Ceramic structures

Abstract

The objective is to provide a ceramic structure in which the end of the first ceramic member is inserted into and engaged with the concave engaging portion of the second ceramic member, such that when a load is applied to the first ceramic member, the stress on the concave engaging portion of the second ceramic member does not increase significantly. [Solution] A ceramic structure comprising a first ceramic member 110 and a second ceramic member 120, wherein the first ceramic member 110 has an elongated shape, and the second ceramic member 120 has a concave engaging portion 120a, the longitudinal end of the first ceramic member 110 is inserted into and engaged with the concave engaging portion 120a of the second ceramic member 120, and the ratio of the length of the concave engaging portion 120a of the second ceramic member 120 in the direction in which the end 110a of the first ceramic member is greater than 1.00 and less than 1.20.

Description

[Technical Field]

[0001] This disclosure relates to ceramic structures. [Background technology]

[0002] Various structures with different engagement mechanisms are known. Furthermore, a variety of materials are used for the components that make up these structures.

[0003] Patent Document 1 discloses an electronic device comprising a housing, a mounting member for mounting the housing to a predetermined mounting position on a vehicle, a receiving unit provided on the housing for receiving predetermined electromagnetic waves arriving from a first direction when the housing is mounted to the mounting position, and a control unit for performing control according to the electromagnetic waves received by the receiving unit, wherein the mounting member is provided on a portion of the housing on a second direction side different from the first direction, and supports the housing from the second direction side. Patent Document 1 also discloses an electronic device in which the mounting member has a first engaging portion protruding upward from a portion of the base body into which the mounting portion is inserted, and the mounting portion has a second engaging portion provided inside the mounting portion that engages with the first engaging portion inserted inside the mounting portion. The mounting member is made of metal.

[0004] Patent Document 2 describes a fixing device mounting structure for attaching a resin fixing device for holding a mating member such as a wire harness to a molded member such as an instrument panel, wherein the resin fixing device comprises a main body portion having a predetermined height in the direction of protrusion of a columnar portion that protrudes in a plate-like manner from the surface of the molded member, and including an insertion hole portion having an elongated hole with a rectangular cross-section, oval shape, etc., formed along the direction of protrusion, and a mounting portion at the end of the main body portion in the direction of protrusion, adjacent to one side of the elongated hole in the short direction relative to the main body portion, and integrally formed with the main body portion with a thickness smaller than the height of the main body portion, and capable of placing a mating member, wherein in the insertion hole portion of the main body portion, the short direction A fixing device mounting structure is disclosed, characterized in that, of the two opposing inner wall surfaces, the main inner wall surface on the side where the aforementioned mounting portion is located has a projection formed to engage with the columnar portion of the molded member, projecting toward the main outer wall surface of the columnar portion facing the main inner wall surface, and in a mounting state in which the insertion hole portion of the main body portion is inserted into the columnar portion of the molded member, when an external force is applied to the aforementioned mounting portion in the projection direction, the main body portion is subjected to a moment based on the fulcrum at the side opposite to the aforementioned mounting portion and the starting end in the projection direction, causing the projection portion of the main inner wall surface to bite into the main outer wall surface, thereby preventing the insertion hole portion of the main body portion from coming out of the columnar portion of the molded member. The structure is made of resin. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-157100 [Patent Document 2] Japanese Patent Publication No. 2023-098216 [Overview of the project] [Problems that the invention aims to solve]

[0006] Conventionally, in a structure in which the end of a first member is inserted into and engaged with a concave engagement portion of a second member, when a load is applied to the first member, stress concentrates in the concave engagement portion of the second member, making it prone to damage and deformation at the concave engagement portion.

[0007] The present disclosure aims to provide a ceramic structure in which the end of the first ceramic member is inserted into and engaged with the concave engaging portion of the second ceramic member, such that when a load is applied to the first ceramic member, the stress on the concave engaging portion of the second ceramic member does not increase significantly. [Means for solving the problem]

[0008] In this disclosure, we investigated a ceramic structure in which the end of a first ceramic member is inserted into and engaged with a concave engaging portion of a second ceramic member, focusing on the shape of the engaging portion. As a result, we found that by controlling the clearance (for example, the ratio of the length of the concave engaging portion of the second member in at least one direction to the length of the end of the first member in that direction), the stress on the concave engaging portion of the second ceramic member does not increase significantly when a load is applied to the first ceramic member in that direction.

[0009] In other words, the present invention is as described in the claims, and the gist of this disclosure is as follows:

[0010] [1] Having a first ceramic member and a second ceramic member, The first ceramic member has an elongated shape, and the second ceramic member has a concave engaging portion. The longitudinal end of the first ceramic member is inserted into and engaged with the concave engaging portion of the second ceramic member, and The ratio of the length of the concave engaging portion of the second ceramic member in the direction described above to the length of the end portion of the first ceramic member in the direction described above is greater than 1.00 and less than 1.20. Ceramic structure. [2] The ceramic structure according to [1], wherein the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the longitudinal length of the first ceramic member is 0.05 or more. [3] The ceramic structure according to [1] or [2] above, wherein the concave engaging portion is in the shape of a rectangular parallelepiped. [4] A ceramic structure according to any one of [1] to [3] above, wherein the above ratio is 1.02 times or more and 1.16 times or less. [5] The end of the first ceramic member has a convex engaging portion, The concave engagement portion of the second ceramic member described above has a fixing portion, and The convex engaging portion of the first ceramic member is inserted into and engaged with the fixing portion of the second ceramic member. A ceramic structure as described in any one of the above [1] to [4]. [6] The ratio of the length of the fixing portion of the second ceramic member in the direction described above to the length of the convex engaging portion of the first ceramic member in at least one direction is greater than 1.00 and less than 1.20. The ceramic structure described in [5] above. [7] A ceramic structure according to any one of [1] to [6] above, wherein the bulk modulus of at least one of the first ceramic member and the second ceramic member is 100 GPa or more and 280 GPa or less, and the yield strength is 3000 MPa or more and 50000 MPa or less. [8] The ceramic structure according to any one of [1] to [7] above, wherein the total light transmittance at a thickness of 1 mm of at least one of the first ceramic member and the second ceramic member is 50% or more. [9] The ceramic structure according to any one of [1] to [8] above, wherein the three-point bending strength of at least one of the first ceramic member and the second ceramic member is 700 MPa or more.

[10] The ceramic structure according to any one of [1] to [9], wherein at least one of the first ceramic member and the second ceramic member contains zirconia.

Advantages of the Invention

[0011] According to the present disclosure, when a load is applied to the first ceramic member, a ceramic structure can be provided in which the end portion of the first ceramic member is inserted into and engaged with the concave engaging portion of the second ceramic member, and the stress received by the concave engaging portion of the second ceramic member does not increase significantly.

Brief Description of the Drawings

[0012] [Figure 1] FIG. 1 is a schematic diagram for explaining the ceramic structure of the present embodiment (FIG. 1(A): top view of the ceramic structure, FIG. 1(B): cross-sectional view of the ceramic structure (A-A cross-section), FIG. 1(C): cross-sectional view of the ceramic structure (B-B cross-section)). [Figure 2] FIG. 2 is a schematic diagram for explaining the first ceramic member and the second ceramic member of the ceramic structure of the present embodiment. [Figure 3] FIG. 3 is a schematic diagram for explaining the ceramic structure of the present embodiment (FIG. 3(A): top view of the ceramic structure, FIG. 3(B): cross-sectional view of the ceramic structure (C-C cross-section)). [Figure 4] FIG. 4 is a schematic diagram for explaining the first ceramic member and the second ceramic member of the ceramic structure of the present embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the structure used in the simulation in Example 1 and Comparative Example 1. [[ID=2,8]] [Figure 6] FIG. 6 is a schematic diagram showing the structure used in the simulation in Comparative Example 1 and Comparative Example 2. [Figure 7] FIG. 7 is a schematic diagram showing the structure used in the simulation in Example 2, Comparative Example 3, Comparative Example 5 and Comparative Example 7. [Figure 8] Figure 8 is a schematic diagram showing the structures used in the simulations for Comparative Example 2, Reference Example 4, Reference Example 6, and Reference Example 8. [Modes for carrying out the invention]

[0013] The embodiments of this disclosure will be described in detail below. However, this disclosure is not limited to the embodiments described below and can be implemented in various modifications within the scope of the gist of this disclosure. In addition, the same elements will be denoted by the same reference numerals in the description of the drawings, and redundant descriptions will be omitted. Furthermore, this disclosure will include any combination of each configuration and parameter disclosed herein, as well as any combination of the upper and lower limits of the values ​​disclosed herein.

[0014] Ceramic structures The ceramic structure of this embodiment is It has a first ceramic member and a second ceramic member, The first ceramic member has an elongated shape, and the second ceramic member has a concave engaging portion. The longitudinal end of the first ceramic member is inserted into and engaged with the concave engaging portion of the second ceramic member, and The ratio of the length of the concave engaging portion of the second ceramic member in the direction described above to the length of the end portion of the first ceramic member in the direction described above is greater than 1.00 and less than 1.20.

[0015] In this embodiment of the ceramic structure, in which the end of the first ceramic member, particularly the longitudinal end of the first ceramic member, is inserted into and engaged with the concave engaging portion of the second ceramic member, reducing the clearance between the end and the concave engaging portion prevents a significant increase in stress on the concave engaging portion of the second ceramic member when a load is applied to the first ceramic member, particularly when the load is applied in a specific direction at the end of the first ceramic member, specifically, for example, in at least one of the above directions.

[0016] The disclosers have found that, in a structure in which the end of a first member is inserted into and engaged with a concave engaging portion of a second member, ceramic materials, which have a high bulk modulus and yield strength, exhibit different behavior with respect to "the clearance width of the concave engaging portion" and "the maximum principal stress received by the second member when a load is applied to the first member." Specifically, when a load is applied to the first member, for structures made of other materials, reducing the clearance width significantly increases the maximum principal stress received by the second member, whereas for structures made of ceramics, reducing the clearance width suppresses the increase in the maximum principal stress received by the second member compared to other materials.

[0017] Based on this knowledge, we conceived of the above-mentioned ceramic structure.

[0018] Although not limited to theory, in the above ceramic structure, the structure is made of ceramics, which are materials with high bulk modulus and yield strength. As a result, when a load is applied to the first ceramic member, the deformation of the first ceramic member is small. Therefore, by reducing the clearance width of the concave engagement portion, the stress received by the second ceramic member is distributed within the concave engagement portion, stress concentration is suppressed, and as a result, the increase in stress received by the concave engagement portion of the second ceramic member is suppressed compared to other materials.

[0019] Figure 1 is a schematic diagram showing one embodiment of the ceramic structure of this embodiment, but is not limited to this case. Figure 1(A) is a top view of the ceramic structure 10, Figure 1(B) is a cross-sectional view (AA section) of the ceramic structure 10, and Figure 1(C) is a cross-sectional view (BB section) of the ceramic structure.

[0020] The ceramic structure 10 shown in Figure 1 comprises a first ceramic member 110 and a second ceramic member 120. The first ceramic member 110 has an elongated shape, particularly a plate-like shape. The second ceramic member 120 has a concave engaging portion 120a.

[0021] In this embodiment, "long shape" refers to a shape whose length in the longitudinal direction is longer than the length in any direction perpendicular to this longitudinal direction, and is not particularly limited as long as the longitudinal direction and the short direction can be distinguished, and includes, for example, cylindrical, prismatic, plate-shaped, etc. Typically, in a long shape, the length in the longitudinal direction may be 1.2 times or more, 1.5 times or more, 2.0 times or more, 3.0 times or more, 4.0 times or more, or 5.0 times or more, and may be 1000 times or less, 500 times or less, 100 times or less, 80 times or less, 60 times or less, 40 times or less, 20 times or less, or 10 times or less. The above ratios may be between 1.2 and 1000 times, 1.2 and 500 times, 1.2 and 100 times, 1.5 and 80 times, 2.0 and 60 times, 3.0 and 40 times, 4.0 and 20 times, or 5.0 and 10 times.

[0022] Furthermore, the "long shape" may be a plate shape, in which case the length in the thickness direction of the plate shape may be 1 / 1000 or more, 1 / 500 or more, 1 / 100 or more, 1 / 50 or more, 1 / 30 or more, or 1 / 20 or more of the thickness in the longitudinal direction, and may be 1 / 3 or less, 1 / 5 or less, 1 / 7 or less, or 1 / 10 or less. Also, the above ratios may be 1 / 1000 or more and 1 / 3 or less, 1 / 500 or more and 1 / 3 or less, 1 / 100 or more and 1 / 3 or less, 1 / 50 or more and 1 / 5 or less, 1 / 30 or more and 1 / 7 or less, or 1 / 20 or more and 1 / 10 or less.

[0023] The ceramic structure 10 is configured such that the longitudinal end 110a of the first ceramic member is inserted into and engaged with the concave engaging portion 120a of the second ceramic member 120. In the ceramic structure 10, the ratio of the length of the concave engaging portion 120a of the second ceramic member 120 in at least one direction to the length of the end 110a of the first ceramic member in that direction is greater than 1.00 and less than 1.20. In a ceramic structure made of ceramics, when the above ratio is within a small predetermined range, the increase in stress received by the concave engaging portion of the second ceramic member when a load is applied to the first ceramic member in that direction is suppressed compared to other materials. Therefore, "at least one direction of the end of the first ceramic member" may preferably be the direction in which a load is applied to the first ceramic member. Also, if the "long shape" is a plate shape, "at least one direction of the end of the first ceramic member" may be the thickness direction.

[0024] In the ceramic structure of this embodiment, the ratio of the length of the concave engaging portion of the second ceramic member in the direction described above to the length of the end of the first ceramic member in at least one direction is preferably more than 1.00 times and less than 1.20 times, and between 1.02 times and 1.16 times. The above ratio may be 1.02 times or more, 1.04 times or more, or 1.05 times or more, and may be 1.16 times or less, 1.14 times or less, 1.12 times or less, or 1.10 times or less, and examples include 1.04 times or more and 1.14 times or less, or 1.05 times or more and 1.12 times or less.

[0025] Figure 2 is a schematic diagram showing one embodiment of the ceramic structure of this embodiment, specifically the first ceramic member and the second ceramic member, but is not limited to this case. Figure 2(A) shows the first ceramic member, and Figure 2(B) shows the second ceramic member.

[0026] The first ceramic member 110 shown in Figure 2(A) has a longitudinal end 110a. The length 110b of the end of the first ceramic member in at least one direction is the length from one surface to the other in that direction of the end 110a of the first ceramic member.

[0027] The second ceramic member 120 shown in Figure 2(B) has a concave engaging portion 120a. The length 120b of the concave engaging portion of the second ceramic member 120 in at least one direction is the length from one inner wall to the other inner wall of the concave engaging portion 120a in that direction.

[0028] In this embodiment, the ratio of the length 120b of the concave engagement portion of the second ceramic member 120 in the direction described above to the length 110b of the longitudinal end of the first ceramic member in the direction described above is greater than 1.00 and less than 1.20. In the ceramic structure 10 of this embodiment, when the above ratio is close to 1.00, that is, when the clearance width is small, the increase in stress experienced by the second ceramic member is suppressed compared to other materials.

[0029] In the ceramic structure of this embodiment, the concave engaging portion of the second ceramic member is not particularly limited, but may be in the shape of a rectangular parallelepiped.

[0030] As shown in Figure 1 above, the second ceramic member 120 has a rectangular parallelepiped-shaped concave engaging portion 120a, as illustrated in the AA cross section of the ceramic structure 10 (Figure 1(B)) and the BB cross section of the ceramic structure 10 (Figure 1(C)).

[0031] In this embodiment, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the longitudinal length of the first ceramic member is not particularly limited, but may be 0.05 or more, 0.10 or more, or 0.15 or more, and may be 0.30 or less, 0.25 or less, or 0.20 or less. The ratio may be 0.05 or more and 0.30 or less, or 0.10 or more and 0.25 or less. By setting the ratio within the above numerical range, the increase in stress received by the concave engaging portion of the second ceramic member when a load is applied to the first ceramic member can be further suppressed.

[0032] Furthermore, the ratio of the longitudinal length of the end of the first ceramic member that is inserted into and engaged with the second ceramic member to the length of the end of the first ceramic member in at least one direction is not particularly limited, but may be 1.5 or more, 1.8 or more, or 2.0 or more, and may be 5.0 or less, or 4.0 or less. The ratio may be 1.5 or more and 5.0 or less, or 2.0 or more and 4.0 or less. By setting the ratio within the above numerical range, the increase in stress received by the concave engaging portion of the second ceramic member when a load is applied to the first ceramic member can be further suppressed.

[0033] In Figure 1(A) above, the longitudinal length 110e of the first ceramic member is the length from one surface to the other in the longitudinal direction of the first ceramic member 110. Furthermore, the longitudinal length 110f of the end of the first ceramic member that is inserted into and engaged with the second ceramic member is the length from the surface of the end 110a of the first ceramic member to the surface 120e of the concave engaging portion of the second ceramic member in the longitudinal direction.

[0034] 《Ceramic structure; embodiment in which the first ceramic member has a convex engaging portion》 In addition to the structure described above, the ceramic structure of this embodiment may have the following structure: The end of the first ceramic member has a convex engaging portion, The concave engagement portion of the second ceramic member has a fixing portion, The convex engaging portion of the first ceramic member is inserted into and engaged with the fixing portion of the second ceramic member.

[0035] Figure 3 is a schematic diagram showing one embodiment of the ceramic structure of this embodiment, but is not limited to this case. Figure 3(A) is a top view of the ceramic structure 10, and Figure 3(B) is a cross-sectional view (CC section) of the ceramic structure 10.

[0036] The ceramic structure 10 shown in Figure 3 comprises a first ceramic member 110 and a second ceramic member 120. The first ceramic member 110 has an elongated shape, particularly a plate-like shape. The longitudinal end 110a of the first ceramic member has a convex engaging portion 110c. The second ceramic member 120 has a concave engaging portion 120a, and the concave engaging portion 120a has a fixing portion 120c. The convex engaging portion 110c of the first ceramic member 110 is inserted into and engaged with the fixing portion 120c of the second ceramic member 120. Preferably, the ratio of the length of the fixing portion 120c of the second ceramic member 120 in at least one direction to the length of the convex engaging portion 110c of the first ceramic member 110 in that direction is greater than 1.00 and less than 1.20.

[0037] Compared to a ceramic structure in which the longitudinal end 110a of the first ceramic member is inserted into and engaged with the concave engaging portion 120a of the second ceramic member 120, in a ceramic structure in which the end 110a of the first ceramic member is inserted into and engaged with the concave engaging portion 120a of the second ceramic member 120, and the convex engaging portion 110c of the first ceramic member 110 is inserted into and engaged with the fixing portion 120c of the second ceramic member 120, the stress received by the second ceramic member can be better distributed when a load in this direction is applied to the first ceramic member. As a result, the increase in stress received by the concave engaging portion of the second ceramic member can be better suppressed, and furthermore, the stress received by the concave engaging portion of the second ceramic member can be reduced.

[0038] In the ceramic structure of this embodiment, the ratio of the length of the fixing portion of the second ceramic member in the direction described above to the length of the convex engaging portion of the first ceramic member in at least one direction is not particularly limited, but is preferably greater than 1.00 and less than 1.20, and more preferably 1.02 or more and 1.18 or less. The above ratio may be 1.02 or more, 1.04 or more, or 1.05 or more, and may be less than 1.20, 1.19 or less, 1.18 or less, or 1.17 or less, and examples include 1.04 or more and 1.18 or less, or 1.05 or more and 1.17 or less.

[0039] Figure 4(A) is a schematic diagram showing one embodiment of the first ceramic member in a configuration in which the first ceramic member has a convex engaging portion, but is not limited to this case.

[0040] The first ceramic member 110 shown in Figure 4(A) has a longitudinal end 110a, and the end 110a of the first ceramic member has a convex engaging portion 110c. The length 110b of the end of the first ceramic member in at least one direction is the length from one end to the other of the end 110a of the first ceramic member in that direction. The length 110d of the convex engaging portion of the first ceramic member in at least one direction is the length from one surface to the other of the convex engaging portion 110c in that direction.

[0041] Figure 4(B) is a schematic diagram showing one embodiment of the second ceramic member in the ceramic structure of this embodiment, in which the first ceramic member has a convex engaging portion, but is not limited to this case.

[0042] The second ceramic member 120 shown in Figure 4(B) has a concave engaging portion 120a, and the concave engaging portion 120a has a fixing portion 120c. The length 120b of the concave engaging portion of the second ceramic member 120 in at least one direction is the length from the inner wall of one end of the concave engaging portion 120a to the inner wall of the other end in that direction. The length 120d of the fixing portion of the second ceramic member in at least one direction is the length from the inner wall of one end of the fixing portion 120c to the inner wall of the other end in that direction.

[0043] In this embodiment, the ratio of the length 120b of the concave engaging portion of the second ceramic member 120 in this direction to the length 110b of the end of the first ceramic member in at least one direction is greater than 1.00 and less than 1.20, and the ratio of the length of the fixing portion of the second ceramic member in this direction to the length of the convex engaging portion of the first ceramic member in at least one direction is greater than 1.00 and less than 1.20. As a result, when a load in this direction is applied to the first ceramic member, the stress can be better distributed, thereby mitigating the stress on the concave engaging portion of the second ceramic member.

[0044] In this embodiment, the ratio of the longitudinal length of the convex engaging portion of the first ceramic member, which is inserted into and engaged with the fixing portion of the second ceramic member, to the longitudinal length of the first ceramic member is not particularly limited, but may be 0.02 or more, or 0.03 or more, and may be 0.20 or less, 0.10 or less, or 0.05 or less. The ratio may be 0.02 or more and 0.20 or less, or 0.02 or more and 0.10 or less. By setting the ratio within the above numerical range, the increase in stress received by the concave engaging portion of the second ceramic member when a load is applied to the first ceramic member can be further suppressed.

[0045] Furthermore, the ratio of the length in the longitudinal direction of the convex engaging portion of the first ceramic member, which is inserted into and engaged with the second ceramic member, to the length in at least one direction of the convex engaging portion of the first ceramic member is not particularly limited, but may be 0.50 or more, 0.80 or more, or 1.0 or more, and may be 3.0 or less, 2.0 or less, or 1.5 or less. Examples of the ratio include 0.50 or more and 3.0 or less, or 0.80 or more and 2.0 or less. By setting the ratio within the above numerical range, the increase in stress received by the concave engaging portion of the second ceramic member when a load is applied to the first ceramic member can be further suppressed.

[0046] The longitudinal length 110g of the convex engaging portion of the first ceramic member, which is inserted into and engaged with the fixing portion of the second ceramic member, is the length from the surface 110a of the convex engaging portion of the first ceramic member to the surface 120f of the fixing portion of the second ceramic member, in the longitudinal direction.

[0047] In the ceramic structure of this embodiment, the convex engaging portion at the end of the first ceramic member may have rounded corners in a plan view, and the entire end in at least one direction of the end may be curved.

[0048] In the ceramic structure of this embodiment, there may be multiple convex engaging portions at the end of the first ceramic member, and the structure may include two to four such convex engaging portions.

[0049] Ceramic Structures; Components The following sections will describe the various components of the ceramic structure.

[0050] The ceramic structure comprises a first ceramic member and a second ceramic member.

[0051] <First ceramic component> (Material of the first ceramic component) The material of the first ceramic member is not particularly limited, but any ceramic can be used. Specifically, oxide ceramics, nitride ceramics, carbide ceramics, boride ceramics, or combinations thereof can be used.

[0052] Examples of oxide ceramics include, but are not limited to, zirconia, alumina, titanium oxide, and tungsten oxide. Examples of nitride ceramics include, but are not limited to, aluminum nitride and titanium nitride. Examples of carbide ceramics include, but are not limited to, silicon carbide and tungsten carbide. Examples of boride ceramics include, but are not limited to, aluminum boride and yttrium boride. The material of the first ceramic member is not particularly limited, but preferably includes oxide ceramics, such as zirconia (ZrO2), alumina (Al2O3), titanium oxide (TiO2), ceria (CeO2), silica (SiO2), magnesia (MgO), tin oxide (SnO2), and mullite (Al6O2). 13One or more selected from the group consisting of Si2) and barium titanate (BaTiO3), further one or more selected from the group consisting of zirconia, alumina and titanium oxide, still further preferably including zirconia, and still more preferably being zirconia.

[0053] The zirconia may be zirconia in which a stabilizing element is dissolved, preferably zirconia in which yttrium is dissolved, more preferably zirconia in which 2 mol% or more and 4 mol% or less of yttrium is dissolved in terms of Y2O3. Further, examples of the zirconia include zirconia in which yttrium and lanthanum are dissolved, and zirconia in which 2 mol% or more and 4 mol% or less of yttrium in terms of Y2O3 and 3 mol% or more and 5 mol% or less of lanthanum in terms of La2O3 are dissolved.

[0054] (Density of the first ceramic member) The density of the first ceramic member is 6.00 g / cm 3 or more and 6.20 g / cm 3 or less. The above density may be, for example, 6.05 g / cm 3 or more, 6.08 g / cm 3 or more or 6.10 g / cm 3 or more, and may be 6.18 g / cm 3 or less or 6.15 g / cm 3 or less, and may be 6.05 g / cm 3 or more and 6.18 g / cm 3 or less, or 6.08 g / cm 3 or more and 6.15 g / cm 3 or less. The above density can be determined by a bulk density test according to JIS R1634:1998.

[0055] (Young's modulus of the first ceramic member) The Young's modulus of the first ceramic member is typically 150 GPa or more and 250 GPa or less. This Young's modulus may be, for example, 170 GPa or more, 190 GPa or more, 195 GPa or more, or 200 GPa or more, or 250 GPa or less, 230 GPa or less, or 210 GPa or less. Examples include 170 GPa or more and 230 GPa or less, 190 GPa or more and 230 GPa or less, or 200 GPa or more and 210 GPa or less. This Young's modulus can be determined by a static modulus test in accordance with JIS R1602:1995.

[0056] (Poisson's ratio of the first ceramic component) The Poisson's ratio of the first ceramic member is typically between 0.25 and 0.35. The above Poisson's ratio may also be, for example, 0.28 or higher, or 0.30 or higher, or 0.34 or lower, or 0.32 or lower. Examples include 0.28 to 0.34 or 0.30 to 0.32. The above Poisson's ratio can be determined by ultrasonic pulse testing in accordance with JIS R1602:1995.

[0057] (Bulk modulus of the first ceramic component) The bulk modulus of the first ceramic member is preferably 100 GPa or more and 280 GPa or less. The above bulk modulus may be, for example, 110 GPa or more, 130 GPa or more, or 150 GPa or more, or 250 GPa or less, 230 GPa or less, or 210 GPa or less, and is preferably 110 GPa or more and 250 GPa or less, and more preferably 130 GPa or more and 230 GPa or less. The bulk modulus (K) of the first ceramic member is derived from the following formula using the Young's modulus (E) and Poisson's ratio (ν) of the first ceramic member. K = E / 3(1-2ν)

[0058] (Shear modulus of the first ceramic component) The shear modulus of the first ceramic member is said to be between 55 GPa and 100 GPa. The above shear modulus may be, for example, 60 GPa or more, 65 GPa or more, or 70 GPa or more, or 95 GPa or less, 90 GPa or less, or 85 GPa or less, and examples include 60 GPa or more and 95 GPa or less, or 65 GPa or more and 90 GPa or less. The shear modulus (G) of the first ceramic member is derived from the following formula using the Young's modulus (E) and Poisson's ratio (ν) of the first ceramic member. G = E / 2(1+ν)

[0059] (Yield strength of the first ceramic) The yield strength of the first ceramic member is preferably 3000 MPa or more and 50000 MPa or less. The above yield strength may be, for example, 3500 MPa or more, 3800 MPa or more, or 4000 MPa or more, or 30000 MPa or less, 10000 MPa or less, or 8000 MPa or less, and is preferably 3500 MPa or more and 30000 MPa or less, and more preferably 3800 MPa or more and 8000 MPa or less. The above yield strength can be determined by a tensile test in accordance with JIS R1606:1995.

[0060] (Total light transmittance of the first ceramic component) The total light transmittance of the first ceramic member is preferably 50% or more. The above total light transmittance is preferably 50% or more, 55% or more, even more preferably 58% or more, and even more preferably 60% or more, as this facilitates application to dental members. There is no particular upper limit, but for example, the total light transmittance may be 80% or less, 75% or less, or 70% or less. Examples of the above total light transmittance include 50% to 80%, 55% to 80%, 58% to 75%, or 60% to 70%. The above total light transmittance can be measured in accordance with JIS K 7361-1:1997, using a disc-shaped sintered body with a sample thickness of 1 mm and a surface roughness Ra ≤ 0.02 μm on both sides as the measurement sample, and using a haze meter equipped with a D65 light source (for example, haze meter NDH4000, manufactured by Nippon Denshoku Co., Ltd.) as the measurement device.

[0061] (Three-point bending strength of the first ceramic component) The three-point bending strength of the first ceramic member is preferably 700 MPa or more and 1200 MPa or less. The above three-point bending strength may be, for example, 750 MPa or more, 800 MPa or more, or 830 MPa or more, or 1100 MPa or less, 1050 MPa or less, or 1000 MPa or less, and examples include 750 MPa or more and 1100 MPa or less, 800 MPa or more and 1050 MPa or less, or 830 MPa or more and 1000 MPa or less. The above three-point bending strength can be determined by a three-point bending strength test in accordance with JIS R 1601:2008, with a support distance of 30 mm and a load applied in the horizontal direction to the measurement sample. Prior to measurement, the measurement sample should be in the shape of a column with a width of 4 mm, a thickness of 3 mm, and a length of 45 mm.

[0062] The first ceramic member preferably has a bulk modulus of 100 GPa or more and 280 GPa or less, and a yield strength of 3000 MPa or more and 50000 MPa or less, and more preferably has a bulk modulus of 130 GPa or more and 230 GPa or less, and a yield strength of 3800 MPa or more and 8000 MPa or less. By setting the values ​​within the above range, it becomes easier to suppress the increase in stress experienced by the concave engagement portion of the second ceramic member when a load is applied to the first ceramic member.

[0063] The first ceramic component can be manufactured by molding raw material powder and then sintering the resulting molded body.

[0064] The method for forming the first ceramic member can be, for example, by forming the raw material powder constituting the first ceramic member by uniaxial press molding, cold isostatic press molding (CIP molding), casting, extrusion molding, injection molding, sheet molding, etc., but is not limited to these cases.

[0065] The method for sintering the first ceramic member is arbitrary. Examples of sintering methods include one or more selected from the group consisting of atmospheric pressure sintering, pressure sintering, and vacuum sintering, with at least one of atmospheric pressure sintering and pressure sintering, and more preferably atmospheric pressure sintering and pressure sintering. When a binder is added to the raw material powder constituting the first ceramic member, degreasing may be performed before sintering. The binder may be, for example, a binder that can be used for granulation and molding of ceramics, and specifically may be an organic binder.

[0066] The first ceramic member is not particularly limited, but can be manufactured by the following method. First, the raw material powder of the ceramics constituting the first ceramic member, a solvent, and an organic binder are mixed, and the resulting mixture is injection molded to form an injection molded body having a desired shape. Next, the injection molded body is degreased and sintered by pressure sintering to obtain the first ceramic member.

[0067] <Second ceramic component> For the material, density, Young's modulus, Poisson's ratio, bulk modulus, shear modulus, yield strength, total light transmittance, and three-point bending strength of the second ceramic member, refer to the description in "<First Ceramic Member>" above. Furthermore, for the molding and sintering methods of the second ceramic member, refer to the description in "<First Ceramic Member>" above.

[0068] The first ceramic member and the second ceramic member may be made of different materials, but it is preferable that they be made of the same material. It is preferable that at least one of the first ceramic member and the second ceramic member contains zirconia, and it is even more preferable that both the first and second ceramic members contain zirconia. Furthermore, it is preferable that both the first and second ceramic members have a bulk modulus of 100 GPa or more and 280 GPa or less, and a yield strength of 3000 MPa or more and 50000 MPa or less, and it is even more preferable that they have a bulk modulus of 130 GPa or more and 230 GPa or less, and a yield strength of 3800 MPa or more and 8000 MPa or less.

[0069] Applications of ceramic structures, etc. The applications of ceramic structures are not particularly limited, but they can be applied to conventional applications of ceramic structures, such as structural members, optical members, dental members, etc. Furthermore, they can be applied to decorative items, watches, casings and other accessories where durability is required, and exterior components for portable electronic devices such as mobile phones. [Examples]

[0070] The present disclosure will be further described with reference to the following embodiments, but the scope of the present disclosure is not limited to these embodiments.

[0071] Example 1: (When the first ceramic member does not have a convex engaging portion) Simulations were conducted using the structure shown in Figure 5 for zirconia (ZrO2) which has the following physical properties as a ceramic. Density: 6.08g / cm 3 Young's modulus: 200 GPa Poisson's ratio: 0.31 Bulk modulus: 175.0 GPa Shear modulus: 76.3 GPa Yield strength: 4000 MPa Total light transmittance: 62% 3-point bending strength: 850 MPa

[0072] Finite element analysis (software name: Ansys Workbench Mechanical 2023R2, manufactured by ANSYS) was used for the simulation, under the following conditions. Formulation: Penalty method Small slippage: OFF Vertical stiffness coefficient: 0.01 Stabilization damping coefficient: 1 Coefficient of friction: 0.2 Behavior: Asymmetric Contact adjustment: No gap insertion.

[0073] For the simulation, a load of 50,000 N was applied to a plate-shaped member (corresponding to the first ceramic member) at a point of force application with a length of 100 mm and a width of 5 mm, 61.7 mm from one end of the first ceramic member. The maximum principal stress experienced at the concave engagement portion of the member with a concave engagement portion (corresponding to the second ceramic member) was calculated. The zirconia parameters used in the simulation were density, Young's modulus, Poisson's ratio, bulk modulus, shear modulus, and yield strength. The dimensions of the structure shown in Figure 5 and the maximum principal stress are shown in Table 1.

[0074] In the structure shown in Figure 5, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the longitudinal length of the first ceramic member was 0.12 (24 mm / 200 mm). Furthermore, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the thickness length of the end of the first ceramic member was 2.40 (24 mm / 10 mm).

[0075] Comparative Example 1 The simulation was performed in the same manner as in Example 1, except that the structure shown in Figure 6 was used instead of the structure shown in Figure 5. The dimensions and maximum principal stress of the structure shown in Figure 6 are as shown in Table 1.

[0076] In the structure shown in Figure 6, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the longitudinal length of the first ceramic member was 0.12 (24 mm / 200 mm). Furthermore, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the thickness length of the end of the first ceramic member was 2.40 (24 mm / 10 mm).

[0077] (Reference Examples 1 and 2) Instead of ZrO2 as a ceramic, acrylonitrile-butadiene-styrene resin (ABS) with the following physical properties as a non-ceramic material (resin material) was used for the structures shown in Figure 5 (Reference Example 1) and Figure 6 (Reference Example 2), and simulations were performed using the same method as in Example 1. The dimensions and maximum principal stresses of each structure are shown in Table 1. The load used in the simulation was 5,000 N. Density: 1.03g / cm 3 Young's modulus: 1.63 GPa Poisson's ratio: 0.41 Bulk modulus: 3.0 GPa Shear modulus: 0.6 GPa Yield strength: 27 MPa

[0078] [Table 1]

[0079] Table 1 shows the evaluation results for structures without convex engaging portions. In structures made of resin material, when the ratio of the thickness direction length of the concave engaging portion of the second member to the thickness direction length of the end of the first member is reduced, specifically when the above ratio is changed from 1.20 times to 1.10 times, the maximum principal stress experienced by the member with the concave engaging portion increased significantly from 149.5 MPa to 339.8 MPa (the increase rate of the maximum principal stress was 127% (339.8 MPa / 149.5 MPa × 100 - 100 [%])). This means that the maximum principal stress increased significantly by reducing the clearance width (setting the above ratio to more than 1.00 times and less than 1.20 times).

[0080] On the other hand, in ceramic structures made of ceramics, when the above ratio was reduced, that is, when the clearance width of the concave engagement was reduced, specifically when the above ratio was changed from 1.20 times to 1.10 times, the maximum principal stress experienced by the member having the concave engagement portion only changed from 420.3 MPa to 521.4 MPa (the increase rate of the maximum principal stress was 24% (521.4 MPa / 420.3 MPa × 100 - 100 [%])). This means that when the clearance width was reduced (the above ratio was set to more than 1.00 times and less than 1.20 times), the maximum principal stress did not increase significantly, and the increase in the maximum principal stress was suppressed compared to structures made of resin material.

[0081] Example 2: When the first ceramic member has a convex engaging portion. The simulation was performed in the same manner as in Example 1, except that the structure shown in Figure 7 was used instead of the structure shown in Figure 5, and the load was applied at a position 61.7 mm from one end that did not have a convex engaging portion. The dimensions of the structure shown in Figure 7 and the maximum principal stress are as shown in Table 2.

[0082] In the structure shown in Figure 7, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the longitudinal length of the first ceramic member was 0.15 (31 mm / 207 mm). Furthermore, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the thickness length of the end of the first ceramic member was 3.10 (31 mm / 10 mm).

[0083] Furthermore, in the structure shown in Figure 7, the ratio of the longitudinal length of the convex engaging portion of the first ceramic member, which is inserted into and engaged with the fixing portion of the second ceramic member, to the longitudinal length of the first ceramic member was 0.031 (6.5 mm / 207 mm). Also, the ratio of the longitudinal length of the convex engaging portion of the first ceramic member, which is inserted into and engaged with the second ceramic member, to the thickness length of the convex engaging portion of the first ceramic member was 1.08 (6.5 mm / 6 mm).

[0084] Comparative Example 2 The simulation was performed in the same manner as in Example 1, except that the structure shown in Figure 8 was used instead of the structure shown in Figure 5. The dimensions and maximum principal stress of the structure shown in Figure 8 are as shown in Table 2.

[0085] In the structure shown in Figure 8, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the longitudinal length of the first ceramic member was 0.15 (31 mm / 207 mm). Furthermore, the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the thickness length of the end of the first ceramic member was 3.10 (31 mm / 10 mm).

[0086] Furthermore, in the structure shown in Figure 8, the ratio of the longitudinal length of the convex engaging portion of the first ceramic member, which is inserted into and engaged with the fixing portion of the second ceramic member, to the longitudinal length of the first ceramic member was 0.031 (6.5 mm / 207 mm). Also, the ratio of the longitudinal length of the convex engaging portion of the first ceramic member, which is inserted into and engaged with the second ceramic member, to the thickness length of the convex engaging portion of the first ceramic member was 1.08 (6.5 mm / 6 mm).

[0087] (Reference Examples 3 and 4) Instead of ZrO2 as a ceramic, ABS resin (with the same physical properties as in Reference Examples 1 and 2) was used as a non-ceramic material, and simulations were performed on the structures shown in Figure 7 (Reference Example 3) and Figure 8 (Reference Example 4) using the same method as in Example 1. The maximum principal stresses for each are shown in Table 2. The load in the simulation was set to 5,000 N.

[0088] (Reference Examples 5 and 6) Instead of ZrO2 as a ceramic material, stainless steel (SUS) with the following properties was used as a non-ceramic material, and simulations were performed in the same manner as in Example 1 for the structures shown in Figure 7 (Reference Example 5) and Figure 8 (Reference Example 6). The dimensions and maximum principal stresses of each structure are shown in Table 2. Density: 7.75g / cm 3 Young's modulus: 193 GPa Poisson's ratio: 0.31 Bulk modulus: 169.0 GPa Shear modulus: 73.7 GPa Yield strength: 207 MPa

[0089] (Reference Examples 7 and 8) Instead of ZrO2 as a ceramic material, cast iron with the following properties as a non-ceramic material was used, and simulations were performed in the same manner as in Example 1 for the structures shown in Figure 7 (Reference Example 7) and Figure 8 (Reference Example 8). The dimensions and maximum principal stresses of each structure are shown in Table 2. Density: 6.99g / cm 3 Young's modulus: 89 GPa Poisson's ratio: 0.26 Bulk modulus: 62.1 GPa Shear modulus: 35.5 GPa Yield strength: 80 MPa

[0090] [Table 2]

[0091] Table 2 shows the evaluation results for structures with convex engagement portions. The presence of convex engagement portions tended to reduce the maximum principal stress compared to structures without them. In particular, in ceramic structures made of ceramics, reducing the ratio of the thickness direction length of the concave engagement portion of the second ceramic member to the thickness direction length of the end of the first ceramic member—that is, reducing the clearance width of the concave engagement portion—not only suppressed the increase in the maximum principal stress experienced by the second ceramic member, but also reduced the maximum principal stress. On the other hand, in structures made of materials other than ceramics, reducing the above ratio increased the maximum principal stress experienced by the member with the concave engagement portion.

[0092] While preferred embodiments of the ceramic structures of this disclosure have been described, those skilled in the art will understand that modifications are possible without departing from the claims. [Explanation of Symbols]

[0093] 10 Ceramic Structures 110 First ceramic component 110a End of the first ceramic member 110b Length in the thickness direction of the end of the first ceramic member 110c Convex engagement part 110d Length in the thickness direction of the convex engaging portion 110e Longitudinal length of the first ceramic member 110f The longitudinal length of the end of the first ceramic member that is inserted into and engaged with the second ceramic member. 110g The longitudinal length of the convex engaging portion of the first ceramic member that is inserted into and engaged with the fixing portion of the second ceramic member. 120 Second ceramic component 120a Concave engagement part 120b Length in the thickness direction of the concave engagement portion 120c Fixed part 120d Length in the thickness direction of the fixing part 120e Surface of the concave engagement portion of the second ceramic member 120f Surface of the fixing part of the second ceramic member

Claims

1. It has a first ceramic member and a second ceramic member, The first ceramic member has an elongated shape, and the second ceramic member has a concave engaging portion. The longitudinal end of the first ceramic member is inserted into and engaged with the concave engaging portion of the second ceramic member, and The ratio of the length of the concave engaging portion of the second ceramic member in the direction to the length of the end portion of the first ceramic member in at least one direction is greater than 1.00 and less than 1.

20. Ceramic structure.

2. The ceramic structure according to claim 1, wherein the ratio of the longitudinal length of the end of the first ceramic member inserted into and engaged with the second ceramic member to the longitudinal length of the first ceramic member is 0.05 or more.

3. The ceramic structure according to claim 1 or 2, wherein the concave engaging portion is in the shape of a rectangular parallelepiped.

4. The ceramic structure according to claim 1 or 2, wherein the ratio is 1.02 times or more and 1.16 times or less.

5. The end of the first ceramic member has a convex engaging portion, The concave engaging portion of the second ceramic member has a fixing portion, The convex engaging portion of the first ceramic member is inserted into and engaged with the fixing portion of the second ceramic member. The ceramic structure according to claim 1 or 2.

6. The ratio of the length of the fixing portion of the second ceramic member in the direction to the length of the convex engaging portion of the first ceramic member in at least one direction is greater than 1.00 and less than 1.

20. The ceramic structure according to claim 5.

7. The ceramic structure according to claim 1 or 2, wherein the bulk modulus of at least one of the first ceramic member and the second ceramic member is 100 GPa or more and 280 GPa or less, and the yield strength is 3000 MPa or more and 50000 MPa or less.

8. The ceramic structure according to claim 1 or 2, wherein the total light transmittance at a thickness of 1 mm in at least one of the first ceramic member and the second ceramic member is 50% or more.

9. The ceramic structure according to claim 1 or 2, wherein the three-point bending strength of at least one of the first ceramic member and the second ceramic member is 700 MPa or more.

10. The ceramic structure according to claim 1 or 2, wherein at least one of the first ceramic member and the second ceramic member contains zirconia.

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