High-temperature-resistant zirconia fastener and manufacturing method thereof

Abstract

The invention relates to the technical field of fastener preparation, in particular to a high-temperature-resistant zirconium oxide fastener and a manufacturing method thereof.The manufacturing method comprises the following steps that high-purity zirconium oxide powder is selected as a raw material, the zirconium oxide powder is pretreated, and uniform and fine powder particles are obtained; pressing the zirconium oxide powder into a fastener blank in a required shape by adopting a hot press molding process; sintering the fastener blank into a compact zirconium oxide fastener by adopting an electric furnace sintering process according to the phase change characteristic and sintering kinetics of zirconium oxide; the sintered zirconia fastener is subjected to polishing and sand blasting surface treatment until the surface smoothness of zirconia meets the requirement, and the volume change of zirconia in the phase change process is successfully reduced by precisely controlling sintering process parameters and combining with pretreatment of a hot press molding process, so that the surface smoothness of the zirconia fastener is improved. Therefore, generation of internal cracks and overall deformation of the fastener are effectively restrained.

Description

Technical Field

[0001] The invention relates to the technical field of fastener preparation, and in particular to a high temperature resistant zirconia fastener and a manufacturing method thereof. Background Art

[0002] Zirconia (ZrO2), as a high-performance ceramic material, has become an ideal material choice for many high-temperature, high-pressure and corrosive environments due to its unique physical and chemical properties, such as extremely high melting point (about 2700℃), excellent hardness and wear resistance, good chemical inertness and stable structure at high temperatures. Especially in high-end manufacturing fields such as aerospace, automobile manufacturing, and petrochemicals, there is an increasing demand for fasteners that can withstand extreme temperature changes. Zirconia fasteners are widely used in key components such as engine parts, heat exchangers, catalytic converters, etc. in these fields due to their excellent high-temperature resistance to ensure safe and reliable operation of the equipment.

[0003] Although zirconia materials have many advantages, processing them into high-performance fasteners faces many challenges. Traditional zirconia fastener manufacturing methods, such as powder metallurgy and direct sintering, often have problems such as long preparation cycle, high energy consumption, and low yield.

[0004] During the high-temperature sintering process, the volume change associated with the transformation of zirconia from the monoclinic phase to the tetragonal phase can easily lead to cracks, deformation or dimensional instability inside the fasteners, affecting their mechanical properties and reliability. Summary of the invention

[0005] The purpose of the present invention is to provide a high-temperature resistant zirconia fastener and a method for manufacturing the same, which solves the problem that during the high-temperature sintering process, due to the phase change characteristics of volume change accompanied by the transformation of zirconia from a monoclinic phase to a tetragonal phase, cracks, deformation or dimensional instability are easily generated inside the fastener, affecting its mechanical properties and reliability.

[0006] To achieve the above object, the present invention provides a method for manufacturing a high temperature resistant zirconia fastener, comprising the following steps:

[0007] Select high-purity zirconium oxide powder as raw material, pre-treat the zirconium oxide powder to obtain uniform and fine powder particles;

[0008] The zirconium oxide powder is pressed into a fastener blank of a desired shape by a hot pressing process;

[0009] According to the phase change characteristics and sintering dynamics of zirconium oxide, the fastener blank is sintered into a dense zirconium oxide fastener by using an electric furnace sintering process;

[0010] The sintered zirconia fasteners are subjected to surface treatments such as polishing and sandblasting until the surface finish of the zirconia meets the requirements.

[0011] Among them, in “selecting high-purity zirconium oxide powder as raw material, pre-treating the zirconium oxide powder, and obtaining uniform and fine powder particles”, the method includes the following steps:

[0012] According to the application environment and performance requirements of fasteners, zirconium oxide powder with a purity of not less than 99.5% is selected as the raw material;

[0013] According to the design size and shape of the fastener, the required zirconium oxide powder particle size range is determined, and the powder particle size ranges from submicron to several microns;

[0014] The selected zirconium oxide powder and additives are mixed evenly, the mixture is put into a ball mill for ball milling, zirconium oxide balls are selected, and the speed and filling rate of the ball mill are adjusted;

[0015] Use a vibrating screen to screen and grade the ball-milled powder to remove oversized particles and agglomerates to obtain a powder with uniform particle size distribution;

[0016] The sieved and graded powder is placed in a drying device, and after hot air drying, the powder is taken out and molded.

[0017] Among them, in “using a vibrating screen to screen and grade the ball-milled powder to remove oversized particles and agglomerates to obtain a powder with uniform particle size distribution”, the method also includes:

[0018] During the screening and grading process, the aperture of the screen and the parameters of the grading equipment are adjusted according to the required particle size range to ensure uniform particle size distribution of the powder after screening and grading.

[0019] Among them, in “using a hot pressing process to press zirconium oxide powder into a fastener blank of a desired shape”, the method includes the following steps:

[0020] Manufacture molds according to the design drawings of fasteners;

[0021] Preheat the mold before hot pressing to eliminate the temperature difference stress inside the mold;

[0022] The pretreated zirconium oxide powder is evenly filled into the preheated mold. The powder is filled tightly without gaps during the filling process. After the filling is completed, the powder is preliminarily compacted using a compacting tool;

[0023] The mold containing the compacted powder is placed in a hot press and hot pressed according to the preset temperature, pressure and time;

[0024] After the hot pressing is completed, the mold and the blank are cooled to room temperature, the blank is demoulded, and the burrs on the surface are removed.

[0025] Among them, in “placing the mold containing the compacted powder into a hot press and performing hot pressing molding according to a preset temperature, pressure and time”, the method also includes:

[0026] During the hot pressing process, it is necessary to monitor the temperature changes of the mold and the blank, as well as the stability and uniformity of the pressure, and to control the heating rate and cooling rate of the hot press.

[0027] Among them, in “according to the phase change characteristics and sintering dynamics of zirconium oxide, an electric furnace sintering process is used to sinter the fastener blank into a dense zirconium oxide fastener”, the method includes the following steps:

[0028] After inspecting the fastener blank, clean it to remove stains, grease and impurities on the surface;

[0029] Preheat the electric furnace to a temperature that reaches the temperature required by the phase change characteristics of zirconium oxide;

[0030] The fastener blank is placed on a sintering platform in an electric furnace, and the heating rate, sintering temperature, holding time and threshold value of the heating rate of the electric furnace are set;

[0031] During the sintering process, the control system of the electric furnace monitors the sintering temperature, heating rate and holding time in real time and keeps them within the preset range;

[0032] After sintering, take out the fasteners from the electric furnace, remove the sintering residues on the surface, and clean and dry the fasteners.

[0033] Among them, in the step of “the sintering temperature, heating rate and holding time are monitored in real time by the control system of the electric furnace during the sintering process and kept within a preset range”, the method comprises the following steps:

[0034] Observe the color change, volume shrinkage and shape stability characteristics of the green body, and adjust the heating rate, sintering temperature or holding time during the sintering process.

[0035] Among them, in “polishing and sandblasting the sintered zirconia fasteners until the surface finish of the zirconia meets the requirements”, the method includes the following steps:

[0036] Use a coarse-grained polishing wheel and polishing agent to evenly polish the fasteners, checking the polishing effect during the polishing process until preliminary smoothness is achieved;

[0037] After rough polishing, use fine-grained polishing tools and polishing agents for fine polishing, and repeat the operation until the surface of the fastener reaches a mirror effect;

[0038] Adjust the abrasive particle size, spray pressure and spray time of the sandblasting equipment, use fine diamond abrasive particles to spray onto the surface of the fasteners, and inspect and clean the fasteners.

[0039] A high temperature resistant zirconia fastener, prepared by the high temperature resistant zirconia fastener manufacturing method

[0040] A high temperature resistant zirconia fastener and a manufacturing method thereof of the present invention comprises the following steps: selecting high purity zirconia powder as raw material, pre-treating the zirconia powder to obtain uniform and fine powder particles; using a hot pressing process to press the zirconia powder into a fastener blank of a desired shape; using an electric furnace sintering process to sinter the fastener blank into a dense zirconia fastener according to the phase change characteristics and sintering dynamics of zirconia; performing surface treatment of polishing and sandblasting on the sintered zirconia fastener until the surface finish of the zirconia meets the requirements. This solution uses high quality zirconia powder and undergoes strict hot pressing and sintering processes to improve the strength and hardness of the fastener. The sintering process parameters are controlled to further optimize the high temperature resistance of the fasteners. After surface treatment processes such as polishing and sandblasting, the surface of the fasteners reaches an extremely high degree of smoothness. By precisely controlling the sintering process parameters (such as heating rate, sintering temperature, holding time and cooling rate) and combining the pretreatment of the hot pressing process, this patented solution successfully reduces the volume change of zirconia during the phase change process, thereby effectively inhibiting the generation of internal cracks and overall deformation of the fasteners. In this way, by precisely controlling the sintering process parameters and combining the pretreatment of the hot pressing process, this patented solution successfully reduces the volume change of zirconia during the phase change process, thereby effectively inhibiting the generation of internal cracks and overall deformation of the fasteners. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0042] Figure 1 The present invention is a flowchart of a method for manufacturing a high temperature resistant zirconia fastener.

[0043] Figure 2 The present invention selects high-purity zirconium oxide powder as raw material, pre-treats the zirconium oxide powder, and obtains uniform and fine powder particles.

[0044] Figure 3 The present invention is a flow chart of using a hot pressing process to press zirconium oxide powder into a fastener blank of a desired shape.

[0045] Figure 4The present invention is a flow chart of sintering a fastener blank into a dense zirconia fastener using an electric furnace sintering process according to the phase change characteristics and sintering dynamics of zirconia.

[0046] Figure 5 The present invention is a flow chart of performing surface treatment of polishing and sandblasting on sintered zirconia fasteners until the surface finish of the zirconia reaches the required level. DETAILED DESCRIPTION

[0047] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0048] See also Figures 1 to 5 , Figure 1 It is a flow chart of a method for manufacturing a high temperature resistant zirconia fastener of the present invention; Figure 2 This is a flow chart of the present invention, which uses high-purity zirconium oxide powder as raw material, pre-treats the zirconium oxide powder, and obtains uniform and fine powder particles; Figure 3 It is a flow chart of the present invention for pressing zirconium oxide powder into a fastener blank of a desired shape by a hot pressing forming process; Figure 4 It is a flow chart of the present invention for sintering a fastener blank into a dense zirconia fastener using an electric furnace sintering process according to the phase change characteristics and sintering dynamics of zirconia; Figure 5 The present invention is a flow chart of performing surface treatment of polishing and sandblasting on sintered zirconia fasteners until the surface finish of the zirconia reaches the required level.

[0049] A method for manufacturing a high temperature resistant zirconia fastener comprises the following steps:

[0050] S1: Select high-purity zirconium oxide powder as raw material, pre-treat the zirconium oxide powder to obtain uniform and fine powder particles:

[0051] S11: According to the application environment and performance requirements of the fasteners, zirconium oxide powder with a purity of not less than 99.5% is selected as the raw material;

[0052] S12: Determine the required zirconia powder particle size range according to the design size and shape of the fastener, and the powder particle size ranges from submicron to several microns;

[0053] S13: uniformly mixing the selected zirconium oxide powder and the additive, placing the mixture in a ball mill for ball milling, selecting zirconium oxide balls, and adjusting the rotation speed and filling rate of the ball mill;

[0054] S14: Use a vibrating screen to screen and grade the ball-milled powder to remove oversized particles and agglomerates to obtain powder with uniform particle size distribution. During the screening and grading process, adjust the aperture of the screen and the parameters of the grading equipment according to the required particle size range to ensure that the powder after screening and grading has uniform particle size distribution;

[0055] S15: The sieved and graded powder is placed in a drying device, and after hot air drying, the powder is taken out and molded.

[0056] In this embodiment:

[0057] 1. Raw material selection

[0058] 1.1 Purity and particle size control of zirconium oxide powder

[0059] Purity requirements: Zirconia powder with a purity of not less than 99.5% is selected as the raw material to ensure the high temperature performance and chemical stability of the fasteners. High-purity zirconium oxide powder can reduce the impact of impurities on material properties, especially at high temperatures, where impurities may become crack sources or reduce the creep resistance of the material.

[0060] Particle size control: The particle size distribution of zirconium oxide powder is critical to the subsequent molding and sintering process. The ideal particle size range should be between submicron and several microns, depending on the required fastener size and shape. Uniform particle size distribution helps to achieve higher density and more uniform microstructure, thereby improving the mechanical properties and high temperature resistance of the fastener.

[0061] 1.2 Selection of additives (if necessary)

[0062] In some cases, a small amount of sintering aid, plasticizer or stabilizer can be added to improve the formability or sintering performance of zirconia powder. For example, adding an appropriate amount of yttrium oxide (Y2O3) can stabilize tetragonal zirconia and prevent it from transforming into monoclinic phase at high temperature, thereby avoiding volume change and crack generation.

[0063] 2. Powder processing

[0064] 2.1 Ball milling

[0065] The selected zirconium oxide powder is ball-milled to further refine the particle size and improve its dispersibility. During the ball-milling process, the powder particle size can be precisely controlled by adjusting parameters such as ball-milling media, ball-milling time and rotation speed.

[0066] 2.2 Screening and grading

[0067] The powder after ball milling needs to go through screening and classification steps to remove oversized particles and agglomerates to ensure that the particle size distribution of the powder meets the requirements of the subsequent molding process. Screening and classification can be carried out by vibrating screens, airflow classification and other methods.

[0068] 2.3 Drying and storage

[0069] Drying is a key step to remove residual moisture and volatile substances in powders. Usually, hot air drying, vacuum drying or freeze drying are used to prevent powders from agglomerating or deteriorating during storage and transportation.

[0070] When storing, the dried zirconium oxide powder should be placed in a sealed, dry, and cool environment to prevent it from absorbing moisture or reacting with other chemicals.

[0071] S2: Use hot pressing process to press the zirconium oxide powder into the required shape of the fastener blank:

[0072] S21: manufacturing a mold according to the design drawing of the fastener;

[0073] S22: Preheat the mold before hot pressing to eliminate the temperature difference stress inside the mold;

[0074] S23: evenly filling the pretreated zirconium oxide powder into the preheated mold, the powder is filled tightly without gaps during the filling process, and after the filling is completed, the powder is preliminarily compacted using a compacting tool;

[0075] S24: placing the mold containing the compacted powder into a hot press, and performing hot pressing molding according to a preset temperature, pressure and time. During the hot pressing process, it is necessary to monitor the temperature changes of the mold and the blank, as well as the stability and uniformity of the pressure, and it is also necessary to control the heating rate and cooling rate of the hot press;

[0076] S25: After the hot pressing is completed, the mold and the blank are cooled to room temperature, the blank is demoulded, and the burrs on the surface are removed.

[0077] In this embodiment:

[0078] Powder pretreatment and inspection

[0079] Before hot pressing, the zirconia powder needs to be pre-treated, including screening to remove oversized or undersized particles to ensure uniform particle size distribution; drying to remove moisture from the powder to avoid bubbles or affect the density of the green body during the molding process; at the same time, if sintering aids or plasticizers are added, they must be fully mixed with the zirconia powder. In addition, the quality of the pre-treated powder must be checked to ensure that it meets the requirements of hot pressing.

[0080] Mold preparation and preheating

[0081] According to the design drawings of the fasteners, high-precision molds are carefully manufactured. The mold materials must have good high temperature resistance and wear resistance to ensure that no deformation or wear occurs during the hot pressing process. The inside of the mold must be smooth and flawless, and coated with a layer of suitable mold release agent to facilitate smooth demolding of the formed blank. Before hot pressing, the mold must also be preheated. The preheating temperature must be determined based on the phase change characteristics of zirconium oxide and the heating capacity of the hot press to eliminate the temperature difference stress inside the mold and improve the molding efficiency.

[0082] Powder filling and compacting

[0083] The pretreated zirconium oxide powder is evenly filled into the preheated mold. During the filling process, it is necessary to ensure that the powder is filled tightly without gaps to ensure that the green body after molding has uniform density and good mechanical properties. After filling, the powder is initially compacted using a special compacting tool to eliminate the gaps between the powders and increase the initial density of the green body.

[0084] Hot Press Forming

[0085] The mold containing the compacted powder is placed in a hot press and hot pressed according to the preset process parameters (such as temperature, pressure and time). During the hot pressing process, it is necessary to pay close attention to the temperature changes of the mold and the green body, as well as the stability and uniformity of the pressure, to ensure that the green body is fully densified under appropriate conditions. At the same time, it is also necessary to pay attention to controlling the heating rate and cooling rate of the hot press to avoid cracks or deformation inside the green body due to too rapid temperature changes.

[0086] Demolding and post-processing

[0087] After hot pressing, the mold and the blank are cooled to a suitable temperature before demoulding. The demoulding should be done gently and evenly to avoid damage to the blank. The blank needs to be post-processed after demoulding, such as removing burrs and cleaning, to ensure that it meets the requirements of subsequent sintering or processing. At the same time, the size, shape and appearance of the blank need to be checked to ensure that it meets the design requirements.

[0088] S3: According to the phase change characteristics and sintering dynamics of zirconium oxide, the fastener blank is sintered into a dense zirconium oxide fastener using an electric furnace sintering process:

[0089] S31: After inspecting the fastener blank, clean the blank to remove stains, grease and impurities on the surface;

[0090] S32: preheating the electric furnace to a temperature that reaches a temperature value required by the phase change characteristics of zirconium oxide;

[0091] S33: placing the fastener blank on a sintering platform in the electric furnace, and setting the thresholds of the heating rate, sintering temperature, holding time and cooling rate of the electric furnace;

[0092] S34: During the sintering process, the control system of the electric furnace monitors the values ​​of the sintering temperature, heating rate and holding time in real time, keeps them within a preset range, observes the color change, volume shrinkage and shape stability characteristics of the green body, and adjusts the heating rate, sintering temperature or holding time during the sintering process;

[0093] S35: After sintering, take out the fastener from the electric furnace, remove the sintering residue on the surface, and clean and dry the fastener.

[0094] In this embodiment:

[0095] Preparation and inspection before sintering

[0096] Before sintering, the fastener blank must first be thoroughly inspected, including size, shape, appearance, and the integrity of the internal structure, to ensure that the blank meets the quality requirements before sintering. At the same time, the blank must be thoroughly cleaned to remove surface stains, grease, and impurities to avoid contamination or affect the sintering quality during the sintering process. In addition, the electric furnace must be preheated, and the preheating temperature must be determined based on the phase change characteristics of zirconium oxide and sintering kinetics to fully prepare for the subsequent sintering process.

[0097] Green body placement and sintering parameter setting

[0098] The cleaned and inspected fastener blanks are carefully placed on the sintering platform in the electric furnace, ensuring that the blanks are kept at an appropriate distance to avoid adverse effects caused by mutual contact during the sintering process. At the same time, according to the phase change temperature and sintering dynamics of zirconia, the key parameters of the electric furnace such as heating rate, sintering temperature, holding time and cooling rate are accurately set. The setting of these parameters is crucial to obtaining high-quality zirconia fasteners.

[0099] Sintering process monitoring and adjustment

[0100] During the sintering process, it is necessary to pay close attention to the temperature changes in the electric furnace and the sintering state of the green body. Through the control system of the electric furnace, real-time monitoring of parameters such as sintering temperature, heating rate and holding time are carried out to ensure that they are always kept within the preset range. At the same time, it is also necessary to observe the characteristics of the green body such as color change, volume shrinkage and shape stability, so as to timely discover and adjust problems in the sintering process. If necessary, the parameters such as heating rate, sintering temperature or holding time can be appropriately adjusted to obtain the best sintering effect.

[0101] Post-sintering treatment and quality control

[0102] After sintering, the fasteners are taken out of the electric furnace after the furnace and the blank are cooled to a suitable temperature. At this time, the sintered fasteners need to be post-processed, such as removing sintering residues on the surface, cleaning and drying. At the same time, the sintered fasteners are fully quality controlled, including dimensional measurement, appearance inspection, mechanical property testing, etc., to ensure that they meet the design requirements and quality standards. In addition, the data during the sintering process needs to be recorded and analyzed in order to continuously optimize the sintering process and improve production efficiency and quality level.

[0103] S4: Polishing and sandblasting the sintered zirconia fasteners until the surface finish of the zirconia meets the requirements;

[0104] S41: Use a coarse-grained polishing wheel and polishing agent to evenly polish the fasteners, checking the polishing effect during the polishing process until preliminary smoothness is achieved;

[0105] S42: After rough polishing, use fine-grained polishing tools and polishing agents for fine polishing, and repeat the operation until the surface of the fastener reaches a mirror effect;

[0106] S43: Adjust the abrasive particle size, spray pressure and spray time of the sandblasting equipment, and use fine diamond abrasive particles to spray onto the surface of the fasteners to inspect and clean the fasteners.

[0107] In this embodiment,

[0108] Initial cleaning

[0109] Before polishing and sandblasting, the sintered zirconia fasteners need to be cleaned. The purpose of this step is to remove dust, oil and other impurities on the surface of the fasteners to provide a clean foundation for subsequent surface treatment. Usually a soft brush, dust-free cloth or compressed air is used for cleaning to ensure that the surface of the fastener is clean and free of dirt.

[0110] Rough polishing

[0111] After the initial cleaning, the next step is rough polishing. The main purpose of rough polishing is to remove the larger unevenness and burrs on the surface of the fastener to make the surface smoother. Use a coarse-grained polishing wheel or polishing cloth with an appropriate amount of polishing agent to evenly polish the fastener. During the polishing process, the polishing effect needs to be constantly checked until the desired initial smoothness is achieved.

[0112] Fine polishing

[0113] After rough polishing, the surface of the fastener is relatively smooth, but there may still be tiny flaws and unevenness. Therefore, fine polishing is required to further improve the surface finish. Fine polishing uses fine-grained polishing tools and polishing agents to polish the fasteners more carefully. Through repeated operations and inspections, ensure that the fastener surface reaches the required mirror effect or high finish.

[0114] Sandblasting

[0115] The last step is sandblasting, which is mainly used to remove tiny scratches and residues on the surface of fasteners, while increasing the surface roughness and improving the bonding strength with other materials. During the sandblasting process, fine abrasive particles (such as corundum, glass beads, etc.) are sprayed at high speed onto the surface of the fastener. By adjusting the parameters of the sandblasting equipment (such as abrasive particle size, spray pressure and spray time), the sandblasting effect can be accurately controlled to ensure that the surface of the fastener meets the final finish and roughness requirements. After the sandblasting is completed, the fasteners must be finally inspected and cleaned to ensure that their surface quality meets the design requirements.

[0116] A high temperature resistant zirconia fastener is prepared by the high temperature resistant zirconia fastener manufacturing method, and its structure and effect are as follows:

[0117] Material composition: This high temperature resistant zirconia fastener is made of high purity zirconia powder through precise hot pressing and high temperature sintering process. The selection of zirconia material ensures that the fastener has excellent stability and reliability in high temperature environment.

[0118] Precision molding: The fasteners are formed by hot pressing, which achieves accurate replication of the shape and high-density structure of the fasteners by precisely controlling the molding pressure and temperature. This precision molding technology ensures that the fasteners can maintain shape stability and dimensional consistency during the sintering process.

[0119] Surface treatment: The surface of the fasteners is polished and sandblasted to meet extremely high requirements for smoothness and roughness. This not only improves the aesthetics of the fasteners, but also enhances their bonding strength with other materials and corrosion resistance.

[0120] Internal structure design: The internal structure of the fastener is reasonably designed to avoid stress concentration areas and reduce the risk of cracks and deformation caused by thermal stress in high temperature environments. At the same time, the optimization of the internal structure also improves the mechanical properties and reliability of the fastener.

[0121] What is disclosed above is only one or more preferred embodiments of the present application, and cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A method for manufacturing a high temperature resistant zirconia fastener, characterized in that: The steps include: Select high-purity zirconium oxide powder as raw material, pre-treat the zirconium oxide powder to obtain uniform and fine powder particles; The zirconium oxide powder is pressed into a fastener blank of a desired shape by a hot pressing process; According to the phase change characteristics and sintering dynamics of zirconium oxide, the fastener blank is sintered into a dense zirconium oxide fastener by using an electric furnace sintering process; The sintered zirconia fasteners are subjected to surface treatments such as polishing and sandblasting until the surface finish of the zirconia meets the requirements.

2. The method for manufacturing a high temperature resistant zirconia fastener according to claim 1, characterized in that: In "selecting high-purity zirconium oxide powder as raw material, pre-treating the zirconium oxide powder, and obtaining uniform and fine powder particles", the method includes the following steps: According to the application environment and performance requirements of fasteners, zirconium oxide powder with a purity of not less than 99.5% is selected as the raw material; According to the design size and shape of the fastener, the required zirconium oxide powder particle size range is determined, and the powder particle size ranges from submicron to several microns; The selected zirconium oxide powder and additives are mixed evenly, the mixture is put into a ball mill for ball milling, zirconium oxide balls are selected, and the speed and filling rate of the ball mill are adjusted; Use a vibrating screen to screen and grade the ball-milled powder to remove oversized particles and agglomerates to obtain a powder with uniform particle size distribution; The sieved and graded powder is placed in a drying device, and after hot air drying, the powder is taken out and molded.

3. The method for manufacturing a high temperature resistant zirconia fastener according to claim 2, characterized in that: In "using a vibrating screen to screen and grade the ball-milled powder to remove oversized particles and agglomerates to obtain a powder with uniform particle size distribution", the method further includes: During the screening and grading process, the aperture of the screen and the parameters of the grading equipment are adjusted according to the required particle size range to ensure uniform particle size distribution of the powder after screening and grading.

4. The method for manufacturing a high temperature resistant zirconia fastener according to claim 1, characterized in that: In "using a hot pressing process to press zirconium oxide powder into a fastener blank of a desired shape", the method includes the following steps: Manufacture molds according to the design drawings of fasteners; Preheat the mold before hot pressing to eliminate the temperature difference stress inside the mold; The pretreated zirconium oxide powder is evenly filled into the preheated mold. The powder is filled tightly without gaps during the filling process. After the filling is completed, the powder is preliminarily compacted using a compacting tool; The mold containing the compacted powder is placed in a hot press and hot pressed according to the preset temperature, pressure and time; After the hot pressing is completed, the mold and the blank are cooled to room temperature, the blank is demoulded, and the burrs on the surface are removed.

5. The method for manufacturing a high temperature resistant zirconia fastener according to claim 4, characterized in that: In "placing the mold containing the compacted powder into a hot press and performing hot pressing molding according to a preset temperature, pressure and time", the method further includes: During the hot pressing process, it is necessary to monitor the temperature changes of the mold and the blank, as well as the stability and uniformity of the pressure, and to control the heating rate and cooling rate of the hot press.

6. The method for manufacturing a high temperature resistant zirconia fastener according to claim 1, characterized in that: In "According to the phase change characteristics and sintering kinetics of zirconium oxide, an electric furnace sintering process is used to sinter the fastener blank into a dense zirconium oxide fastener", the method includes the following steps: After inspecting the fastener blank, clean it to remove stains, grease and impurities on the surface; Preheat the electric furnace to a temperature that reaches the temperature required by the phase change characteristics of zirconium oxide; The fastener blank is placed on a sintering platform in an electric furnace, and the heating rate, sintering temperature, holding time and threshold value of the heating rate of the electric furnace are set; During the sintering process, the control system of the electric furnace monitors the sintering temperature, heating rate and holding time in real time and keeps them within the preset range; After sintering, take out the fasteners from the electric furnace, remove the sintering residues on the surface, and clean and dry the fasteners.

7. The method for manufacturing a high temperature resistant zirconia fastener according to claim 6, characterized in that: In the process of "monitoring the sintering temperature, heating rate and holding time in real time through the control system of the electric furnace and keeping them within a preset range", the method includes the following steps: Observe the color change, volume shrinkage and shape stability characteristics of the green body, and adjust the heating rate, sintering temperature or holding time during the sintering process.

8. The method for manufacturing a high temperature resistant zirconia fastener according to claim 1, characterized in that: In "polishing and sandblasting the sintered zirconia fastener until the surface finish of the zirconia meets the requirements", the method includes the following steps: Use a coarse-grained polishing wheel and polishing agent to evenly polish the fasteners, checking the polishing effect during the polishing process until preliminary smoothness is achieved; After rough polishing, use fine-grained polishing tools and polishing agents for fine polishing, and repeat the operation until the surface of the fastener reaches a mirror effect; Adjust the abrasive particle size, spray pressure and spray time of the sandblasting equipment, use fine diamond abrasive particles to spray onto the surface of the fasteners, and inspect and clean the fasteners.

9. A high temperature resistant zirconia fastener, characterized in that: Prepared by the high temperature resistant zirconia fastener manufacturing method according to any one of claims 1 to 8.

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