Figure Description

[0026] Figure 1 A schematic diagram of the preparation process for glass-infiltrated zirconia bioceramic materials using the low-temperature introduction method; Figure 2 The XRD pattern of the glass micropowder prepared in Example 3; Figure 3 The XRD pattern of the glass micropowder after surface pyrolysis carbon layer preparation in Example 3; Figure 4 Images of the test mold and the sample from Example 3 before, during, and after the test; Figure 5 The load-displacement curves during the biaxial bending test in Example 1 are shown. Figure 6 The load-displacement curves during the biaxial bending test in Example 2 are shown. Figure 7 The load-displacement curves during the biaxial bending test in Example 3 are shown. Figure 8 The load-displacement curves during the biaxial bending test are shown in Comparative Example 3. Detailed Implementation

[0027] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0028] Example 1: A method for preparing glass-infiltrated zirconia bioceramic materials using a low-temperature introduction method (see schematic diagram of the preparation process). Figure 1 (As shown), including the following steps: S1. Preparation of glass micro powder: First, SiO2, La2O3, ZrO2, Al2O3, and CeO2 were used as the permeation phase raw materials. They were accurately weighed in a mass ratio of 30:25:18:22:5 and placed in a crucible. The crucible was melted at 1600℃ for 2 h and then quenched in water to obtain transparent glass fragments. The glass fragments were then placed in a planetary ball mill and milled at 300 r / min for 12 h using anhydrous ethanol as the medium and zirconia balls as the grinding media. Finally, the resulting slurry was sieved through a 200-mesh standard sieve and dried at 80℃ for 12 h to obtain glass micro powder.

[0029] S2. Preparation of pyrolytic carbon-coated glass permeable particles: The glass micropowder obtained in S1 was evenly spread in the homogenization zone of the pyrolytic carbon deposition furnace, and the furnace temperature was raised to 900℃ at a heating rate of 5℃ / min. Then, methane precursor (flow rate of 200 mL / min) was introduced and the deposition was carried out at this temperature for 1 h. After the deposition was completed, the mixture was cooled to room temperature at 5℃ / min under argon protection to obtain pyrolytic carbon-coated glass permeable particles with a complete core-shell structure. The carbon layer was of uniform thickness and well bonded to the glass matrix.

[0030] S3. Preparation of the green body: First, 5% of the mass of 3Y-PSZ powder, pyrolytic carbon-coated glass permeable particles obtained from S2 were weighed and placed together with 3Y-PSZ nanoparticles with a particle size of 30 nm in deionized water. 0.1% of the total mass of 3Y-PSZ powder and pyrolytic carbon-coated glass permeable particles, 0.1% of ammonium polyacrylate dispersant, and 2% of polyvinyl alcohol binder were added. The mixture was dispersed at 400 W ultrasonic power for 8 h to obtain a uniform slurry with a solid content of 30 vol%. Then, the slurry was spray-granulated (inlet temperature 140℃, outlet temperature 75℃) to obtain a composite dry-pressed powder with excellent flowability. Next, the composite dry-pressed powder was filled into a stainless steel mold and dry-pressed using a three-stage gradient pressurization method: first, pressurized to 40 MPa and held for 3 min; then, pressurized to 80 MPa and held for 8 min; finally, pressurized to 190 MPa and held for 15 min. After demolding, the green blank is placed in a constant temperature drying oven and dried at 80℃ for 2 hours to eliminate internal stress and improve the strength of the green blank, so as to obtain a uniformly dense green blank to be sintered.

[0031] S4, oxygen-free pre-sintering: The green blanks to be sintered obtained from S3 were placed in an atmosphere tube furnace and evacuated to a vacuum of 1.0 × 10⁻⁶.-3 After Pa, high-purity argon gas with a purity ≥99.999% was introduced, and the gas flow rate was controlled at 360 mL / h to maintain an oxygen-free atmosphere. The temperature was increased to 240℃ at 0.3℃ / min and held for 3 h; then, the temperature was further increased to 1200℃ at 1℃ / min and held for 16 h for pre-sintering. After sintering, the temperature was cooled to room temperature at 3℃ / min to obtain a pre-sintered green body with a complete pyrolytic carbon layer and refined zirconia grain size.

[0032] S5, Low oxygen permeability: The pre-sintered green body obtained from S4 was placed in an oxidation furnace, and an Ar-O2 mixed gas (total flow rate 120 mL / h, argon:oxygen = 14:1) was introduced. Sintering was carried out using a gradient heating process: the temperature was increased to 850℃ at 3℃ / min and held for 3 h to allow the pyrolytic carbon to slowly oxidize under controlled low oxygen conditions and uniformly release CO2 gas; then the temperature was increased to 1250℃ at 2℃ / min and held for 8 h to allow the glass liquid phase to fully wet and fill the micropores under capillary force; after the holding period, the temperature was cooled to room temperature with the furnace at 3℃ / min to obtain the glass-infiltrated zirconia bioceramic composite material.

[0033] Example 2: A method for preparing glass-infiltrated zirconia bioceramic materials using a low-temperature introduction method includes the following steps: S1. Preparation of glass micro powder: First, SiO2, La2O3, ZrO2, Al2O3, and CeO2 were used as the permeation phase raw materials. They were accurately weighed in a mass ratio of 35:20:15:25:5 and placed in a crucible. The crucible was melted at 1600℃ for 2 h and then quenched in water to obtain transparent glass fragments. The glass fragments were then placed in a planetary ball mill and milled at 300 r / min for 12 h using anhydrous ethanol as the medium and zirconia balls as the grinding media. Finally, the resulting slurry was sieved through a 200-mesh standard sieve and dried at 80℃ for 12 h to obtain glass micro powder.

[0034] S2. Preparation of pyrolytic carbon-coated glass permeable particles: The glass micropowder obtained in S1 was evenly spread in the homogenization zone of the pyrolytic carbon deposition furnace, and the furnace temperature was raised to 950℃ at a heating rate of 7.5℃ / min. Then, an ethanol precursor was introduced (flow rate of 200 mL / min), and the deposition was maintained at this temperature for 2 h. After deposition, the mixture was cooled to room temperature at 5℃ / min under argon protection to obtain pyrolytic carbon-coated glass permeable particles with a complete core-shell structure. The carbon layer was of uniform thickness and well bonded to the glass matrix.

[0035] S3. Preparation of the green body: First, 12.5% ​​of the mass of 3Y-PSZ powder, pyrolytic carbon-coated glass permeable particles obtained from S2 were weighed and placed together with 3Y-PSZ nanoparticles with a particle size of 50 nm in deionized water. 1.05% of the total mass of 3Y-PSZ powder and pyrolytic carbon-coated glass permeable particles, ammonium polyacrylate dispersant, and 5% polyvinyl alcohol binder were added. The mixture was dispersed at 500 W ultrasonic power for 10 h to obtain a uniform slurry with a solid content of 30 vol%. Then, the slurry was spray-granulated (inlet temperature 150℃, outlet temperature 95℃) to obtain a composite dry-pressed powder with excellent flowability. Next, the composite dry-pressed powder was filled into a stainless steel mold and dry-pressed using a three-stage gradient pressurization method: first, pressurized to 55 MPa and held for 4 min; then, pressurized to 110 MPa and held for 10 min; finally, pressurized to 200 MPa and held for 16.5 min. After demolding, the green blank is placed in a constant temperature drying oven and dried at 100℃ for 3 hours to eliminate internal stress and improve the strength of the green blank, thus obtaining a uniformly dense green blank to be sintered.

[0036] S4, oxygen-free pre-sintering: The green blanks to be sintered obtained from S3 were placed in an atmosphere tube furnace and evacuated to a vacuum of 1.0 × 10⁻⁶. -3 After Pa, high-purity argon gas with a purity ≥99.999% was introduced, and the gas flow rate was controlled at 420 mL / h to maintain an oxygen-free atmosphere. The temperature was increased to 280℃ at 0.75℃ / min and held for 4 h; then the temperature was increased to 1220℃ at 2℃ / min and held for 22 h for pre-sintering; after sintering, the temperature was cooled to room temperature at 4℃ / min to obtain a pre-sintered green body with a complete pyrolytic carbon layer and refined zirconia grain size.

[0037] S5, Low oxygen permeability: The pre-sintered green body obtained from S4 was placed in an oxidation furnace, and an Ar-O2 mixed gas (total flow rate 240 mL / h, argon:oxygen = 18.5:1) was introduced. Sintering was carried out using a gradient heating process: the temperature was increased to 900℃ at 4℃ / min and held for 5.5 h to allow the pyrolytic carbon to slowly oxidize under controlled low oxygen conditions and uniformly release CO2 gas; then the temperature was increased to 1300℃ at 3℃ / min and held for 10 h to allow the glass liquid phase to fully wet and fill the micropores under capillary force; after the holding period, the temperature was cooled to room temperature with the furnace at 4℃ / min to obtain the glass-infiltrated zirconia bioceramic composite material.

[0038] Example 3: A method for preparing glass-infiltrated zirconia bioceramic materials using a low-temperature introduction method includes the following steps: S1. Preparation of glass micro powder: First, SiO2, La2O3, ZrO2, Al2O3, and CeO2 were used as the permeation phase raw materials. They were accurately weighed in a mass ratio of 38:25:18:15:4 and placed in a crucible. The crucible was melted at 1600℃ for 2 h and then quenched in water to obtain transparent glass fragments. The glass fragments were then placed in a planetary ball mill and milled at 300 r / min for 12 h using anhydrous ethanol as the medium and zirconia balls as the grinding media. Finally, the resulting slurry was sieved through a 200-mesh standard sieve and dried at 80℃ for 12 h to obtain glass micro powder.

[0039] S2. Preparation of pyrolytic carbon-coated glass permeable particles: The glass micropowder obtained in S1 was evenly spread in the homogenization zone of the pyrolytic carbon deposition furnace, and the furnace temperature was raised to 1000℃ at a heating rate of 10℃ / min. Then, propane precursor (flow rate of 200 mL / min) was introduced and the deposition was maintained at this temperature for 3 h. After deposition, the particles were cooled to room temperature at 5℃ / min under argon protection to obtain pyrolytic carbon-coated glass permeable particles with a complete core-shell structure. The carbon layer was of uniform thickness and well bonded to the glass matrix.

[0040] S3. Preparation of the green body: First, pyrolytic carbon-coated glass permeable particles obtained from S2, accounting for 20% of the mass of 3Y-PSZ powder, were weighed and placed together with 3Y-PSZ nanoparticles with a particle size of 80 nm in deionized water. Then, 2% of the total mass of 3Y-PSZ powder and pyrolytic carbon-coated glass permeable particles as ammonium polyacrylate dispersant and 8% as polyvinyl alcohol binder were added. The mixture was dispersed at 600 W ultrasonic power for 12 h to obtain a uniform slurry with a solid content of 30 vol%. Next, the slurry was spray-granulated (inlet temperature 160℃, outlet temperature 115℃) to obtain a composite dry-pressed powder with excellent flowability. Then, the composite dry-pressed powder was filled into a stainless steel mold and dry-pressed using a three-stage gradient pressurization method: first, pressurized to 70 MPa and held for 5 min; then, pressurized to 140 MPa and held for 12 min; finally, pressurized to 210 MPa and held for 18 min. After demolding, the green blank is placed in a constant temperature drying oven and dried at 120℃ for 4 hours to eliminate internal stress and improve the strength of the green blank, so as to obtain a uniformly dense green blank to be sintered.

[0041] S4, oxygen-free pre-sintering: The green blanks to be sintered obtained from S3 were placed in an atmosphere tube furnace and evacuated to a vacuum of 1.0 × 10⁻⁶. -3After Pa, high-purity argon gas with a purity ≥99.999% was introduced, and the gas flow rate was controlled at 480 mL / h to maintain an oxygen-free atmosphere. The temperature was increased to 320℃ at 1.2℃ / min and held for 5 h; then, the temperature was further increased to 1250℃ at 3℃ / min and held for 28 h for pre-sintering. After sintering, the temperature was cooled to room temperature at 5℃ / min to obtain a pre-sintered green body with a complete pyrolytic carbon layer and refined zirconia grain size.

[0042] S5, Low oxygen permeability: The pre-sintered green body obtained from S4 was placed in an oxidation furnace, and an Ar-O2 mixed gas (total flow rate 360 ​​mL / h, argon:oxygen = 23:1) was introduced. Sintering was carried out using a gradient heating process: the temperature was increased to 950℃ at 5℃ / min and held for 8 h to allow the pyrolytic carbon to slowly oxidize under controlled low oxygen conditions and uniformly release CO2 gas; then the temperature was further increased to 1350℃ at 4℃ / min and held for 12 h to allow the glass liquid phase to fully wet and fill the micropores under capillary force; after the holding period, the temperature was cooled to room temperature with the furnace at 5℃ / min to obtain the glass-infiltrated zirconia bioceramic composite material.

[0043] Comparative Example 1: A low-temperature infiltration method for preparing glass-infiltrated zirconia bioceramic materials differs from that of Example 1 in that S2 is omitted, 3Y-PSZ ceramic particles are directly used as raw materials in S3, the dry pressing pressure is changed to a constant 30 MPa, the holding time is the same as in Example 1, the holding time for oxygen-free pre-sintering in S4 is 4 h, and before low-oxygen infiltration in S5, the glass micropowder obtained in S1 is coated on the surface of the pre-sintered green body obtained after oxygen-free pre-sintering in S4. The remaining steps are the same as in Example 1.

[0044] Comparative Example 2: A low-temperature infiltration method for preparing glass-infiltrated zirconia bioceramic materials differs from that of Example 2 in that S2 is omitted, 3Y-PSZ ceramic particles are directly used as raw materials in S3, the dry pressing pressure is changed to a constant 30 MPa, the holding time is the same as in Example 2, the holding time for oxygen-free pre-sintering in S4 is 4 h, and before low-oxygen infiltration in S5, the glass micropowder obtained in S1 is coated on the surface of the pre-sintered body obtained after oxygen-free pre-sintering in S4. The remaining steps are the same as in Example 2.

[0045] Comparative Example 3: A low-temperature infiltration method for preparing glass-infiltrated zirconia bioceramic materials differs from that of Example 3 in that S2 is omitted, 3Y-PSZ ceramic particles are directly used as raw materials in S3, the dry pressing pressure is changed to a constant 30 MPa, the holding time is the same as in Example 3, the holding time for oxygen-free pre-sintering in S4 is 4 h, and before low-oxygen infiltration in S5, the glass micropowder obtained in S1 is coated on the surface of the pre-sintered body obtained after oxygen-free pre-sintering in S4. The remaining steps are the same as in Example 3.

[0046] Experimental Example 1: XRD Analysis Taking Example 3 as an example, XRD analysis was performed on the products obtained before and after pyrolytic carbon deposition on the surface of glass micropowder. The experimental results are as follows: Figure 2 and Figure 3 As shown.

[0047] The results showed that after step S2, the XRD pattern of the glass micropowder showed obvious carbon peaks, confirming that a pyrolytic carbon layer had been successfully deposited on its surface.

[0048] Test Example 2: Biaxial Bending Test Biaxial bending tests were performed on the glass-infiltrated zirconia bioceramic composite materials prepared in Examples 1-3 and Comparative Examples 1-3, respectively.

[0049] According to the biaxial bending strength test standard in ISO 6872:2024, the international standard for dental ceramic materials, a universal testing machine was used for biaxial bending strength testing. The sample size was 15 (± 0.5) mm × 1.5 (± 0.2) mm, the loading range was 2 kN, the loading speed was 0.5 mm / min, and the inlet force was set to 5 N. The computer collected relevant data through load and displacement sensors. The biaxial bending strength was obtained by the following calculation formula:

[0050] in: In the formula: σ is the biaxial bending strength, MPa; P is the maximum load, N; b is the thickness of the sample, in mm; υ is the Poisson's ratio of the material, taken as 0.25; r1 is the radius of the supporting circle, in mm; r2 is the radius of the load area, in mm; r3 is the sample radius, in mm.

[0051] The biaxial bending performance test process is as follows: Figure 4 As shown in the figure, the figure includes the test mold and the sample of Example 3 before, during and after the test.

[0052] The load-displacement correlation data of Examples 1-3 and Comparative Example 3 during the biaxial bending test are as follows: Figures 5-8 As shown in Table 1, the biaxial bending strength results are as follows.

[0053] Table 1 Biaxial Bending Strength Results

[0054] Depend on Figures 5-8It can be seen that the glass-infiltrated zirconia bioceramic materials prepared by the low-temperature infiltration method in Examples 1-3 still exhibit the typical brittle fracture characteristics of ceramic materials. However, the peak load of their load-displacement curves is significantly higher than that of Comparative Example 3, indicating that the fracture strength of the material has been significantly improved. The results listed in Table 1 show that the biaxial bending strength of the glass-infiltrated zirconia bioceramic materials prepared by the low-temperature infiltration method in Examples 1-3 of this invention all exceed 500 MPa, fully meeting the mechanical property requirements of the international standard ISO 6872:2024 for dental ceramic materials (anterior restorations ≥100 MPa, molar restorations ≥500 MPa). Among them, the glass-infiltrated zirconia bioceramic material prepared by the low-temperature infiltration method in Example 3, while ensuring a high glass phase infiltration content, still achieves a biaxial bending strength of 565 MPa, while the biaxial bending strength of Comparative Example 3 (material prepared by the traditional high-temperature infiltration method) is 379 MPa. Based on this calculation, the biaxial bending strength of the sample in Example 3 is increased by 49.1% compared with Comparative Example 3, showing a significant strength improvement effect.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing glass-infiltrated zirconia bioceramic materials using a low-temperature introduction method, characterized in that, Includes the following steps: S1. Preparation of glass micro powder: First, SiO2, La2O3, ZrO2, Al2O3 and CeO2 are used as raw materials and melted at high temperature to obtain glass fragments. Then, they are ball-milled and sieved to obtain glass powder. S2. Preparation of pyrolytic carbon-coated glass permeable particles: The glass micropowder obtained in S1 was subjected to surface layered pyrolytic carbon deposition to obtain pyrolytic carbon-coated glass permeable particles; S3. Preparation of the green body: Zirconia matrix, dispersant, binder and S2-derived pyrolytic carbon-coated glass permeable particles are mixed evenly in a dispersion medium to obtain a mixed slurry. The mixed slurry is then spray-granulated to obtain a composite dry-pressed powder. Finally, the composite dry-pressed powder is dry-pressed and dried to obtain a green body. S4, oxygen-free pre-sintering: The green blank obtained from S3 was sintered under a protective atmosphere to obtain a pre-sintered green body. S5, Low oxygen permeability: The pre-sintered green body obtained by S4 was sintered in a mixed atmosphere of Ar and O2 to obtain glass-infiltrated zirconia bioceramic material.

2. The method for preparing glass-infiltrated zirconia bioceramic materials by low-temperature introduction according to claim 1, characterized in that, The mass ratio of SiO2, La2O3, ZrO2, Al2O3 and CeO2 in S1 is (25-38):(10-25):(5-18):(15-25):(0-5).

3. The method for preparing glass-infiltrated zirconia bioceramic materials by low-temperature introduction according to claim 1, characterized in that, The carbon source for the pyrolytic carbon deposition in S2 is at least one of methane, ethanol and propane. The deposition heating rate is 5-10℃ / min, the deposition temperature is 900-1000℃, and the deposition time is 1-3 h.

4. The method for preparing glass-infiltrated zirconia bioceramic materials by low-temperature introduction according to claim 1, characterized in that, In S3, the zirconium oxide matrix is ​​3Y-PSZ powder with a particle size of 30-80 nm; the amount of pyrolytic carbon-coated glass permeable particles added is 5 wt%-20 wt% of the mass of 3Y-PSZ powder; the dispersant is ammonium polyacrylate, and the amount added is 0.1 wt%-2 wt% of the total mass of pyrolytic carbon-coated glass permeable particles and 3Y-PSZ powder; the binder is polyvinyl alcohol, and the amount added is 2 wt%-8 wt% of the total mass of pyrolytic carbon-coated glass permeable particles and 3Y-PSZ powder.

5. The method for preparing glass-infiltrated zirconia bioceramic materials by low-temperature introduction according to claim 1, characterized in that, The slurry in S3 is mixed evenly by ultrasonic dispersion, with an ultrasonic dispersion power of 400-600 W and a time of 8-12 h. The inlet temperature for spray granulation is 140-160℃, and the outlet temperature is 75-115℃. The conditions for dry pressing are as follows: first, increase the pressure to 40-70 MPa and hold for 3-5 min; then increase to 80-140 MPa and hold for 8-12 min; finally, increase to 190-210 MPa and hold for 15-18 min. The drying process is carried out at a temperature of 80-120℃ for 2-4 hours.

6. The method for preparing glass-infiltrated zirconia bioceramic materials by low-temperature introduction according to claim 1, characterized in that, The protective atmosphere in S4 is argon, with a flow rate of 360-480 mL / h. The sintering conditions are as follows: first, heat to 240-320℃ at a rate of 0.3-1.2℃ / min and hold for 3-5 h; then heat to 1200-1250℃ at a rate of 1-3℃ / min and hold for 16-28 h; finally, cool to room temperature at a rate of 3-5℃ / min.

7. The method for preparing glass-infiltrated zirconia bioceramic materials by low-temperature introduction according to claim 1, characterized in that, The total flow rate of the Ar and O2 mixture in S5 is 120-360 mL / h, and the flow rate ratio of argon to oxygen is (14-23):

1. The sintering conditions are as follows: first, heat to 850-950℃ at a rate of 3-5℃ / min and hold for 3-8 h; then heat to 1250-1350℃ at a rate of 2-4℃ / min and hold for 8-12 h; finally, cool to room temperature at a rate of 3-5℃ / min.

8. A glass-permeable zirconia bioceramic material, characterized in that, It is prepared by the method described in any one of claims 1-7.

9. The application of the glass-infiltrated zirconia bioceramic material according to claim 8 in the preparation of medical implant components.

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