Design method of sintering clamp for photocuring large-size special-shaped ceramic component

Abstract

The invention relates to the technical field of ceramic additive manufacturing and high-temperature sintering tools, in particular to a design method of a sintering clamp for photocuring a large-size special-shaped ceramic component. Aiming at the problems of free opening edge curling, thin-wall collapse, cracks, overall warping and the like which are easy to occur during sintering of a photocuring ceramic green body, the method comprises the following steps: firstly, acquiring three-dimensional geometric information of a component and partitioning, and identifying an instability mode and a sensitive area; and then a boundary strategy of shape limitation without shrinkage limitation, controlled sliding, partition supporting and intersection area receding is constructed, structural design and material selection of the supporting ring, the inner supporting core, the burning bearing base, the low-friction isolation layer and the positioning groove are completed, and assembly and use specifications are formed. The sintering bearing clamp obtained by the method can inhibit out-of-plane instability while allowing the component to shrink, reduce shrinkage retardation stress, and improve the sintering formability stability, size consistency and finished product yield of the component. The ice cream barrel-shaped silicon nitride ceramic piece is taken as an embodiment, so that the sintering defect risk can be obviously reduced, and the engineering popularization value is good.

Description

A design method for sintering fixtures for large-size irregularly shaped ceramic components for photopolymerization. Technical Field

[0001] This invention relates to the field of ceramic additive manufacturing and high-temperature sintering tooling technology, and more specifically to a design method for sintering fixtures for large-size irregularly shaped ceramic components that are photocured. Background Technology

[0002] High-performance ceramic components, due to their high hardness, high strength, high temperature resistance, corrosion resistance, and excellent dielectric properties, have wide applications in aerospace, weaponry, electronics, and energy. With the continuous increase in demands for lightweight equipment, integrated structural functions, and complex configurations, ceramic components are gradually showing a development trend towards larger sizes, thinner walls, irregular shapes, and cross-scale structural integration using ribs and lattices. Traditional processes such as slip casting, dry pressing, static pressing, and machining are limited by mold dependence, insufficient forming freedom, difficulty in demolding complex spatial structures, and high processing costs, making it difficult to efficiently manufacture these complex ceramic components.

[0003] Photopolymer additive manufacturing, including DLP and SLA, enables high-precision and rapid prototyping of complex ceramic structures, providing a new approach for manufacturing large-sized, irregularly shaped ceramic components. However, photopolymer-printed ceramic green bodies typically contain a high proportion of organic binders, and these green bodies undergo significant mass loss, porosity evolution, and volume shrinkage during debinding and sintering. Furthermore, liquid phase or viscous flow windows may appear during high-temperature sintering, leading to a decrease in the mechanical support capacity of the components. For large-sized, thin-walled, irregularly shaped components, the sintering process is prone to the following problems due to factors such as wall thickness differences, structural discontinuities, uneven temperature fields, and frictional boundary conditions:

[0004] (1) Free edge areas, such as the rim, may experience curling, wavy undulations, or roundness instability, leading to a decrease in dimensional and shape accuracy;

[0005] (2) Thin-walled shells collapse, bulge, or become elliptic out-of-plane unstable under the influence of gravity and viscous flow;

[0006] (3) Stress concentration occurs in the rib-rib intersection area and the thickness transition area due to asynchronous shrinkage, which can easily lead to cracks or delamination.

[0007] (4) When there is significant friction or local adhesion between the component and the graphite bearing plate, the shrinkage displacement is hindered, which further induces overall warping, local cracking and uncontrollable shape.

[0008] Existing sintering methods mostly employ graphite flat plates, single powder bed supports, or simple rigid restraint structures. Flat plate sintering struggles to suppress out-of-plane instability of thin-walled, large curved surfaces; powder bed supports are prone to uneven support, localized subsidence, or poor venting on large, irregularly shaped parts; while rigid restraints easily transform free shrinkage into shrinkage-resisting stress, leading to "the more restrained, the more cracking." Therefore, there is an urgent need for a sintering fixture design method for photopolymerization printing of large, irregularly shaped ceramic components. This method should be able to achieve zoned support, controlled sliding, and clearance at intersection zones while ensuring component shrinkage, thereby improving the morphological stability, dimensional consistency, and yield of the sintering process. Summary of the Invention

[0009] To address the problems of free edge curling, thin-wall collapse, overall warping, and cracking at rib intersections that easily occur during the sintering process of large-sized irregularly shaped ceramic components manufactured by photopolymer additive manufacturing, this invention proposes a sintering fixture design method for photopolymer additive manufacturing of large-sized irregularly shaped ceramic components. This invention identifies the structural features of the component by partitioning them and constructs fixture boundary conditions that are "shape-limited but not shrinkage-limited, controlled slip, and partitioned support," enabling the component shrinkage process to have a pre-set deformation path, thereby improving the shape stability, dimensional consistency, and yield of the finished product during the sintering process.

[0010] The technical solution adopted by this invention to solve its technical problem is:

[0011] A method for designing sintering fixtures for large-sized irregularly shaped ceramic components for photopolymerization includes the following steps:

[0012] S1. Obtain the three-dimensional geometric and structural features of the photocurable ceramic green blank to be sintered, including wall thickness distribution, curvature distribution, free boundary position, rib distribution and their intersection area, thickness transition area and assembly reference surface; based on the above information, divide the component into at least the free edge area, thin-walled shell area, thickness transition area, rib intersection area and positioning reference area.

[0013] S2. Identify the instability and defect modes that may occur during the sintering process for each zone, including at least free edge curling, wave undulation or roundness instability, thin-walled shell collapse, bulging or ellipticization, cracks in the thick-thin transition zone and rib intersection zone, and overall warping caused by contact friction.

[0014] S3. Determine the fixture boundary strategy as shape-limiting but not shrinkage-limiting. Set a controlled sliding boundary at the contact interface between the component and the fixture. At the same time, adopt clearance and buffer boundaries for the rib intersection area and the thickness transition area.

[0015] S4. A support ring is designed to support the free edge area. The support ring matches the shape of the free edge of the component and provides circumferential support and limitation for the free edge area. A low-friction isolation layer and shrinkage gap are provided between the support ring and the component so that the component can achieve micro-slippage at the support ring during the sintering shrinkage process.

[0016] S5. An inner support core is designed to support the thin-walled shell area. The inner support core matches the contour of the inner surface of the thin-walled shell of the component and is a detachable structure. A low-friction isolation layer and an isolation gap are provided between the inner support core and the component.

[0017] S6. The firing base is designed to provide symmetrical load-bearing capacity. A low-friction isolation layer is provided at the interface between the firing base and the component. A positioning groove is configured to realize the assembly and positioning of the support ring, inner support core and component. The positioning groove and the component adopt a clearance fit and are provided with a low-friction isolation layer.

[0018] S7. Based on the sintering temperature, atmosphere conditions and component material system, select the materials for the support ring, inner support core and sintering base, determine the material system, laying method and thickness parameters of the low friction isolation layer, and form the fixture assembly process, gap setting principle and sintering usage specifications.

[0019] Furthermore, the support ring is either an integral or segmented structure; when it is a segmented structure, the number of segments is 2 to 12.

[0020] Furthermore, the shrinkage gap is the radial gap d between the support ring and the outer surface of the component, and the value of d ranges from 0.5 to 3.0 mm.

[0021] Furthermore, the inner support core is a segmented or wedge-block combined detachable structure, with 3 to 8 segments. The segmented inner support core uses snap-fit ​​connections, bolt fixation, or elastic fitting splicing methods to achieve firm fixation and easy disassembly; the wedge-block combined inner support core is assembled through a wedge-block locking mechanism, with each wedge of the inner support core combined through plug-in locking, elastic buckles, or bolt fixation methods, making the assembly process simple, disassembly convenient, and maintaining sufficient support force during sintering.

[0022] Furthermore, the low-friction isolation layer includes one or more of BN coating, graphite sheet, and BN-based composite isolation layer; wherein the thickness of the BN coating is 20-100 μm, and the thickness of the graphite sheet or BN-based composite isolation layer is 0.2-1.0 mm.

[0023] Furthermore, the number of positioning grooves is 4 to 12, evenly distributed circumferentially. The positioning grooves are rectangular or arc-shaped, and the depth and width of each positioning groove are optimized according to the shape of the component and sintering requirements to ensure positioning stability and support effect on the contact surface between the fixture and the component. The positioning grooves are evenly distributed circumferentially along the component, and their cooperation with other structural components within the fixture ensures that the component can be stably positioned without shifting or loosening during the sintering process.

[0024] A sintering fixture for sintering large-sized irregularly shaped ceramic components for photocuring, the fixture being derived from a design method for sintering fixtures for large-sized irregularly shaped ceramic components for photocuring, comprising:

[0025] The firing base is used to provide symmetrical load-bearing, and a low-friction isolation layer is set at the interface between it and the ceramic component;

[0026] The support ring, which matches the shape of the free edge of the ceramic component, is used to provide circumferential support and limit the free edge area of ​​the ceramic component. A low-friction isolation layer and shrinkage gap are provided between the support ring and the ceramic component.

[0027] The inner support core matches the contour of the inner surface of the thin-walled shell of the ceramic component. It is set inside the ceramic component and is a detachable structure. There is an isolation gap between the inner support core and the inner surface of the ceramic component, and a low-friction isolation layer is set at the contact point.

[0028] The positioning groove is used to assemble and position the support ring, inner support core and ceramic components. The positioning groove and the ceramic components are clearance fit and a low friction isolation layer is provided.

[0029] Furthermore, the inner support surface of the ring is provided with a rounded transition or a slight taper.

[0030] Furthermore, the materials of the firing base, the support ring, and the inner support core are selected from one or more of Si3N4, C, and BN-based composite materials.

[0031] To more comprehensively and clearly disclose the technical concept and implementation logic of this invention, the core design of the above technical solution is as follows:

[0032] This invention provides a design method for sintering fixtures of large-sized irregularly shaped ceramic components for photopolymerization. The method is applicable to the degreased green body of ceramic green bodies formed by DLP or SLA photopolymerization, and is particularly suitable for large-sized irregularly shaped components with thin-walled shells, free edges, ribbed reinforcement structures, and thick-thin coupling transition structures. The design method includes the following steps:

[0033] S1: Component Information Acquisition and Functional Partitioning

[0034] Obtain the geometric and structural features of the component to be fired, including the component's outline, wall thickness distribution, curvature distribution, free boundary location, rib distribution and their intersection area, thickness transition area, and assembly reference surface; divide the component into zones based on wall thickness, curvature variation and rib distribution to form functional zoning results including at least a free edge zone, thin-walled shell zone, rib intersection area, thickness transition area and positioning reference area.

[0035] S2: Instability Mode Identification and Sensitive Area Determination

[0036] For each functional zone, identify the instability and defect modes that may occur during the sintering process, including: free edge curling, wavy, roundness instability, thin-walled shell collapse, bulging, ellipticization, bottom surface friction locking leading to overall warping, and stress concentration in the rib intersection area or thick-thin transition area leading to cracks; based on the above identification results, determine the deformation-sensitive area and the key area that needs to be "buffered".

[0037] S3: Boundary control strategy determined, shape-bound but not contraction-bound + controlled slip.

[0038] Determine the fixture boundary control strategy based on the zoning and sensitive area results:

[0039] (a) A lifting and limiting boundary is used in the free edge area to suppress curling and roundness instability;

[0040] (b) Use internal support boundaries for thin-walled shell regions to suppress collapse and ellipticization;

[0041] (c) Use clearance and buffer boundaries in the rib intersection area and the thickness transition area to reduce stress concentration;

[0042] (d) Introduce a low-friction isolation layer at the interface between the component and the fixture to form a controlled slip interface to reduce shrinkage resistance stress and the risk of adhesion.

[0043] S4: Ring design, free-flowing mouth rim area constraint

[0044] The support ring is designed according to the shape of the free edge of the component. The support ring is used to provide circumferential support and limit. The support ring can be an integral or segmented structure. A low-friction isolation layer is set at the contact point between the support ring and the component, and the required gap for radial and axial shrinkage is reserved so that the component can achieve micro-slippage at the support ring during the sintering shrinkage process, avoiding tearing or warping caused by rigid locking.

[0045] S5: Internal support core design prevents collapse in thin-walled shell areas.

[0046] The inner support core is designed according to the inner surface contour of the thin-walled shell of the component. The inner support core is preferably a segmented detachable structure or a wedge block combination structure, which is used to support the shape of the thin-walled shell during the high-temperature softening stage of sintering. A suitable gap is set between the inner support core and the component, and a low-friction layer is added to reduce friction lock-up and adhesion caused by large-area bonding, while allowing controlled micro-slippage during the component shrinkage process.

[0047] S6: The design of the firing base and positioning groove ensures symmetrical load-bearing and assembly positioning.

[0048] The base is designed to provide overall load-bearing and symmetrical support, and an isolation layer is set at the interface between the component and the base to form a low-friction sliding boundary. The positioning groove is designed for the relative positioning of the support ring, inner support core and component and to prevent assembly misalignment. The contact parts between the positioning parts and the component adopt clearance fit and low-friction layer treatment to avoid positioning constraints from being transformed into shrinkage resistance.

[0049] S8: Formulation of material and interface layer selection and usage specifications

[0050] Based on the sintering temperature, atmosphere conditions, and component material system, the material selection of the support ring, inner support core, and sintering base is determined, and the material system and laying method of the low friction layer are determined; the fixture assembly process, gap setting principle, clearance groove setting principle, and sintering usage specifications are formed, thereby obtaining a sintering fixture assembly suitable for the component.

[0051] The beneficial effects of the present invention, a design method for sintering fixtures for large-size irregularly shaped ceramic components for photopolymerization, are as follows:

[0052] (1) Limiting shape but not shrinkage, improving shape stability: By supporting and limiting the free edge with the support ring and supporting the thin-walled shell with the inner support core, the out-of-plane instability of edge curling, collapse and ellipticization during the high-temperature softening stage of sintering can be significantly suppressed, and the shape retention ability can be improved.

[0053] (2) Controlled slippage reduces shrinkage resistance stress and adhesion risk: A low-friction isolation layer is set at the interface between the component and the fixture to enable the component to have micro-slippage capability during shrinkage, avoiding overall warping and local tearing caused by friction lock-up or local adhesion, and improving sintering yield.

[0054] (3) Displacement and buffering in the intersection area to reduce the probability of failure in the crack-sensitive area: Displacement grooves / avoidance grooves are set in the intersection area of ​​ribs and the thick-thin transition area, and buffer layers are configured to effectively absorb local shrinkage differences and assembly errors, reduce stress concentration, and significantly reduce the risk of cracks and delamination in the intersection area.

[0055] (4) Wide range of applications and strong transferability: This design method establishes a general design step and boundary strategy for large-size irregular ceramic components for photopolymerization printing. In addition to silicon nitride ceramics, it can also be applied to the sintering shape control of various components such as lattice shells, thick and thin coupled structural parts, and complex internal cavity shells, and has good engineering promotion value. Attached Figure Description

[0056] The present invention will now be described in further detail with reference to the accompanying drawings and specific implementation methods.

[0057] Figure 1 is a design flowchart of a sintering fixture for large-size irregularly shaped ceramic components that are photocured.

[0058] Figure 2 is a schematic diagram of risk zone identification for ceramic components;

[0059] Figure 3 is a schematic diagram of the assembly of ceramic components and sintering fixtures;

[0060] Figure 4 is a schematic diagram of the sintering fixture.

[0061] In the diagram: 1. Ceramic component; 2. Inner support core; 3. Positioning groove; 4. Low-friction isolation layer; 5. Firing base; 6. Support ring. Detailed Implementation

[0062] The present invention will be further described below with reference to the accompanying drawings. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. The fixture design method described in this invention is applicable to large-size irregular-shaped ceramic components formed by photopolymerization, and is particularly suitable for components with thin-walled shells, free edges, ribs, reinforcing structures, and thick-thin transition zones. For ease of explanation, this embodiment uses a large-size silicon nitride ceramic printed by photopolymerization as an example.

[0063] Example 1: Design and application of ice cream cylinder-shaped silicon nitride ceramic sintering fixture

[0064] 1. Component and Risk Area Identification

[0065] In this embodiment, the irregular component is a degreased green blank of silicon nitride ceramic obtained by photopolymerization printing. Its structural features include: a large-diameter free edge at the lower end, a thin-walled conical shell section, and a thickness transition structure in a local area.

[0066] The ceramic component 1 is functionally divided, including:

[0067] Free edge region A: Prone to curling, undulation, and instability of roundness;

[0068] Thin-walled region B of the conical shell: prone to collapse, bulging or ellipticization during the high-temperature softening stage of sintering;

[0069] Rib-rib intersection area C: Due to asynchronous local shrinkage, stress concentration and cracks are prone to occur;

[0070] Bottom contact area D: Friction or adhesion with the bearing surface can hinder shrinkage displacement, thereby inducing overall warping or local cracking.

[0071] Based on this, the control objectives of the fixture for the component are determined as follows: under the premise of allowing the component to shrink according to the sintering law, suppress edge curling and out-of-plane instability of the conical shell, reduce stress concentration in the rib intersection area, and avoid warping and cracking caused by bottom surface friction lock-up.

[0072] 2. Overall structure of the fixture

[0073] As shown in Figures 2 and 3, the sintering fixture of this embodiment includes: an inner support core 2, a positioning groove 3, a low-friction isolation layer 4, a sintering base 5, and a support ring 6. The above structures together construct the fixture boundary conditions of "limited shape but not limited contraction, controlled sliding, zoned support, and yielding at intersection areas".

[0074] Among them: Inner support core 2: used to support the thin-walled area of ​​the conical shell to prevent collapse; Positioning groove 3: used for coaxial positioning of the fixture and the component and to prevent assembly misalignment. Low friction isolation layer 4: set at the contact interface between the component and the fixture to reduce friction and adhesion; Bearing base 5: used for overall load bearing and symmetrical support; Support ring 6: used to support and limit the free edge of the opening.

[0075] 3. Design of inner support core 2

[0076] An inner support core 2 is disposed inside the ceramic component 1 to support the thin-walled region B of the conical shell. The inner support core 2 is preferably a segmented, detachable structure or a wedge-block combination structure for easy removal after assembly and sintering. An isolation layer is placed between the inner support core 2 and the ceramic component 1, with a gap reserved to allow controlled micro-slippage during the shrinkage process of the ceramic component 1, thereby suppressing out-of-plane instability such as conical shell collapse, bulging, and ellipticization during the high-temperature softening stage of sintering.

[0077] 4. Design of positioning groove 3

[0078] The positioning groove 3 is used to achieve coaxial positioning of the ceramic component 1, the support ring 6, and the inner support core 2, preventing uneven circumferential shrinkage or support imbalance caused by assembly eccentricity. A low-friction isolation layer 4 is added to the contact area between the positioning groove 3 and the ceramic component 1, and an appropriate gap is set to avoid the positioning component rigidly clamping the ceramic component 1, thereby preventing the positioning constraint from evolving into shrinkage resistance stress.

[0079] 5. Fixture material and low-friction layer design

[0080] The materials for the support ring 6, inner support core 2, and firing base 5 can be high-temperature resistant and chemically stable ceramic materials or composite materials, typically Si3N4, C, or BN-based composite materials. The low-friction isolation layer 4 is typically a BN coating or graphite sheet. The selection of these materials should be compatible with the sintering atmosphere, temperature regime, and component material system, and should avoid adverse reactions or adhesion with the components.

[0081] 6. Design of the firing base 5

[0082] The firing base 5 is used to support the overall weight of the support ring 6, the inner support core 2, and the ceramic component 1. It preferably adopts a symmetrical structure to reduce warping caused by offset. The contact interface of the firing base 5 is covered with a low-friction isolation layer 4 to reduce shrinkage resistance caused by bottom surface friction lock-up.

[0083] 7. Design of the support ring 6

[0084] The support ring 6 is circumferentially arranged below the free area of ​​the large port rim of the ceramic component 1. Its inner support surface matches the shape of the rim, and it is preferably provided with a rounded transition or a slight taper to avoid sharp corner indentations. The support ring 6 can adopt an integral structure or a segmented structure, preferably with 2 to 12 segments, to improve the ability to make room for shrinkage.

[0085] A low-friction isolation layer 4 is provided in the contact area between the support ring 6 and the ceramic component 1, so that the component can undergo micro-slippage at the support ring during the sintering shrinkage process, thereby suppressing edge curling and ellipticization while avoiding tearing.

[0086] 8. Fixture assembly and sintering usage steps, detailed implementation process

[0087] The fixture assembly and sintering steps in this embodiment are as follows:

[0088] Step A: Base preparation

[0089] Place the firing base 5 on the horizontal firing surface and lay a low-friction isolation layer 4 on the base to form a low-friction, slip-able interface and provide local stress relief.

[0090] Step B: Inner support core assembly

[0091] The inner support core 2 is divided into segments. The inner support core 2 is first assembled on the firing base 5, and a low-friction isolation layer 4 is brushed onto the contact position between the inner support core 2 and the ceramic component 1.

[0092] Step C: Lug Assembly and Displacement Verification

[0093] Install the support ring 6 on the firing base according to the positioning groove 3 to prevent the support ring 6 from shifting. Lay a low-friction isolation layer 4 on the contact surface between the support ring 6 and the edge of the ceramic component 1.

[0094] Step D: Component placement and coaxial positioning

[0095] The ceramic component 1 is placed on the support ring 6 so that it is coaxial with the inner support core 2; the ceramic component 1 and the fixture are positioned by the positioning groove 3 to ensure that the circumferential position of the ceramic component 1 is stable and that the positioning part does not form a rigid clamp on the ceramic component 1.

[0096] Step E: Overall inspection and sintering in the furnace

[0097] After assembly, the symmetry and coaxiality of the fixture assembly are checked. The fixture assembly is then placed into the sintering furnace and sintered according to the predetermined sintering process. Because the fixture provides controlled slip and zoned support boundary conditions, the ceramic component 1 can achieve "shape restriction without shrinkage restriction" during sintering shrinkage, thereby suppressing edge curling and out-of-plane instability of the conical shell, and reducing the probability of cracks occurring in the rib intersection area.

Claims

1. A method for designing sintering fixtures for large-size irregularly shaped ceramic components for photopolymerization, characterized in that, Includes the following steps: S1. Obtain the three-dimensional geometric and structural features of the photocurable ceramic green body to be sintered, including wall thickness distribution, curvature distribution, free boundary position, rib distribution and their intersection area, thickness transition area, and assembly reference surface; based on the above information, divide the component into at least the free edge area, thin-walled shell area, thickness transition area, rib intersection area, and positioning reference area; S2. Identify the instability and defect modes that may occur during the sintering process for each zone, including at least the free edge curling, wave undulation or roundness instability, thin-walled shell collapse, bulging or ellipticization, cracks in the thickness transition area and rib intersection area, and overall warping caused by contact friction; S3. Determine that the fixture boundary strategy is to limit the shape but not the contraction, set a controlled sliding boundary at the contact interface between the component and the fixture, and adopt clearance and buffer boundaries for the rib intersection area and the thickness transition area. S4. A support ring is designed to support the free edge area. The support ring matches the shape of the free edge of the component, providing circumferential support and limiting the free edge area. A low-friction isolation layer and shrinkage gap are provided between the support ring and the component, allowing the component to micro-slip at the support ring during sintering shrinkage. S5. An inner support core is designed to support the thin-walled shell area. The inner support core matches the contour of the inner surface of the thin-walled shell of the component and is a detachable structure. A low-friction isolation layer and isolation gap are provided between the inner support core and the component. S6. A firing base is designed to provide symmetrical load-bearing. A low-friction isolation layer is provided at the contact interface between the firing base and the component. A positioning groove is configured to realize the assembly positioning of the support ring, inner support core, and component. The positioning groove and the component adopt a clearance fit and are provided with a low-friction isolation layer. S7. Based on the sintering temperature, atmosphere conditions, and component material system, the materials of the support ring, inner support core, and firing base are selected. The material system, laying method, and thickness parameters of the low-friction isolation layer are determined, forming the fixture assembly process, gap setting principle, and sintering usage specifications.

2. The method for designing a sintering fixture for large-size irregularly shaped ceramic components for photopolymerization according to claim 1, characterized in that, The support ring can be an integral or segmented structure; when it is a segmented structure, the number of segments is 2 to 12.

3. The design method for a sintering fixture for large-size irregularly shaped ceramic components for photopolymerization according to claim 1, characterized in that, The shrinkage gap is the radial gap d between the support ring and the outer surface of the component, and the value of d ranges from 0.5 to 3.0 mm.

4. The design method for a sintering fixture for large-size irregularly shaped ceramic components for photopolymerization according to claim 1, characterized in that, The inner support core is a detachable structure with a segmented or wedge-block combination, and the number of segments is 3 to 8. The segmented inner support core adopts a snap-fit ​​connection, bolt fixation or elastic fitting splicing method to achieve firm fixation and easy disassembly. The wedge-block combination inner support core is assembled by a wedge-block locking mechanism. The wedge blocks of the inner support core are combined by a plug-in locking, elastic buckle or bolt fixation method, which makes the assembly process simple, the disassembly convenient, and maintains sufficient support force during sintering.

5. The design method for a sintering fixture for large-size irregularly shaped ceramic components for photopolymerization according to claim 1, characterized in that, The low-friction isolation layer includes one or more of BN coating, graphite sheet, and BN-based composite isolation layer; wherein the thickness of the BN coating is 20-100 μm, and the thickness of the graphite sheet or BN-based composite isolation layer is 0.2-1.0 mm.

6. The method for designing a sintering fixture for large-size irregularly shaped ceramic components for photopolymerization according to claim 1, characterized in that, The number of positioning slots is 4 to 12 and they are evenly distributed along the circumference. The shape of the positioning slots is rectangular or arc-shaped. The depth and width of each positioning slot are optimized according to the shape of the component and the sintering requirements to ensure the positioning stability and support effect on the contact surface between the fixture and the component. The positioning slots are evenly distributed along the circumference of the component, and their cooperation with other structural components in the fixture ensures that the component can be stably positioned without shifting or loosening during the sintering process.

7. A sintering fixture for sintering large-sized irregularly shaped ceramic components using photocuring, characterized in that, The firing fixture is obtained by the design method described in claim 1 and includes: a firing base (5) for providing symmetrical bearing, wherein a low-friction isolation layer (4) is provided at the contact interface between the base and the ceramic component (1); a support ring (6) for matching the shape of the free edge of the ceramic component (1) and for providing circumferential lifting and limiting of the free edge area of ​​the ceramic component (1), wherein a low-friction isolation layer (4) and a shrinkage gap are provided between the support ring (6) and the ceramic component (1); an inner support core (2) for matching the contour of the inner surface of the thin-walled shell of the ceramic component (1), being located inside the ceramic component (1) and being a detachable structure, wherein an isolation gap exists between the inner support core (2) and the inner surface of the ceramic component (1), and a low-friction isolation layer (4) is provided at the contact point; and a positioning groove (3) for assembling and positioning the support ring (6), the inner support core (2) and the ceramic component (1), wherein the positioning groove (3) and the ceramic component (1) are in clearance fit and a low-friction isolation layer (4) is provided.

8. A sintering fixture for sintering large-size irregularly shaped ceramic components for photopolymerization according to claim 7, characterized in that, The inner support surface of the ring (6) is provided with a rounded transition.

9. A sintering fixture for sintering large-size irregularly shaped ceramic components for photocuring, as described in claim 7, is characterized in that... The materials of the heating base (5), the support ring (6) and the inner support core (2) are selected from one or more of Si3N4, C and BN based composite materials.

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