Production and forming method and system for a silicon carbide ceramic sealing component

Abstract

The present invention relates to the field of silicon carbide ceramic materials, and specifically to a production and forming method and system for silicon carbide ceramic sealing components. Based on the deformation characteristics of silicon carbide slurry during the pre-drying process and the tolerance characteristics of the outer shape of the sealing components, the pre-dried silicon carbide slurry is subjected to die pressing. Based on the internal structure change characteristics of the green body during the sintering process, the sintering abnormal areas of the green body are identified, and the sintering operation parameters of the sintering abnormal areas are adjusted. Based on the global cooling characteristics of the silicon carbide ceramic sealing components, the internal stress difference characteristics between different-sized parts inside the silicon carbide ceramic sealing components are estimated, and the active cooling operation parameters for the silicon carbide ceramic sealing components are adjusted. The present invention can regulate the generation and forming processes for silicon carbide ceramic sealing components with irregular shapes, improve the uniformity of micropore distribution and internal stress distribution, and enhance the flexural strength and wear resistance and lubricity.

Description

Technical Field

[0001] The present invention relates to the field of silicon carbide ceramic materials, and particularly to a production and forming method and system for silicon carbide ceramic sealing components. Background Art

[0002] Silicon carbide ceramics have the characteristics of low density, high hardness, good wear resistance, high temperature resistance, corrosion resistance, etc., and are widely used in the production of mechanical components. Silicon carbide ceramic sealing components can meet the requirements of high mechanical sealing performance and low friction loss in different scenarios. For regular-shaped sealing components such as silicon carbide ceramic sealing rings and sealing rings, only processes such as raw material mixing, molding by pressing, and sintering are required to obtain the finished sealing components, without the need to additionally consider the non-uniform internal stress distribution caused by non-uniform cooling during the sintering process of silicon carbide materials.

[0003] In actual scenarios, more irregular-shaped silicon carbide ceramic sealing components are needed to meet the sealing requirements of special-shaped mechanical equipment. Considering the structural size anisotropy of irregular-shaped silicon carbide ceramic sealing components in three-dimensional space, it will affect the fusion tightness of silicon carbide materials in different parts during sintering and the cooling efficiency of different parts during cooling. The spatial difference in the fusion tightness of silicon carbide materials in different parts of the sealing component results in the inability to uniformly form a microporous structure in the sealing component, reducing the uniform penetration of lubricant inside the sealing component; in addition, the spatial difference in the cooling efficiency of different parts inside the sealing component leads to non-uniform internal stress distribution in the sealing component, reducing the bending strength of the sealing component. Therefore, how to detect and control the production and forming of irregular-shaped silicon carbide ceramic sealing components to improve the uniformity of the internal micropore distribution and internal stress distribution of the sealing component is of great significance for improving the bending strength and wear resistance and lubricity of silicon carbide ceramic sealing components. Summary of the Invention

[0004] In order to address the spatial differences in the fusion tightness of silicon carbide materials and the cooling efficiency caused during the production and forming of irregular-shaped silicon carbide ceramic sealing components, corresponding adjustments are made in processes such as molding by pressing, sintering, and cooling to improve the uniformity of the internal micropore distribution and internal stress distribution of the sealing component and enhance the wear resistance, lubricity, and bending strength of the silicon carbide ceramic sealing component. The present invention provides a production and forming method for silicon carbide ceramic sealing components, and the method includes the following steps:

[0005] S1: Obtain the deformation characteristics of the silicon carbide slurry during pre-drying, and based on the deformation characteristics and the outer tolerance characteristics of the sealing component, perform molding by pressing on the silicon carbide slurry that has completed pre-drying to obtain a green body;

[0006] S2: Obtain the internal structure change characteristics of the green body during sintering. Based on the internal structure change characteristics, identify the sintering abnormal area of the green body and adjust the sintering operation parameters of the sintering abnormal area;

[0007] S3: Conduct thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component; Based on the global cooling characteristics, estimate the internal stress difference characteristics between different parts within the sealing component, and thereby adjust the active cooling operation parameters of the sealing component.

[0008] Preferably, in S1, obtain the deformation characteristics of the silicon carbide slurry during pre-drying. Based on the deformation characteristics and the external tolerance characteristics of the sealing component, perform molding pressing on the silicon carbide slurry that has completed pre-drying to obtain a green body. Specifically:

[0009] Conduct visible light vision identification and absorption spectrum identification on the silicon carbide slurry during pre-drying to obtain the volume change data and solvent content change data of the silicon carbide slurry during pre-drying; Based on the volume change data and the solvent content change data, obtain the correlation characteristics between the volume shrinkage rate and the solvent content reduction rate of the silicon carbide slurry during pre-drying, and use this as the deformation characteristics of the silicon carbide slurry during pre-drying;

[0010] Based on the deformation characteristics and the external tolerance characteristics of the sealing component, determine the volume of the silicon carbide slurry that has completed pre-drying required for molding pressing, and thereby mold and form the corresponding volume of the silicon carbide slurry into a green body; wherein, the external tolerance characteristics of the sealing component refer to the allowable range of volume deviation between the desired volume and the actual volume of the sealing component.

[0011] Preferably, in S2, obtain the internal structure change characteristics of the green body during sintering. Based on the internal structure change characteristics, identify the sintering abnormal area of the green body and adjust the sintering operation parameters of the sintering abnormal area. Specifically:

[0012] Conduct thermal infrared vision identification on the green body during sintering to obtain the microporous structure change characteristics inside the green body; wherein, the microporous structure change characteristics include the micropore size change characteristics and the micropore distribution density change characteristics inside the green body during sintering;

[0013] Based on the microporous structure change characteristics, estimate the change trend of the micropore occupation range inside the green body during sintering, and thereby identify the sintering abnormal area of the green body; Based on the micropore size and micropore distribution density of the sintering abnormal area, adjust the sintering heat flow temperature and coverage area output to the sintering abnormal area.

[0014] Preferably, in S3, a thermal identification is performed on the sintered sealing component to obtain the global cooling characteristics of the sealing component, specifically:

[0015] A thermal identification is performed on the sintered sealing component to obtain the global cooling characteristics of the sealing component under natural cooling conditions; wherein, the global cooling characteristics refer to the cooling rate characteristics of each part within the sealing component.

[0016] Preferably, in S3, based on the global cooling characteristics, the internal stress difference characteristics between different parts within the sealing component are estimated, and thereby the active cooling operation parameters for the sealing component are adjusted, specifically:

[0017] Based on the global cooling characteristics, the change difference in the cooling rate between two adjacent parts with different thicknesses within the sealing component is determined; based on the change difference in the cooling rate, the internal stress difference characteristics between two adjacent parts with different thicknesses are estimated; wherein, the internal stress difference characteristics include the internal stress magnitude and direction difference characteristics between two adjacent parts with different thicknesses.

[0018] Based on the internal stress difference characteristics between two adjacent parts with different thicknesses, it is determined whether an internal stress anisotropy event will occur between two adjacent parts with different thicknesses; when an internal stress anisotropy event occurs, the flow rate and the airflow delivery coverage area of the active cooling air flow delivered to two adjacent parts with different thicknesses are adjusted.

[0019] On the other hand, the present invention provides a production and molding system for a silicon carbide ceramic sealing component, and the system includes the following modules:

[0020] A deformation identification module, configured to obtain the deformation characteristics of the silicon carbide slurry during pre-drying;

[0021] A molding control module, configured to perform molding on the pre-dried silicon carbide slurry based on the deformation characteristics and the external shape tolerance characteristics of the sealing component to obtain a green body;

[0022] A structure change identification module, configured to obtain the internal structure change characteristics of the green body during sintering;

[0023] A sintering adjustment module, configured to identify the sintering abnormal area of the green body based on the internal structure change characteristics and adjust the sintering operation parameters of the sintering abnormal area;

[0024] A thermal identification module, configured to perform a thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component;

[0025] A cooling adjustment module, which is used to estimate the internal stress difference characteristics between different parts in the sealing component based on the global cooling characteristics, so as to adjust the active cooling operation parameters of the sealing component.

[0026] Preferably, the deformation recognition module is used to obtain the deformation characteristics of the silicon carbide slurry during pre-drying, specifically:

[0027] Perform visible light vision recognition and absorption spectrum recognition on the silicon carbide slurry during pre-drying to obtain the volume change data and solvent content change data of the silicon carbide slurry during pre-drying; based on the volume change data and the solvent content change data, obtain the correlation characteristics between the volume shrinkage rate and the solvent content reduction rate of the silicon carbide slurry during pre-drying, and use this as the deformation characteristics of the silicon carbide slurry during pre-drying;

[0028] The molding control module is used to perform molding on the pre-dried silicon carbide slurry based on the deformation characteristics and the external tolerance characteristics of the sealing component to obtain a green body, specifically:

[0029] Based on the deformation characteristics and the external tolerance characteristics of the sealing component, determine the volume of the pre-dried silicon carbide slurry required for molding, and thus mold the corresponding volume of the silicon carbide slurry into a green body; wherein, the external tolerance characteristics of the sealing component refer to the allowable range of volume deviation between the expected volume and the actual volume of the sealing component.

[0030] Preferably, the structure change recognition module is used to obtain the internal structure change characteristics of the green body during sintering, specifically:

[0031] Perform thermal infrared vision recognition on the green body during sintering to obtain the microporous structure change characteristics inside the green body; wherein, the microporous structure change characteristics include the micropore size change characteristics and the micropore distribution density change characteristics inside the green body during sintering;

[0032] The sintering adjustment module is used to identify the sintering abnormal area of the green body based on the internal structure change characteristics and adjust the sintering operation parameters of the sintering abnormal area, specifically:

[0033] Based on the microporous structure change characteristics, estimate the change trend of the micropore occupancy range inside the green body during sintering, and thus identify the sintering abnormal area of the green body; based on the micropore size and micropore distribution density of the sintering abnormal area, adjust the sintering heat flow temperature and coverage area output to the sintering abnormal area.

[0034] Preferably, the thermal recognition module is used to perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component, specifically:

[0035] Perform thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component under natural cooling conditions; wherein, the global cooling characteristics refer to the cooling rate characteristics of all parts within the sealing component respectively.

[0036] Preferably, the cooling adjustment module is used to estimate the internal stress difference characteristics between different parts within the sealing component based on the global cooling characteristics, and thereby adjust the active cooling operation parameters of the sealing component, specifically:

[0037] Based on the global cooling characteristics, determine the change difference in the cooling rate between two adjacent parts with different thicknesses within the sealing component; based on the change difference in the cooling rate, estimate the internal stress difference characteristics between two adjacent parts with different thicknesses; wherein, the internal stress difference characteristics include the internal stress magnitude and direction difference characteristics between two adjacent parts with different thicknesses.

[0038] Based on the internal stress difference characteristics between two adjacent parts with different thicknesses, determine whether an internal stress anisotropy event will occur between two adjacent parts with different thicknesses; when an internal stress anisotropy event occurs, adjust the flow rate of the active cooling air flow transported to and the air flow transport coverage area of two adjacent parts with different thicknesses.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] Obtain the deformation characteristics of the silicon carbide slurry during pre-drying, and based on the deformation characteristics and the outer shape tolerance characteristics of the sealing component, perform die pressing on the silicon carbide slurry that has completed pre-drying to obtain a green body. The prepared silicon carbide slurry is not suitable for direct die pressing due to a large solvent content, and the silicon carbide slurry obtained after the sintering process will undergo volume shrinkage, and the volume shrinkage ratios of silicon carbide slurries with different material weight ratios are also different. Considering that the reduction in the solvent content inside the silicon carbide slurry is the cause of volume shrinkage, perform correlation analysis on the volume change data and solvent content change data of the prepared silicon carbide slurry to obtain the correlation characteristics between the volume shrinkage rate and the solvent content reduction rate of the silicon carbide slurry during pre-drying, providing a reliable reference for subsequent determination of the required volume of the silicon carbide slurry for die pressing. According to the deformation characteristics of the silicon carbide slurry during pre-drying and the allowable range of volume deviation between the expected volume and the actual volume of the sealing component, determine the volume of the silicon carbide slurry that has completed pre-drying required for die pressing, thereby accurately determining the volume of the silicon carbide slurry that has completed pre-drying required for die pressing while fully considering the volume shrinkage effect of the silicon carbide slurry and the outer shape volume tolerance range of the sealing component, effectively reducing the occurrence probability of defective products formed due to excessive shrinkage of the green body after the sintering process.

[0041] Obtain the characteristics of the internal structure change of the green body during sintering. Based on the characteristics of the internal structure change, identify the sintering abnormal areas of the green body, and adjust the sintering operation parameters of the sintering abnormal areas. Based on the characteristics of the change in the micropore size and the change in the micropore distribution density inside the green body during sintering, estimate the change trend of the occupied range of the micropores inside the green body during sintering. Based on this, adaptively reduce the sintering heat flow temperature and the coverage area output to the sintering abnormal areas within the allowable sintering temperature range, effectively inhibit the shrinking trend of the micropores in the sintering abnormal areas, and enable the sintering abnormal areas to maintain a sufficient number and size of micropore structures.

[0042] Perform thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component; based on the global cooling characteristics, estimate the internal stress difference characteristics between different parts inside the sealing component, and based on this, adjust the active cooling operation parameters of the sealing component. In order to timely and precisely inhibit the continuous expansion trend of the internal stress difference between different parts inside the sealing component, it is necessary to perform global cooling state identification on the sintered sealing component to obtain the cooling and temperature reduction conditions of each part within the global range of the sealing component, based on this determine the change difference in the cooling rate between two adjacent parts with different thicknesses inside the sealing component, based on this estimate the internal stress magnitude and direction deviation characteristics between two adjacent parts with different thicknesses, and adaptively adjust the active cooling operation parameters of the sealing component to improve the uniformity of the internal stress distribution of the sealing component. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. Among them:

[0044] Figure 1 is a flowchart of a production and forming method of a silicon carbide ceramic sealing component provided by the present invention.

[0045] Figure 2 is a relationship curve between the volume shrinkage rate of the silicon carbide slurry during pre-drying and the proportion of the solvent content.

[0046] Figure 3 is a thermal infrared image of the green body under different sintering conditions during sintering.

[0047] Figure 4 is related to Figure 3 the corresponding internal stress distribution diagram of the green body.

[0048] Figure 5 is a relationship diagram between the flexural stress and the compressive stress of the sealing component and the temperature during the cooling and temperature reduction period.

[0049] Figure 6 It is a structural diagram of a production and forming system for silicon carbide ceramic sealing components provided by the present invention. Specific embodiments

[0050] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Additionally, it should be noted that for the sake of description, only the parts related to the present invention are shown in the drawings rather than all the structures. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0051] The terms "include" and "have" in the present invention and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0052] Referring to the embodiments herein means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present invention. The phrase appears at various positions in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0053] Please refer to Figure 1 As shown, the present invention provides a production and forming method for silicon carbide ceramic sealing components, and the method includes the following steps:

[0054] S1: Obtain the deformation characteristics of the silicon carbide slurry during pre-drying, and based on the deformation characteristics and the tolerance characteristics of the outer shape of the sealing component, perform die pressing on the silicon carbide slurry that has completed pre-drying to obtain a green body.

[0055] Further, in S1, obtaining the deformation characteristics of the silicon carbide slurry during pre-drying, and based on the deformation characteristics and the tolerance characteristics of the outer shape of the sealing component, performing die pressing on the silicon carbide slurry that has completed pre-drying to obtain a green body, specifically:

[0056] Perform visible light visual recognition and absorption spectrum recognition on the silicon carbide slurry during pre-drying to obtain the volume change data and solvent content change data of the silicon carbide slurry during pre-drying; based on the volume change data and solvent content change data, obtain the correlation characteristics between the volume shrinkage rate and the solvent content reduction rate of the silicon carbide slurry during pre-drying, and use this as the deformation characteristics of the silicon carbide slurry during pre-drying;

[0057] Based on the deformation characteristics and the external tolerance characteristics of the sealing component, determine the volume of the silicon carbide slurry that has completed pre-drying required for molding, and use this to mold the silicon carbide slurry with the corresponding volume into a green body; wherein, the external tolerance characteristics of the sealing component refer to the allowable range of volume deviation between the expected volume and the actual volume of the sealing component.

[0058] The production and molding of silicon carbide ceramic sealing components mainly include processes such as slurry preparation, molding, sintering, and cooling in sequence. Slurry preparation is the basis of the entire production and molding process, and the component ratio of the prepared slurry directly affects the molding structure quality of the sealing component. Generally speaking, slurry preparation is to mix materials such as silicon carbide powder, boron carbide powder, sintering aids, binders, dispersants, solvents, etc. according to the corresponding weight ratio to obtain silicon carbide slurry; among them, the sintering aids can be but are not limited to alumina and / or yttrium oxide, the binder can be but are not limited to polyvinyl alcohol, the dispersant can be but are not limited to polyethyleneimine or organosilane, and the solvent can be but are not limited to deionized water and / or absolute ethanol. After fully and evenly mixing the above materials, a wet silicon carbide slurry is obtained, and the internal cohesion of the silicon carbide slurry is poor. If the silicon carbide slurry is directly molded, it is impossible to ensure that the silicon carbide slurry forms a solid green body. In addition, the solvent in the silicon carbide slurry volatilizes during the sintering process, and the volume shrinkage of the silicon carbide slurry will occur. Among them, the volume shrinkage ratio of the silicon carbide slurry is related to the volatilization disappearance ratio of the solvent inside the slurry. The greater the volatilization disappearance ratio of the solvent inside the slurry after the sintering process, the greater the volume shrinkage ratio of the slurry itself after the sintering process, and the volume shrinkage ratios corresponding to the sintered silicon carbide slurries formed by different material weight ratios are also different under the condition of the same solvent volatilization disappearance ratio. If the same volume of silicon carbide slurry is filled into the mold according to the expected volume of the sealing component finished product (for example, the expected volume of the sealing component finished product is , and the volume of the silicon carbide slurry filled into the mold is also ), the actual volume of the finally obtained sealing component finished product will be smaller than the above expected volume due to the shrinkage effect of the slurry, and the finally obtained sealing component will become a waste product due to its too small volume, reducing the production yield of the sealing component.

[0059] As can be seen from the above analysis, the silicon carbide slurry directly prepared is not suitable for direct molding due to its large solvent content, and the silicon carbide slurry directly prepared will undergo volume shrinkage during the sintering process, and the volume shrinkage ratios of silicon carbide slurries with different material weight ratios are also different. In order to make the silicon carbide slurry have sufficient viscosity and formability for molding and to pre-determine the volume shrinkage ratio of the silicon carbide slurry due to solvent volatilization, pre-drying treatment is carried out after the silicon carbide slurry is prepared, and the pre-drying treatment can be achieved by irradiating infrared microwaves to the silicon carbide slurry or heating the silicon carbide slurry at a matching temperature. During the pre-drying process of the silicon carbide slurry, the solvent will volatilize to a certain extent, causing the volume of the silicon carbide slurry to shrink accordingly. At this time, identifying the silicon carbide slurry can obtain the volume change and solvent residue amount of the silicon carbide slurry during the pre-drying process, providing a reliable basis for determining the volume shrinkage effect state of the currently prepared silicon carbide slurry. Specifically, during the pre-drying process of the silicon carbide slurry, visible light vision recognition and absorption spectrum recognition are carried out on it to obtain the volume change data and solvent content change data of the silicon carbide slurry during the pre-drying process; among them, the above volume change data can be obtained by taking visible light images of the silicon carbide slurry and contour recognition to determine the external contour characteristics of the silicon carbide slurry itself, so as to obtain the volume size change data (i.e., volume reduction change data) of the silicon carbide slurry in different dimensions. Please refer to Figure 2 , the silicon carbide slurry will shrink both horizontally and vertically, and the horizontal shrinkage rate is basically higher than the vertical shrinkage rate; in addition, the higher the original solvent volume ratio of the silicon carbide slurry, the higher its shrinkage rate (horizontal shrinkage rate and vertical shrinkage rate).

[0060] Solvents such as ionic water and / or absolute ethanol inside the silicon carbide slurry have different characteristic absorption wavelengths. When the content of deionized water and / or absolute ethanol inside the silicon carbide slurry is higher, the absorption intensity of the corresponding characteristic absorption wavelength light is also higher. By carrying out absorption spectrum recognition and analysis on the silicon carbide slurry, the solvent content change data inside the silicon carbide slurry can be obtained. The reduction of the solvent content inside the silicon carbide slurry causes volume reduction. By correlating and analyzing the volume size change data and the internal solvent content change data of the silicon carbide slurry, the correlation relationship between the volume reduction rate and the solvent content reduction rate of the silicon carbide slurry during the pre-drying process is obtained. The above correlation relationship can be, but is not limited to, the volume reduction ratio of the silicon carbide slurry when the internal solvent content ratio of the silicon carbide slurry decreases by one percentage point during the pre-drying process (i.e., the deformation characteristics of the silicon carbide slurry during the pre-drying process), so as to quantitatively calibrate the volume reduction degree of the silicon carbide slurry due to solvent volatilization during the pre-drying process, providing a reliable reference for determining the required volume for molding the silicon carbide slurry subsequently.

[0061] The silicon carbide ceramic sealing component has a corresponding tolerance for the external shape and volume in practical applications, that is, the actual volume of the silicon carbide ceramic sealing component has an up-and-down floating deviation relative to the expected volume, and it can also be considered that the silicon carbide ceramic sealing component is a qualified product, which can be directly applied to the sealing scenario. In order to make the green body after molding pass through the sintering process, so that the actual volume of the obtained silicon carbide ceramic sealing component is adapted to the above-mentioned tolerance of the external shape and volume, the volume of the silicon carbide slurry that has completed pre-drying required for molding can be determined according to the deformation characteristics of the above-mentioned silicon carbide slurry during the pre-drying process and the allowable range of the volume deviation between the expected volume and the actual volume of the sealing component. In this way, the volume of the silicon carbide slurry that has completed pre-drying required for molding can be accurately determined by fully considering the volume shrinkage effect of the silicon carbide slurry and the tolerance range of the external shape and volume of the sealing component, effectively reducing the occurrence probability of defective products formed due to excessive shrinkage of the green body after passing through the sintering process.

[0062] S2: Obtain the internal structure change characteristics of the green body during sintering, based on the internal structure change characteristics, identify the sintering abnormal area of the green body, and adjust the sintering operation parameters of the sintering abnormal area.

[0063] Further, in S2, obtaining the internal structure change characteristics of the green body during sintering, based on the internal structure change characteristics, identifying the sintering abnormal area of the green body, and adjusting the sintering operation parameters of the sintering abnormal area, specifically:

[0064] Perform thermal infrared vision recognition on the green body during sintering to obtain the change characteristics of the microporous structure inside the green body; among them, the change characteristics of the microporous structure include the change characteristics of the micropore size and the change characteristics of the micropore distribution density inside the green body during sintering;

[0065] Based on the change characteristics of the microporous structure, estimate the change trend of the occupied range of micropores inside the green body during sintering, so as to identify the sintering abnormal area of the green body; based on the micropore size and micropore distribution density of the sintering abnormal area, adjust the sintering heat flow temperature and coverage area output to the sintering abnormal area.

[0066] The lubricity problem also needs to be considered during the use of the silicon carbide ceramic sealing component. In order to improve the lubrication performance of the silicon carbide ceramic seal, lubricants are usually added to the silicon carbide ceramic sealing component, and the microporous structure of the silicon carbide ceramic sealing component itself is conducive to adsorbing lubricants, so that the lubricants penetrate evenly inside the silicon carbide ceramic sealing component to form good lubrication performance. Generally speaking, the more and more evenly distributed the microporous structure of the silicon carbide ceramic sealing component is, the more and more evenly the lubricants penetrate and adhere to the silicon carbide ceramic sealing component. The number, size and distribution density of the microporous structure of the silicon carbide ceramic sealing component depend on the heating degree of different areas of the green body during sintering, and the physical state of the microporous structure of the sealing component can be changed by adjusting the heating state of the green body during sintering.

[0067] The high-temperature environment during the sintering of the green body causes stress to form inside the green body. These changes match the internal structure, causing slight changes in the tightness of the bonding of the materials inside the green body, thereby forming a microporous structure. Please refer to Figure 3 , where (a)-(f) in the figure respectively correspond to the thermal infrared images of the green body at the sintering heating temperatures of 400 °C, 500 °C, 600 °C, 650 °C, 700 °C, and 750 °C. Please refer to Figure 4 , where (a)-(f) in the figure are respectively based on Figure 3 The internal stress distribution diagrams of the green body corresponding to (a)-(f) in are converted. By performing thermal infrared imaging and internal stress distribution analysis on the green body during sintering, the microporous structure formed inside the green body during sintering can be accurately identified. Specifically, first perform thermal infrared imaging on the green body during sintering to obtain the thermal infrared image of the green body (i.e., Figure 3 ); then analyze the thermal infrared image to obtain the magnitude of the internal stress distribution of the green body (i.e., Figure 4 ), determine the change characteristics of the micropore size and the change characteristics of the micropore distribution density inside the green body, and then determine the change characteristics of the micropore size and the change characteristics of the micropore distribution density inside the green body, quantitatively determine the change of the micropore size and the change of the number of micropores distributed per unit area inside the green body during sintering, providing a reliable basis for adjusting the heating state of the green body during sintering in the future.

[0068] The silicon carbide material inside the green body will turn into a molten state during sintering. If the sintering heating temperature of a certain area inside the green body is higher, the silicon carbide material in the corresponding area will fuse more tightly under the action of stress, and the microporous structure in the corresponding area will show a shrinking trend in terms of size and quantity, and the structure in the corresponding area will be more compact, and a uniform microporous structure distribution cannot be formed. From the above analysis, it can be seen that changing the sintering heating temperature of the green body during sintering will form different thermal stress effects inside the green body, and different thermal stress effects will affect the change trends of the microporous structure inside the green body in terms of size and quantity. Thus, by Figure 4The size distribution of the internal stress formed by the green body at different sintering heating temperatures can be used to estimate the characteristics of the change in the micropore size and the change in the micropore distribution density inside the green body during sintering, so as to obtain the change trend of the occupied range of the micropores inside the green body during sintering. Generally speaking, the higher the sintering heating temperature of a certain area inside the green body during sintering, the greater the corresponding internal stress formed. At this time, the micropore size in this area will become smaller and the micropore distribution density will also become smaller (that is, the number of micropores in the unit volume space will also become smaller); conversely, the micropore size in this area will become larger and the micropore distribution density will also become larger (that is, the number of micropores in the unit volume space will also become larger). If the above-mentioned change trend of the occupied range of the micropores indicates that the average micropore size and / or the average micropore distribution density in a certain area of the green body show a decreasing trend, the corresponding area will be determined as the sintering abnormal area of the green body; otherwise, the corresponding area will not be determined as the sintering abnormal area of the green body. Then, based on the micropore size and the micropore distribution density in the sintering abnormal area, within the allowable range of the sintering temperature (that is, within the temperature range that ensures the normal progress of sintering), the temperature and the coverage area of the sintering heat flow output to the sintering abnormal area are adaptively reduced to effectively inhibit the trend of micropore shrinkage in the sintering abnormal area, so that the sintering abnormal area maintains a sufficient number and size of micropore structures.

[0069] S3: Perform thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component; based on the global cooling characteristics, estimate the internal stress difference characteristics between different parts inside the sealing component, and adjust the active cooling operation parameters of the sealing component accordingly.

[0070] Furthermore, in S3, performing thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component specifically includes:

[0071] Perform thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component under natural cooling conditions; wherein, the global cooling characteristics refer to the cooling rate characteristics of all parts inside the sealing component respectively.

[0072] After the green body is sintered, it is formed and solidified into a sealing component. At this time, the whole sealing component is in a high-temperature state and needs to be cooled down for a certain period of time to obtain the final product. The cooling rate and uniformity of the sealing component directly affect the internal stress distribution of the sealing component. For a sealing component with a regular shape, only by ensuring that the whole sealing component is in a stable temperature environment can uniform cooling of all areas below the sealing component be achieved; however, for an irregular-shaped sealing component, the thickness of some parts of the sealing component in a certain direction is greater than that of other parts. Under the same natural cooling conditions, the natural cooling rate of the thicker parts is lower than that of the thinner parts. As the cooling of the sealing component progresses, the temperature difference between the thicker parts and the thinner parts becomes larger, and correspondingly, the stress difference between the thicker parts and the thinner parts also becomes larger. Please refer to Figure 5 , there is a corresponding relationship between the flexural stress and compressive stress formed in the parts of the sealing component and the temperature of the component. If the temperature difference between parts with different thicknesses during cooling is not suppressed in time, it will lead to the occurrence of internal stress anisotropy events between parts with different thicknesses (that is, the stress difference between the flexural stress or compressive stress between parts with different thicknesses exceeds the preset difference threshold within the corresponding spatial range), which is likely to cause fractures between parts with different thicknesses. In order to accurately suppress the continuous expansion of the stress difference between parts with different thicknesses in time, it is necessary to globally identify the cooling state of the sintered sealing component to obtain the cooling situation of each part globally subordinate to the sealing component. Specifically, the sintered sealing component can be dynamically identified by thermal infrared to obtain the change characteristics of the cooling rate of each part of the sealing component under the current natural cooling conditions (that is, the temperature drop value of each part per unit time), so as to accelerate the heat dissipation efficiency of some parts with slower cooling in the follow-up and achieve uniform cooling of all parts as much as possible.

[0073] Furthermore, in S3, based on the global cooling characteristics, estimate the internal stress difference characteristics between different parts in the sealing component, and adjust the active cooling operation parameters of the sealing component accordingly. Specifically:

[0074] Based on the global cooling characteristics, determine the change difference in the cooling rate between two adjacent parts with different thicknesses in the sealing component; based on the change difference in the cooling rate, estimate the internal stress difference characteristics between two adjacent parts with different thicknesses; among them, the internal stress difference characteristics include the internal stress magnitude and direction difference characteristics between two adjacent parts with different thicknesses;

[0075] Based on the internal stress difference characteristics between two adjacent parts with different thicknesses, determine whether an internal stress anisotropy event will occur between the two adjacent parts with different thicknesses; when an internal stress anisotropy event occurs, adjust the flow rate and the air flow delivery coverage area of the active cooling air flow delivered to the two adjacent parts with different thicknesses.

[0076] Through the above analysis, it can be seen that if the cooling efficiency difference between two different parts in the sealing component is large, it will also cause a large internal stress difference between the above two parts. Especially for two different adjacent parts in terms of position, if the internal stress difference between the two adjacent different parts exceeds the upper limit of the internal stress difference that the silicon carbide ceramic itself can withstand, the probability of fracture occurring at the connection of the two adjacent different parts will increase. In order to suppress the risk of fracture caused by large internal stress differences within the entire sealing component, based on the global cooling characteristics of the sealing component, determine the change difference in the cooling rate between any two adjacent parts with different thicknesses within the sealing component, so as to estimate the internal stress magnitude and direction deviation characteristics between any two adjacent parts with different thicknesses, that is, the internal stress magnitude difference value and the internal stress direction angle difference value between any two adjacent parts with different thicknesses, thereby determining whether an internal stress anisotropy event will occur between the two adjacent parts with different thicknesses. If the stress difference within the corresponding spatial angle range of the internal stress between the two adjacent parts with different thicknesses exceeds the preset difference threshold, it is determined that an internal stress anisotropy event has occurred; otherwise, it is determined that no internal stress anisotropy event has occurred. And when an internal stress anisotropy event occurs, mark the part with a slower cooling rate among the two adjacent parts with different thicknesses, so as to increase the cooling efficiency of the above part with a slower cooling rate; specifically, the flow rate and the air flow delivery coverage area of the active cooling air flow delivered to the above part with a slower cooling rate can be increased, effectively suppressing the cooling efficiency difference between the two adjacent parts with different thicknesses and improving the uniformity of the internal stress distribution of the sealing component.

[0077] Please refer to Figure 6 As shown, the present invention provides a production and forming system for a silicon carbide ceramic sealing component, and the system includes the following modules:

[0078] A deformation recognition module, configured to obtain the deformation characteristics of the silicon carbide slurry during pre-drying;

[0079] A molding control module, configured to perform molding on the silicon carbide slurry that has completed pre-drying based on the deformation characteristics and the outer shape tolerance characteristics of the sealing component to obtain a green body;

[0080] A structure change recognition module, configured to obtain the internal structure change characteristics of the green body during sintering;

[0081] The sintering adjustment module is used to identify the sintering abnormal areas of the green body based on the internal structure change characteristics and adjust the sintering operation parameters of the sintering abnormal areas;

[0082] The thermal identification module is used to perform thermal identification on the sintered sealing component to obtain the global cooling characteristics of the sealing component;

[0083] The cooling adjustment module is used to estimate the internal stress difference characteristics between different parts of the sealing component based on the global cooling characteristics, and thereby adjust the active cooling operation parameters of the sealing component.

[0084] Furthermore, the deformation identification module is used to obtain the deformation characteristics of the silicon carbide slurry during pre-drying, specifically:

[0085] Perform visible light vision identification and absorption spectrum identification on the silicon carbide slurry during pre-drying to obtain the volume change data and solvent content change data of the silicon carbide slurry during pre-drying; based on the volume change data and solvent content change data, obtain the correlation characteristics between the volume shrinkage rate and the solvent content reduction rate of the silicon carbide slurry during pre-drying, and use this as the deformation characteristics of the silicon carbide slurry during pre-drying;

[0086] The molding control module is used to perform molding on the pre-dried silicon carbide slurry based on the deformation characteristics and the external shape tolerance characteristics of the sealing component to obtain the green body, specifically:

[0087] Based on the deformation characteristics and the external shape tolerance characteristics of the sealing component, determine the volume of the pre-dried silicon carbide slurry required for molding, and thereby mold the corresponding volume of the silicon carbide slurry into a green body; wherein, the external shape tolerance characteristics of the sealing component refer to the allowable range of volume deviation between the expected volume and the actual volume of the sealing component.

[0088] Furthermore, the structure change identification module is used to obtain the internal structure change characteristics of the green body during sintering, specifically:

[0089] Perform thermal infrared vision identification on the green body during sintering to obtain the microporous structure change characteristics inside the green body; wherein, the microporous structure change characteristics include the micropore size change characteristics and the micropore distribution density change characteristics inside the green body during sintering;

[0090] The sintering adjustment module is used to identify the sintering abnormal areas of the green body based on the internal structure change characteristics and adjust the sintering operation parameters of the sintering abnormal areas, specifically:

[0091] Based on the microporous structure change characteristics, estimate the change trend of the micropore occupation range inside the green body during sintering, and thereby identify the sintering abnormal areas of the green body; based on the micropore size and micropore distribution density of the sintering abnormal areas, adjust the sintering heat flow temperature and coverage area output to the sintering abnormal areas.

[0092] Further, the thermal recognition module is used to perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component, specifically:

[0093] Perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component under natural cooling conditions; wherein, the global cooling characteristics refer to the cooling rate characteristics of all parts within the sealing component.

[0094] Further, the cooling adjustment module is used to estimate the internal stress difference characteristics between different parts within the sealing component based on the global cooling characteristics, so as to adjust the active cooling operation parameters of the sealing component, specifically:

[0095] Based on the global cooling characteristics, determine the change difference in the cooling rate between two adjacent parts with different thicknesses within the sealing component; based on the change difference in the cooling rate, estimate the internal stress difference characteristics between two adjacent parts with different thicknesses; wherein, the internal stress difference characteristics include the internal stress magnitude and direction difference characteristics between two adjacent parts with different thicknesses.

[0096] Based on the internal stress difference characteristics between two adjacent parts with different thicknesses, determine whether an internal stress anisotropy event will occur between two adjacent parts with different thicknesses; when an internal stress anisotropy event occurs, adjust the flow rate and the air flow delivery coverage area of the active cooling air flow for the two adjacent parts with different thicknesses.

[0097] The production and forming system of the silicon carbide ceramic sealing component of the present invention corresponds to the operation and effect of the above-mentioned production and forming method of the silicon carbide ceramic sealing component, and the production and forming system of the silicon carbide ceramic sealing component will not be repeated here.

[0098] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of adding a necessary general hardware platform, and of course, it can also be implemented by a combination of hardware and software. Based on such an understanding, the above technical solution, in essence, or the part that contributes to the prior art can be embodied in the form of a computer product. The present invention can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program codes.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Other embodiments can also be adopted. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A production and molding method for a silicon carbide ceramic sealing component, characterized in that, The method includes the following steps: S1: Obtain the deformation characteristics of the silicon carbide slurry during pre-drying. Based on the deformation characteristics and the outer shape tolerance characteristics of the sealing component, perform die pressing on the silicon carbide slurry that has completed pre-drying to obtain a green body. Specifically: Perform visible light vision recognition and absorption spectrum recognition on the silicon carbide slurry during pre-drying to obtain the volume change data and solvent content change data of the silicon carbide slurry during pre-drying; based on the volume change data and the solvent content change data, obtain the correlation characteristics between the volume shrinkage rate and the solvent content reduction rate of the silicon carbide slurry during pre-drying, and use this as the deformation characteristics of the silicon carbide slurry during pre-drying; Based on the deformation characteristics and the outer shape tolerance characteristics of the sealing component, determine the volume of the silicon carbide slurry that has completed pre-drying required for die pressing, and use this to press the corresponding volume of the silicon carbide slurry into a green body; wherein, the outer shape tolerance characteristics of the sealing component refer to the allowable range of volume deviation between the expected volume and the actual volume of the sealing component; S2: Obtain the internal structure change characteristics of the green body during sintering. Based on the internal structure change characteristics, identify the sintering abnormal area of the green body and adjust the sintering operation parameters of the sintering abnormal area. Specifically: Perform thermal infrared vision recognition on the green body during sintering to obtain the microporous structure change characteristics inside the green body; wherein, the microporous structure change characteristics include the micropore size change characteristics and micropore distribution density change characteristics inside the green body during sintering; Based on the microporous structure change characteristics, estimate the change trend of the micropore occupancy range inside the green body during sintering, and use this to identify the sintering abnormal area of the green body; based on the micropore size and micropore distribution density of the sintering abnormal area, adjust the sintering heat flow temperature and coverage area output to the sintering abnormal area; S3: Perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component; based on the global cooling characteristics, estimate the internal stress difference characteristics between different parts of the sealing component, and use this to adjust the active cooling operation parameters of the sealing component.

2. The method according to claim 1, wherein In S3, perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component. Specifically: Perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component under natural cooling conditions; wherein, the global cooling characteristics refer to the cooling rate characteristics of all parts inside the sealing component.

3. The method according to claim 2, wherein In S3, based on the global cooling characteristics, estimate the internal stress difference characteristics between different parts of the sealing component, and use this to adjust the active cooling operation parameters of the sealing component. Specifically: Based on the global cooling feature, determine the difference in the cooling rate change between two adjacent parts with different thicknesses within the sealing component; based on the difference in the cooling rate change, estimate the internal stress difference feature between two adjacent parts with different thicknesses; wherein, the internal stress difference feature includes the internal stress magnitude and direction difference feature between two adjacent parts with different thicknesses. Based on the internal stress difference feature between two adjacent parts with different thicknesses, determine whether an internal stress anisotropy event will occur between two adjacent parts with different thicknesses; when an internal stress anisotropy event occurs, adjust the flow rate and the airflow delivery coverage area of the active cooling air flow delivered to two adjacent parts with different thicknesses.

4. A production and molding system for a silicon carbide ceramic sealing component, characterized in that, The system includes the following modules: A deformation identification module, configured to obtain the deformation feature of the silicon carbide slurry during pre-drying, specifically: Perform visible light vision identification and absorption spectrum identification on the silicon carbide slurry during pre-drying to obtain the volume change data and the solvent content change data of the silicon carbide slurry during pre-drying; based on the volume change data and the solvent content change data, obtain the correlation feature between the volume shrinkage rate and the solvent content reduction rate of the silicon carbide slurry during pre-drying, and use this as the deformation feature of the silicon carbide slurry during pre-drying. A molding control module, configured to perform molding on the pre-dried silicon carbide slurry based on the deformation feature and the outer shape tolerance feature of the sealing component to obtain a green body, specifically: Based on the deformation feature and the outer shape tolerance feature of the sealing component, determine the volume of the pre-dried silicon carbide slurry required for molding, and thus mold the silicon carbide slurry with the corresponding volume into a green body; wherein, the outer shape tolerance feature of the sealing component refers to the allowable range of the volume deviation between the expected volume and the actual volume of the sealing component. A structure change identification module, configured to obtain the internal structure change feature of the green body during sintering, specifically: Perform thermal infrared vision identification on the green body during sintering to obtain the microporous structure change feature inside the green body; wherein, the microporous structure change feature includes the micropore size change feature and the micropore distribution density change feature inside the green body during sintering. A sintering adjustment module, configured to identify the sintering abnormal area of the green body based on the internal structure change feature and adjust the sintering operation parameters of the sintering abnormal area, specifically: Based on the microporous structure change feature, estimate the change trend of the micropore occupancy range inside the green body during sintering, and thus identify the sintering abnormal area of the green body; based on the micropore size and the micropore distribution density of the sintering abnormal area, adjust the temperature and the coverage area of the sintering heat flow output to the sintering abnormal area. A thermal identification module, configured to perform thermal identification on the sintered sealing component to obtain the global cooling feature of the sealing component. A cooling adjustment module, configured to estimate the internal stress difference feature between different parts of the sealing component based on the global cooling feature, and thus adjust the active cooling operation parameters of the sealing component.

5. The system according to claim 4, wherein: the thermal recognition module is configured to perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component, specifically: perform thermal recognition on the sintered sealing component to obtain the global cooling characteristics of the sealing component under natural cooling conditions; wherein, the global cooling characteristics refer to the respective cooling rate characteristics of all parts within the sealing component.

6. The system according to claim 5, wherein: the cooling adjustment module is configured to estimate the internal stress difference characteristics between different parts within the sealing component based on the global cooling characteristics, and thereby adjust the active cooling operation parameters for the sealing component, specifically: determine the difference in cooling rate changes between two adjacent parts with different thicknesses within the sealing component based on the global cooling characteristics; estimate the internal stress difference characteristics between two adjacent parts with different thicknesses based on the difference in cooling rate changes; wherein, the internal stress difference characteristics include the internal stress magnitude and direction difference characteristics between two adjacent parts with different thicknesses; judge whether an internal stress anisotropy event will occur between two adjacent parts with different thicknesses based on the internal stress difference characteristics between two adjacent parts with different thicknesses; when an internal stress anisotropy event occurs, adjust the flow rate and the air flow delivery coverage area of the active cooling air flow delivered to two adjacent parts with different thicknesses.

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