Co-firing preparation method of zirconia bicolor ceramic

Abstract

The invention relates to the technical field of ceramic materials, and discloses a zirconium oxide bicolor ceramic co-firing preparation method, which comprises the following steps: adjusting a powder formula, carrying out compression molding twice by using red and black zirconium oxide, and carrying out cold isostatic pressing molding, air sintering, hot isostatic pressing sintering, reduction sintering and other sintering modes to obtain the zirconium oxide bicolor ceramic. According to the preparation method, the performance of a red product can be ensured, and the color consistency and stability of a black product can be maintained, so that the double-color zirconia ceramic product with various colors, high performance and good color consistency is prepared, and the double-color zirconia ceramic product has a good market application prospect and can meet multiple requirements of different customers.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic materials, and in particular to a method for co-firing and preparing zirconia two-color ceramics. Background Art

[0002] Zirconia (chemical formula: ZrO2), as a cutting-edge new ceramic material, exhibits excellent electrical conductivity, significant thermal expansion performance, extremely low friction coefficient, unparalleled chemical stability, and excellent corrosion and erosion resistance. Among many ceramic materials, zirconium oxide stands out with its excellent high-temperature stability, excellent thermal insulation performance, extremely low thermal conductivity, and thermal expansion coefficient similar to that of metals. It is particularly worth mentioning that the unique martensitic phase transformation characteristics of zirconium oxide make it an extremely outstanding reinforcing agent in the field of composite materials. In addition, zirconium oxide also has a high refractive index, which provides unlimited possibilities for the preparation of colorful translucent polycrystalline materials. These materials can not only present a colorful appearance like natural gemstones, but also show a colorful charm like gemstone jewelry, thus showing extremely broad application potential in the current market.

[0003] However, for conventional zirconia ceramic material-related products on the current market, the main sintering method is still limited to air sintering, and the color of the product is limited to pure black or pure white. The preparation process of black zirconia products mainly relies on two ways: one is to pre-mix white zirconia powder with colorants and then form and sinter; the other is to convert white zirconia products into black through a vacuum blackening sintering process. However, the blackening process has high requirements for the temperature field and furnace equipment, and the color consistency of the product is difficult to guarantee; and if ordinary colorants are added, the color is very likely to bleed and volatilize after multiple high-temperature reaction sintering, thus affecting the final quality of the product.

[0004] Therefore, it has become an urgent task to improve and upgrade the existing zirconia ceramic material preparation technology.

[0005] The above information is presented as background information only to assist with understanding the present disclosure and no determination or admission is made as to whether any of the above may be used as prior art with respect to the present disclosure. Summary of the invention

[0006] The invention provides a co-firing preparation method of zirconia two-color ceramics to solve the problems existing in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for preparing a zirconia two-color ceramic by co-firing, the method comprising:

[0009] The red granulation powder and the black granulation powder are respectively pressed and formed in a profiling steel die; the red granulation powder comprises the following components in weight percentage: 92%-93% zirconium oxide, 3%-5% red colorant, and 2.5% stabilizer; the black granulation powder comprises the following components in weight percentage: 92%-93% zirconium oxide, 5% black colorant, and 2.5% stabilizer;

[0010] Put the green compact after the primary pressing into the profiling mold and perform secondary pressing;

[0011] The green body after the secondary pressing is subjected to cold isostatic pressing;

[0012] The green body formed by cold isostatic pressing is subjected to debinding and pre-sintering after debinding; subsequently, high-temperature sintering is performed in an air atmosphere to obtain a primary sintered green body;

[0013] The primary fired green body is subjected to hot isostatic pressing sintering in an inert atmosphere; subsequently, reduction sintering is performed at a high temperature in a reducing atmosphere to obtain a triple-sintered two-color ceramic green body;

[0014] The two-color ceramic body is finely processed to obtain a zirconia ceramic product.

[0015] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the red colorant is cerium oxide.

[0016] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the black colorant includes iron, chromium and nickel in a mass ratio of 2:2:1.

[0017] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the indicators of the red granulation powder and the black granulation powder are:

[0018] D50 is 0.1-0.3μm, fluidity is 45-55S, bulk density is 1.25-1.45g / cm3, and powder shrinkage is 20%-21%.

[0019] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the pressing pressure of the one-time pressing molding is 1T-3T, and the holding time is 2S.

[0020] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the pressing pressure of the secondary pressing molding is 30-35T, and the density of the green embryo after the secondary pressing molding is 3.0±0.2g / cm3.

[0021] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, in an air atmosphere, the sintering temperature is 1420-1490° C., the holding time is 1.5-2.5 h, the heating rate is 3-4° C. / min, and the number of layers is 1-4.

[0022] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the temperature of hot isostatic pressing sintering in an inert atmosphere is 1230-1350° C., and the holding time is 1-3 hours.

[0023] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the reduction sintering temperature is 1390-1430° C., and the holding time is 1-3 hours.

[0024] Furthermore, in the co-firing preparation method of the zirconia two-color ceramic, the reducing atmosphere is a mixed atmosphere of nitrogen and hydrogen.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a method for preparing a zirconia two-color ceramic co-firing. The method adjusts the powder formula, performs two-time pressing and molding using red and black zirconium oxides, and undergoes a variety of sintering methods such as cold isostatic pressing, air sintering, hot isostatic pressing, and reduction sintering. This ensures the performance of the red product while maintaining the color consistency and stability of the black product. Thus, a two-color zirconia ceramic product with diverse colors, high performance, and good color consistency is prepared. The product has good market application prospects and can meet the multiple requirements of different customers.

[0027] The present invention has other features and advantages, which will be apparent from or will be described in detail in the accompanying drawings and the following detailed description incorporated herein, which together serve to explain the specific principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a schematic flow chart of a method for preparing a zirconia two-color ceramic by co-firing provided in an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of a green body formed by one-time pressing according to an embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of a green body formed by one-time pressing according to an embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of two green embryos tightly combined after secondary pressing and molding mentioned in an embodiment of the present invention;

[0033] Figure 5 is a schematic diagram of a zirconia ceramic component mentioned in an embodiment of the present invention;

[0034] Figure 6 This is a rendering of the color of the boundary line before adjusting the granulation powder mentioned in the embodiment of the present invention;

[0035] Figure 7 This is a diagram showing the effect of improving the color cross-linking at the boundary line after adjusting the granulated powder mentioned in the embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0037] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0038] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0039] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0040] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0041] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0042] In this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0043] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0044] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0045] Please refer to Figure 1 , is a schematic flow chart of a method for preparing a zirconia two-color ceramic co-firing according to Embodiment 1 of the present invention, which is suitable for preparing zirconia ceramic parts, such as a dial. The method specifically comprises the following steps:

[0046] S101. Pressing the red granulation powder and the black granulation powder into shapes in a contoured steel die respectively; the red granulation powder comprises the following components in weight percentage: 92%-93% zirconium oxide, 3%-5% red colorant, and 2.5% stabilizer; the black granulation powder comprises the following components in weight percentage: 92%-93% zirconium oxide, 5% black colorant, and 2.5% stabilizer.

[0047] It should be noted that this step is to put the pre-prepared red granulation powder and black granulation powder into their respective profiling steel molds for one-time pressing and molding. During the process, the one-time molding pressure of the two powders is ensured to be close, and the green body density is consistent to meet the process requirements. The profiling steel mold is designed according to the shape of a part of the final product (such as a dial) to ensure that the green body pressed once has the required shape and size, such as Figure 2 and Figure 3 shown.

[0048] In red granulated powder, zirconium oxide is the main material, which provides high hardness, high strength and wear resistance of the ceramic. The red colorant gives the ceramic a red appearance, and the stabilizer is used to improve the stability and sintering performance of the material.

[0049] In black granulated powder, zirconium oxide and stabilizers are similar to those in red granulated powder, but the content of black colorant is relatively high to form a distinct black color.

[0050] In one implementation of this embodiment, the red colorant is cerium oxide.

[0051] It should be noted that cerium oxide, as a commonly used ceramic colorant, has good stability and high temperature resistance, can maintain a bright red color during high-temperature sintering, and has little effect on the performance of the zirconia matrix.

[0052] The black colorant includes iron, chromium and nickel in a mass ratio of 2:2:1. This combination can provide a stable black effect and is not prone to color change during high-temperature sintering. Iron, chromium and nickel are common metal elements, and their addition to ceramics can form stable compounds, thereby giving the ceramics a black appearance.

[0053] The indicators of the red granulation powder and the black granulation powder are:

[0054] D50 is 0.1-0.3μm, fluidity is 45-55S, bulk density is 1.25-1.45g / cm3, and powder shrinkage is 20%-21%.

[0055] It should be noted that D50 is an important parameter for measuring the particle size distribution of powders, indicating that 50% of the particles in the powder have a diameter smaller than this value. In this embodiment, the D50 of the granulated powder is controlled within the range of 0.1-0.3 μm, which helps to obtain uniform and fine ceramic products.

[0056] Fluidity is an important indicator for measuring the fluidity of powders, and is usually measured by a Hall flow meter. In this embodiment, the fluidity of the granulated powder is controlled within the range of 45-55S, which is conducive to uniform filling and pressing of the powder.

[0057] The bulk density refers to the density of the powder in a naturally stacked state. In this embodiment, the bulk density of the granulated powder is controlled within the range of 1.25-1.45 g / cm³, which helps to obtain a higher green density during the pressing process.

[0058] The powder shrinkage rate refers to the ratio of the volume shrinkage of the powder due to high temperature during the sintering process. In this embodiment, the shrinkage rate of the granulated powder is controlled within the range of 20%-21%, which helps to obtain a ceramic product with stable size and regular shape.

[0059] In summary, by carefully selecting the components of the red colorant and the black colorant and strictly controlling the key indicators of the granulated powder, this embodiment successfully prepared a zirconia two-color ceramic product with excellent performance and stable color.

[0060] In one implementation of this embodiment, the pressing pressure of the one-time pressing molding is 1T-3T, and the holding time is 2S.

[0061] It should be noted that the size of the pressing pressure directly affects the density and strength of the green body. If the pressure is too small, the green body density may be insufficient, affecting the densification and performance during the subsequent sintering process; if the pressure is too large, the mold may be damaged or the green body may be deformed. Therefore, choosing the right pressing pressure is crucial to obtaining high-quality green bodies.

[0062] The holding time refers to the period of time during which the pressing pressure remains unchanged after reaching the set value. The length of the holding time has an important influence on the density distribution and uniformity of the green body. If the holding time is too short, it may lead to uneven density distribution inside the green body, affecting the performance of the final product; if the holding time is too long, it may increase production costs and reduce production efficiency. Therefore, the reasonable selection of the holding time is the key to ensuring the quality of the green body.

[0063] In summary, by precisely controlling the pressing pressure and holding time of the primary pressing process, the present embodiment can produce a green body with uniform density and good strength, laying a solid foundation for the subsequent sintering and processing process. The optimization of this process parameter not only helps to improve the quality and performance of the product, but also reduces production costs and improves production efficiency.

[0064] S102, placing the green compact after the primary pressing into a contouring mold, and performing secondary pressing.

[0065] It should be noted that this step is to put the red and black green pieces after the first pressing into a larger imitation mold (such as a dial) and perform a second pressing. The purpose of this step is to tightly combine the two green pieces together, such as Figure 4 As shown, it is prepared for the subsequent co-firing process.

[0066] S103, performing cold isostatic pressing on the green body after the secondary pressing.

[0067] It should be noted that this step is to subject the combined green body after secondary pressing to cold isostatic pressing. Cold isostatic pressing is a technique that applies uniform pressure in a high-pressure liquid medium to increase the density and uniformity of the green body, reduce porosity, and thus improve the mechanical properties of the final product.

[0068] In one implementation of this embodiment, the pressing pressure of the secondary pressing molding is 30-35T, and the density of the green embryo after the secondary pressing molding is 3.0±0.2g / cm3.

[0069] It should be noted that the selection of this pressure range is based on the strength of the green embryo after the first press molding and the density and performance requirements of the final product. Compared with the first press molding, the second press molding requires a higher pressure to ensure the close bonding between the red and black green embryos and to further improve the overall density and strength of the green embryo. By precisely controlling the pressing pressure, it can be ensured that the green embryo can be uniformly densified during the subsequent sintering process, thereby obtaining a final product with excellent performance.

[0070] The density of the green embryo is an important indicator to measure its degree of densification, which directly affects the performance of the final product. In this embodiment, by accurately controlling the process parameters of the secondary pressing molding, such as pressing pressure and holding time, the density of the green embryo can be successfully controlled within a relatively narrow range. The selection of this density not only ensures the stability and density of the green embryo during the sintering process, but also avoids the sintering difficulties and cost increase caused by too high density.

[0071] In summary, by precisely controlling the pressing pressure of the secondary pressing and the density requirement of the green embryo, the present embodiment can prepare a green embryo with a uniform and dense structure and good performance.

[0072] S104, debinding the green body formed by cold isostatic pressing, and pre-sintering after debinding; then, sintering at high temperature in air atmosphere to obtain a primary sintered green body.

[0073] It should be noted that after cold isostatic pressing, this step requires the green body to be debinded to remove the binder and other organic matter added during the pressing process. After debinding, the green body is pre-sintered at a lower temperature to further consolidate its structure, improve the strength of the green body, prevent cracking, and remove residual moisture and gas. Subsequently, sintering is carried out in a high-temperature air atmosphere to obtain a primary sintered green body to ensure the color consistency of the green body.

[0074] In one implementation of this embodiment, in an air atmosphere, the sintering temperature is 1420-1490° C., the holding time is 1.5-2.5 h, the heating rate is 3-4° C. / min, and the number of layers is 1-4.

[0075] It should be noted that the selection of this temperature range is based on the characteristics of the materials used and the performance requirements of the desired product. Within this temperature range, the material can undergo sufficient physical and chemical reactions, thereby achieving densification and improved performance. At the same time, avoiding excessively high sintering temperatures can reduce energy consumption and production costs, and prevent deformation or cracking of the material due to overheating.

[0076] The length of the holding time has an important influence on the densification and grain growth of the material. In this embodiment, by accurately controlling the holding time, it is possible to ensure that the material reaches an ideal degree of densification during the sintering process, while avoiding performance degradation caused by excessive grain growth. The setting of the holding time also needs to take into account production efficiency and cost factors to ensure efficient production while meeting product performance requirements.

[0077] The influence of the selection of the heating rate on the sintering process is mainly reflected in two aspects: first, to avoid excessive thermal stress and cracking of the material due to too fast heating; second, to ensure that the material has enough time to be preheated and heated evenly during the heating process, so as to achieve more uniform sintering. In this embodiment, by controlling the heating rate within a reasonable range, the stability and controllability of the sintering process can be ensured.

[0078] The number of layers directly affects the heat transfer efficiency in the sintering furnace and the uniformity of heating of the material. In this embodiment, by properly controlling the number of layers, it is possible to ensure that each layer of material can obtain sufficient heat for sintering, while avoiding the problems of uneven heat transfer and insufficient sintering caused by too many layers. In addition, a reasonable number of layers can also help improve the utilization rate and production efficiency of the sintering furnace.

[0079] In summary, by precisely controlling process parameters such as sintering temperature, holding time, heating rate, and number of layers, this embodiment can produce ceramic products with excellent performance and uniform structure.

[0080] S105, hot isostatic pressing the primary sintered green body under an inert atmosphere; then, reduction sintering is performed under a reducing atmosphere at a high temperature to obtain a triple sintered two-color ceramic green body.

[0081] It should be noted that this step is to hot isostatically press the primary sintered blank under an inert atmosphere. Hot isostatic pressing combines high temperature and high pressure, which helps to further improve the density and uniformity of the ceramic. Subsequently, high-temperature reduction sintering is carried out under a reducing atmosphere. The purpose of this step is to stabilize the color of the ceramic. Under a reducing atmosphere, the reducing atmosphere generally does not react with the colorant, thereby maintaining the stability and consistency of the color. The standard sample is tested by a colorimeter, and its black L value is stable within 3-4.

[0082] In one implementation of this embodiment, the temperature of hot isostatic pressing sintering in an inert atmosphere is 1230-1350° C., and the holding time is 1-3 hours.

[0083] It should be noted that this temperature range is selected to ensure that the material can be fully densified under high pressure and inert atmosphere, while avoiding excessively high temperatures that may cause damage to the material structure or degradation of its performance.

[0084] The length of the holding time has an important influence on the densification degree and grain growth of the material. Within this time range, the material can fully undergo physical and chemical reactions to achieve higher density and more uniform structure. At the same time, a reasonable holding time can also help improve production efficiency and reduce costs.

[0085] In one implementation of this embodiment, the reducing atmosphere is a mixed atmosphere of nitrogen and hydrogen, the temperature of the reducing sintering is 1390-1430° C., and the holding time is 1-3 hours.

[0086] It should be noted that nitrogen, as an inert gas, can remove oxygen during the sintering process, thereby preventing the material from oxidizing at high temperatures. This is essential for maintaining the color and performance stability of the material.

[0087] The reduction sintering is carried out in a nitrogen atmosphere at a temperature of 1390°C-1430°C. This temperature range is chosen to ensure that the material can be further densified in a reducing atmosphere and stabilize its color and performance. At the same time, a higher sintering temperature also helps to eliminate residual pores and defects in the material and improve the overall quality of the product.

[0088] The holding time is also set to 1-3h. Similar to hot isostatic pressing sintering, a reasonable holding time can ensure that the material undergoes sufficient physical and chemical reactions in a reducing atmosphere, achieving higher density and more uniform structure.

[0089] In summary, by precisely controlling the process parameters of hot isostatic pressing sintering and reduction sintering, this embodiment can produce a zirconia two-color ceramic product with excellent performance and stable color. The optimization of these process parameters not only helps to improve the quality and performance stability of the product, but also reduces production costs and improves production efficiency. At the same time, the use of nitrogen as a reducing atmosphere also effectively prevents the oxidation reaction of the material at high temperature, ensuring that the color and performance of the product are not affected.

[0090] S106, fine-processing the two-color ceramic body to obtain a zirconia ceramic product.

[0091] It should be noted that this step is to fine-process the two-color ceramic body after three sintering. Fine processing includes flat grinding, CNC processing, polishing, laser engraving and other processes to remove surface defects generated during the sintering process and obtain the required surface finish and dimensional accuracy. The final result is a zirconia ceramic part with excellent performance and color consistency, such as a dial. Figure 5 shown.

[0092] Although the terms such as one-shot pressing and sintering are used more frequently in this application, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.

[0093] The present invention provides a method for preparing a zirconia two-color ceramic co-firing. The method adjusts the powder formula, performs two-time pressing and molding using red and black zirconium oxides, and undergoes a variety of sintering methods such as cold isostatic pressing, air sintering, hot isostatic pressing, and reduction sintering, so that the performance of the red product can be ensured while maintaining the color consistency and stability of the black product, thereby preparing a two-color zirconia ceramic product with diverse colors, high performance, and good color consistency.

[0094] Precisely because compared with traditional single-color zirconia ceramic parts, the two-color zirconia ceramic parts of the present invention show significant diversity advantages in appearance color. At the same time, the products also have excellent mechanical properties and excellent color consistency. These characteristics make the two-color zirconia ceramic products of the present invention more competitive in the market, and can better serve the customer groups with increasingly stringent requirements on product quality and appearance. By adjusting the granulation powder formula, the color cross-linking range of the junction line before improvement is 0.24mm, and the junction line is vague and unclear; after improvement, the color cross-linking range of the junction line is 0.03mm, and the junction line is clear. The improvement effect diagram of the color cross-linking of the junction line before and after adjusting the granulation powder is as shown in the figure Figure 6 and 7 shown.

[0095] Finally, it should be noted that although the above embodiments have been described in the specification and drawings of this application, this does not limit the scope of patent protection of this application. All technical solutions generated by replacing or modifying equivalent structures or equivalent processes based on the essential concept of this application using the contents recorded in the specification and drawings of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, are included in the scope of patent protection of this application.

Claims

1. A method for preparing a zirconia two-color ceramic by co-firing, characterized in that: The method comprises: The red granulation powder and the black granulation powder are respectively pressed and formed in a profiling steel die; the red granulation powder comprises the following components in weight percentage: 92%-93% zirconium oxide, 3%-5% red colorant, and 2.5% stabilizer; the black granulation powder comprises the following components in weight percentage: 92%-93% zirconium oxide, 5% black colorant, and 2.5% stabilizer; Put the green compact after the primary pressing into the profiling mold and perform secondary pressing; The green body after the secondary pressing is subjected to cold isostatic pressing; The green body formed by cold isostatic pressing is subjected to debinding and pre-sintering after debinding; subsequently, high-temperature sintering is performed in an air atmosphere to obtain a primary sintered green body; The primary fired green body is subjected to hot isostatic pressing sintering in an inert atmosphere; subsequently, reduction sintering is performed at a high temperature in a reducing atmosphere to obtain a triple-sintered two-color ceramic green body; The two-color ceramic body is finely processed to obtain a zirconia ceramic product.

2. The method for preparing zirconia two-color ceramic by co-firing according to claim 1, characterized in that: The red colorant is cerium oxide.

3. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: The black colorant includes iron, chromium and nickel in a mass ratio of 2:2:

1.

4. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: The indicators of the red granulation powder and the black granulation powder are: D50 is 0.1-0.3μm, fluidity is 45-55S, bulk density is 1.25-1.45g / cm3, and powder shrinkage is 20%-21%.

5. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: The pressing pressure of the one-time pressing molding is 1T-3T, and the holding time is 2S.

6. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: The pressing pressure of the secondary pressing molding is 30-35T, and the density of the green embryo after the secondary pressing molding is 3.0±0.2g / cm3.

7. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: In air atmosphere, the sintering temperature is 1420-1490°C, the holding time is 1.5-2.5h, the heating rate is 3-4°C / min, and the number of layers is 1-4.

8. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: The temperature of hot isostatic pressing sintering in an inert atmosphere is 1230-1350°C, and the holding time is 1-3h.

9. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: The temperature of reduction sintering is 1390-1430°C, and the holding time is 1-3h.

10. The co-firing preparation method of zirconia two-color ceramics according to claim 1, characterized in that: The reducing atmosphere is a mixed atmosphere of nitrogen and hydrogen.

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