Ultrafast manufacturing method of zirconium carbide ceramic and zirconium carbide ceramic prepared by same

Abstract

The invention belongs to the field of material preparation, and particularly discloses an ultra-fast manufacturing method of zirconium carbide ceramic and the zirconium carbide ceramic prepared through the ultra-fast manufacturing method. The ultra-fast manufacturing method comprises the steps that zirconium carbide raw material powder, a sintering aid and a forming aid are mixed; or mixing the zirconium carbide raw material powder, the sintering aid, the carbon source and the forming aid to prepare a zirconium carbide ceramic green body with a complex shape; and putting the prepared zirconium carbide ceramic green body into an ultra-fast high-temperature sintering device for ultra-fast high-temperature sintering to obtain a zirconium carbide ceramic product. By means of the arrangement, the ultra-fast manufacturing method can obtain the heating rate larger than 1000 DEG C / min and the sintering temperature larger than 3000 DEG C under the die-free and pressure-free conditions so as to accelerate removal of forming auxiliaries and enhance wetting and mass transfer efficiency of liquid-phase sintering auxiliaries and carbon thermal reduction reaction kinetics, and ultra-fast preparation of zirconium carbide ceramics in complex shapes is achieved.

Description

Technical Field

[0001] The invention belongs to the field of material processing, and in particular relates to an ultra-fast manufacturing method of zirconium carbide ceramics and the prepared zirconium carbide ceramics. Background Art

[0002] Zirconium carbide ceramics have excellent comprehensive properties such as high melting point, high elastic modulus, and radiation resistance, and have broad application prospects in the fields of aviation, aerospace, and nuclear industry. However, like other ultra-high temperature ceramics, due to the strong covalent bonds and low self-diffusion coefficient of zirconium carbide ceramics, samples with relatively high density can generally only be obtained under high temperature (>2000℃) and high pressure (>30MPa). The sintering properties can also be improved by introducing different sintering aids to achieve the preparation of zirconium carbide ceramics. Among the conventional preparation methods of zirconium carbide ceramics, hot pressing sintering and spark plasma sintering have long sintering times and require additional pressure, which is not conducive to the industrial production of zirconium carbide ceramics and cannot be used for the production of zirconium carbide ceramics with complex structures. Conventional pressureless sintering requires reaching a higher temperature and a longer holding time, which not only places high demands on equipment, but also consumes a lot of energy throughout the process, making it also unsuitable for industrial production.

[0003] Therefore, it is necessary to design a pressureless rapid sintering technology to reduce the time and energy consumption of the entire preparation process of zirconium carbide ceramics, and at the same time improve its sintering performance by adding sintering aids to realize the industrial production of zirconium carbide ceramics. Summary of the Invention

[0004] In order to overcome the shortcomings of the existing technology, the present invention provides an ultra-fast manufacturing method for zirconium carbide ceramics. The ultra-fast manufacturing method can realize the rapid manufacturing of zirconium carbide ceramics, reduce the time and energy consumption of the entire preparation process of zirconium carbide ceramics, and improve the sintering performance of zirconium carbide ceramics, so as to realize the industrial production of zirconium carbide ceramics.

[0005] Another object of the present invention is to provide a zirconium carbide ceramic prepared by the above-mentioned ultra-rapid manufacturing method of zirconium carbide ceramic.

[0006] The technical solution of the present invention to solve the above technical problems is:

[0007] An ultra-fast manufacturing method for zirconium carbide ceramics comprises the following steps:

[0008] Step 1: fully mixing zirconium carbide raw material powder and a sintering aid, or fully mixing zirconium carbide raw material powder, a sintering aid, and a carbon source to prepare a zirconium carbide ceramic green body; wherein the sintering aid is a single substance;

[0009] Step 2: feeding the prepared zirconium carbide ceramic green body into an ultra-rapid high temperature sintering device for ultra-rapid high temperature sintering to obtain zirconium carbide ceramic;

[0010] In a preferred embodiment of the present invention, in step 1, the process for preparing the zirconium carbide ceramic green body is as follows:

[0011] S101: mixing zirconium carbide raw material powder and a sintering aid with anhydrous ethanol, or mixing zirconium carbide raw material powder, a sintering aid, and a carbon source with anhydrous ethanol to obtain a mixed slurry; wherein the amount of the sintering aid introduced is 0.25-5wt%, and the amount of the carbon source introduced is 0-5wt%;

[0012] S102: transferring the mixed slurry to a planetary ball mill or a roller ball mill, and further mixing the slurry by the planetary ball mill or the roller ball mill;

[0013] S103: After ball milling for 12-24 hours, the remixed slurry is transferred to a rotary evaporator; the heating temperature and speed of the rotary evaporator are set to dry the slurry in the rotary evaporator to obtain a preliminarily dried powder;

[0014] S104: transferring the preliminarily dried powder to an oven for further drying;

[0015] S105: After the dried powder is passed through a 50-200 mesh sieve, the filtered powder is placed in a stainless steel dry pressing mold; the powder is dry pressed using a dry pressing machine, wherein the pressure of the dry pressing machine is set to 5-20 MPa and the pressure holding time is 10-20 seconds, thereby obtaining a pressed sample;

[0016] S106: vacuum-seal the pressed sample, and transfer the vacuum-seal sample to a cold isostatic pressing device for further pressing, wherein the pressure in the cold isostatic pressing device is 200-250 MPa, and the holding time is 150-300 seconds, to finally obtain a zirconium carbide ceramic green body.

[0017] In a preferred embodiment of the present invention, in step 1, a zirconium carbide ceramic green body is prepared by 3D printing, and the specific process is as follows:

[0018] The zirconium carbide ceramic slurry required for 3D printing is prepared, the prepared zirconium carbide ceramic slurry is transferred to a 3D printer, and the zirconium carbide ceramic green body is printed by the 3D printer.

[0019] In a preferred embodiment of the present invention, the specific process for preparing the zirconium carbide ceramic slurry required for 3D printing is as follows:

[0020] S111: Fully mixing zirconium carbide raw material powder, a sintering aid, and a carbon source, then adding the mixture as a solute to deionized water as a solvent at a ratio of 40-80 wt% of the mixture to the total mass of the solution; simultaneously, adding a dispersant at a mass fraction of 0.5-2 wt% to the mixed system, and stirring until the mixture is uniformly mixed;

[0021] S112: Transfer the prepared solution to a beaker for magnetic stirring, wherein the speed of the magnetic stirring device is set to 200-400 rpm and the stirring time is 8-24 hours;

[0022] S113: After the solution is stirred evenly, a thickener and a binder are added to the solution at a mass fraction of 0.3-1.5 wt %;

[0023] S114: magnetically stirring the solution again until the solution is fully mixed, wherein the speed of the magnetic stirring device is set to 200-400 rpm and the stirring time is 4-8 hours;

[0024] S115: mechanically stirring the solution after magnetic stirring again until the solution reaches a stable state; wherein the rotation speed of the mechanical stirring device is set to 600-900 rpm, and the stirring time is 3-6 hours, thereby obtaining zirconium carbide ceramic slurry.

[0025] In a preferred embodiment of the present invention, the dispersant is compounded from an ionic dispersant and a non-ionic dispersant, wherein the ionic dispersant is one or more of sodium polyacrylate, ammonium polyacrylate, sodium lauryl sulfate, and cetyltrimethylammonium bromide; the non-ionic dispersant is one or more of polyvinyl pyrrolidone, polyethylene glycol, and fatty alcohol polyoxyethylene ether; the ionic dispersant and the non-ionic dispersant are mixed in a ratio of 1:0.5-2; the thickener is one or more of nanocrystalline cellulose (NCC / CNF), sodium alginate, guar gum, xanthan gum, polyacrylamide (PAM), and polyvinyl alcohol (PVA); and the binder is one or more of polyethylene glycol (PEG), paraffin, epoxy resin, acrylic resin, hydroxypropyl methylcellulose, and polyvinyl pyrrolidone.

[0026] In a preferred embodiment of the present invention, the specific process of transferring the prepared zirconium carbide ceramic slurry to a 3D printer and printing a zirconium carbide ceramic green body by the 3D printer is as follows:

[0027] S116: transferring the treated zirconium carbide ceramic slurry to a vacuum stirrer, and stirring the zirconium carbide ceramic slurry by the vacuum stirrer; during this process, the vacuum stirrer is set to rotate forward and reverse, and the stirring direction of the vacuum stirrer is changed every 2-6 minutes, and this cycle is repeated for 40-120 minutes to obtain the final zirconium carbide ceramic slurry;

[0028] S117: Transferring the zirconium carbide ceramic slurry into a syringe, and connecting the syringe to an extrusion-type 3D printer;

[0029] S118: Importing the pre-modeled model into the extrusion 3D printer, and then setting the parameters of the extrusion 3D printer, wherein the extrusion speed of the extrusion 3D printer is 0.1-10 mm / s, the printing speed is 1-20 mm / s, and the layer height is 0.3-0.8 mm;

[0030] S119: Starting the extrusion 3D printer to start printing, and naturally air-drying the printed zirconium carbide ceramic green body at room temperature for 8-24 hours.

[0031] In a preferred embodiment of the present invention, in step 2, the process of ultra-rapid high-temperature sintering of the zirconium carbide ceramic green body is as follows:

[0032] S201: placing the obtained zirconium carbide ceramic green body in a crucible in a heating chamber of an ultra-rapid high-temperature sintering device, and filling the crucible with carbon-based conductive powder;

[0033] S202: performing vacuum treatment on the heating chamber of the ultra-rapid high temperature sintering equipment until the vacuum degree in the heating chamber drops to -0.01 MPa;

[0034] S203: introducing argon gas into the heating chamber of the ultra-fast high temperature sintering equipment;

[0035] S204: Repeat step S203 twice to ensure that the heating chamber of the ultra-fast high-temperature sintering equipment is in a flowing argon atmosphere;

[0036] S205: Setting process parameters for an ultra-rapid high-temperature sintering device; the ultra-rapid high-temperature sintering device applies current to electrodes in a heating chamber, and the applied current passes through the carbon-based conductive powder to cause the carbon-based conductive powder to generate Joule heat and heat the encapsulated zirconium carbide ceramic green body, thereby preparing the zirconium carbide ceramic.

[0037] In a preferred embodiment of the present invention, the carbon-based conductive powder is one or more of carbon black, graphite, graphene, carbon fiber, and carbon nanomaterials.

[0038] In a preferred embodiment of the present invention, in step S205, the heating method used for the zirconium carbide ceramics with different structures is a direct heating method or a two-step sintering method, wherein:

[0039] Zirconium carbide ceramics with conventional configurations:

[0040] The direct heating method is to heat the zirconium carbide ceramic green body to the sintering temperature at a heating rate of more than 1000°C / min, and then keep the temperature;

[0041] The two-step sintering method is to heat the zirconium carbide ceramic green body to the melting point of the added element at a heating rate of more than 1000° C. / min, and then heat it to the sintering temperature at a heating rate of more than 500° C. / min.

[0042] 3D printed zirconium carbide ceramics:

[0043] The direct heating method is to first heat to 800-1200°C at a heating rate of 100°C / min, and then heat to the sintering temperature at a heating rate of >1000°C / min;

[0044] The two-step sintering method is to first heat the zirconium carbide ceramic green body to 800-1200°C at a heating rate of 100°C / min, then heat the green body to the melting point of the added element at a heating rate of >1000°C / min, and then heat to the sintering temperature at a heating rate of >500°C / min.

[0045] A zirconium carbide ceramic prepared by the ultra-fast manufacturing method of zirconium carbide ceramic.

[0046] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0047] 1. The present invention's ultra-rapid manufacturing method for zirconium carbide ceramics utilizes the latest ultra-rapid high-temperature sintering technology. This method utilizes a carbon-based conductive powder as a heat source, applying an electric current to the powder to generate a significant amount of Joule heat. The sample is then placed within the carbon-based conductive powder, where the generated Joule heat is transferred to the sample through thermal radiation and conduction, completing the sintering process. Compared to traditional layered structures, the use of a powder heating medium effectively improves sample sintering uniformity, facilitating the production of larger samples. Furthermore, a heating rate exceeding 1000°C / min can be achieved, significantly reducing the time and energy consumption required for ceramic sample production. Furthermore, the entire preparation process requires no additional pressure, resulting in low production costs and facilitating the industrialized production of zirconium carbide ceramics.

[0048] 2. The ultra-fast manufacturing method of zirconium carbide ceramics of the present invention introduces different types of single substances as liquid-phase sintering aids, which effectively reduces the temperature required for pressureless sintering of zirconium carbide ceramics. At the same time, the free carbon that may exist in the original zirconium carbide powder is consumed through reaction, preventing its graphitization and affecting the densification degree of zirconium carbide. At the same time, the introduction of an appropriate amount of carbon source helps the single substance to react to form hard carbides, thereby effectively inhibiting the grain growth of the zirconium carbide ceramics and improving its mechanical properties. In addition, the extremely small amount of sintering aid introduced (0.25-5wt%) ensures that the high-temperature performance of the zirconium carbide ceramics is not affected. Combined with the latest ultra-fast high-temperature sintering technology, the extremely high heating rate can effectively reduce the evaporation of the single substance additives during the heating process, thereby ensuring a certain utilization rate.

[0049] 3. The ultra-fast manufacturing method of the present invention can achieve a heating rate of >1000°C / min and a sintering temperature of >3000°C under moldless and pressureless conditions. In the process of preparing zirconium carbide with complex shapes, a heating rate of 100°C / min can accelerate the removal of forming additives. Ultra-fast preparation of complex-shaped zirconium carbide ceramics can be achieved without changing heating equipment, greatly shortening the entire preparation process.

[0050] 4. The zirconium carbide ceramics prepared by the ultra-fast manufacturing method of the present invention have a simple formula, cheap raw materials, and a simple and easy preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a structural diagram of the equipment used in the ultra-fast manufacturing method of zirconium carbide ceramics of the present invention;

[0052] Figure 2 This is a SEM image of a cross-sectional polished surface of a zirconium carbide ceramic produced by the first ultra-rapid production method of zirconium carbide ceramic described in Example 1;

[0053] Figure 3 This is a surface XRD pattern of the first zirconium carbide ceramic prepared using the ultra-rapid manufacturing method for zirconium carbide ceramics described in Example 1;

[0054] Figure 4 It is the temperature rise curve of the entire preparation process of the sample;

[0055] Figure 5 is a SEM image of a cross-sectional polished surface of a second zirconium carbide ceramic prepared using the ultra-rapid manufacturing method for zirconium carbide ceramics described in Example 1;

[0056] Figure 6 This is a surface XRD pattern of a second zirconium carbide ceramic prepared using the ultra-rapid manufacturing method for zirconium carbide ceramics described in Example 1;

[0057] Figure 7 It is the temperature rise curve of the entire sample preparation process. DETAILED DESCRIPTION

[0058] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0059] Example 1

[0060] The ultra-fast manufacturing method of zirconium carbide ceramics of the present invention comprises the following steps:

[0061] Step 1: Mixing zirconium carbide raw material powder and a sintering aid with a solvent, or fully mixing zirconium carbide raw material powder, a sintering aid and a carbon source to prepare a zirconium carbide ceramic green body; the specific steps are:

[0062] S101: zirconium carbide raw material powder (particle size 100 nm-10 μm) is mixed with a sintering aid (Zr, Cr, Ti, B, etc.) and a carbon source (carbon black, graphite, etc.) using anhydrous ethanol as a solvent to obtain a mixed slurry; wherein the amount of the sintering aid introduced is 0.25 wt%-5 wt% and the amount of the carbon source introduced is 0 wt%-5 wt%;

[0063] S102: transferring the mixed slurry to a planetary ball mill or a roller ball mill, and further mixing the slurry by the planetary ball mill or the roller ball mill;

[0064] S103: After ball milling for 12-24 hours, the remixed slurry is transferred to a rotary evaporator; the heating temperature and speed of the rotary evaporator are set appropriately to dry the slurry in the rotary evaporator; during this process, the slurry in the flask can be observed to see whether it has dried, that is, whether it has turned into a powder; after the rotary evaporation is completed, the powder has been preliminarily dried, and a preliminarily dried powder is obtained;

[0065] S104: transferring the preliminarily dried powder to an oven for further drying;

[0066] S105: After the dried powder is passed through a 50-200 mesh sieve, an appropriate amount of the filtered powder is placed in a stainless steel dry pressing mold; the powder is dry pressed using a dry pressing machine, wherein the pressure of the dry pressing machine is set to 5-20 MPa and the pressure holding time is 10-20 seconds to obtain a pressed sample;

[0067] S106: The pressed sample is vacuum-sealed and transferred to a cold isostatic pressing device for further pressing. The pressure in the cold isostatic pressing device is set to 200-250 MPa and the holding time is 150s-300s, so that the density distribution of the sample is more uniform and the possibility of sample deformation and cracking is reduced. At this point, the preparation of the zirconium carbide ceramic green body is completed.

[0068] Step 2: feeding the prepared zirconium carbide ceramic green body into an ultra-rapid high-temperature sintering device for ultra-rapid high-temperature sintering to obtain zirconium carbide ceramic; specifically:

[0069] S201: placing the obtained zirconium carbide ceramic green body in a crucible in a heating chamber of an ultra-rapid high-temperature sintering device, and filling the crucible with carbon-based conductive powder (such as carbon black, graphite, graphene, carbon fiber, carbon nanomaterials, etc., which have conductive carbon-based powders);

[0070] S202: performing vacuum treatment on the heating chamber of the ultra-rapid high temperature sintering equipment until the vacuum degree in the heating chamber drops to -0.01 MPa;

[0071] S203: introducing argon gas into the heating chamber of the ultra-fast high temperature sintering equipment;

[0072] S204: Repeat step S203 twice to ensure that the heating chamber of the ultra-fast high-temperature sintering equipment is in a flowing argon atmosphere;

[0073] S205: Setting process parameters for an ultra-fast high-temperature sintering device. The ultra-fast high-temperature sintering device applies current to electrodes in a heating chamber. The applied current passes through the carbon-based conductive powder to cause the carbon-based conductive powder to generate a large amount of Joule heat and heat the wrapped zirconium carbide ceramic green body, thereby preparing zirconium carbide ceramics.

[0074] Step 3: Measure various characteristics and properties of zirconium carbide ceramics to determine whether the prepared zirconium carbide ceramics meet the standards, specifically:

[0075] The sintered zirconium carbide ceramic green body was removed and ultrasonically cleaned, and the relative density of the zirconium carbide ceramic green body was measured using the Archimedean drainage method. The polished surface of the zirconium carbide ceramic was preliminarily characterized using a scanning electron microscope and an X-ray diffractometer to observe the microstructure and phase composition of the zirconium carbide ceramic. The performance of the zirconium carbide ceramic was evaluated using a Vickers hardness tester to determine whether the prepared zirconium carbide ceramic met the standards.

[0076] Finally, the ultra-fast manufacturing method of zirconium carbide ceramics of the present invention has the following advantages compared to traditional preparation methods:

[0077] (1) The ultra-fast manufacturing method of zirconium carbide ceramics of the present invention is based on the latest ultra-fast high-temperature sintering technology. By using carbon-based conductive powder as a heat source and applying current to the carbon-based conductive powder, a large amount of Joule heat is generated. The sample is placed in the middle of the carbon-based conductive powder, and the generated Joule heat is transferred to the sample through thermal radiation and heat conduction to complete sintering. Compared with the traditional layered structure, the use of powder heating medium can effectively improve the uniformity of sample sintering, facilitate the manufacture of larger-sized samples, and achieve a heating rate of >1000℃ / min, greatly shortening the time and energy consumption of ceramic sample production. At the same time, the entire preparation process does not require additional pressure, and the production cost is low, which is conducive to the industrial production of zirconium carbide ceramics.

[0078] (2) The ultra-fast manufacturing method of zirconium carbide ceramics of the present invention introduces different types of simple substances as liquid-phase sintering aids, which effectively reduces the temperature required for pressureless sintering of zirconium carbide ceramics and consumes free carbon that may exist in the original zirconium carbide powder through reaction, preventing its graphitization and affecting the densification degree of zirconium carbide; at the same time, by introducing an appropriate amount of carbon source, it helps the simple substance reaction to generate hard carbide, thereby effectively inhibiting the grain growth of zirconium carbide ceramics and improving its mechanical properties. In addition, the extremely small amount of sintering aid introduced (0.25-5wt%) ensures that the high-temperature performance of zirconium carbide ceramics is not affected; combined with the latest ultra-fast high-temperature sintering technology, the extremely high heating rate can effectively reduce the evaporation of simple substance additives during the heating process, thereby ensuring a certain utilization rate.

[0079] (3) The zirconium carbide ceramics prepared by the ultra-fast manufacturing method of the present invention have a simple formula, cheap raw materials, and a simple and easy preparation method. The two prepared powders are placed in a planetary ball mill or a roller ball mill in an appropriate ratio, and then an appropriate amount of solution is added and the prepared jar is placed on the planetary ball mill or the roller ball mill. The ball milling time is only 12-24 hours. After the ball milling is completed, the zirconium carbide ceramics are removed and dried by rotary evaporation before use. The whole process is simple to operate, highly automated, and does not require excessive human intervention.

[0080] (4) The present invention adopts different processes to prepare zirconium carbide ceramics. The direct heating method is to heat the sample to the sintering temperature at a heating rate of >1000℃ / min and then keep it warm. This method is simple. The two-step sintering method is to heat the sample to the melting point of the added element at a heating rate of >1000℃ / min and then heat it to the sintering temperature at a heating rate of >500℃ / min. Only a short time of heat preservation (10-30s) or no heat preservation is required. After the element introduced in the latter part of the process melts into a liquid phase, the predetermined heating rate is reduced to allow the formed liquid phase to have sufficient time for wetting and mass transfer, thereby accelerating the entire densification process and greatly shortening the preparation time of the entire zirconium carbide ceramics.

[0081] (5) The ultra-fast manufacturing method of zirconium carbide ceramics of the present invention adopts P-UHS technology, which adopts simple equipment and low construction cost, and can achieve a heating rate greater than 1000℃ / min, and at the same time has an extremely high temperature upper limit (greater than 3000℃), and the sintering process does not require additional pressure field. It can meet the requirements of rapid high temperature and does not require additional pressure. It is the preferred method for industrial production of zirconium carbide ceramics and production of zirconium carbide ceramics with complex configurations; at the same time, in order to reduce the temperature required for pressureless sintering of zirconium carbide ceramics, the present invention introduces different types of liquid phase sintering aids, such as zirconium , chromium, titanium, silicon, boron and other elements. The introduced elements can effectively remove the free carbon that may exist in the original zirconium carbide powder through reaction, thereby avoiding its graphitization at high temperature. At the same time, an appropriate amount of carbon source, such as graphite, carbon black, etc., can be introduced to make the added elements react with them to generate hard carbides, thereby effectively inhibiting the excessive growth of zirconium carbide ceramic grains, enhancing mechanical properties, and achieving the density of zirconium carbide ceramics; the extremely small amount of sintering aids introduced also ensures the purity of zirconium carbide ceramics, thereby greatly reducing the loss of its high-temperature performance; and the entire preparation process is simple to operate, just set up the appropriate process and run it directly.

[0082] Specific case 1

[0083] like Figure 1-Figure 4 As shown, this case adopts the ultra-fast manufacturing method of zirconium carbide ceramics described in Example 1 to manufacture zirconium carbide ceramics, specifically:

[0084] S1: Prepared zirconium carbide powder (500 nm) and elemental chromium powder (300 nm) were mixed with anhydrous ethanol, and the mixed slurry was sent to a planetary ball mill for ball milling, wherein the amount of elemental chromium introduced was 1 wt%; the parameters of the planetary ball mill were set to 300 r / min, and the ball milling time was 12 h;

[0085] S2: The milled slurry was transferred to a flask of a rotary evaporator for drying. When the slurry was completely dried and turned into powder, it was taken out and placed in an oven to continue drying for 12 hours;

[0086] S3: Take out the dried powder, take 2.9g of powder with weighing paper, and transfer it to a stainless steel mold with a diameter of 20mm, and transfer the stainless steel mold to a dry press for dry pressing, wherein the pressure of the dry press is 10MPa and the holding time is 10s; after the dry pressing is completed, the pressed sample is vacuum-sealed, and then the vacuum-sealed sample is transferred to a cold isostatic press for further pressing, and the parameters of the cold isostatic press are adjusted to 200MPa and the holding time is 300s. After the pressing is completed, the zirconium carbide ceramic green body is taken out to obtain.

[0087] S4: The obtained zirconium carbide ceramic green body is placed in a crucible in a heating chamber of an ultra-rapid high temperature sintering device, and the inner space of the insulating crucible is filled with carbon-based conductive powders, such as carbon black, graphite, graphene, carbon fiber, carbon nanomaterials, etc., which have conductive carbon-based powders, until the lower electrode is covered; then the sample is placed above the lower electrode, and the placement depth of the sample is adjusted to ensure that the sample is located between the upper electrode and the lower electrode. At the same time, the computer is operated to control the position of the upper electrode so that it is located in a suitable position to ensure that the sample is located between the upper electrode and the lower electrode (such as Figure 1 Then fill the insulated crucible with carbon-based powder, cover it with the insulation end cover, and close the furnace door of the heating chamber;

[0088] S5: Turn on the vacuum pump to vacuum the heating chamber of the ultra-rapid high-temperature sintering equipment until the vacuum degree in the heating chamber drops to -0.01 MPa; introduce argon into the heating chamber of the ultra-rapid high-temperature sintering equipment (repeat twice) to ensure that the heating chamber of the ultra-rapid high-temperature sintering equipment is a flowing argon atmosphere, thereby ensuring that the entire preparation process is carried out under an argon atmosphere of 1 atm; at the same time, operate the computer to connect the programmable power supply, and set the process parameters through a self-programmed program, wherein the maximum applied current is 52A, the heating rate is 2000℃ / min, the sintering temperature is 2100℃, and the holding time is 60s. In this way, ultra-rapid pressureless preparation of zirconium carbide ceramics can be achieved within a few minutes, and the prepared zirconium carbide ceramics are taken out after the equipment cools down;

[0089] S6: After ultrasonic cleaning of the zirconium carbide ceramics, the relative density thereof was measured by the Archimedean drainage method, and the relative density was 99%; the polished surface of the prepared zirconium carbide ceramics was subjected to SEM (such as Figure 2 As shown), XRD (as Figure 3 Finally, the prepared zirconium carbide ceramics were subjected to Vickers hardness measurement, and the measurement result was: 22.01±0.7GPa.

[0090] Specific case 2

[0091] like Figure 5-Figure 7 As shown, this case adopts the ultra-fast manufacturing method of zirconium carbide ceramics described in Example 1 to manufacture zirconium carbide ceramics, specifically:

[0092] S1: Prepared zirconium carbide powder (500 nm) and elemental titanium powder (450 nm) were mixed with anhydrous ethanol, and the mixed slurry was sent to a planetary ball mill for ball milling. The amount of elemental titanium introduced was 0.5 wt % and an appropriate amount of carbon black (100 nm) was also introduced. The parameters of the planetary ball mill were set to 300 r / min and the ball milling time was 12 h.

[0093] S2: The milled slurry was transferred to a flask of a rotary evaporator for drying. When the slurry was completely dried and turned into powder, it was taken out and placed in an oven to continue drying for 8 hours.

[0094] S3: Take out the dried powder, take 2.5g of powder with weighing paper, and transfer it to a stainless steel mold with a diameter of 20mm, and transfer the stainless steel mold to a dry press for dry pressing, wherein the pressure of the dry press is 10MPa and the holding time is 10s; after the dry pressing is completed, the pressed sample is vacuum-sealed, and then the vacuum-sealed sample is transferred to a cold isostatic press for further pressing, and the parameters of the cold isostatic press are adjusted to 200MPa and the holding time is 300s. After the pressing is completed, the zirconium carbide ceramic green body is taken out to obtain the green body;.

[0095] S4: The obtained zirconium carbide ceramic green body is placed in a crucible in the heating chamber of the ultra-rapid high temperature sintering equipment, and the inner space of the insulating crucible is filled with graphite powder in the crucible until it covers the lower electrode; then the sample is placed above the lower electrode, and the placement depth of the sample is adjusted to ensure that the sample is located between the upper electrode and the lower electrode. At the same time, the computer is operated to control the position of the upper electrode so that it is located in a suitable position to ensure that the sample is located between the upper electrode and the lower electrode (such as Figure 1 Then fill the insulating crucible with graphite powder, cover it with the insulation end cover, and close the furnace door of the heating chamber;

[0096] S5: Turn on the vacuum pump to vacuum the heating chamber of the ultra-fast high-temperature sintering equipment until the vacuum degree in the heating chamber drops to -0.01MPa; introduce argon into the heating chamber of the ultra-fast high-temperature sintering equipment (repeat twice) to ensure that the heating chamber of the ultra-fast high-temperature sintering equipment is a flowing argon atmosphere, thereby ensuring that the entire preparation process is carried out under an argon atmosphere of 1atm; at the same time, operate the computer to connect the programmable power supply, and set the process parameters through self-programming, first heating at a rate of 2000℃ / min to the melting point of titanium element 1700℃, and then heating at a rate of 500℃ / min to the target temperature 2200℃, without insulation. In this way, ultra-fast pressureless preparation of zirconium carbide ceramics can be achieved within a few minutes, and the prepared zirconium carbide ceramics can be taken out after the equipment cools down;

[0097] S6: After ultrasonic cleaning of the zirconium carbide ceramics, the relative density thereof was measured by the Archimedean drainage method. The relative density was 96%. The polished surface of the prepared zirconium carbide ceramics was subjected to SEM (such as Figure 4 As shown), XRD (as Figure 5 Finally, the prepared zirconium carbide ceramics were subjected to Vickers hardness measurement, and the measurement result was: 18.54±0.86GPa.

[0098] Table 1: Comparison of process performance of samples prepared by the present invention and samples prepared by other inventions

[0099]

[0100] Example 2

[0101] The ultra-fast manufacturing method of zirconium carbide ceramics of the present invention comprises the following steps:

[0102] Step 1: Fully mix zirconium carbide raw material powder, sintering aid, and carbon source to prepare a zirconium carbide ceramic green body;

[0103] In this embodiment, zirconium carbide ceramic green body is prepared by 3D printing, and the specific process is as follows:

[0104] 1) Prepare zirconium carbide ceramic slurry required for 3D printing; specifically:

[0105] S111: Fully mixing zirconium carbide raw material powder (with a particle size of 100 nm-10 μm), a sintering aid (e.g., Zr, Cr, Ti, B, etc., with a particle size of 100 nm-1 μm), and a carbon source (e.g., carbon black, graphite, etc., with a particle size of 100 nm-1 μm), then adding the mixture as a solute to deionized water as a solvent in a ratio of 40 wt%-80 wt% of the mixture mass to the total mass of the solution; simultaneously, adding a dispersant with a mass fraction of 0.5 wt%-5 wt% to the mixed system, and stirring until the mixture is uniformly mixed;

[0106] In this embodiment, the dispersant is a compound of an ionic dispersant and a non-ionic dispersant, wherein the ionic dispersant is one or more of sodium polyacrylate, ammonium polyacrylate, sodium lauryl sulfate, and hexadecyltrimethylammonium bromide; the non-ionic dispersant is one or more of polyvinyl pyrrolidone, polyethylene glycol, and fatty alcohol polyoxyethylene ether; the ionic dispersant and the non-ionic dispersant are mixed in a ratio of 1:0.5-2.

[0107] S112: Transfer the prepared solution to a beaker for magnetic stirring. The speed of the magnetic stirring device is set to 200-400 rpm and the stirring time is 8-24 hours to ensure that the powder is evenly dispersed.

[0108] S113: After the solution is stirred evenly, a thickener and a binder are added to the solution with a mass fraction of 0.3-1.5 wt% to adjust the viscosity of the slurry to ensure the printing quality. In this embodiment, the thickener is one or more of nanocrystalline cellulose (NCC / CNF), sodium alginate, guar gum, xanthan gum, polyacrylamide (PAM), and polyvinyl alcohol (PVA); the binder is one or more of polyethylene glycol (PEG), paraffin, epoxy resin, acrylic resin, hydroxypropyl methylcellulose, and polyvinyl pyrrolidone.

[0109] S114: magnetically stirring the solution again until the solution is fully mixed, wherein the speed of the magnetic stirring device is set to 200-400 rpm and the stirring time is 4-8 hours;

[0110] S115: mechanically stirring the solution after magnetic stirring again until the solution reaches a stable state; wherein the rotation speed of the mechanical stirring device is set to 600-900 rpm, and the stirring time is 3-6 hours, and finally a zirconium carbide ceramic slurry is obtained.

[0111] 2) transferring the prepared zirconium carbide ceramic slurry to a 3D printer and printing a zirconium carbide ceramic green body using the 3D printer; specifically:

[0112] S116: transferring the treated zirconium carbide ceramic slurry to a vacuum stirrer to remove bubbles in the zirconium carbide ceramic slurry to the greatest extent possible, and stirring the zirconium carbide ceramic slurry through the vacuum stirrer; in order to prevent the Weissenberg effect, the vacuum stirrer is set to rotate forward and reverse, and the stirring direction of the vacuum stirrer is changed every 2-6 minutes, and this cycle is repeated for 40-120 minutes to obtain the final zirconium carbide ceramic slurry;

[0113] S117: Transferring the zirconium carbide ceramic slurry into a syringe, and connecting the syringe to an extrusion-type 3D printer;

[0114] S118: Importing the pre-modeled model into the extrusion 3D printer, and then setting parameters for the extrusion 3D printer, wherein the extrusion speed of the extrusion 3D printer is set to 0.1-10 mm / s, the printing speed is set to 1-20 mm / s, and the layer height is set to 0.3-0.8 mm;

[0115] S119: Starting the extrusion 3D printer to start printing, and naturally air-drying the printed zirconium carbide ceramic green body at room temperature for 8-24 hours.

[0116] Step 2: feeding the prepared zirconium carbide ceramic green body into an ultra-rapid high-temperature sintering device for ultra-rapid high-temperature sintering to obtain zirconium carbide ceramic; specifically:

[0117] S201: placing the obtained zirconium carbide ceramic green body in a crucible in a heating chamber of an ultra-rapid high-temperature sintering device, and filling the crucible with carbon-based conductive powder (such as carbon black, graphite, graphene, carbon fiber, carbon nanomaterials, etc., which have conductive carbon-based powders);

[0118] S202: performing vacuum treatment on the heating chamber of the ultra-rapid high temperature sintering equipment until the vacuum degree in the heating chamber drops to -0.01 MPa;

[0119] S203: introducing argon gas into the heating chamber of the ultra-fast high temperature sintering equipment;

[0120] S204: Repeat step S203 twice to ensure that the heating chamber of the ultra-fast high-temperature sintering equipment is in a flowing argon atmosphere;

[0121] S205: Setting process parameters for an ultra-fast high-temperature sintering device. The ultra-fast high-temperature sintering device applies current to electrodes in a heating chamber. The applied current passes through the carbon-based conductive powder to cause the carbon-based conductive powder to generate a large amount of Joule heat and heat the wrapped zirconium carbide ceramic green body, thereby preparing zirconium carbide ceramics.

[0122] Step 3: Measure various characteristics and properties of zirconium carbide ceramics to determine whether the prepared zirconium carbide ceramics meet the standards, specifically:

[0123] The sintered zirconium carbide ceramic green body was removed and ultrasonically cleaned, and the relative density of the zirconium carbide ceramic green body was measured using the Archimedean drainage method. The polished surface of the zirconium carbide ceramic was preliminarily characterized using a scanning electron microscope and an X-ray diffractometer to observe the microstructure and phase composition of the zirconium carbide ceramic. The performance of the zirconium carbide ceramic was evaluated using a Vickers hardness tester to determine whether the prepared zirconium carbide ceramic met the standards.

[0124] In addition to the advantages (1)-(5) described in Example 1, the present invention also has the following advantages:

[0125] The present invention achieves high-quality manufacturing of zirconium carbide ceramic green bodies with complex configurations by adjusting the dosage and type of binder and dispersant and adjusting various parameters of the 3D printer. The dispersant is a compound of ionic dispersant and non-ionic dispersant, which can effectively disperse the ceramic slurry, thereby achieving higher printing accuracy. At the same time, ultra-fast high-temperature sintering technology is used to achieve ultra-fast sample debinding. Compared with the traditional debinding time of more than 8 hours, this technology can achieve sample debinding within 30 minutes. At the same time, the powder structure can better wrap the sample and make it heated evenly, thereby ensuring the quality of debinding. At the same time, debinding and sintering are carried out in the same heating equipment, which can greatly shorten the time of the entire preparation process. In addition, the ultra-fast heating rate can also further reduce the sintering temperature of the zirconium carbide ceramic, so that the energy consumption of the entire process is further reduced.

[0126] Specific case 3

[0127] This case uses the ultra-fast manufacturing method of zirconium carbide ceramics described in Example 2 to manufacture zirconium carbide ceramics, specifically:

[0128] S1: prepare zirconium carbide powder (500nm), elemental zirconium powder (800nm) and carbon black (100nm), and the amount of elemental zirconium introduced is 3wt%; the above powders are mixed with deionized water as a solvent at a mass fraction of 80wt%, and 1wt% of a prepared dispersant is introduced at the same time, wherein the mass ratio of ammonium polyacrylate to polyvinyl pyrrolidone in the dispersant is 1:1.5, and then the prepared solution is transferred to a beaker for magnetic stirring. The speed of the magnetic stirring device used is set to 300rpm, and the stirring time is 24h to ensure that the powder can be evenly dispersed; after the solution is evenly stirred, an appropriate amount of nanocrystalline cellulose (NCC) with a concentration of 100mg / ml is introduced to adjust the viscosity of the slurry to ensure the quality of printing, and finally the solution is magnetically stirred again to achieve sufficient mixing (the speed of the magnetic stirring device used is: 300rpm, stirring time: 8h), and finally mechanical stirring is performed (the speed of the mechanical stirring device used is: 600rpm. Stirring time: 6h) until the solution reaches a stable state;

[0129] S2: The treated slurry is transferred to a vacuum agitator to remove bubbles in the slurry to the greatest extent possible. To prevent the Weissenberg effect, the vacuum agitator is set to rotate forward and reverse, and the stirring direction of the vacuum agitator is changed every 3 minutes. This cycle is repeated for 60 minutes to obtain the final slurry.

[0130] S3: Transfer the slurry into a syringe, connect the syringe to the extrusion 3D printer, import the pre-built model into the extrusion 3D printer, and set the extrusion 3D printer parameters to 1 mm / s extrusion speed, 15 mm / s printing speed, and 0.5 mm layer height. Then start the machine to start printing. Allow the printed sample to air dry at room temperature for 12 hours.

[0131] S4: The obtained zirconium carbide ceramic green body is placed in a crucible in the heating chamber of the ultra-rapid high temperature sintering equipment, and the inner space of the insulating crucible is filled with graphite powder in the crucible until it covers the lower electrode; then the sample is placed above the lower electrode, and the placement depth of the sample is adjusted to ensure that the sample is located between the upper electrode and the lower electrode. At the same time, the computer is operated to control the position of the upper electrode so that it is located in a suitable position to ensure that the sample is located between the upper electrode and the lower electrode (such as Figure 1 Then fill the insulating crucible with graphite powder, cover it with the insulation end cover, and close the furnace door of the heating chamber;

[0132] S5: Turn on the vacuum pump to vacuum the heating chamber of the ultra-fast high-temperature sintering equipment until the vacuum degree in the heating chamber drops to -0.01 MPa; introduce argon into the heating chamber of the ultra-fast high-temperature sintering equipment (repeat twice) to ensure that the heating chamber of the ultra-fast high-temperature sintering equipment is a flowing argon atmosphere, thereby ensuring that the entire preparation process is carried out under an argon atmosphere of 1 atm; at the same time, operate the computer to connect the programmable power supply, and set the process parameters through self-programming. First, increase the temperature to 1000°C at a heating rate of 100°C / min and keep it warm for 10 minutes to ensure that the glue in the sample is completely discharged. Subsequently, increase the temperature to the target temperature of 2000°C at a heating rate of 1000°C / min and keep it warm for 1 minute; in this way, ultra-fast pressureless preparation of zirconium carbide ceramics with complex configurations can be achieved within a few minutes, and the prepared zirconium carbide ceramics are taken out after the equipment cools down;

[0133] S6: After ultrasonic cleaning of the taken-out zirconium carbide ceramic, the relative density thereof was measured by the Archimedean drainage method. The measurement result showed that the relative density was 96%.

[0134] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. An ultra-fast manufacturing method for zirconium carbide ceramics, characterized in that: The following steps are involved: Step 1: fully mixing zirconium carbide raw material powder and a sintering aid, or fully mixing zirconium carbide raw material powder, a sintering aid, and a carbon source to prepare a zirconium carbide ceramic green body; wherein the sintering aid is a single substance; Step 2: The prepared zirconium carbide ceramic green body is fed into an ultra-rapid high temperature sintering device for ultra-rapid high temperature sintering to obtain zirconium carbide ceramic.

2. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 1, characterized in that: In step 1, the process for preparing zirconium carbide ceramic green body is as follows: S101: mixing zirconium carbide raw material powder and a sintering aid with anhydrous ethanol, or mixing zirconium carbide raw material powder, a sintering aid, and a carbon source with anhydrous ethanol to obtain a mixed slurry; wherein the amount of the sintering aid introduced is 0.25-5wt%, and the amount of the carbon source introduced is 0-5wt%; S102: transferring the mixed slurry to a planetary ball mill or a roller ball mill, and further mixing the slurry by the planetary ball mill or the roller ball mill; S103: After ball milling for 12-24 hours, the remixed slurry is transferred to a rotary evaporator; the heating temperature and speed of the rotary evaporator are set to dry the slurry in the rotary evaporator to obtain a preliminarily dried powder; S104: transferring the preliminarily dried powder to an oven for further drying; S105: After the dried powder is passed through a 50-200 mesh sieve, the filtered powder is placed in a stainless steel dry pressing mold; the powder is dry pressed using a dry pressing machine, wherein the pressure of the dry pressing machine is set to 5-20 MPa and the pressure holding time is 10-20 seconds, thereby obtaining a pressed sample; S106: vacuum-seal the pressed sample, and transfer the vacuum-seal sample to a cold isostatic pressing device for further pressing, wherein the pressure in the cold isostatic pressing device is 200-250 MPa, and the holding time is 150-300 seconds, to finally obtain a zirconium carbide ceramic green body.

3. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 1, characterized in that: In step 1, zirconium carbide ceramic green body is prepared by 3D printing. The specific process is as follows: The zirconium carbide ceramic slurry required for 3D printing is prepared, the prepared zirconium carbide ceramic slurry is transferred to a 3D printer, and the zirconium carbide ceramic green body is printed by the 3D printer.

4. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 3, characterized in that: The specific process for preparing zirconium carbide ceramic slurry required for 3D printing is as follows: S111: Fully mixing zirconium carbide raw material powder, a sintering aid, and a carbon source, then adding the mixture as a solute to deionized water as a solvent at a ratio of 40-80 wt% of the mixture to the total mass of the solution; simultaneously, adding a dispersant at a mass fraction of 0.5-2 wt% to the mixed system, and stirring until the mixture is uniformly mixed; S112: Transfer the prepared solution to a beaker for magnetic stirring, wherein the speed of the magnetic stirring device is set to 200-400 rpm and the stirring time is 8-24 hours; S113: After the solution is stirred evenly, a thickener and a binder are added to the solution at a mass fraction of 0.3-1.5 wt %; S114: magnetically stirring the solution again until the solution is fully mixed, wherein the speed of the magnetic stirring device is set to 200-400 rpm and the stirring time is 4-8 hours; S115: mechanically stirring the solution after magnetic stirring again until the solution reaches a stable state; wherein the rotation speed of the mechanical stirring device is set to 600-900 rpm, and the stirring time is 3-6 hours, thereby obtaining zirconium carbide ceramic slurry.

5. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 4, characterized in that: The dispersant is compounded by an ionic dispersant and a non-ionic dispersant, wherein the ionic dispersant is one or more of sodium polyacrylate, ammonium polyacrylate, sodium lauryl sulfate, and cetyltrimethylammonium bromide; the non-ionic dispersant is one or more of polyvinyl pyrrolidone, polyethylene glycol, and fatty alcohol polyoxyethylene ether; the ionic dispersant and the non-ionic dispersant are mixed in a ratio of 1:0.5-2; the thickener is one or more of nanocrystalline cellulose (NCC / CNF), sodium alginate, guar gum, xanthan gum, polyacrylamide (PAM), and polyvinyl alcohol (PVA); and the binder is one or more of polyethylene glycol (PEG), paraffin, epoxy resin, acrylic resin, hydroxypropyl methylcellulose, and polyvinyl pyrrolidone.

6. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 4, characterized in that: The specific process of transferring the prepared zirconium carbide ceramic slurry to a 3D printer and printing a zirconium carbide ceramic green body through the 3D printer is as follows: S116: transferring the treated zirconium carbide ceramic slurry to a vacuum stirrer, and stirring the zirconium carbide ceramic slurry by the vacuum stirrer; during this process, the vacuum stirrer is set to rotate forward and reverse, and the stirring direction of the vacuum stirrer is changed every 2-6 minutes, and this cycle is repeated for 40-120 minutes to obtain the final zirconium carbide ceramic slurry; S117: Transferring the zirconium carbide ceramic slurry into a syringe, and connecting the syringe to an extrusion-type 3D printer; S118: Importing the pre-modeled model into the extrusion 3D printer, and then setting the parameters of the extrusion 3D printer, wherein the extrusion speed of the extrusion 3D printer is 0.1-10 mm / s, the printing speed is 1-20 mm / s, and the layer height is 0.3-0.8 mm; S119: Starting the extrusion 3D printer to start printing, and naturally air-drying the printed zirconium carbide ceramic green body at room temperature for 8-24 hours.

7. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 1, characterized in that: In step 2, the process of ultra-fast high-temperature sintering of the zirconium carbide ceramic green body is as follows: S201: placing the obtained zirconium carbide ceramic green body in a crucible in a heating chamber of an ultra-rapid high-temperature sintering device, and filling the crucible with carbon-based conductive powder; S202: performing vacuum treatment on the heating chamber of the ultra-rapid high temperature sintering equipment until the vacuum degree in the heating chamber drops to -0.01 MPa; S203: introducing argon gas into the heating chamber of the ultra-fast high temperature sintering equipment; S204: Repeat step S203 twice to ensure that the heating chamber of the ultra-fast high-temperature sintering equipment is in a flowing argon atmosphere; S205: Setting process parameters for an ultra-rapid high-temperature sintering device; the ultra-rapid high-temperature sintering device applies current to electrodes in a heating chamber, and the applied current passes through the carbon-based conductive powder to cause the carbon-based conductive powder to generate Joule heat and heat the encapsulated zirconium carbide ceramic green body, thereby preparing the zirconium carbide ceramic.

8. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 7, characterized in that: The carbon-based conductive powder is one or more of carbon black, graphite, graphene, carbon fiber, and carbon nanomaterials.

9. The ultra-fast manufacturing method of zirconium carbide ceramics according to claim 7, characterized in that: In step S205, the heating method used for the zirconium carbide ceramics with different structures is a direct heating method or a two-step sintering method, wherein: Zirconium carbide ceramics with conventional configurations: The direct heating method is to heat the zirconium carbide ceramic green body to the sintering temperature at a heating rate of more than 1000°C / min, and then keep the temperature; The two-step sintering method is to heat the zirconium carbide ceramic green body to the melting point of the added element at a heating rate of more than 1000° C. / min, and then heat it to the sintering temperature at a heating rate of more than 500° C. / min. 3D printed zirconium carbide ceramics: The direct heating method is to first heat to 800-1200°C at a heating rate of 100°C / min, and then heat to the sintering temperature at a heating rate of >1000°C / min; The two-step sintering method is to first heat the zirconium carbide ceramic green body to 800-1200°C at a heating rate of 100°C / min, then heat the green body to the melting point of the added element at a heating rate of >1000°C / min, and then heat to the sintering temperature at a heating rate of >500°C / min.

10. A zirconium carbide ceramic prepared by the ultra-rapid manufacturing method of zirconium carbide ceramic according to any one of claims 1 to 9.

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