Rapid sintering method of zirconia ceramic for dentistry and zirconia ceramic

Abstract

The invention provides a rapid sintering method of zirconia ceramic for dentistry and zirconia ceramic, the rapid sintering method of zirconia ceramic for dentistry comprises the following steps: obtaining a pre-sintered body prepared from zirconia powder with stable yttrium oxide, and obtaining a standard active sintering temperature of the zirconia powder; the pre-sintered body is subjected to final sintering in a preset final sintering stage, the zirconia ceramic is obtained, the preset highest sintering temperature in the preset final sintering stage is higher than the standard active sintering temperature, and the difference value between the preset highest sintering temperature and the standard active sintering temperature ranges from 10 DEG C to 60 DEG C. According to the embodiment of the invention, the preset highest sintering temperature in the preset final sintering stage is set to exceed the standard active sintering temperature by 10-60 DEG C, so that the highest sintering temperature of the final sintering process is improved, the final sintering time of the zirconia ceramic is shortened, the production efficiency of the zirconia ceramic product is improved, and the production cost is reduced. And meanwhile, the material can obtain excellent mechanical properties and transparency within an extremely short time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dental materials, in particular to a zirconia ceramic rapid sintering method and zirconia ceramic. BACKGROUND

[0002] Zirconia material is widely used in the production of dentures due to its good hardness, toughness, wear resistance and biocompatibility. The material made of zirconia doped with yttria can stabilize the tetragonal phase of zirconia, so that it can exist stably at room temperature. Zirconia dental material undergoes two-stage heat treatment curve of pre-sintering and final sintering to finally produce zirconia ceramic products.

[0003] At present, the final sintering time of zirconia ceramic products is generally 2-5h, which is very long, resulting in very low production efficiency of zirconia ceramic products.

[0004] Therefore, the prior art has defects and needs to be improved and developed. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a zirconia ceramic rapid sintering method and zirconia ceramic for dental use aiming at the above-mentioned defects of the prior art, so as to solve the problem of long final sintering time of zirconia ceramic products in the prior art, which results in very low production efficiency of zirconia ceramic products.

[0006] The technical solution adopted by the present application to solve the technical problem is as follows:

[0007] The first aspect of the present application provides a zirconia ceramic rapid sintering method for dental use, which comprises:

[0008] obtaining a pre-sintered body prepared from yttria-stabilized zirconia powder, and obtaining a standard active sintering temperature of the zirconia powder;

[0009] sintering the pre-sintered body in a predetermined final sintering stage to obtain a zirconia ceramic, wherein the predetermined maximum sintering temperature in the predetermined final sintering stage is greater than the standard active sintering temperature, and the difference between the predetermined maximum sintering temperature and the standard active sintering temperature is 10-60℃.

[0010] According to the above technical means, the present application sets the predetermined maximum sintering temperature in the predetermined final sintering stage to be 10-60℃ higher than the standard active sintering temperature, which increases the maximum sintering temperature of the final sintering process, shortens the final sintering time of the zirconia ceramic, and further improves the production efficiency of the zirconia ceramic product, while ensuring that the material obtains excellent mechanical properties and transmittance in a very short time.

[0011] In one embodiment of the present application, the pre-sintered body prepared from yttria-stabilized zirconia powder is obtained by:

[0012] The yttria-stabilized zirconia powder is pressed into a zirconia ceramic body through a cold isostatic pressing process;

[0013] The body is pre-sintered to obtain a pre-sintered body.

[0014] According to the above technical means, the sintering process of the embodiment of the present application is suitable for the zirconia ceramic body pressed through the cold isostatic pressing process, and can obtain a zirconia ceramic with excellent mechanical properties and transmittance.

[0015] In an embodiment of the present application, the shortest final sintering time of the pre-sintered body in the predetermined final sintering stage is 27 min.

[0016] According to the above technical means, the embodiment of the present application increases the highest sintering temperature of the final sintering process, so that the phase transition and atomic activity in the material are more active, and then matches a special sintering process, shortens the final sintering time to 27 min, and can ensure that the material can obtain excellent mechanical properties and transmittance.

[0017] In an embodiment of the present application, the predetermined final sintering stage includes:

[0018] The first stage: entering the furnace at a temperature of 700-900℃;

[0019] The second stage: increasing the furnace temperature to 1100℃ in 1 min;

[0020] The third stage: increasing the furnace temperature to 1300℃ in 4-7 min;

[0021] The fourth stage: increasing the furnace temperature to the predetermined highest sintering temperature in 7-15 min;

[0022] The fifth stage: holding the furnace temperature at the predetermined highest sintering temperature for 15 min;

[0023] The sixth stage: cooling to 150℃ and discharging.

[0024] According to the above technical means, the embodiment of the present application shortens the final sintering time through the precise control of the six stages, and can ensure excellent mechanical properties and transmittance.

[0025] In an embodiment of the present application, the grain size of the zirconia ceramic is 0.1-0.6 μm.

[0026] According to the above technical means, the embodiment of the present application controls the grain size of the zirconia ceramic to be 0.1-0.6 μm, which can significantly improve the optical, mechanical and thermal properties thereof.

[0027] In an embodiment of the present application, the content of yttria in the zirconia powder is 2.5-8 mol%.

[0028] According to the technical means, the zirconia ceramic is prepared by adding 2.5-8 mol% yttrium oxide as a stabilizer in the zirconia ceramic, so that the phase structure, mechanical properties, thermal stability and chemical durability of the zirconia ceramic are significantly optimized.

[0029] In an embodiment of the present application, the content of zirconia in the zirconia powder is 89.5-97% by mass percentage.

[0030] According to the technical means, the content of zirconia in the embodiment of the present application is high. Pure zirconia will undergo a monoclinic phase to tetragonal phase transition during heating / cooling, accompanied by a volume change of 3-5%, which is easy to cause cracking. Under high zirconia content, the dopant replaces Zr 4+ by solid solution to form oxygen vacancies, stabilizing the tetragonal phase to room temperature and avoiding phase transition brittleness.

[0031] In an embodiment of the present application, the particle size of the zirconia powder is 30-100 μm.

[0032] According to the technical means, the embodiment of the present application uses a 30-100 μm particle size of a spherical powder as a production raw material. The surface energy of the 30-100 μm particle size powder is moderate, which avoids the serious agglomeration of superfine powder and ensures the sintering activity.

[0033] In an embodiment of the present application, the zirconia powder further comprises aluminum oxide, iron oxide, erbium oxide and praseodymium oxide; the content of the aluminum oxide is less than or equal to 0.5% by mass percentage, and the sum of the contents of the iron oxide, the erbium oxide and the praseodymium oxide is less than or equal to 1.5% by mass percentage.

[0034] According to the technical means, the aluminum oxide in the zirconia powder of the embodiment of the present application can be adsorbed on the surface of the zirconia grain to reduce the grain boundary migration rate, prevent abnormal grain growth during sintering, and stabilize the tetragonal phase of the zirconia, reduce the phase transition to the monoclinic phase during sintering or use, and avoid cracking caused by volume expansion. The erbium oxide introduces a pink tone, which is used for natural tooth color matching of dental ceramics (such as all-ceramic crowns); the praseodymium oxide provides a yellow tone, and the combination of the erbium oxide and the praseodymium oxide can adjust the color system to be closer to the natural tooth color.

[0035] The second aspect of the embodiment of the present application provides a zirconia ceramic, wherein the zirconia ceramic is prepared by the rapid sintering method of the zirconia ceramic for dental use as described above.

[0036] The embodiment of the present application achieves the beneficial effects:

[0037] First, the embodiment of the application sets the predetermined maximum sintering temperature in the predetermined final sintering stage to be 10-60℃ higher than the standard active sintering temperature, thereby increasing the maximum sintering temperature of the final sintering process, shortening the final sintering time of the zirconia ceramic, and further improving the production efficiency of the zirconia ceramic product, while ensuring that the material obtains excellent mechanical properties and transparency in a very short time.

[0038] Second, the embodiment of the application shortens the final sintering time through precise control of six stages, while ensuring excellent mechanical properties and transparency; and controls the grain size of the zirconia ceramic to be 0.1-0.6μm, thereby significantly improving the optical, mechanical and thermal properties thereof. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a flowchart of a preferred embodiment of a rapid sintering method for zirconia ceramic for dental use in the application.

[0040] Figure 2 is a schematic diagram of the crystal type conversion of zirconia material in the application.

[0041] Figure 3 is a normal material organization of the grain when sintering at the standard active sintering temperature as the maximum temperature.

[0042] Figure 4 is the over-sintered organization of the grain when sintering at the predetermined maximum sintering temperature as the maximum temperature in the application. DETAILED DESCRIPTION

[0043] To make the purpose, technical solutions and advantages of the application clearer and more explicit, the application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application and do not limit the application.

[0044] The zirconia dental material undergoes a pre-sintering and a final sintering heat treatment curve to finally produce a zirconia ceramic product. Among them, the pre-sintering is completed at the factory, and the final sintering is completed at the denture processing factory. The embodiment of the application adjusts the final sintering process of the product, reduces the final sintering time, and at the same time obtains a product with performance equivalent to that of the traditional sintering process, thereby improving the production efficiency of the zirconia ceramic.

[0045] Please refer to Figure 1 , Figure 1 is a flowchart of a rapid sintering method for zirconia ceramic for dental use in the application. As shown in Figure 1 , the rapid sintering method for zirconia ceramic for dental use in the embodiment of the application comprises the following steps:

[0046] Step S100, obtaining a pre-sintered body prepared from a yttria-stabilized zirconia powder, and obtaining a standard active sintering temperature of the zirconia powder.

[0047] Among them, pure zirconia has monoclinic, tetragonal and cubic three crystal forms, respectively denoted as m-ZrO2, t-ZrO2 and c-ZrO2. The densities are 5.65 g / cm 3 , 6.10 g / cm 3 and 6.27 g / cm 3 , respectively. c-ZrO2 is fluorite structure (a = b = c), Zr+ constitutes a face-centered cubic structure, and oxygen atoms occupy 8 tetrahedral center interstitial positions. When c-ZrO2 transforms into t-ZrO2, the c-axis becomes longer (a = b < c); when t-ZrO2 transforms into m-ZrO2, a ≠ b ≠ c. And the three crystal forms are stable at low, medium and high temperature zones, respectively. Among them, t-ZrO2 and c-ZrO2 cannot exist at room temperature. The specific conditions of the phase transition of various types are shown in Figure 2 .

[0048] When t-ZrO2 transforms into m-ZrO2, a volume expansion of about 7% occurs, so the volume expansion of pure ZrO2 ceramic caused by phase transition during cooling will cause the product to crack, and even cause the product to break. Therefore, pure ZrO2 ceramic has little production value. In order to eliminate the destructive effect caused by this volume change, adding an appropriate amount of cubic oxide can eliminate the transformation between monoclinic phase and tetragonal phase in pure zirconia, which is called the stabilization of ZrO2. The mechanism of commonly used stabilizers Y2O3, CaO and MgO is that Y 3+ , Ca + , Mg + and other cations can replace Zr 4+Forming substitution solid solution, preventing phase transformation during cooling of ZrO2 ceramic product, so that high temperature stable t-ZrO2 and c-ZrO2 can also be stable or metastable at room temperature. According to its stability at room temperature, it can be divided into fully stable ZrO2 (FSZ, fully stabilized zirconia), partially stable ZrO2 (PSZ, partially stabilized zirconia) and tetragonal ZrO2 polycrystal (TZP, tetragonal zirconia polycrystal). TZP represents: t-ZrO2 is fully metastable single-phase polycrystalline zirconia ceramic at room temperature, in addition to the content of stabilizer affecting its stability, sintering process can also affect the stability of t-ZrO2. The zirconia ceramic produced by the embodiments of the application is a TZP tetragonal phase, and the amount of tetragonal phase is large, so that the ceramic has excellent mechanical properties.

[0049] The sintering process is a key link in the preparation of ceramic products, and the most important link in sintering is the sintering temperature. After slip casting, the green body contains many pores, and the particles are only in point contact. Through the sintering process, the contact area between the particles is expanded, the particles are aggregated, and the volume is shrunk. Specifically, the center distance of the particles is approached, and the grain boundary is gradually formed; the shape of the pores changes, the volume shrinks, and the connected pores gradually become isolated pores and gradually shrink to be excluded, and finally become a dense body.

[0050] Exemplarily, the standard active sintering temperature of the zirconia powder is the active sintering temperature of the zirconia powder marked by the manufacturer. Specifically, the manufacturer can change the active sintering temperature of the powder by adjusting the formula when producing the zirconia powder, therefore, the manufacturer will mark the active sintering temperature of the zirconia powder. The standard of the active sintering temperature is the highest temperature under the highest temperature 1-4h holding process for obtaining better mechanical properties and transparency of the same type (dental) product, while reducing the deformation degree of the material.

[0051] As shown in Figure 1 The rapid sintering method of the zirconia ceramic for dental use according to the embodiments of the application further comprises the following steps:

[0052] In step S200, the pre-sintered body is subjected to final sintering in a predetermined final sintering stage to obtain a zirconia ceramic, wherein the predetermined highest sintering temperature in the predetermined final sintering stage is greater than the standard active sintering temperature, and the difference between the predetermined highest sintering temperature and the standard active sintering temperature is 10-60℃.

[0053] In the final sintering process, the yttria toughened zirconia powder is driven by high temperature energy and surface energy activity, and tetragonal polycrystal organization is gradually formed in the material, accompanied by grain formation and grain growth. Generally, at the standard active sintering temperature of the zirconia powder, the yttria toughened zirconia ceramic grain size is kept at 0.1-0.6 μm, the grains are uniform and do not abnormally grow. At the standard active sintering temperature, the zirconia ceramic product can obtain excellent mechanical properties and transparency. When the highest temperature of the final sintering is set to be higher than the standard active sintering temperature without changing other parameters, the yttria toughened zirconia material is driven by the increased thermal driving energy, leading to grain growth, and the average grain size is greater than 0.8 μm, thus leading to the decrease of the mechanical properties of the material and the rapid decrease of the transparency, which affects the aesthetic effect of the material.

[0054] The standard active sintering temperature of the existing zirconia powder is generally between 1500-1530 ℃, and actually fluctuates between 5 ℃. The zirconia crystallization has two directions, one is phase transition, and the other is rapid grain growth after phase transition. In order to limit the grain growth after crystallization, manufacturers generally recommend not to sinter above the active temperature of the powder. However, if the rapid phase transition of the grains can be well controlled and the crystallization is completed at the same time, the effect of rapid sintering can be achieved, and excellent mechanical properties and transparency can be obtained.

[0055] In the embodiment of the present application, the predetermined highest sintering temperature in the final sintering stage is set to be 10-60 ℃ higher than the standard active sintering temperature, and the sintering process is changed, thereby shortening the production time of the zirconia ceramic. If the standard active sintering temperature recommended by the manufacturer is 1500 ℃, then the predetermined highest sintering temperature in the final sintering stage of the present application is between 1510-1560 ℃; if the standard active sintering temperature recommended by the manufacturer is 1530 ℃, then the predetermined highest sintering temperature in the final sintering stage of the present application is between 1540-1590 ℃.

[0056] The embodiment of the present application increases the highest sintering temperature of the final sintering process, so that the phase transition and atomic activity in the material are more active. Therefore, a specific sintering process is matched to ensure that the material obtains excellent mechanical properties and transparency in a very short time.

[0057] In the embodiment of the present application, the "pre-sintered body prepared from the yttria stabilized zirconia powder" in the step S100 specifically comprises: pressing the yttria stabilized zirconia powder into a zirconia ceramic green body through a cold isostatic pressing process; and pre-sintering the green body to obtain a pre-sintered body.

[0058] The cold isostatic pressing forming process (CIP) is a forming technology that uses high-pressure liquid as a pressure transmission medium to apply isotropic (uniform) pressure to powder materials at room temperature or low temperature. The core principle is to uniformly transmit pressure to the powder in the mold through the incompressibility of the liquid to densify the powder and form a green body with high strength and high uniformity. The product production process applicable to the present application is powder mixing-dry pressing-cold isostatic pressing-gel removal-pre-sintered pre-sintered body.

[0059] The sintering process of the embodiment of the present application is applicable to a zirconia ceramic green body pressed by the cold isostatic pressing forming process, and can obtain a zirconia ceramic with excellent mechanical properties and transmittance.

[0060] In an embodiment of the present application, the shortest final sintering time of the pre-sintered body in the predetermined final sintering stage is 27 min.

[0061] As shown in Figure 3 and Figure 4 , Figure 3 is a normal material organization with normal grain when sintering at the standard active sintering temperature as the highest temperature; Figure 4 is a over-sintered organization with grain growth when sintering at the predetermined highest sintering temperature as the highest temperature in the present application. Therefore, the embodiment of the present application increases the highest sintering temperature of the final sintering process to make the phase transition and atomic activity in the material more active, and then matches a special sintering process to ensure that the material obtains excellent mechanical properties and transmittance in a very short time. Figure 3 Corresponding to the normal material organization with normal grain, the material needs to be kept at the highest temperature for 1.5-4 h, and the material can reach a transmittance (visible light transmittance 1.0±0.02 mm) of more than 40%. The embodiment of the present application shortens the final sintering holding time and can make the material transmittance reach more than 95% of its own limit transmittance, and the final sintering time can be shortened to 27 min at the lowest.

[0062] The limit transmittance refers to the maximum light transmittance of the material in an ideal state (no defect, no scattering, no absorption), which is determined by the electronic structure, lattice vibration mode (phonon) and the like of the material itself. For example, if the theoretical limit transmittance of zirconia ceramic is 50%, the present application reaches more than 95% of its own limit transmittance, which means that the actual light transmittance is 47.5%, which means that only 5% of the theoretical light transmittance is lost, indicating that the material has approached an optically perfect state.

[0063] In the embodiment of the present application, the predetermined final sintering stage includes:

[0064] First stage: enter the furnace at a temperature of 700-900°C;

[0065] Second stage: increase the furnace temperature to 1100°C in 1 min;

[0066] Third stage: 4-7 minutes to increase the furnace temperature to 1300℃;

[0067] Fourth stage: 7-15 minutes to increase the furnace temperature to the predetermined maximum sintering temperature;

[0068] Fifth stage: the furnace temperature is kept at the predetermined maximum sintering temperature for 15 minutes;

[0069] Sixth stage: cooling to 150℃ and discharging.

[0070] The first stage is an initial heating stage, which functions to slowly preheat and eliminate the temperature difference between the inside and outside of the green body to avoid thermal shock cracking. Directly entering the high-temperature furnace from room temperature can cause a too large temperature difference between the surface and the center, leading to thermal stress cracks. The initial temperature range of 700℃-900℃ is close to the glass transition temperature of zirconia, at which the material begins to soften and can effectively buffer thermal stress.

[0071] The second stage is a rapid heating stage, which functions to activate the diffusion mechanism and start preliminary densification. At 1100℃, the atomic diffusion coefficient is significantly improved, and the powder particles begin to adjust their positions through sliding and rotation to reduce pores.

[0072] The third stage is a medium-speed heating stage, which functions to balance densification and grain control. At 1300℃, the particle contact points begin to form necks through evaporation-condensation or volume diffusion, and the strength of the green body is significantly improved; medium-speed heating can gradually change the pores from open pores to closed pores, reducing defects caused by gas escape during subsequent sintering.

[0073] The fourth stage is a precise temperature control stage, which functions to achieve final densification and performance regulation. The maximum sintering temperature is the critical point of densification, at which the pores are basically eliminated, and the phase transition ratio of tetragonal phase to monoclinic phase can be controlled in this stage.

[0074] The fifth stage is a holding stage, which functions to ensure sintering uniformity and performance stability. Holding can make the internal temperature of the green body uniform, avoiding deformation or cracking caused by uneven density.

[0075] The sixth stage is a controlled cooling stage, which functions to avoid thermal shock and performance degradation. Rapid cooling can cause thermal shock cracks, and controlling the cooling rate can make the green body shrink uniformly.

[0076] The six-stage precise control of the embodiments of the present application shortens the final sintering time while ensuring excellent mechanical properties and transmittance.

[0077] In an embodiment of the present application, the grain size of the zirconia ceramic is 0.1-0.6μm.

[0078] The zirconia ceramic of the embodiment of the present application has a grain size of 0.1-0.6 μm, which can significantly improve the optical, mechanical and thermal properties thereof.

[0079] In the embodiment of the present application, the content of yttrium oxide in the zirconia powder is 2.5-8 mol%.

[0080] The molar percentage (mol%) refers to the proportion of the moles of a component in the mixture to the total moles. The content of yttrium oxide in the zirconia powder is 2.5-8 mol%, which refers to the molar fraction of yttrium oxide in the zirconia matrix. If the content of yttrium oxide is too low (<2.5 mol%), the tetragonal phase is unstable, and part of it is converted into monoclinic phase at room temperature, which weakens the toughening effect. If the content of yttrium oxide is too high (>8 mol%), the proportion of cubic phase increases, and the phase transition driving force is insufficient, which reduces the toughening effect.

[0081] In the embodiment of the present application, 2.5-8 mol% of yttrium oxide is added to the zirconia ceramic as a stabilizer, which can significantly optimize the phase structure, mechanical properties, thermal stability and chemical durability thereof.

[0082] In one embodiment of the present application, the content of zirconia in the zirconia powder is 89.5-97% in terms of mass percentage.

[0083] The content of zirconia in the embodiment of the present application is high. Since pure zirconia will undergo a phase transition from monoclinic phase to tetragonal phase during heating / cooling, accompanied by a volume change of 3-5%, it is easy to cause cracking. Under high content of zirconia, the dopant replaces Zr 4+ by solid solution to form oxygen vacancies, which stabilizes the tetragonal phase to room temperature and avoids the phase transition brittleness.

[0084] In the embodiment of the present application, the particle size of the zirconia powder is 30-100 μm.

[0085] The zirconia powder in the embodiment of the present application is the raw material for producing ceramic products, which specifically refers to the combination of monoclinic zirconia and yttrium oxide, trace elements, adhesive binder, dispersant and the like. The ceramic product production raw material is a 30-100 μm particle size spherical powder.

[0086] The present application uses a 30-100 μm particle size spherical powder as the production raw material. The surface energy of the 30-100 μm particle size powder is moderate, which avoids the serious agglomeration of superfine powder and ensures the sintering activity.

[0087] In one embodiment of the present application, the zirconia powder further comprises aluminum oxide, iron oxide, erbium oxide and praseodymium oxide; the content of the aluminum oxide is less than or equal to 0.5% in terms of mass percentage, and the sum of the contents of the iron oxide, the erbium oxide and the praseodymium oxide is less than or equal to 1.5%.

[0088] In the embodiment of the present application, the trace components in the zirconia powder further include: aluminum oxide ≤0.5%, the sum of iron oxide, erbium oxide and praseodymium oxide ≤1.5%, and other oxides ≤0.5%.

[0089] In the embodiment of the present application, the aluminum oxide in the zirconia powder serves as a grain growth inhibitor, can be adsorbed on the surface of the zirconia grains, reduces the grain boundary migration rate, prevents abnormal grain growth during sintering, and stabilizes the tetragonal phase of the zirconia, reduces the phase transition to monoclinic phase during sintering or use, and avoids the cracking caused by volume expansion.

[0090] The following specific embodiments are listed for illustration.

[0091] Step A1, the yttria-stabilized zirconia powder is pressed into a zirconia ceramic body by a cold isostatic pressing forming process;

[0092] Step A2, the body is pre-sintered to obtain a pre-sintered body;

[0093] Step A3, the standard active sintering temperature of the zirconia powder is 1500℃;

[0094] Step A4, the pre-sintered body is put into the furnace at a high temperature of 700-900℃;

[0095] Step A5, the furnace temperature is raised to 1100℃ in 1 minute;

[0096] Step A6, the furnace temperature is raised to 1300℃ in 4-7 minutes;

[0097] Step A7, the furnace temperature is raised to 1510-1560℃ in 7-15 minutes;

[0098] Step A8, the furnace temperature is kept at 1510-1560℃ for 15 minutes;

[0099] Step A9, the temperature is lowered to 150℃ and the furnace is taken out.

[0100] The present application also discloses a zirconia ceramic, which is prepared by the rapid sintering method of the zirconia ceramic for dentistry.

[0101] The application provides a zirconia ceramic fast sintering method and zirconia ceramic, and the zirconia ceramic fast sintering method comprises the following steps: obtaining a pre-sintered body prepared from yttria-stabilized zirconia powder, and obtaining a standard active sintering temperature of the zirconia powder; sintering the pre-sintered body in a predetermined final sintering stage to obtain the zirconia ceramic, wherein a predetermined maximum sintering temperature in the predetermined final sintering stage is greater than the standard active sintering temperature, and the difference between the predetermined maximum sintering temperature and the standard active sintering temperature is 10-60 DEG C. According to the embodiment of the application, the predetermined maximum sintering temperature in the predetermined final sintering stage is set to be 10-60 DEG C higher than the standard active sintering temperature, the maximum sintering temperature of the final sintering process is improved, the final sintering time of the zirconia ceramic is shortened, and the production efficiency of the zirconia ceramic product is improved, and meanwhile, the material can obtain excellent mechanical properties and transmittance in a very short time.

[0102] It should be understood that the application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the application.

Claims

1. A method for rapid sintering of dental zirconia ceramic, characterized by, The method comprises the following steps: obtaining a pre-sintered body prepared from yttria-stabilized zirconia powder, and obtaining a standard active sintering temperature of the zirconia powder; sintering the pre-sintered body in a predetermined final sintering stage to obtain a zirconia ceramic, wherein a predetermined maximum sintering temperature in the predetermined final sintering stage is greater than the standard active sintering temperature, and the difference between the predetermined maximum sintering temperature and the standard active sintering temperature is 10-60℃.

2. The rapid sintering method of dental zirconia ceramic according to claim 1, characterized in that, The method comprises the following steps: obtaining a pre-sintered body prepared from yttria-stabilized zirconia powder, and obtaining a standard active sintering temperature of the zirconia powder; pressing the yttria-stabilized zirconia powder into a zirconia ceramic green body through a cold isostatic pressing process; 3. The method of rapid sintering of dental zirconia ceramic according to claim 1, characterized in that, pre-sintering the green body to obtain a pre-sintered body.

4. The rapid sintering method of dental zirconia ceramic according to claim 1, characterized in that, The shortest final sintering time of the pre-sintered body in a predetermined final sintering stage is 27 min. The predetermined final sintering stage comprises: a first stage: entering the furnace at a temperature of 700-900℃; a second stage: increasing the furnace temperature to 1100℃ in 1 min; a third stage: increasing the furnace temperature to 1300℃ in 4-7 min; a fourth stage: increasing the furnace temperature to the predetermined maximum sintering temperature in 7-15 min; a fifth stage: maintaining the furnace temperature at the predetermined maximum sintering temperature for 15 min; 5. The method of rapid sintering of dental zirconia ceramic according to claim 1, characterized in that, a sixth stage: cooling to 150℃ and discharging the furnace.

6. The method of rapid sintering of dental zirconia ceramic according to claim 1, characterized in that, The grain size of the zirconia ceramic is 0.1-0.6 μm.

7. The method of rapid sintering of dental zirconia ceramic according to claim 1, characterized in that, The content of yttria in the zirconia powder is 2.5-8 mol%.

8. The method of rapid sintering of dental zirconia ceramic according to claim 1, characterized in that, The content of zirconia in the zirconia powder is 89.5-97% by mass percentage.

9. The method of rapid sintering of dental zirconia ceramic according to claim 1, characterized in that, The particle size of the zirconia powder is 30-100 μm.

10. A zirconia ceramic, characterized by, The zirconia powder further comprises aluminum oxide, iron oxide, erbium oxide and praseodymium oxide; the content of the aluminum oxide is less than or equal to 0.5% by mass percentage, and the sum of the contents of the iron oxide, the erbium oxide and the praseodymium oxide is less than or equal to 1.5% by mass percentage. The zirconia ceramic is prepared by the method for rapidly sintering a dental zirconia ceramic according to any one of claims 1-9.

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