KR20220033572A - Method for manufacturing ceramic structure having functionally graded structure and ceramic structure having functionally graded structure manufactured thereby - Google Patents

Abstract

The present invention relates to a method for manufacturing a ceramic structure made of a plurality of materials by using a 3D printer, and a ceramic structure manufactured thereby. The present invention provides a method for manufacturing a ceramic structure having a functional gradient structure using a mixed material in which different types of materials are mixed. According to the present invention, a ceramic structure made of heterogeneous materials having different physical properties and a mixture of heterogeneous materials can be integrally formed and a sintering shrinkage of a plurality of printing materials and a mixture thereof is controlled, thereby providing an effect of preventing peeling, cracking, and shape deformation of the structure. In addition, a bonding surface between the heterogeneous materials is controlled by a graded structure, thereby preventing rapid change in physical properties and improving bonding characteristics between the heterogeneous materials. At this time, in functional gradient structure part, functional gradient structure conditions such as the thickness and shape of each composition can be precisely controlled layer by layer. Therefore, the method provides an effect of manufacturing a high-functionality and high-quality ceramic structure with high structural precision combining heterogeneous physical properties. The method comprises a first and second printing material preparation step, a mixed printing material preparation step, printing steps, and a sintering step.

Description

A method for manufacturing a ceramic structure having a sloped functional structure and a ceramic structure having a sloped functional structure manufactured thereby

The present invention relates to a method for manufacturing a ceramic structure having a slanted functional structure using a 3D printer, and to a ceramic structure including a slanted functional structure manufactured by the method.

Gradient functional material refers to the controlled connectivity of two materials by gradually changing the composition, microstructure, or pore structure in one structure to reduce stress caused by abrupt change in properties that may occur at the contact surface of two materials. In particular, a general gradient functional material is a method of joining two materials in a gradient manner through gradual change by inserting an intermediate layer by giving different materials a change in composition. Interface separation due to the difference in thermal residual stress that may occur in the joint part due to different thermal expansion coefficients of the two materials for bonding a combination of materials with different physical properties, that is, a ceramic with excellent high temperature resistance and a metal with high mechanical strength. And it is used for the purpose of alleviating the fracture phenomenon, and is widely used in various fields such as high-temperature materials, energy-absorbing materials, structural materials, and biomaterials.

Methods for manufacturing such a gradient functional material include PVD method, CVD method, plasma spraying method, composite electroforming method, process bonding method, gas atmosphere heat treatment method, etc. It is a method of making a dense slanted functional material by plasticizing treatment. The gradient function temporary molded article is manufactured by a slurry step addition method, a centrifugal method, a particle arrangement method, a particle spraying method, a thin film lamination method, a powder lamination filling method, and the like. The subsequent firing methods include the discharge plasma sintering method, the self-heating reaction synthesis method, the hot pressing method, the hot isostatic pressing sintering method, and the atmospheric pressure sintering method. The conventional method of manufacturing the inclined functional material has a limitation in that it is difficult to precisely control the thickness between the compositions, and it is more difficult to control the three-dimensional shape as well as to control the inclined functional part.

On the other hand, 3D printing technology scans a desired three-dimensional shape or designs it through computer modeling and differentiates it into two dimensions, using materials having properties necessary for the final product, such as polymers, metals, ceramics, and composites, layer by layer. It is a technology that creates three-dimensional structures by stacking them. Recently, 3D printing technology, where only one material was applied, has been developed, and a technology that can apply multiple materials has been developed. In addition, Patent Document 1 (Republic of Korea Patent No. 10-1754771, Ceramic 3D Printing Device and 3D Printing Method) and Patent Document 2 (Korean Patent Registration No. 10-2109664, Apparatus for manufacturing a structure having a gradient of properties and the same) In the method of manufacturing a structure having a gradient of properties used), the possibility of using different materials between layers is suggested by introducing a method of supplying materials to a transparent film layer by layer. In other words, by supplying materials of different compositions layer by layer, the inclined functional structure is realized, and at the same time, by utilizing the features of 3D printing technology, it is possible to simultaneously control the three-dimensional shape, which was difficult to implement with the conventional inclined functional structure manufacturing method. 3D printed structure). In addition, Patent Document 3 (Korean Patent Publication No. 10-2019-0100854 Multi-material-based 3D printing technology for manufacturing inclined functional composite material) presents a similar technology as a molded body.

However, when a ceramic material is introduced as a material, the inclined functional structure and three-dimensional shape realized by 3D printing are applied to the step of making the above-mentioned molded body, and the stability of the structure through the degreasing process to remove organic matter and inter-particle bonding. The 'sintering' process, which is a high-temperature heat treatment process to secure mechanical properties and mechanical properties, is always accompanied. At this time, the shrinkage of the structure occurs due to the inter-particle bonding, and the shrinkage rate is different depending on the applied composition. control is needed At this time, when the sintering shrinkage rate for each composition is not controlled, distortion, peeling, and fracture of the printed structure occur, and even if the three-dimensional shape is controlled with 3D printing technology, eventually peeling and fracture between the compositions occurs and the inclined functional structure is converted into two types of material. The reason for applying the joint disappears. In addition, each crystal phase of the ceramic changes according to the sintering temperature, and if the sinterable temperature is different, simultaneous sintering becomes impossible even if the ceramic is printed on one structure at the same time. For example, in the case of glass, a relatively low sintering temperature is required, but in the case of silicon nitride, etc., a high sintering temperature is required, so silicon nitride is not sintered when it matches the temperature of the glass, and when it matches the temperature of silicon nitride, the glass melts This happens. Therefore, it should be controlled by a material composition combination that can control the heat treatment temperature condition together.

In addition, in the case of ceramics, the density and response to light (light absorption, light scattering, etc.) are different depending on the composition, and in particular, when applied to 3D printing of the light polymerization method, the material density or light absorption and light scattering by composition applied to the inclined functional structure Light irradiation conditions should be set by examining the characteristics. This is because the thickness of one layer that is cured by light is different depending on the corresponding properties for each composition, and in 3D printing, which produces a three-dimensional shape by stacking two-dimensional structures layer by layer, the thickness of one layer that can be printed by composition in the inclined structure must be controlled and adjusted.

Accordingly, the inventors of the present invention studied to solve the problems of the prior art to be solved in order to apply the ceramic 3D printing technology to the manufacture of the ceramic-ceramic inclined functional structure, and to provide a method for effectively manufacturing the inclined functional structure ceramic three-dimensional structure. As a result, the present invention has been reached.

Republic of Korea Patent No. 10-1754771 Republic of Korea Patent Registration No. 10-2109664 Republic of Korea Patent Publication No. 10-2019-0100854

An object of the present invention is to provide a method for manufacturing a ceramic structure having a gradient functional structure and a ceramic structure having a gradient functional structure manufactured by the method.

In order to achieve the above object,

In one aspect of the present invention,

preparing a first printing material and a second printing material having a matched sintering shrinkage ratio X1 by controlling the physical properties of the first printing material and the second printing material different therefrom;

adjusting the mixing ratio of the first printing material and the second printing material having the matching sintering shrinkage ratio, so that the composition ratio of the first printing material and the second printing material has a gradient functional structure, preparing a mixed printing material;

supplying the first printing material to a 3D printer to print a part of the structure;

supplying the plurality of mixed printing materials to a 3D printer to print a part of the structure and an inclined functional structure in contact with one side;

supplying the second printing material to a 3D printer to print the other portion of the structure in contact with the inclined functional structure portion of the structure from the other side; and

Sintering the printed structure; including, wherein the sintering shrinkage ratio X2 of the plurality of mixed printing materials is in the range of ±1.5% compared to the sintering shrinkage ratio X1 of the first printing material and the second printing material. A method of manufacturing a ceramic structure is provided.

In addition, in another aspect of the present invention

a part of the structure manufactured by the above method and formed by the first printing material;

an inclined functional structure part in contact with a part of the structure at one side and formed by a plurality of mixed printing materials in which the composition ratio of the first printing material and the second printing material is inclined; and

It provides a ceramic structure having an inclined functional structure comprising a; the other part of the structure which is in contact with the inclined functional structure part of the structure and is formed by the second printing material.

According to the present invention, it is possible to integrally form a ceramic structure composed of a dissimilar material having different physical properties and a mixture of dissimilar materials, and control the sintering shrinkage rate of a plurality of printing materials and the mixed material to prevent peeling, cracking and shape deformation of the structure. It has a preventable effect. In addition, it is possible to prevent a sudden change in physical properties and improve the bonding characteristics between different materials by controlling the bonding surface between dissimilar materials with an inclined functional structure. In this case, the inclined functional structure part can precisely control the gradient functional structure conditions such as the thickness and shape of each composition layer by layer. Accordingly, there is an effect of manufacturing a high-functional, high-quality ceramic structure having high structural precision and combining different types of physical properties.

1 is a graph measuring sintering shrinkage with respect to the particle size and inorganic content of ceramic powder of a printing material including alumina or zirconia according to an experimental example of the present invention.
2 is an image showing a schematic manufacturing process of an alumina-zirconia structure to which an intermediate layer is introduced according to an experimental example of the present invention and a state of interlayer separation after sintering.
3 is an image observed with a scanning electron microscope (SEM) of the laminated structure of the alumina-zirconia structure to which the intermediate layer is introduced according to an experimental example of the present invention.
4 is an SEM image of observing grain growth after sintering of a mixed printing material (alumina 80% by weight and zirconia 20% by weight) and an unmixed printing material (alumina 100% by weight) according to an experimental example of the present invention.
5 is a graph of measuring sintering shrinkage according to composition by sintering a plurality of alumina-zirconia mixed printing materials of different compositions according to Experimental Example 3 of the present invention at 1500°C.
6 is a graph of measuring sintering shrinkage according to composition by sintering a plurality of alumina-zirconia mixed printing materials of different compositions according to Experimental Example 4 of the present invention at 1500°C.
7 is a graph of measuring sintering shrinkage according to composition by sintering a plurality of alumina-zirconia mixed printing materials of different compositions according to Experimental Example 5 of the present invention at 1500°C.
8 is a schematic image of an alumina-zirconia structure having a gradient functional structure according to an experimental example of the present invention.
9 is a graph measuring light curing conditions according to the composition of a plurality of alumina-zirconia printing materials of different compositions according to an experimental example of the present invention.
10 is an image obtained by photographing a cross-section of an alumina-zirconia structure having a slanted functional structure printed according to an experimental example of the present invention with a scanning electron microscope, and an image mapped thereto through EDX.
11 is an SEM image of a cross-section of an alumina-zirconia structure including an inclined functional structure sintered at 1500° C. after printing according to an experimental example of the present invention.
12 is a scanning electron microscope (SEM) image of each layer made of a different composition of an alumina-zirconia structure including a gradient functional structure after printing according to an experimental example of the present invention and sintered at 1500° C. through EDX. It is a graph showing the image and the composition of each layer.
13 is a scanning electron microscope (SEM) image of the particle structure of each layer portion having a different composition of an alumina-zirconia structure having a gradient functional structure prepared according to an experimental example of the present invention.
14 is a graph measuring the density change according to the composition of each layer portion having a different composition of an alumina-zirconia structure having a gradient functional structure prepared according to an experimental example of the present invention.
15 is an image showing a ceramic structure having an inclined functional structure implemented by modeling a three-dimensional shape according to an experimental example of the present invention.
16 is an image of a ceramic structure having an inclined functional structure printed in a three-dimensional shape modeled according to an experimental example of the present invention and sintering the same.
17 is an image after sintering a ceramic structure printed in a modeled three-dimensional shape according to an experimental example of the present invention.

Since the present invention can make various changes and thus various embodiments can be made, specific embodiments will be presented below and described in detail.

In addition, all terms in this specification that are not specifically defined may be used in a meaning that can be understood by all those of ordinary skill in the art to which the present invention belongs.

However, it should be understood that the present invention is not intended to be limited only to the specific embodiments to be described below, and includes all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Accordingly, there may be other equivalents and modifications to the embodiment described herein, and the embodiment presented herein is only the most preferred embodiment.

Hereinafter, the present invention will be described in detail.

In one aspect of the present invention,

preparing a first printing material and a second printing material having a matched sintering shrinkage ratio X1 by controlling the physical properties of the first printing material and the second printing material different therefrom;

adjusting the mixing ratio of the first printing material and the second printing material having the matching sintering shrinkage ratio, so that the composition ratio of the first printing material and the second printing material has a gradient functional structure, preparing a mixed printing material;

supplying the first printing material to a 3D printer to print a part of the structure;

supplying the plurality of mixed printing materials to a 3D printer to print a part of the structure and an inclined functional structure in contact with one side;

supplying the second printing material to a 3D printer to print the other portion of the structure in contact with the inclined functional structure portion of the structure from the other side; and

Sintering the printed structure; including, wherein the sintering shrinkage ratio X2 of the plurality of mixed printing materials is in the range of ±1.5% compared to the sintering shrinkage ratio X1 of the first printing material and the second printing material. A method of manufacturing a ceramic structure is provided.

Hereinafter, the method for manufacturing a ceramic structure provided in one aspect of the present invention will be described in detail for each step.

The method of the present invention includes the step of preparing a first printing material and a second printing material having a matched sintering shrinkage ratio X1 by controlling the physical properties of the first printing material and the second printing material different therefrom.

The printing material may include inorganic ceramic powder and a dispersant.

The printing material may be a photocurable ceramic slurry including a photocurable resin.

The first printing material and the second printing material are different materials from each other.

In the present invention, the heterogeneous material not only means materials completely different from each other, but also all materials except for the same material but different physical properties such as particle size, viscosity, and concentration, different pre-treated materials, and materials that are physically and chemically identical includes materials.

The structure printed by supplying the printing material including the ceramic powder requires sintering. The sintering shrinkage rate refers to the extent to which the volume or size of the sintered body is reduced during sintering. The same sintering shrinkage means that the sintering shrinkage is within the error range ± 1%, preferably 0%.

Specifically, the shrinkage rate according to the change of the specific physical property of each material is checked, and each material is prepared with the corresponding physical property when the shrinkage rates of both materials match.

The method of the present invention adjusts the mixing ratio of the first printing material and the second printing material having the matching sintering shrinkage ratio, so that the composition ratio of the first printing material and the second printing material has a gradient functional structure, the matching sintering shrinkage ratio and preparing a plurality of mixed printing materials having X2.

At this time, the sintering shrinkage ratio X2 of the plurality of mixed printing materials is in the range of ±1.5% compared to the sintering shrinkage ratio X1 of the first printing material and the second printing material. Preferably within ±1%, more preferably within the range of 0%.

The structure printed by supplying the printing material including the ceramic powder requires sintering. The sintering shrinkage rate refers to the extent to which the volume or size of the sintered body is reduced during sintering.

In addition, the agreement of the sintering shrinkage means that the sintering shrinkage is a numerical value within the error range ± 1%. That is, the difference between the interlayer sintering shrinkage in the inclination function section between the first printing material and the second printing material may be controlled to 0% to 1%, and preferably may be controlled close to 0%. If it is greater than 1%, there may be problems that cause warping of the structure along with cracks or splays between materials due to the difference in shrinkage.

4 is an SEM image of observing grain growth after sintering of a mixed printing material (alumina 80 wt% and zirconia 20 wt% mixed slurry) and an unmixed printing material (alumina 100 wt% slurry) according to an experimental example of the present invention; am. Looking at this, it was confirmed that the grain growth of alumina was reduced just by mixing zirconia with alumina, even though the inorganic content of the slurry before and after mixing was the same at 50% by volume. Therefore, it can be seen that the shrinkage rate during sintering is increased in the case of a slurry in which alumina and zirconia are mixed than in a slurry having a composition of 100% by weight of alumina.

Therefore, even after matching the sintering shrinkage ratio of the first printing material and the second printing material and mixing and maintaining the same inorganic content of the mixed printing material, the sintering shrinkage ratio X2 of the mixed printing material is increased compared to the matched sintering shrinkage ratio X1 may appear as At this time, the sintering shrinkage ratio X2 of the plurality of mixed printing materials is in the range of ±1.5%, preferably in the range of ±1%, and more preferably 0% compared to the sintering shrinkage ratio X1 of the first printing material and the second printing material. The difference between the sintering shrinkage rates X1 and X2 may be controlled to 0% to 1.5%, preferably 0% to 1%, and more preferably close to 0%.

The sintering shrinkage ratio X1 of the first printing material and the second printing material and the sintering shrinkage ratio X2 of the plurality of mixed printing materials do not match, or are in the range of ±1.5%, and preferably differ by more than the range of ±1% In the case of sintering, the part and the inclination function according to the different degree of contraction of the part of the structure printed with the first printing material and the inclined function structure part of the structure printed with the mixed printing material, and other parts of the structure printed with the second printing material There is a problem in that peeling, cracking, and shape deformation of the structure may occur between the structural part and the other parts.

If the sintering shrinkage ratio of the first printing material, the second printing material, and the mixed printing material is the same, the degree of shrinkage of the part, the inclined functional structure part, and the other part is the same, so that the above problem can be solved.

In the step of preparing the plurality of mixed printing materials, the density of the plurality of mixed printing materials of different compositions is gradually changed by adjusting the mixing ratio of the first printing material and the second printing material having a different density. It can be carried out to have

In the case of manufacturing a ceramic structure using heterogeneous ceramic powders with different densities as a material, even if the sintering shrinkage of each printing material including the ceramic powders with different densities is the same, the interface between different materials or compositions due to the rapid density difference between the two materials Interlayer separation may occur because bonding is not made in the

Accordingly, it is possible to solve the problem by introducing a gradient function structure in which the composition change gradually appears so that a rapid composition change does not occur. The bonding between materials with a large density difference is made into a slanted structure to relieve residual stress between layers during sintering to facilitate bonding. A plurality of mixed printing materials are prepared by adjusting the mixing ratio so that the composition ratio of the first printing material and the second printing material has a gradient functional structure.

The method includes, after the step of preparing a plurality of mixed printing materials, before the step of supplying a first printing material to print a part of the structure,

The method may further include controlling physical properties of the first printing material and the second printing material so that the sintering shrinkage ratio X1 of the first printing material and the second printing material matches the sintering shrinkage ratio X2 of the plurality of mixed printing materials.

As described above, controlling the physical properties of the first printing material and the second printing material so that the sintering shrinkage ratio X2 of the plurality of mixed printing materials and the sintering shrinkage ratio X1 of the first printing material and the second printing material, which are increased due to mixing, match can do. Specifically, the content of the inorganic material (ceramic powder) included in the first printing material and the second printing material may be adjusted. Accordingly, the sintering shrinkage ratio of the unmixed first and second printing materials and the plurality of mixed printing materials can be adjusted to be more consistent.

In addition, the agreement of the sintering shrinkage means that the sintering shrinkage is a numerical value within the error range ± 1%. That is, the difference between the sintering shrinkage ratio of the first printing material and the second printing material may be controlled to 0% to 1%, and preferably may be controlled close to 0%. If it is greater than 1%, there may be problems that cause warping of the structure along with cracks or splays between materials due to the difference in shrinkage.

The manufacturing method of the present invention includes the step of supplying the first printing material to a 3D printer to print a part of the structure.

The above step is a step of molding the printing material into a desired shape using a 3D printer. A first printing material is printed to form part of the ceramic structure.

The 3D printer is a multilayer printing device, and may be a method in which a single layer is stacked from an upper layer to a lower layer, but is not limited thereto. Additive 3D printing is a technology that continuously reconstructs a digitized three-dimensional product design into a two-dimensional section, then prints and laminates raw materials layer by layer to manufacture products.

The manufacturing method of the present invention supplies the plurality of mixed printing materials to a 3D printer to contact a part of the structure from one side. and printing the inclined functional structure.

The above step is a step of molding the printing material into a desired shape using a 3D printer. Printing is performed so that the mixed printing material forms an inclined functional structure portion in contact with a portion of the ceramic structure at one side.

The manufacturing method of the present invention includes the step of supplying the second printing material to a 3D printer to print the other portion of the structure in contact with the inclined functional structure portion of the structure from the other side.

The above step is a step of molding the printing material into a desired shape using a 3D printer. The second printing material is printed so as to form another portion in contact with the inclined functional structure portion of the ceramic structure from the other side.

The manufacturing method of the present invention includes the step of sintering the printed structure.

The step is a step of heating the printed structure with a printing material including ceramic powder at a high temperature so that the powder particles go through a thermal activation process to adhere and solidify in bulk form. At this time, since the printed structure is formed of a plurality of different materials, cracks and shape changes due to a difference in shrinkage may become problems.

Controlling the physical properties of the first printing material and the second printing material may be performed by adjusting the particle size of the ceramic powder included in the printing material. During the sintering process, the powder inside the printed structure is merged with each other and the pores are reduced, resulting in densification. The densification behavior may vary depending on the size of the powder particles, and this may be adjusted to control the sintering shrinkage rate.

Controlling the physical properties of the first printing material and the second printing material may be performed by adjusting the inorganic content of the printing material.

Since sintering is generally performed at a high temperature of 700° C. or higher, the solvent included in the printing material may be evaporated and decomposed. The sintering shrinkage rate can be controlled by adjusting the content of inorganic substances, which are ceramic powders included in the printing material.

The sintering shrinkage rates X1 and X2 may be controlled in the range of 10% to 40%. Sintering If the sintering shrinkage rate is less than 10%, it is not a big problem, but sufficient sintering is not performed, so structural stability should be sufficiently reviewed. On the other hand, when the sintering shrinkage rate exceeds 40%, it is difficult to control the isotropic shrinkage of the three-dimensional structure due to excessive shrinkage of the structure size, which may lead to distortion. and cracking.

The inorganic content of the printing material may be 40% by volume to 70% by volume, preferably 40% by volume to 60% by volume.

The particle size of the ceramic powder included in the printing material may be 0.01 μm to 10 μm.

The first printing material includes alumina, the second printing material includes zirconia, and the particle size of the alumina is 0.1 μm to 10 μm, and the particles of zirconia The size may be 0.01 μm to 1 μm.

The first printing material includes alumina, the second printing material includes zirconia, and the inorganic content of the first printing material is 46% by volume to 56% by volume, and The inorganic content may be 46% by volume to 54% by volume.

The first printing material includes alumina, the second printing material includes zirconia, and the particle size of the alumina is 0.2 μm to 0.5 μm, and the particles of zirconia The size is 0.2 μm to 0.5 μm, the inorganic content of the first printing material is 46% to 56% by volume, the inorganic content of the second printing material is 46% to 54% by volume, and the plurality of mixed printing materials are The inorganic content of is 48 vol% to 54 vol%, and in the plurality of mixed printing materials, the composition ratio of alumina and zirconia may change inclination in the range of 0.1 wt% to 99.9 wt%.

supplying the first printing material to a 3D printer to print a part of the structure;

supplying the plurality of mixed printing materials to a 3D printer to print a part of the structure and an inclined functional structure in contact with one side; and

Supplying the second printing material to a 3D printer to print the other part of the structure in contact with the inclined portion of the structure from the other side;

Supplying the first printing material to a 3D printer by controlling the thickness, forming a layer constituting a part of the structure, and photocuring it (step 1);

A step of supplying a plurality of mixed printing materials to a 3D printer by sequentially controlling the thickness according to the composition ratio, forming a layer forming an inclined portion in contact with a part of the structure and photocuring it (step 2);

Supplying a second printing material by controlling the thickness to a 3D printer, forming a layer constituting the other portion of the structure in contact with the inclined portion of the structure from the other side, and photocuring it (step 3); and

Repeating the steps 1 to 3 to laminate the structure; may be performed including.

The step 1 is a step of printing a layer constituting a part of the structure for which the physical properties of the first printing material are required, the printing material is constantly controlled to a specific thickness, and is photocured to a target shape by irradiating light. An uncured first printing material may remain in a portion not irradiated with light.

Between a portion of the structure composed of the first printing material and the other portion of the structure composed of the second printing material, a layer forming a part of the inclined functional structure portion that can have a physical property gradient according to the mixing ratio of the first printing material and the second printing material As a printing step, a plurality of mixed printing materials are sequentially supplied according to the composition ratio in contact with the part where the first printing material is cured in step 1, the thickness is controlled as in step 1, and the light is irradiated to the target shape get angry

The step 3 is a step of forming a layer constituting the other part of the structure in which the physical properties of the second printing material are required. It is a step of forming the remaining part of the monolayer of the structure to be composed of the second printing material in a target shape by irradiating light after uniformly controlling the thickness to the same thickness.

By repeating 'steps 1 to 3' of forming one layer of the structure, the entire shape of the target structure may be laminated and manufactured. The lamination modeling may be performed in a top-down lamination method.

The ceramic powder contained in the first printing material gradually increases from one side of the inclined functional structure part in contact with a part of the structure made of the first printing material to the other side of the inclined functional structure part in contact with the other part of the structure made of the second printing material. A plurality of mixed printing materials of different composition ratios may be sequentially supplied to print the inclined functional structure so that the ceramic powder contained in the second printing material is mixed at a low ratio, while being mixed at a low ratio to a gradually high ratio.

The method may further include washing the uncured material between steps 1 and 2 or between steps 2 and 3 . This is a step for preventing the first printing material, the second printing material, and the mixed printing material from being mixed in the process of forming the same monolayer. By including the step of washing the uncured printing material among the first printing materials in step 1, it is possible to provide an area for the mixed printing material to be cured, and to mix with the first printing material, respectively, so that there is no mixing between different materials. It is possible to effectively control the physical properties of each adjacent part made of the printing material.

The thickness may be controlled to 1 μm to 200 μm.

The photo-curing is a step of curing the printed material into a preset shape. The time required for light curing may vary depending on the physical properties of the printing material, particle conditions, mixing ratio, and thickness.

The time for irradiating light during the light curing may be 1 s to 10 s.

In the sintering step, the first printing material, the second printing material, and the mixed printing material constituting the ceramic structure may be heated to a common sintering temperature at which crystal phases and physical properties can be maintained.

The heating temperature in the sintering step may be 800 ℃ to 1600 ℃.

supplying the first printing material to a 3D printer to print a part of the structure;

supplying the plurality of mixed printing materials to a 3D printer to print a part of the structure and an inclined functional structure in contact with one side; and

Supplying the second printing material to a 3D printer to print the other portion of the structure in contact with the inclined functional structure portion of the structure from the other side;

forming a first printing material part including a plurality of layers by supplying the first printing material to a 3D printer by controlling the thickness and performing additive manufacturing;

supplying a plurality of mixed printing materials to a 3D printer by sequentially controlling the thickness according to the composition ratio, and forming a slanted structure part in contact with the upper surface of the first printing material part; and

It may be performed through; supplying the second printing material by controlling the thickness to a 3D printer, and forming a second printing material part in contact with the upper surface of the inclined structure part by lamination molding.

The ceramic structure including the first printing material, the second printing material, and a plurality of mixed printing materials may be manufactured by forming one layer with a single material, respectively, and stacking molding.

By supplying the first printing material to a 3D printer to control the thickness uniformly, and by irradiating light to photocurate into a target shape, one layer of the first printing material part can be formed, and this is repeatedly performed and laminated molding to form a plurality of A first printing material portion comprising a layer may be formed. The first printing material part may constitute a part of the ceramic structure.

A number of mixed printing materials can be sequentially supplied to a 3D printer with different composition ratios to uniformly control the thickness, and by irradiating light to photocurate into a target shape to form a layer of the inclined structure, repeating this It is possible to form an inclined structure portion in contact with the upper surface of a portion of the structure by lamination molding in a target shape. The inclined structure portion may constitute the inclined functional structure portion of the ceramic structure.

The plurality of layers included in the inclined structure may be formed by varying a mixing ratio of mixed printing materials constituting each layer. Specifically, from one side of the inclined structure portion in contact with the first printing material portion to the other side of the inclined structure portion contacting the second printing material portion, the first printing material is mixed at a higher ratio to a lower ratio within a certain range, while the second The printing material may be formed by varying the mixing ratio so as to gradually mix from a low ratio to a high ratio.

A second printing material is supplied to a 3D printer to control the thickness uniformly, and by irradiating light to photocurate into a target shape, one layer of the second printing material part can be formed, and this is repeated and laminated in a target shape A second printing material portion including a plurality of layers may be formed by molding. The second printing material part may constitute another part of the ceramic structure.

The thickness may be controlled from 1 μm to 200 μm.

According to the present invention, it is possible to integrally form a ceramic structure composed of a dissimilar material having different physical properties and a mixture of dissimilar materials, and control the sintering shrinkage rate of a plurality of printing materials and the mixed material to prevent peeling, cracking, and shape deformation of the structure It has a preventable effect. In addition, it is possible to prevent a sudden change in physical properties and improve the bonding characteristics between different materials by controlling the bonding surface between dissimilar materials with an inclined functional structure. In this case, the inclined functional structure part can precisely control the gradient functional structure conditions such as the thickness and shape of each composition layer by layer. Accordingly, there is an effect of manufacturing a high-functional, high-quality ceramic structure in which the structural precision is high and different types of physical properties are combined.

In another aspect of the present invention,

A portion of the structure manufactured by the method for manufacturing a ceramic structure having an inclined function structure according to an aspect of the present invention, and formed by the first printing material;

an inclined functional structure part in contact with a part of the structure at one side and formed by a plurality of mixed printing materials in which the composition ratio of the first printing material and the second printing material is inclined; and

It provides a ceramic structure having an inclined functional structure comprising a; the other part of the structure which is in contact with the inclined functional structure part of the structure and is formed by the second printing material.

Hereinafter, the ceramic structure provided in one aspect of the present invention will be described in detail for each configuration.

A part of the structure is formed of a first material, and corresponds to a material different from the second material, as will be described later.

In the present invention, the heterogeneous material not only means materials completely different from each other, but also all materials except for the same material but different physical properties such as particle size, viscosity, and concentration, different pre-treated materials, and materials that are physically and chemically identical includes materials.

The inclined portion is formed in contact with a portion of the structure from one side, and is formed of a mixed material obtained by mixing a first material and a second material in a predetermined ratio.

The inclined functional structure portion may be composed of different composition ratios by varying the mixing ratio of the first material and the second material, which are dissimilar materials, and specifically, the second material at one side of the inclined functional structure portion in contact with a part of the structure made of the first material. In the direction of the other side of the inclined functional structure part in contact with the other part of the structure composed of

The other portion of the structure is configured to be in contact with the inclined functional structure portion of the structure from the other side, and is formed of a second material that is a different material from the first material.

The structure of the present invention has an effect of preventing a sudden change in physical properties and improving the bonding characteristics between different materials by controlling the bonding surface between different materials to a slope function structure using a mixed material of different materials. In this case, the inclined functional structure part can precisely control the gradient functional structure conditions such as the thickness and shape of each composition layer by layer. Accordingly, it is possible to provide a high-functional, high-quality ceramic structure having high structural precision and combining different types of physical properties.

Hereinafter, the present invention will be described in more detail through experimental examples. The scope of the present invention is not limited to specific examples and experimental examples, and should be interpreted by the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

Experimental Example 1

As an embodiment of the present invention, the following experiment was performed to confirm the change in shrinkage according to the particle size and content (inorganic content, volume %) of zirconia and alumina included in the printing material.

Alumina particles of 0.2 μm, alumina particles of 0.5 μm, and zirconia particles of 0.2 μm were uniformly distributed in the photocurable resin to prepare photocurable ceramic slurries, respectively. It was prepared by mixing so that the content of inorganic substances (alumina, zirconia) compared to the photocurable resin was 48% to 56% by volume, and after printing using a light-curing 3D printer, the printed ceramic structure was sintered at the same time. After each sintering at 1500 °C, which is a possible temperature, the shrinkage rate of the line shrinking compared to before sintering was evaluated. The results of the above experiments are shown in FIG. 1 .

According to FIG. 1, as the inorganic material (alumina or zirconia) content increases, the sintering shrinkage of the printing material decreases.

Looking at the graph of sintering shrinkage according to the content of alumina having a particle size of 0.2 μm and alumina having a particle size of 0.5 μm, when the particle size of alumina is reduced from 0.5 μm to 0.2 μm, the overall graph of the change in sintering shrinkage according to the alumina content moves upward. appeared in the form That is, it was confirmed that as the particle size of the ceramic powder of the same type decreased, the sintering shrinkage rate increased. The sintering shrinkage ratio of the material with 0.2 μm alumina content of 52 vol% and the material with 0.5 μm alumina content of 48 vol% was about 17.5%, which was consistent with the result.

Looking at the graph in the case where the particle sizes of alumina and zirconia powder, which are different types of material, are the same, the decrease in the sintering shrinkage change graph according to the inorganic material content was different. A material with a 0.2 μm alumina content of 49 vol% and a material with a 0.2 μm zirconia content of 49 vol% had a sintering shrinkage ratio of 19%, a material with a 0.2 μm alumina content of 50 vol% and a material with a 0.2 μm zirconia content of 50 vol% It was confirmed that the phosphorus material had a sintering shrinkage rate of 18.7%.

According to the experimental results, by adjusting the particle size and inorganic content, the material having a 0.2 μm alumina content of 52 vol%, the material having the 0.5 μm alumina content of 48 vol%, the material having the 0.2 μm alumina content of 49 vol%, and 0.2 μm zirconia When preparing a material with a content of 49 vol%, a material with a 0.2 μm alumina content of 50 vol% and a material with a 0.2 μm zirconia content of 50 vol% It could be expected that problems such as peeling and cracking due to sintering shrinkage would not occur.

Experimental Example 2

Even if the sintering shrinkage rate is the same, interlayer bonding may be difficult due to differences in physical properties such as density between materials, and separation between layers may occur. In order to prevent this, the following experiment was performed to check whether the interlayer separation after manufacturing and sintering the alumina-zirconia structure in which the intermediate layer was introduced by mixing the composition of the two materials.

Alumina particles of 0.2 μm and zirconia particles of 0.2 μm were uniformly distributed in the photocurable resin to prepare photocurable ceramic slurries, respectively. It was prepared by mixing so that the content of inorganic substances (alumina, zirconia) compared to the photocurable resin was 50% by volume. In addition, two mixed slurries were prepared by mixing them so that alumina:zirconia=8:2, 2:8 composition ratio (wt%) and inorganic content was 50 vol%. A ceramic structure having an intermediate layer introduced therein was printed using an alumina slurry, a zirconia slurry, and a mixed slurry.

A slanted structure was formed by printing a single layer of alumina slurry, a mixed slurry of 8:2 (alumina: zirconia) composition, a mixed slurry of 2:8 (alumina: zirconia) composition, and a zirconia slurry in this order to a thickness of 20 µm. According to the different composition of each slurry, 100 layers were sequentially laminated and molded under conditions of photocuring for 7 seconds, 10 seconds, 17 seconds, and 20 seconds per layer, followed by printing a ceramic structure and sintering at 1500°C.

Alumina and zirconia are materials with a large difference in densities, with densities of 3.987 g/cm3 and 5.68 g/cm3, respectively. It was prepared by introducing an intermediate layer using a mixed slurry of :8. A schematic manufacturing process is shown in FIG. 2 .

In addition, the structure obtained by degreasing the inclined structure printed with four different composition slurries of the prepared alumina-zirconia structure at 650 °C was observed with an optical microscope. 2 shows the results.

In addition, the alumina slurry and the mixed slurry having the alumina:zirconia composition ratio of 8:2 and 2:8 (wt%) and the inclined structure molded body printed with the zirconia slurry were observed by scanning electron microscope (FE-SEM) for each composition. The results are shown in FIG. 3 .

In addition, the structure printed with the alumina slurry and the alumina:zirconia composition ratio of 8:2 (wt%) was sintered at 1500°C, and the interlayer interface was observed with a scanning electron microscope (FE-SEM). is shown in Figure 4.

Referring to FIG. 2, as derived in Experimental Example 1, the sintering shrinkage of the photocurable ceramic slurry containing 50% by volume of 0.2 μm alumina and 0.2 μm zirconia, respectively, is 18.7%, but it contains a large amount of alumina and alumina. (alumina:zirconia=8:2) layer and a layer containing a large amount of zirconia and zirconia (alumina:zirconia=2:8) maintain bonding after degreasing, respectively, but the alumina:zirconia=8:2 layer with rapid composition change It was confirmed that no bonding was made between the alumina:zirconia 2:8 layers and separation between the layers occurred.

In addition, referring to FIG. 3 , the internal density between the alumina slurry and the mixed slurry of alumina:zirconia composition ratio of 8:2 (wt%), the zirconia slurry and the mixed slurry of the alumina:zirconia composition ratio of 2:8 (wt%) is large. Although there is no difference, it was confirmed that the internal density difference between the mixed slurry having an alumina:zirconia composition ratio of 8:2 (wt%) and the mixed slurry having an alumina:zirconia composition ratio of 2:8 (wt%) was large, and the rapid composition change As a result, it was found that the interlayer separation occurred according to the different structural characteristics between the layers.

Therefore, it can be confirmed that the ceramic structure should be manufactured in consideration of the problem of poor adhesion and bonding due to the density difference as well as the sintering shrinkage rate of heterogeneous materials having a large density difference, and for this purpose, it is necessary to form a sloped functional structure.

In addition, referring to FIG. 4 , it was confirmed that particle growth due to sintering of alumina was reduced by mixing zirconia with alumina even though the inorganic content of the slurry was the same at 50% by volume and particles of the same size were used. Therefore, it could be expected that the sintering shrinkage rate of the structure made of the slurry in which alumina and zirconia were mixed was greater than that of the slurry of 100% by weight of alumina.

Experimental Example 3

For the introduction of the inclined functional structure, the following experiment was performed to confirm the change in the sintering shrinkage according to the mixing ratio of alumina and zirconia.

Alumina particles of 0.2 μm and zirconia particles of 0.2 μm were uniformly distributed in the photocurable resin to prepare photocurable ceramic slurries, respectively. It was prepared by mixing so that the content of inorganic substances (alumina, zirconia) compared to the photocurable resin was 50% by volume. At the same time, the alumina ceramic slurry and the zirconia ceramic slurry were mixed to prepare 10 mixed ceramic slurries of different compositions.

After printing using a photo-curing 3D printer for each composition condition, the printed ceramic structure was sintered at 1500° C., which is the simultaneous sintering temperature of alumina and zirconia, respectively, and the shrinkage of the line compared to before sintering was evaluated. The results are shown in FIG. 5 .

Referring to FIG. 5, the sintering shrinkage of the mixed slurry was approximately 20%, which was constant in almost all compositions. As confirmed in Experimental Example 1, the slurry containing 50% by volume of 0.2 μm alumina particles and the slurry containing 50% by volume of 0.2 μm zirconia particles exhibited 18.7% shrinkage, whereas the slurry mixed therewith had a higher 20% by volume. showed sintering shrinkage. Due to this, a section in which the shrinkage rate is rapidly avoided is formed, and it is expected that bonding between the composition sections after sintering is difficult.

Experimental Example 4

In order to control the difference in shrinkage between the pure composition layer and the mixed composition layer, the inorganic content of the pure alumina layer and the zirconia layer was lowered, and the following experiment was performed.

Alumina particles of 0.2 μm and zirconia particles of 0.2 μm were uniformly distributed in the photocurable resin to prepare photocurable ceramic slurries, respectively. It was prepared by mixing so that the content of inorganic substances (alumina, zirconia) compared to the photocurable resin was 50% by volume. However, since the mixed composition has a higher sintering shrinkage than the pure composition, the alumina and zirconia pure composition layer lowered the inorganic material content and set them to 46% by volume and 45% by volume, respectively. At the same time, the alumina ceramic slurry and the zirconia ceramic slurry were mixed to prepare 10 mixed ceramic slurries of different compositions.

After printing using a photo-curing 3D printer for each composition condition, the printed ceramic structure was sintered at 1500° C., which is the simultaneous sintering temperature of alumina and zirconia, respectively, and the shrinkage of the line compared to before sintering was evaluated. The results are shown in FIG. 6 .

Referring to FIG. 6 , the sintering shrinkage of the mixed slurry was approximately 20%, which was constant in almost all compositions. That is, the slurry mixed with alumina and zirconia showed a sintering shrinkage of 20% by volume regardless of the mixing ratio. In addition, the alumina and zirconia pure composition layer with lowered inorganic material filling rate was also able to match the shrinkage rate to 20% of the mixed slurry. Accordingly, it can be expected that the separation between the layers due to the difference in the shrinkage ratio between the composition layers can be prevented.

Experimental Example 5

As the sintering shrinkage rate increases, the deformation due to sintering of the 3D printed structure may increase, so it is preferable to reduce the sintering shrinkage rate. The sintering shrinkage can be reduced by increasing the inorganic content, and the difference in shrinkage with the pure composition can be reduced even in the mixed composition, so that a similar sintering shrinkage can be induced even when the same inorganic content ratio is applied. The results are shown in FIG. 7 .

Alumina particles of 0.2 μm and zirconia particles of 0.2 μm were uniformly distributed in the photocurable resin to prepare photocurable ceramic slurries, respectively. It was prepared by mixing so that the content of inorganic substances (alumina, zirconia) compared to the photocurable resin was 54% by volume. At the same time, the alumina ceramic slurry and the zirconia ceramic slurry were mixed to prepare a plurality (10 pieces) of mixed ceramic slurries of different compositions.

After printing using a photo-curing 3D printer for each composition condition, the printed ceramic structure was sintered at 1500° C., which is the simultaneous sintering temperature of alumina and zirconia, respectively, and the shrinkage of the line compared to before sintering was evaluated. The results are shown in FIG. 7 .

7, the sintering shrinkage of the mixed slurry is about 16.7% to 17.67%, there is a 1% difference between alumina and zirconia, but the difference between the mixed composition layers forming the inclined functional structure is within ±0.2%. possible was confirmed. That is, it can be expected that separation due to the difference in sintering shrinkage after sintering can be prevented by gradually adjusting the mixing composition between alumina and zirconia.

Experimental Example 6

Using the experimental results of Experimental Example 4, an alumina-zirconia ceramic structure having a gradient functional structure was designed.

Alumina particles of 0.2 μm and zirconia particles of 0.2 μm were uniformly distributed in the photocurable resin to prepare photocurable ceramic slurries, respectively. The alumina and zirconia pure layers were prepared by mixing 46 vol% and 45 vol%, respectively, and the mixed layer between the two compositions so that the content of inorganic substances (alumina, zirconia) compared to the photocurable resin was 50 vol%. A plurality of mixed ceramic slurries of different compositions were prepared by mixing the alumina ceramic slurry and the zirconia ceramic slurry. Specifically, alumina: zirconia composition ratio = 5:95, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10 (weight %), and 10 types of mixed slurries having an inorganic content of 50% by volume compared to the photocurable resin were prepared.

As shown in FIG. 8 , 12 photocurable ceramic slurries were prepared to implement a total of 12 composition gradients with a zirconia slurry, an alumina slurry, and a mixed slurry of zirconia-alumina.

In order to confirm the light curing conditions of the slurries of the 12 different compositions, the following experiment was conducted. The light curing depth for each material with different inorganic content was measured for each light irradiation time.

After applying the slurry of each composition on a transparent glass plate, a 20x12mm size shape was irradiated with 9W/m ² light at each time period, and the uncured part was washed and the cured thickness was measured. The results are shown in FIG. 9 .

As shown in FIG. 9, it was found that photocuring conditions according to each composition were different for 3D printing through photopolymerization as shown in the figure.

If the light irradiation time is longer than the required time, photocuring may occur due to light scattering, and the precision of the printed structure may be reduced. Therefore, it was determined that the light irradiation time should be set according to the thickness of one layer.

In addition, photo-curable 3D printing is a method of curing by irradiating light to a necessary area using a photo-curable ceramic slurry in which ceramic is uniformly dispersed in a photo-curable resin. Therefore, since the photocuring conditions are different depending on the physical properties such as density and light absorption of ceramic particles dispersed in the photocurable resin, the photocuring conditions of each ceramic slurry prepared to implement the gradient functional structure should be optimized for each composition. was judged

That is, it was expected that the coupling force between structures and the precision of the three-dimensional structure implementation could be optimized by controlling the light irradiation time according to each composition.

As shown in FIG. 9, the printed structure was 3D printed using the optimal photo-curing conditions obtained through the above experiment and ceramic slurries of 12 compositions. Specifically, the slurries of the 12 compositions were supplied to a photo-curing 3D printer by setting the thickness of one layer to 20 μm, and the zirconia slurry layer was a mixed slurry layer with a composition ratio of 6:95 (alumina: zirconia, wt%) for 6 seconds. Silver 6 seconds, 10:90 (alumina: zirconia, wt%) mixed slurry layer with a composition ratio of 6 seconds, 20:80 (alumina: zirconia, wt%) composition ratio of the mixed slurry layer is 6 seconds, 30:70 (alumina: The mixed slurry layer of the composition ratio of zirconia, weight %) is 7 seconds, the mixed slurry layer of the 40:60 (alumina: zirconia, weight %) composition ratio is 7 seconds, and the mixed slurry layer of the composition ratio of 50:50 (alumina: zirconia, weight %) Silver 7 seconds, 60:40 (alumina: zirconia, weight %) mixed slurry layer with a composition ratio of 6 seconds, 70:30 (alumina: zirconia, weight %) mixed slurry layer with a composition ratio of 5 seconds, 80:20 (alumina: The mixed slurry layer with a composition ratio of zirconia, weight %) was irradiated with light for 4 seconds, the mixed slurry layer with a composition ratio of 90:10 (alumina:zirconia, weight%) for 3 seconds, and the alumina slurry layer was printed by light irradiation for 2 seconds, respectively.

As a result, a scanning electron microscope (SEM) image of the printed structure and an image mapped thereto through EDX are shown in FIG. 10 .

Referring to FIG. 10 , dark red color indicates alumina and yellow green color indicates zirconia, and it was observed that the printed structure gradually changed from dark red color to light green color. That is, it was confirmed that the printed alumina-zirconia structure molded article (before sintering) having a gradient functional structure had a gradient structure in which the composition change was gradually changed. It was found that a three-dimensional structure in which a change in composition gradually forms a slope function can be implemented using a 3D printer.

Experimental Example 7

The following experiment was performed to confirm the aspect after sintering the alumina-zirconia structure to which the gradient functional structure printed in Experimental Example 4 was introduced.

The 3D-printed structure was sintered at 1500°C, which is the simultaneous sintering temperature of alumina and zirconia slurries. The results are shown in FIG. 11 .

In addition, the alumina-zirconia structure having a tilted functional structure after sintering was observed with a scanning electron microscope (SEM), and then mapped through EDX. The results are shown in Fig. 12, respectively.

In addition, the particle structure of each layer after sintering was observed with a scanning cell microscope (SEM), and the density of each layer was evaluated. The results are shown in FIGS. 13 and 14 .

As shown in FIG. 11, it was confirmed that the alumina-zirconia structure to which the inclined functional structure was introduced was well connected without interlayer separation and separation even after sintering.

In addition, as shown in FIG. 12 , it was confirmed that the composition ratio of alumina and zirconia changes inclination (gradual change) as each layer of the structure goes from the alumina layer to the zirconia layer.

Also, referring to FIG. 13 , in the case of the alumina layer, it was confirmed that the alumina particles were grown by sintering, but as the zirconia particles were mixed, the growth of the alumina particles was reduced. Therefore, the structure of this experimental example, which introduced the inclined function structure, could be connected without interlayer gaping or separation even after sintering was achieved by implementing the composition as a gradient function to gradually control the grain growth by sintering, so that the density was controlled and the shrinkage rate was the same. It was confirmed that it was because it was controllable.

Referring to FIG. 14 , it was shown that the density of the layers constituting the inclined functional structure of the structure decreased linearly from about 6 g/cm 3 to about 4 g/cm 3 , as it went from the alumina layer to the zirconia layer. That is, it was possible to gradually change the large density difference between zirconia and alumina based on the introduction of the inclined functional structure, and it was confirmed that the bonding of two types of alumina-zirconia materials was possible by relieving the residual stress between layers by sintering.

Experimental Example 8

In order to confirm that the three-dimensional shape and composition can be simultaneously controlled using 3D printing technology, an alumina-zirconia ceramic structure having a slanted functional structure inside a complex three-dimensional shape was designed and manufactured. Using the conditions of Experimental Examples 1 to 7, the bonding surface of the alumina-zirconia material was designed to have a gradient functional structure of the composition, and the 3D printer was used to control the three-dimensional shape and control the composition for realizing the inclined functional structure. proceeded.

Alumina particles of 0.2 μm and zirconia particles of 0.2 μm were uniformly distributed in the photocurable resin to prepare photocurable ceramic slurries, respectively. The pure alumina and zirconia parts were controlled to 46 vol% and 45 vol%, respectively, and the inclined functional structure part was prepared by mixing so that the content of inorganic substances (alumina, zirconia) compared to the photocurable resin was 50 vol%. A plurality of mixed ceramic slurries of different compositions were prepared by mixing the alumina ceramic slurry and the zirconia ceramic slurry. Specifically, alumina: zirconia composition ratio = 5:95, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10 (weight %), and 10 types of mixed slurries having an inorganic content of 50% by volume compared to the photocurable resin were prepared.

The zirconia slurry layer is 6 seconds and 5:95 (alumina:zirconia, wt%) composition ratio of the mixed slurry layer is 6 seconds by setting the thickness of one layer of the 12 types of slurries to 20㎛ , 10:90 (alumina: zirconia, weight %) mixed slurry layer for 6 seconds, 20:80 (alumina: zirconia, weight %) mixed slurry layer for 6 seconds, 30:70 (alumina: zirconia, weight) %) The mixed slurry layer of the composition ratio is 7 seconds, the mixed slurry layer of the 40:60 (alumina:zirconia, wt%) composition ratio is 7 seconds, and the mixed slurry layer of the 50:50 (alumina:zirconia, wt%) composition ratio is 7 seconds , 60:40 (alumina: zirconia, weight %) mixed slurry layer with a composition ratio of 6 seconds, 70:30 (alumina: zirconia, weight %) mixed slurry layer with a composition ratio of 5 seconds, 80: 20 (alumina: zirconia, weight %) The mixed slurry layer of the composition ratio is 4 seconds, the 90:10 (alumina:zirconia, wt%) mixed slurry layer is 3 seconds, and the alumina slurry layer is 2 seconds. did. Then, finally, the three-dimensional shape was modeled and the printed structure was co-sintered at 1500°C.

The manufacturing process and appearance after sintering are shown in FIGS. 15 and 16, respectively.

15 and 16, according to the present invention, it was confirmed that a heterogeneous three-dimensional ceramic structure having a tilt function structure in addition to 3D shape control can be manufactured, and the manufactured structure is a tilt function structure and printing structure By optimizing the sintering shrinkage rate and density change through material property control, it was confirmed that high-precision, high-quality products can be provided without gaping or separation of the interlayer interface even after sintering.

In comparison, as shown in FIG. 17, when it failed to match the shrinkage rate between the compositions and to gradually change the density change rate, interlayer splintering and cracks in the structure occurred, so that a sound sintered body could not be obtained.

Claims (18)

preparing a first printing material and a second printing material having a matched sintering shrinkage ratio X1 by controlling the physical properties of the first printing material and the second printing material different therefrom;
adjusting the mixing ratio of the first printing material and the second printing material having the matching sintering shrinkage ratio, so that the composition ratio of the first printing material and the second printing material has a gradient functional structure, preparing a mixed printing material;
supplying the first printing material to a 3D printer to print a part of the structure;
supplying the plurality of mixed printing materials to a 3D printer to print a part of the structure and an inclined functional structure in contact with one side;
supplying the second printing material to a 3D printer to print the other portion of the structure in contact with the inclined functional structure portion of the structure from the other side; and
Sintering the printed structure; including, wherein the sintering shrinkage ratio X2 of the plurality of mixed printing materials is in the range of ±1.5% compared to the sintering shrinkage ratio X1 of the first printing material and the second printing material. A method of manufacturing a ceramic structure.
The method of claim 1,
In the step of preparing the plurality of mixed printing materials, the mixing ratio of the first printing material and the second printing material different therefrom is adjusted so that the density of the plurality of mixed printing materials of different compositions has a gradient function structure in which the density is gradually changed. A method of manufacturing a ceramic structure having a gradient functional structure, characterized in that performed.
The method of claim 1,
The method includes, after the step of preparing a plurality of mixed printing materials, before the step of supplying a first printing material to print a part of the structure,
Controlling the physical properties of the first printing material and the second printing material so that the sintering shrinkage ratio X1 of the first printing material and the second printing material matches the sintering shrinkage ratio X2 of the plurality of mixed printing materials. A method of manufacturing a ceramic structure having a sloped functional structure.
The method of claim 1,
Controlling the physical properties of the first printing material and the second printing material is a method of manufacturing a ceramic structure having an inclined function structure, characterized in that it is performed by a method of adjusting the particle size of the ceramic powder contained in the printing material.
The method of claim 1,
Controlling the physical properties of the first printing material and the second printing material is a method of manufacturing a ceramic structure having a tilt function structure, characterized in that it is performed by a method of adjusting the inorganic content of the printing material.
The method of claim 1,
The sintering shrinkage rate X1 and X2 is a method of manufacturing a ceramic structure having a gradient function, characterized in that controlled in the range of 10% to 40%.
The method of claim 1,
The first printing material or the second printing material is a method of manufacturing a ceramic structure having a slanted functional structure, characterized in that it contains alumina or zirconia (Zirconia).
The method of claim 1,
The inorganic material content of the printing material is a method of manufacturing a ceramic structure having a slanted functional structure, characterized in that 40% by volume to 70% by volume.
The method of claim 1,
A method of manufacturing a ceramic structure having a tilted functional structure, characterized in that the particle size of the ceramic powder included in the printing material is 0.01 μm to 10 μm.
The method of claim 1,
The first printing material includes alumina, the second printing material includes zirconia, and the particle size of the alumina is 0.1 μm to 10 μm, and the particles of zirconia A method of manufacturing a ceramic structure having a sloped functional structure, characterized in that the size is 0.01 μm to 1 μm.
The method of claim 1,
The first printing material includes alumina, the second printing material includes zirconia, and the inorganic content of the first printing material is 46% by volume to 56% by volume, The method for manufacturing a ceramic structure having a gradient functional structure, characterized in that the inorganic content is 46% by volume to 54% by volume.
The method of claim 1,
The first printing material includes alumina, the second printing material includes zirconia, and the particle size of the alumina is 0.2 μm to 0.5 μm, and the particles of zirconia The size is 0.2 μm to 0.5 μm, the inorganic content of the first printing material is 46% to 56% by volume, the inorganic content of the second printing material is 46% to 54% by volume, and the plurality of mixed printing materials are The inorganic content of is 48 vol% to 54 vol%, and in the plurality of mixed printing materials, the composition ratio of alumina and zirconia varies from 0.1% to 99.9% by weight. A method for manufacturing a structure.
The method of claim 1,
supplying the first printing material to a 3D printer to print a part of the structure;
supplying the plurality of mixed printing materials to a 3D printer to print a part of the structure and an inclined functional structure in contact with one side; and
Supplying the second printing material to a 3D printer to print the other part of the structure in contact with the inclined portion of the structure from the other side;
Supplying a first printing material to a 3D printer by controlling the thickness, forming a layer constituting a part of the structure, and photocuring it (step 1);
A step of supplying a plurality of mixed printing materials to a 3D printer by sequentially controlling the thickness according to the composition ratio, forming a layer forming an inclined portion in contact with a part of the structure and photocuring it (step 2);
Supplying a second printing material by controlling the thickness to a 3D printer, forming a layer constituting the other portion of the structure in contact with the inclined portion of the structure from the other side, and photocuring it (step 3); and
A method of manufacturing a ceramic structure having a tilted functional structure, characterized in that it is carried out including; repeating the steps 1 to 3 to laminate the structure.
14. The method of claim 13,
The method for manufacturing a ceramic structure having a gradient functional structure, characterized in that it further comprises the step of washing the uncured material between the steps 1 and 2 or between the steps 2 and 3 .
14. The method of claim 13,
The thickness is a ceramic structure manufacturing method having a slope function, characterized in that the control is 1㎛ to 200㎛.
The method of claim 1,
supplying the first printing material to a 3D printer to print a part of the structure;
supplying the plurality of mixed printing materials to a 3D printer to print a part of the structure and an inclined functional structure in contact with one side; and
Supplying the second printing material to a 3D printer to print the other portion of the structure in contact with the inclined functional structure portion of the structure from the other side;
forming a first printing material part including a plurality of layers by supplying the first printing material to a 3D printer by controlling the thickness and performing additive manufacturing;
supplying a plurality of mixed printing materials to a 3D printer by sequentially controlling the thickness according to the composition ratio, and forming a slanted structure part in contact with the upper surface of the first printing material part; and
A ceramic structure having an inclined function structure, characterized in that it is carried out through; supplying a second printing material by controlling the thickness to a 3D printer, and forming a second printing material part in contact with the upper surface of the inclined structure part by lamination molding manufacturing method.
17. The method of claim 16,
The thickness is a ceramic structure manufacturing method having a slope function, characterized in that the control is 1㎛ to 200㎛.
a portion of the structure fabricated by the method of claim 1 and formed by the first printing material;
an inclined functional structure part in contact with a part of the structure at one side and formed by a plurality of mixed printing materials in which the composition ratio of the first printing material and the second printing material is inclined; and
and the other portion of the structure that is in contact with the inclined functional structure portion of the structure from the other side and is formed by the second printing material.

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