Zirconium oxide toughened aluminum oxide ceramic and preparation method thereof

Abstract

The invention relates to a preparation method of zirconium oxide toughened aluminum oxide ceramic and the zirconium oxide toughened aluminum oxide ceramic. The method comprises the following steps: preparing a ceramic green body from zirconium oxide toughened aluminum oxide granulation powder; sintering the ceramic green body step by step to obtain a ceramic sintered body; and carrying out hot isostatic pressing sintering on the ceramic sintered body to prepare the zirconium oxide toughened aluminum oxide ceramic. The application creatively discovers that the zirconia toughened aluminum oxide ceramic with higher fracture toughness and bending strength can be obtained by adopting a sintering and hot isostatic pressing combined process, so that the condition that a ceramic implant is broken clinically is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and particularly to a zirconia toughened alumina ceramic and a preparation method thereof. Background Art

[0002] Wear of joint prostheses is one of the important factors for late loosening of artificial joints. Its clinical significance lies not only in the mechanical failure caused by the destruction of the prosthesis itself, but also in the fact that wear can produce a large amount of particulate matter that induces the biological reaction of osteolysis around the prosthesis. In terms of wear rate and biocompatibility between wear particles and the human body, the ceramic-on-ceramic interface is better than other artificial joint interfaces such as metal-on-metal and metal-on-polyethylene. The ionic structure of ceramic materials can attract polar liquids, making them evenly cover the ceramic surface, which is conducive to forming a fluid film lubrication effect and providing excellent wear resistance; in addition, the hardness of ceramic materials is much higher than that of metals such as cobalt-chromium alloy, and the chemical properties are stable; the stimulation of ceramic particles to tissues is also much smaller than that of metal particles.

[0003] The biggest potential problem of ceramic materials is the risk of fragmentation. The fragmentation rate of ceramic implants in the 1990s was as high as 0.8%. After several generations of material and process improvements, the current fragmentation rate of ceramic implants is close to 0.001%. The main reason for the fragmentation of ceramic implants is that when accidentally subjected to loads exceeding the limit load, nanoscale cracks continuously expand, so improving the fracture toughness and flexural strength of ceramic materials can effectively reduce the risk of fragmentation and thus improve the reliability of ceramic implants.

[0004] In the zirconia toughened alumina ceramic, fine zirconia crystals and flaky strontium aluminate crystals uniformly distributed in the alumina matrix absorb crack energy and deflect it when the crack propagates, thereby improving the fracture toughness and flexural strength of the product.

[0005] However, the fracture toughness and flexural strength of traditional zirconia toughened alumina ceramic products are still insufficient, and there is still a risk of fragmentation of ceramic implants in clinical applications. Summary of the Invention

[0006] Based on this, it is necessary to provide a preparation method of zirconia toughened alumina ceramic and the zirconia toughened alumina ceramic, further improving the fracture toughness and flexural strength of the zirconia toughened alumina ceramic and reducing the occurrence of fragmentation of ceramic implants in clinical applications.

[0007] The first object of the present application is to provide a preparation method of zirconia toughened alumina ceramic, including:

[0008] Using zirconia toughened alumina granulated powder to make a ceramic green body;

[0009] Subjecting the ceramic green body to stepwise sintering to obtain a ceramic sintered body;

[0010] The ceramic green body is subjected to hot isostatic pressing sintering to produce zirconia toughened alumina ceramics.

[0011] In this application, a method combining hot isostatic pressing sintering with two-step sintering is adopted, which not only obtains a very high density of zirconia toughened alumina ceramic products, but also controls the grain size of the ceramics in the sub-micron level, thereby improving the flexural strength and fracture toughness of the zirconia toughened alumina ceramic products.

[0012] In one of the embodiments, obtaining the ceramic sintered body by stepwise sintering the ceramic green body includes:

[0013] Performing the first-step sintering on the ceramic green body at a first temperature;

[0014] Performing the second-step sintering on the product of the first-step sintering at a second temperature to obtain the ceramic sintered body, where the second temperature is lower than the first temperature;

[0015] Optionally, the first temperature is 1450 - 1600 °C;

[0016] Optionally, the time for the first-step sintering is 1 - 30 minutes;

[0017] Optionally, the second temperature is 70 - 150 °C lower than the first temperature;

[0018] Optionally, the time for the second-step sintering is 1 - 8 hours;

[0019] Optionally, the temperature for hot isostatic pressing sintering is 1300 - 1550 °C, and the pressure is 150 - 200 MPa;

[0020] Optionally, the time for hot isostatic pressing sintering is 0.5 - 4 hours.

[0021] In one of the embodiments, the stepwise sintering and the hot isostatic pressing sintering satisfy at least one of the following characteristics (1) - (3):

[0022] (1) Before performing the first-step sintering, it further includes: slowly heating up to 400 - 700 °C at a heating rate of 0.2 - 2 °C / min, and then quickly heating up to the first temperature at a heating rate of 5 - 15 °C / min;

[0023] (2) Before performing the second-step sintering, it further includes: cooling down from the first temperature to the second temperature at a cooling rate of 5 - 15 °C / min;

[0024] (3) The specific steps of hot isostatic pressing sintering include: pre-pressurizing in an inert gas atmosphere, and then heating up to 1300 - 1550 °C to make the pressure reach 150 - 200 MPa.

[0025] In one embodiment, the zirconia toughened alumina granulated powder satisfies at least one of the following characteristics (1) to (4):

[0026] (1) The particle size D50 of the zirconia toughened alumina granulated powder is 30 to 110 μm;

[0027] (2) The inorganic components of the zirconia toughened alumina granulated powder include alumina and yttrium-stabilized zirconia;

[0028] (3) The organic components of the zirconia toughened alumina granulated powder include at least one of a binder, a plasticizer, and a surfactant.

[0029] In one embodiment, the zirconia toughened alumina granulated powder satisfies at least one of the following characteristics (1) to (3):

[0030] (1) The inorganic components of the zirconia toughened alumina granulated powder further include a doped oxide; optionally, the doped oxide includes at least one of chromium oxide and strontium oxide;

[0031] (2) Based on the total mass of the inorganic components of the zirconia toughened alumina granulated powder, the mass fraction of alumina is 71% to 75%, and the mass fraction of yttrium-stabilized zirconia is 23% to 29%;

[0032] Optionally, based on the total mass of the inorganic components of the zirconia toughened alumina granulated powder, the mass fraction of the doped oxide is 0% to 1.8%;

[0033] (3) The mass ratio of the organic components of the zirconia toughened alumina granulated powder to the inorganic components of the zirconia toughened alumina granulated powder is less than 0.05.

[0034] In one embodiment, forming the zirconia toughened alumina granulated powder into a ceramic green body specifically includes:

[0035] Pressing and cold isostatic pressing the zirconia toughened alumina granulated powder to form a ceramic green body;

[0036] Optionally, the pressure for pressing is 50 to 100 MPa, and the pressing time is 0.5 to 5 minutes;

[0037] Optionally, the pressure for cold isostatic pressing is 150 to 250 MPa, and the pressure holding time is 0.5 to 5 minutes.

[0038] In one embodiment, the relative density of the ceramic sintered body > 95%.

[0039] The second object of the present application is to provide a zirconia toughened alumina ceramic, the flexural strength of the zirconia toughened alumina ceramic > 1000 MPa, and the fracture toughness > 5.30 MPa·m 1 / 2。

[0040] In one of the embodiments, the relative density of the zirconia toughened alumina ceramic is greater than 98%, and the average grain size is less than 1 μm.

[0041] The second object of the present application is to provide the use of the above zirconia toughened alumina ceramic, or the zirconia toughened alumina ceramic prepared by the above preparation method, in the preparation of orthopedic and dental implants.

[0042] The third object of the present application is to provide an orthopedic and dental implant containing the above zirconia toughened alumina ceramic, or the zirconia toughened alumina ceramic prepared by the above preparation method. Detailed Embodiments

[0043] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to relevant embodiments. Preferred embodiments of the present application are given in the embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure content of the present application more thorough and comprehensive.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0045] As mentioned above, the hot isostatic pressing process is a heat treatment process. Post-treatment of sintered ceramic products by hot isostatic pressing can effectively eliminate microvoids in the products, reduce large pores, and heal defects such as microcracks. The hot isostatic pressing process has been applied to metals and their alloy materials to obtain excellent mechanical properties, but the technology of hot isostatic pressing for sintered ceramics is not yet mature, and there is almost no production application.

[0046] For zirconia toughened alumina ceramics, the smaller the particle size, the higher the flexural strength and fracture toughness, because more grain boundaries can absorb the energy when cracks propagate. According to the sintering mechanism of ceramic materials, at the beginning stage of sintering, a higher temperature is beneficial for the adhesion between ceramic particles and material transfer, and can improve the density of ceramic particles; but in the later stage of sintering, with the elimination of voids, a higher sintering temperature makes the grains grow rapidly, which is not conducive to the control of grain size. Therefore, how to further improve the fracture toughness and flexural strength is a difficulty in the preparation of zirconia toughened alumina ceramics.

[0047] To solve the above technical problems, the first aspect of the present application provides a preparation method of the above zirconia toughened alumina ceramic, including:

[0048] Prepare a ceramic green body from zirconia toughened alumina granulated powder;

[0049] Obtain a ceramic sintered body by stepwise sintering the ceramic green body;

[0050] Perform hot isostatic pressing sintering on the ceramic sintered body to make a ceramic sintered body.

[0051] In some embodiments, the particle size D50 of the zirconia toughened alumina granulated powder is 30 - 110 μm, further it can be 30 - 100 μm, and still further it can be 30 - 70 μm.

[0052] In some embodiments, the inorganic components of the zirconia toughened alumina granulated powder include alumina and yttrium-stabilized zirconia.

[0053] In this application, the source of the inorganic components of the zirconia toughened alumina granulated powder is not limited. The zirconia toughened alumina granulated powder can be commercially purchased. It can also be the zirconia toughened alumina granulated powder obtained by mixing and granulating yttrium-stabilized zirconia with an original particle size D50 < 400 nm and alumina raw powder. It can also be prepared by other known methods as long as it can be used to prepare zirconia toughened alumina ceramics.

[0054] In some embodiments, based on the total mass of the inorganic components of the zirconia toughened alumina granulated powder, the mass fraction of alumina is 71% - 75%, and the mass fraction of yttrium-stabilized zirconia is 23% - 29%.

[0055] In some embodiments, the inorganic components of the zirconia toughened alumina granulated powder further include doped oxides to improve the product performance.

[0056] In some embodiments, the doped oxides include at least one of chromium oxide and strontium oxide. Among them, chromium oxide can improve the hardness of the product, and strontium oxide can improve the fracture toughness of the product.

[0057] In some embodiments, based on the total mass of the inorganic components of the zirconia toughened alumina granulated powder, the mass fraction of the doped oxides is 0% - 1.8%.

[0058] In some embodiments, the specific surface area of the zirconia toughened alumina granulated powder is regulated by the specific surface area of the inorganic components. If the specific surface area of the zirconia toughened alumina granulated powder is too small, it will lead to poor sintering activity. If the specific surface area is too large, it will lead to a low green body density before sintering. Both will result in a low density of the ceramic sintered body after two-step sintering, thereby reducing the mechanical properties of the zirconia toughened alumina ceramic product.

[0059] In some embodiments, in order to achieve better sintering effect of zirconia toughened alumina granulated powder, the organic components of the zirconia toughened alumina granulated powder include at least one of a binder, a plasticizer and a surfactant. Specifically, the binder is used to improve the adhesion between oxide powders, the plasticizer is used to improve the plasticity of the ceramic green body, and the surfactant is used to improve the dispersibility of the oxide powders.

[0060] In some embodiments, the mass ratio of the organic components to the inorganic components in the zirconia toughened alumina granulated powder is less than 0.05 to achieve better sintering effect of the ceramic green body.

[0061] In some specific embodiments, fabricating the zirconia toughened alumina granulated powder into a ceramic green body includes:

[0062] Compacting and cold isostatic pressing the zirconia toughened alumina granulated powder to form a ceramic green body.

[0063] In some embodiments, the pressure for compacting is 50 - 100 MPa and the pressing time is 0.5 - 5 minutes.

[0064] In some embodiments, the pressure for cold isostatic pressing is 150 - 250 MPa and the processing time is 0.5 - 5 minutes.

[0065] Specifically, by controlling the specific surface area and particle size of the zirconia toughened alumina granulated powder, a ceramic green body with higher density can be obtained, which is beneficial to obtaining a zirconia toughened alumina ceramic product with higher performance in subsequent processes.

[0066] In some embodiments, obtaining a ceramic sintered body from the ceramic green body by stepwise sintering includes:

[0067] Performing the first - step sintering on the ceramic green body at a first temperature;

[0068] Performing the second - step sintering on the product of the first - step sintering at a second temperature to obtain the ceramic sintered body, where the second temperature is lower than the first temperature.

[0069] In some specific embodiments, the first temperature is 1450 - 1600 °C and the time for the first - step sintering is 1 - 30 minutes to bridge between the zirconia toughened alumina grains in a short time at high temperature and improve the density of the ceramic particles.

[0070] In some specific embodiments, the second temperature is lower than the first temperature, and the sintering time for the second - step sintering is 1 - 8 hours to sinter the grains at a lower temperature for a long time and limit their growth.

[0071] In some specific embodiments, before the first sintering, it further includes: slowly heating to 400 - 700 °C at a heating rate of 0.2 - 2 °C / min, and then rapidly heating to the first temperature at a heating rate of 5 - 15 °C / min.

[0072] In some specific embodiments, before the second sintering, it further includes: cooling to the second temperature at a cooling rate of 5 - 15 °C / min at the first temperature.

[0073] In practical applications, the density of the ceramic sintered body before hot isostatic pressing needs to be > 95% to ensure that there are no open pores. However, although a high sintering temperature can increase the density of the ceramic, it will also cause significant growth of ceramic grains.

[0074] In the present application, through a two-step sintering method creatively, a relatively high sintering temperature can be utilized to quickly cause adhesion of ceramic green body particles and initiate sintering. At the same time, heat preservation at a relatively low sintering temperature is carried out to avoid grain growth, enabling the density of zirconia toughened alumina ceramics to meet the requirements of hot isostatic pressing treatment.

[0075] Furthermore, hot isostatic pressing is used to eliminate voids and complete densification. The hot isostatic pressing (HIP) process is to place the product in a closed container, apply equal pressure in all directions to the product, and apply high temperature at the same time. Under the action of high temperature and high pressure, the product is sintered and densified.

[0076] In some specific embodiments, the temperature of hot isostatic pressing is 1300 - 1550 °C, the pressure is 150 - 200 MPa, and the treatment time is 0.5 - 4 hours, which can improve the density of ceramic products and control the grain size at the sub-micron level at the same time.

[0077] In some specific embodiments, before hot isostatic pressing, it further includes: pre-pressurizing a in an inert gas atmosphere and heating to 1300 - 1550 °C to make the pressure 150 - 200 MPa.

[0078] The present application adopts a combination of hot isostatic pressing sintering and two-step sintering, not only obtaining a very high density of zirconia toughened alumina ceramic products, but also controlling the grain size of the ceramic at the sub-micron level, thereby improving the flexural strength and fracture toughness of zirconia toughened alumina ceramic products.

[0079] In some embodiments, after the ceramic sintered body is densified by hot isostatic pressing treatment, the ceramic sintered body is ground and polished to obtain zirconia toughened alumina ceramics.

[0080] Correspondingly, the first aspect of the present application provides a zirconia toughened alumina ceramic prepared by the above method, with a flexural strength > 1000 MPa and a fracture toughness > 5.30 MPa·m 1 / 2。

[0081] The flexural strength of the zirconia toughened alumina ceramic of the present application is > 1000 MPa, and the fracture toughness is > 5.30 MPa·m 1 / 2 When used for clinical implantation, it can reduce the fragmentation of ceramic implants and has good application prospects.

[0082] In some embodiments, the relative density of the zirconia toughened alumina ceramic is greater than 98%, and the average grain size is less than 1 μm. It is found in the present application that increasing the density of the zirconia toughened alumina ceramic, reducing the porosity, and simultaneously controlling the grain size of the ceramic at the sub-micron level can effectively improve the fracture toughness and flexural strength of the zirconia toughened alumina ceramic. The third aspect of the present application provides the use of the above zirconia toughened alumina ceramic, or the zirconia toughened alumina ceramic prepared by the above preparation method, in the preparation of orthopedic or dental implants.

[0083] In the present application, the term "implant" refers to a medical device product used to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure, such as artificial joints, dental implants, intervertebral fusion devices, etc.

[0084] For example, applying the above zirconia toughened alumina ceramic to joint implants such as artificial femoral heads and artificial femoral condyles is of great significance for improving the friction performance of artificial joints and extending the joint life.

[0085] The fourth aspect of the present application provides an orthopedic or dental implant containing the above zirconia toughened alumina ceramic, the zirconia toughened alumina ceramic prepared by the above preparation method, the flexural strength of the ceramic is > 1000 MPa, and the fracture toughness is > 5.30 MPa·m 1 / 2 It can reduce the risk of fragmentation of implantable devices in the body.

[0086] The following are specific examples.

[0087] The preparation steps of the zirconia toughened alumina granulated powder in the examples of the present application include:

[0088] Mix yttrium-stabilized zirconia powder, alumina powder, inorganic dopants and organic components such as surfactants, binders, and plasticizers in water, make a slurry using a high-energy sand mill, and obtain zirconia toughened alumina granulated powder by spray drying for the preparation of ceramic products.

[0089] Among them, the particle size of the zirconia toughened alumina granulated powder is controlled by the flow rate of the atomizer or the rotation speed of the dispersion disk during spray drying.

[0090] The yttrium-stabilized zirconia powder used in the zirconia toughened alumina granulated powder of each example is sourced from CY3Z of Zirpro (SaintGobain) (specific surface area 8m2 / g), and the alumina powder is sourced from Sumitomo Chemical's AKP-15 (specific surface area 4 m 2 / g), AKP-30 (specific surface area 8 m 2 / g), AKP50 (specific surface area 12 m 2 / g), and AKP700 (specific surface area 25 m 2 / g).

[0091] The usage ratios of yttrium-stabilized zirconia powder and alumina powder are the same in each example and comparative example.

[0092] The specific surface area of the alumina powder used in Examples 1 to 11, Comparative Examples 1 to 10, and 13 to 14 is 12 m 2 / g. The specific surface area of the alumina powder used in Example 12 is 8 m 2 / g. The specific surface area of the alumina powder used in Comparative Example 11 is 4 m 2 / g. The specific surface area of the alumina powder used in Comparative Example 12 is 25 m 2 / g.

[0093] Example 1

[0094] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, which consists of 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide, and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated in a muffle furnace at a heating rate of 1 °C / min to 600 °C to remove the binder, and then rapidly heated at a heating rate of 10 °C / min to 1450 °C, held for 10 min, and then rapidly cooled at a cooling rate of 10 °C / min to 1350 °C and held for 2 hrs. The sintered ceramic body after sintering is heated to 1300 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0095] Example 2

[0096] Zirconia toughened alumina granulated powder with a particle size D50 of 70 μm is used, and its composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. After pouring it into a mold, it is pressed into shape at a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min for degreasing, and then rapidly heated to 1500 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1400 °C at a cooling rate of 10 °C / min, held for 2 hrs. The sintered ceramic body after sintering is heated to 1350 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, after holding for 3 hrs, it is cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0097] Example 3

[0098] Zirconia toughened alumina granulated powder with a particle size D50 of 70 μm is used, and its composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. After pouring it into a mold, it is pressed into shape at a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min for degreasing, and then rapidly heated to 1550 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1450 °C at a cooling rate of 10 °C / min, held for 2 hrs. The sintered ceramic body after sintering is heated to 1400 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, after holding for 3 hrs, it is cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0099] Example 4

[0100] Zirconia toughened alumina granulated powder with a particle size D50 of 70 μm is used, and its composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. After pouring it into a mold, it is pressed into shape at a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min for degreasing, and then rapidly heated to 1450 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1350 °C at a cooling rate of 10 °C / min, held for 2 hrs. The sintered ceramic body after sintering is heated to 1350 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, after holding for 3 hrs, it is cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0101] Example 5

[0102] Zirconia toughened alumina granulated powder with a particle size D50 of 70 μm is used, which consists of 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. After pouring it into a mold, it is pressed into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min to remove binder, and then rapidly heated to 1500 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1400 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1400 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0103] Example 6

[0104] Zirconia toughened alumina granulated powder with a particle size D50 of 70 μm is used, which consists of 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. After pouring it into a mold, it is pressed into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min to remove binder, and then rapidly heated to 1550 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1450 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1450 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0105] Example 7

[0106] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min for degreasing, and then rapidly heated to 1450 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1350 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1400 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0107] Example 8

[0108] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min for degreasing, and then rapidly heated to 1500 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1400 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1450 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0109] Example 9

[0110] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min for degreasing, and then rapidly heated to 1550 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1450 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1500 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0111] Example 10

[0112] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, then rapidly heat it to 1550 °C at a heating rate of 10 °C / min, hold for 10 min, and then rapidly cool it to 1450 °C at a cooling rate of 10 °C / min and hold for 2 hrs. Heat the sintered ceramic body to 1500 °C in a hot isostatic pressing furnace, reach a pressure of 200 MPa, hold for 3 hrs, and then cool it to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0113] Example 11

[0114] Use zirconia toughened alumina granulated powder with a particle size D50 of 50 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, then rapidly heat it to 1550 °C at a heating rate of 10 °C / min, hold for 10 min, and then rapidly cool it to 1450 °C at a cooling rate of 10 °C / min and hold for 2 hrs. Heat the sintered ceramic body to 1450 °C in a hot isostatic pressing furnace, reach a pressure of 150 MPa, hold for 3 hrs, and then cool it to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0115] Example 12

[0116] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, then rapidly heat it to 1600 °C at a heating rate of 10 °C / min, hold for 10 min, and then rapidly cool it to 1500 °C at a cooling rate of 10 °C / min and hold for 2 hrs. The sintered ceramic body after sintering is heated to 1500 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, after holding for 3 hrs, cool it to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0117] Comparative Example 1

[0118] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, then rapidly heat it to 1450 °C at a heating rate of 10 °C / min, hold for 10 min, and then rapidly cool it to 1350 °C at a cooling rate of 10 °C / min and hold for 2 hrs, and then cool it to room temperature with the furnace. Subsequently, obtain the final ceramic product through grinding and polishing.

[0119] Comparative Example 2

[0120] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, then rapidly heat it to 1550 °C at a heating rate of 10 °C / min, hold for 10 min, and then rapidly cool it to 1450 °C at a cooling rate of 10 °C / min and hold for 2 hrs, and then cool it to room temperature with the furnace. Subsequently, obtain the final ceramic product through grinding and polishing.

[0121] Comparative Example 3

[0122] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttria-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, and then rapidly heat it to 1550 °C at a heating rate of 10 °C / min, hold for 120 min, and cool down to room temperature with the furnace. Subsequently, obtain the final ceramic product through grinding and polishing.

[0123] Comparative Example 4

[0124] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttria-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, and then rapidly heat it to 1600 °C at a heating rate of 10 °C / min, hold for 120 min, and cool down to room temperature with the furnace. Subsequently, obtain the final ceramic product through grinding and polishing.

[0125] Comparative Example 5

[0126] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttria-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, and then rapidly heat it to 1450 °C at a heating rate of 10 °C / min, hold for 120 min, and cool down to room temperature with the furnace. Heat the sintered ceramic body to 1500 °C in a hot isostatic pressing furnace, reach a pressure of 150 MPa, hold for 3 hrs, and then cool down to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0127] Comparative Example 6

[0128] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated in a muffle furnace at a heating rate of 1 °C / min to 600 °C for degumming, and then rapidly heated at a heating rate of 10 °C / min to 1450 °C, held for 120 min, and cooled to room temperature with the furnace. The sintered ceramic body after sintering is heated in a hot isostatic pressing furnace to 1550 °C, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0129] Comparative Example 7

[0130] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated in a muffle furnace at a heating rate of 1 °C / min to 600 °C for degumming, and then rapidly heated at a heating rate of 10 °C / min to 1400 °C, held for 10 min, and then rapidly cooled at a cooling rate of 10 °C / min to 1300 °C, held for 2 hrs. The sintered ceramic body after sintering is heated in a hot isostatic pressing furnace to 1250 °C, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0131] Comparative Example 8

[0132] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated in a muffle furnace at a heating rate of 1 °C / min to 600 °C for degumming, and then rapidly heated at a heating rate of 10 °C / min to 1400 °C, held for 10 min, and then rapidly cooled at a cooling rate of 10 °C / min to 1300 °C, held for 2 hrs. The sintered ceramic body after sintering is heated in a hot isostatic pressing furnace to 1300 °C, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0133] Comparative Example 9

[0134] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for degumming, then rapidly heat it to 1400 °C at a heating rate of 10 °C / min, hold for 10 min, and then rapidly cool it to 1300 °C at a cooling rate of 10 °C / min and hold for 2 hrs. Heat the sintered ceramic body to 1350 °C in a hot isostatic pressing furnace, reach a pressure of 150 MPa, hold for 3 hrs, and then cool it to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0135] Comparative Example 10

[0136] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After vacuum packaging the formed green body, further compact it by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. Heat the compacted green body in a muffle furnace at a heating rate of 1 °C / min to 600 °C for degumming, then rapidly heat it to 1550 °C at a heating rate of 10 °C / min, hold for 10 min, and then rapidly cool it to 1450 °C at a cooling rate of 10 °C / min and hold for 2 hrs. Heat the sintered ceramic body to 1500 °C in a hot isostatic pressing furnace, reach a pressure of 100 MPa, hold for 3 hrs, and then cool it to room temperature. Finally, obtain the final ceramic product through grinding and polishing.

[0137] Comparative Example 11

[0138] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min to remove the binder, and then rapidly heated to 1550 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1450 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1450 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0139] Comparative Example 12

[0140] Use zirconia toughened alumina granulated powder with a particle size D50 of 70 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min to remove the binder, and then rapidly heated to 1550 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1450 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1450 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0141] Comparative Example 13

[0142] Use zirconia toughened alumina granulated powder with a particle size D50 of 30 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide. Pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated to 600 °C in a muffle furnace at a heating rate of 1 °C / min to remove the binder, and then rapidly heated to 1550 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1450 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1450 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, held for 3 hrs, and then cooled to room temperature. Finally, the final ceramic product is obtained through grinding and polishing.

[0143] Comparative Example 14

[0144] Using zirconia toughened alumina granulated powder with a particle size D50 of 120 μm, whose composition is 73% alumina, 26% yttrium-stabilized zirconia, 0.5% chromium oxide and 0.5% strontium oxide, pour it into a mold and press it into shape under a pressure of 100 MPa for 1 minute. After the formed green body is vacuum-packed, it is further compacted by cold isostatic pressing at a pressure of 250 MPa for 2 minutes. The compacted green body is heated in a muffle furnace at a heating rate of 1 °C / min to 600 °C for debinding, and then rapidly heated to 1550 °C at a heating rate of 10 °C / min, held for 10 min, and then rapidly cooled to 1450 °C at a cooling rate of 10 °C / min and held for 2 hrs. The sintered ceramic body after sintering is heated to 1450 °C in a hot isostatic pressing furnace, the pressure reaches 150 MPa, after holding for 3 hrs, it is cooled to room temperature. Finally, through grinding and polishing, the final ceramic product is obtained.

[0145] The experimental parameters of each example and comparative example are shown in Table 1.

[0146] Table 1

[0147]

[0148]

[0149] 1. Product density test

[0150] The density after cold isostatic pressing (ceramic green body density) in the examples and comparative examples was measured by the volume method, and the density after sintering (ceramic sintered body density) and after hot isostatic pressing (ceramic product density) in the examples and comparative examples was measured by the Archimedes drainage method, and the relative density was calculated by comparing with the theoretical density. The particle size of the products of the examples and comparative examples after polishing and heat treatment was observed and calculated by SEM. The calculation results are shown in Table 2.

[0151] 2. Average particle size, flexural strength and fracture toughness test

[0152] The flexural strength of the examples and comparative examples was measured by the four-point bending method. The fracture toughness of the examples and comparative examples was measured by the single-edge V-groove specimen test method. The measurement results are shown in Table 2.

[0153] 3. Experimental conclusion

[0154] According to Table 2, it can be seen that the process combining two-step sintering and hot isostatic pressing in Examples 1-12 can achieve a flexural strength > 1000 MPa and a fracture toughness > 5.30 MPa·m 1 / 2 .

[0155] For the processes in Comparative Examples 1-14, it is impossible to simultaneously achieve a flexural strength > 1000 MPa and a fracture toughness > 5.30 MPa·m 1 / 2 .

[0156] Specifically, as can be seen from Table 2, the density of the zirconia toughened alumina product increases with the increase of the sintering temperature and the temperature of hot isostatic pressing.

[0157] According to the results of Examples 2-3, 4-6, and 7-8, by using the method of two-step sintering combined with hot isostatic pressing in this application, the density of the sintered ceramic sintered body can be increased to more than 95%, and the density of zirconia toughened alumina can be stably controlled to be > 98%, and the average particle size < 1.0 μm.

[0158] Comparing Examples 1-3 with Comparative Examples 1-2, it can be seen that in the comparative examples, only the two-step sintering method is used without superimposing hot isostatic pressing, and it is difficult to stably control the density of the ceramic product to be > 98% and the average particle size < 1 μm.

[0159] Comparing Examples 1-3 with Comparative Examples 3-6, it can be seen that in the comparative examples, the one-step sintering method is used, and whether hot isostatic pressing is superimposed or not, it is difficult to stably control the density of the ceramic product to be > 98% and the average particle size < 1 μm.

[0160] According to the comparison between Example 1, 4 and Comparative Examples 7-9, it can be seen that when the first-step sintering temperature is lower than 1450 °C, it is difficult to stably control the density of the ceramic product to be > 98% and the average particle size < 1 μm.

[0161] Comparing Examples 9-10 with Comparative Example 10, it can be seen that to obtain a higher density, a higher hot isostatic pressing pressure needs to be used. The pressure does not change the average particle size after sintering, but if the pressure is too low, a ceramic product that meets the performance requirements cannot be obtained.

[0162] Comparing Example 6, 11-12 with Comparative Examples 11-14, it can be seen that by using a suitable process to change the specific surface area or particle size of the granulated powder, the density of the ceramic product can also be stably controlled to be > 98% and the average particle size < 1 μm; however, if the specific surface area of the granulated powder is too high or too low, or the particle size of the granulated powder is too high or too low, it is difficult to stably control the density of the ceramic product to be > 98% and the average particle size < 1 μm.

[0163] Table 2

[0164]

[0165]

[0166] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0167] The above embodiments only express several implementation manners of the present application, and the description thereof is relatively specific and detailed. However, it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A method for preparing zirconia toughened alumina ceramics, characterized in that, Including: Manufacturing a green ceramic body using zirconia toughened alumina granulated powder; Obtaining a ceramic sintered body by stepwise sintering the green ceramic body; Performing hot isostatic pressing sintering on the ceramic sintered body to manufacture zirconia toughened alumina ceramic.

2. The preparation method according to claim 1, wherein The obtaining of the ceramic sintered body by stepwise sintering the green ceramic body includes: Performing a first-step sintering on the green ceramic body at a first temperature; Performing a second-step sintering on the product of the first-step sintering at a second temperature to obtain the ceramic sintered body, where the second temperature is lower than the first temperature; Optionally, the first temperature is 1450 - 1600 °C; Optionally, the time for the first-step sintering is 1 - 30 minutes; Optionally, the second temperature is 70 - 150 °C lower than the first temperature; Optionally, the time for the second-step sintering is 1 - 8 hours; Optionally, the temperature for hot isostatic pressing sintering is 1300 - 1550 °C, and the pressure is 150 - 200 MPa; Optionally, the time for hot isostatic pressing sintering is 0.5 - 4 hours.

3. The preparation method according to claim 2, wherein, The stepwise sintering and hot isostatic pressing sintering satisfy at least one of the following characteristics (1) - (3): (1) Before performing the first-step sintering, it further includes: slowly heating to 400 - 700 °C at a heating rate of 0.2 - 2 °C / min, and then rapidly heating to the first temperature at a heating rate of 5 - 15 °C / min; (2) Before performing the second-step sintering, it further includes: cooling from the first temperature to the second temperature at a cooling rate of 5 - 15 °C / min; (3) The specific steps of the hot isostatic pressing sintering include: pre-pressurizing in an inert gas atmosphere, and then heating to 1300 - 1550 °C to make the pressure reach 150 - 200 MPa.

4. The preparation method according to claim 1, characterized in that, The zirconia toughened alumina granulated powder satisfies at least one of the following characteristics (1) - (3): (1) The particle size D50 of the zirconia toughened alumina granulated powder is 30 - 110 μm; (2) The inorganic components of the zirconia toughened alumina granulated powder include alumina and yttrium-stabilized zirconia; (3) The organic components of the zirconia toughened alumina granulated powder include at least one of a binder, a plasticizer, and a surfactant.

5. The preparation method according to claim 4, characterized in that, The zirconia toughened alumina granulated powder satisfies at least one of the following characteristics (1) - (3): (1) The inorganic components of the zirconia toughened alumina granulated powder further include doped oxides; optionally, the doped oxides include at least one of chromium oxide and strontium oxide; (2) Calculated based on the total mass of the inorganic components of the zirconia toughened alumina granulated powder, the mass fraction of alumina is 71% - 75%, and the mass fraction of yttrium-stabilized zirconia is 23% - 29%; Optionally, calculated based on the total mass of the inorganic components of the zirconia toughened alumina granulated powder, the mass fraction of the doped oxides is 0% - 1.8%; (3) The mass ratio of the organic components of the zirconia toughened alumina granulated powder to the inorganic components of the zirconia toughened alumina granulated powder is less than 0.

05.

6. The preparation method according to claim 1, characterized in that, Manufacturing the green ceramic body using the zirconia toughened alumina granulated powder specifically includes: Compacting and cold isostatic pressing sintering the zirconia toughened alumina granulated powder to manufacture the green ceramic body; Optionally, the pressure for pressing and forming is 50 to 100 MPa, and the pressing time is 0.5 to 5 minutes; Optionally, the pressure for cold isostatic pressing and sintering is 150 to 250 MPa, and the pressure holding time is 0.5 to 5 minutes.

7. The preparation method according to claim 1, wherein, The relative density of the ceramic sintered body > 95%; and / or The relative density of the zirconia toughened alumina ceramic is greater than 98% and the average particle size is less than 1 μm; and / or The flexural strength of the zirconia toughened alumina ceramic is > 1000 MPa, and the fracture toughness is > 5.30 MPa·m 1 / 2 .

8. Zirconia toughened alumina ceramic prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the zirconia toughened alumina ceramic according to claim 8 in the preparation of orthopedic and dental implants.

10. An orthopedic and dental implant, characterized in that, Containing the zirconia toughened alumina ceramic according to claim 8.

Images