WO2021140775A1

WO2021140775A1 - Ceramic structure

Info

Publication number: WO2021140775A1
Application number: PCT/JP2020/044085
Authority: WO
Inventors: 一輝抜水; 二本松　浩明; 伊藤　貴志
Original assignee: 日本碍子株式会社; エヌジーケイ・アドレック株式会社
Priority date: 2020-01-06
Filing date: 2020-11-26
Publication date: 2021-07-15
Also published as: CN114845978B; JPWO2021140775A1; CN114845978A; JP7164736B2; DE112020006457T5

Abstract

This ceramic structure comprises: ceramic first truss structures provided with a plurality of through-holes that extend in a first direction orthogonal to the thickness direction; and ceramic second truss structures provided with a plurality of through-holes that extend in a second direction that is orthogonal to the thickness direction, the second direction being different from the first direction. In this ceramic structure, the first truss structures and the second truss structures are stacked in the thickness direction.

Description

Ceramic structure

This application claims priority based on Japanese Patent Application No. 2020-000554 filed on January 6, 2020. The entire contents of that application are incorporated herein by reference. This specification discloses techniques relating to ceramic structures. In particular, a technique relating to a ceramic structure having a truss structure will be disclosed.

International Publication WO 2018/047784 (hereinafter referred to as Patent Document 1) discloses a ceramic structure having a truss structure (honeycomb structure). The ceramic structure having a truss structure is characterized by being lightweight and having high strength.

FIG. 8 shows a schematic view of the ceramic structure of Patent Document 1. As shown in FIG. 8, in the ceramic structure 400, a partition wall 422 extending in one direction (Y direction) is provided between the surface layer 402 and the back layer 404. The truss structure is composed of the surface layer 402, the back layer 404, and the partition wall 422. Further, a plurality of through holes 424 extending in the Y direction are formed by the surface layer 402, the back layer 404, and the partition wall 422. The ceramic structure of Patent Document 1 is an integrally molded product and is manufactured by extrusion molding. The ceramic structure 400 is reduced in weight by providing a through hole 424. Further, since the ceramic structure 400 has a truss structure, high strength is also realized. Specifically, the ceramic structure 400 is higher in the direction in which the partition wall 422 (through hole 424) extends (Y-axis direction) and in the thickness direction (Z-axis direction) orthogonal to the surface layer 402 (back layer 404). It is strength. However, the ceramic structure 400 is relatively weak against shearing forces in the X-axis direction (directions orthogonal to the Y-axis direction and the Z-axis direction), particularly in the X-axis direction. The ceramic structure 400 has relatively low strength in a specific direction, and thus has low versatility (uses are limited). It is an object of the present specification to provide a technique for realizing a highly versatile ceramic structure.

The ceramic structure disclosed in the present specification includes a first truss structure made of ceramics provided with a plurality of through holes extending in a first direction orthogonal to the thickness direction, and a first truss structure orthogonal to the thickness direction and in the first direction. May include a second truss structure made of ceramics provided with a plurality of through holes extending in different second directions. Further, the first truss structure and the second truss structure may be laminated in the thickness direction.

Further, the ceramic structure disclosed in the present specification is an integrally molded product in which a plurality of ceramic truss structures provided with a plurality of through holes extending in one direction orthogonal to the thickness direction are laminated in the thickness direction. It may be a ceramic structure of. In this ceramic structure, the truss structures may be laminated so that the through holes extend in two or more directions orthogonal to the thickness direction.

The perspective view of the ceramic structure of 1st Example is shown. A partially enlarged view of the truss structure is shown. The concentration distribution of specific elements contained in the skeleton constituting the truss structure is shown. The figure explaining the positional relationship between the 1st through hole and the 2nd through hole is shown. The perspective view of the ceramic structure of 2nd Example is shown. The figure explaining the positional relationship of the 1st to 3rd through holes is shown. The perspective view of the ceramic structure of 3rd Example is shown. The perspective view of the ceramic structure of the 3rd Example observed from the angle different from FIG. 7A is shown. The figure explaining the feature of the conventional truss structure is shown.

In the ceramic structure disclosed in the present specification, a plurality of ceramic truss structures provided with a plurality of through holes extending in one direction orthogonal to the thickness direction may be laminated in the thickness direction. The ceramic structure may be an integrally molded product in which each truss structure is integrated. In the integrally molded product, each truss structure is integrally formed at the time of the molded body before firing, and by firing the integrally formed molded body, each truss structure after firing is integrated. It means that it is configured as a target. Further, the truss structures may be laminated so that the through holes extend in two or more directions orthogonal to the thickness direction. That is, this ceramic structure is at least orthogonal to the first truss structure made of ceramics provided with a plurality of through holes extending in the first direction orthogonal to the thickness direction, and is orthogonal to the thickness direction and is the first direction. It may include a second truss structure made of ceramics provided with a plurality of through holes extending in different second directions. Further, a ceramic third truss structure (third direction ≠ first and second directions) provided with a through hole extending in the third direction, and a ceramic material having a through hole extending in the fourth direction. A fourth truss structure (fourth direction ≠ first, second, third direction) and the like may be provided.

Each truss structure may be provided with a partition wall that connects the surface layer, the back layer, the surface layer and the back layer, and extends in one direction orthogonal to the thickness direction. A plurality of through holes may be formed by the surface layer, the back layer, and the partition wall. The surface layer of the specific truss structure may also serve as the back layer of the truss structure laminated on the surface layer of the truss structure in the thickness direction. That is, when the second truss structure is laminated on the surface layer of the first truss structure, the surface layer of the first truss structure may be the back layer of the second truss structure. The front surface and the back surface of the ceramic structure may be flat surfaces.

In the ceramic structure described above, the partition wall defining the wall surface of the through hole extends in two or more directions orthogonal to the thickness direction. Therefore, the strength of the specific truss structure can be supplemented by the force applied from the direction in which the strength is relatively weak. Specifically, focusing on a specific truss structure, the specific truss structure is added from a specific direction (hereinafter referred to as a lateral direction) orthogonal to the thickness direction and the direction in which the through hole (bulkhead) extends. Relatively weak against force. However, since the ceramic structure described above resists the force applied from the lateral direction by other truss structures laminated on the specific truss structure, it is possible to improve the strength balance of the ceramic structure in the surface direction. it can. As a result, the above-mentioned ceramic structure can be used for various purposes by solving the problem of the conventional ceramic structure that it is "relatively weak against a force from a specific direction". That is, the ceramic structure is highly versatile.

Note that truss structures having through holes extending in the same direction in the thickness direction may be continuously laminated. For example, first truss structures having through holes extending in the first direction in the thickness direction may be continuously laminated. That is, as long as the truss structures are laminated so that the through holes extend in at least two directions orthogonal to the thickness direction, the stacking order of the truss structures can be arbitrarily changed. However, from the viewpoint of supplementing the lateral strength of the specific truss structure, other truss structures having different through hole extending directions may be laminated on both sides of the specific truss structure in the thickness direction. preferable. That is, it is preferable that the second truss structure having the through holes extending in the second direction different from the first direction is laminated on both sides of the first truss structure having the through holes extending in the first direction.

As described above, the ceramic structure has through holes extending in at least two directions (first direction and second direction). When the first direction and the second direction are non-parallel, the strength balance in the surface direction of the ceramic structure can be improved. For example, if the angle (acute angle) formed by the first direction and the second direction is 10 degrees or more and 90 degrees or less, the first truss structure and the second truss structure complement each other in strength, and the strength balance in the plane direction is good. Will be improved. In particular, if the angle (acute angle) formed by the first direction and the second direction is 80 degrees or more and 90 degrees or less, that is, if the first direction and the second direction are substantially orthogonal to each other, the strength balance in the surface direction is further improved. Can be improved.

When the ceramic structure has through holes extending in three or more different directions, the above relationship may be satisfied in any two directions. For example, the ceramics structure has a first truss structure having a first through hole extending in the first direction, a second truss structure having a second through hole extending in the second direction (≠ the first direction), and a third direction. In a ceramics structure having a third truss structure having a third through hole extending in (≠ 1st direction, 2nd direction), the angle θ1 formed by the 1st direction and the 3rd direction, and the 2nd and 3rd directions are When the angle θ2 formed and the angle θ3 formed by the first direction and the second direction are set, the following equations (1) and (2) may be satisfied. By satisfying the following equations (1) and (2), at least the angle θ3 formed by the first through hole and the second through hole (first direction and second direction) can be set to 60 degrees or more, and they are lateral to each other. The strength in the direction can be supplemented.
50 degrees ≤ θ1, θ2 ≤ 70 degrees ... (1)
θ1 + θ2 + θ3 = 180 degrees ... (2)

Each truss structure constituting the ceramic structure may be made of the same material. For example, the material of each truss structure may be SiC quality, mullite quality, ZrO2 quality, or SiC-SiC quality. The term "Si-SiC quality" means a material containing SiC particles as a main component and metallic Si between the SiC particles. By forming each truss structure with SiC material, the open porosity of the surface layer portion of the skeleton constituting each truss structure can be lowered, and the strength of each truss structure itself is improved. The open porosity of the skeleton of each truss structure may be, for example, less than 5%, 3% or less, and particularly preferably 1% or less. The skeleton constituting the truss structure may have substantially no pores. By setting the porosity of the skeleton to less than 5%, the strength and thermal conductivity of the skeleton can be further improved. The porosity of the skeleton of each truss structure can be measured in accordance with JIS R 1655 (a method for testing the porosity distribution of a molded body by a mercury press-fitting method for fine ceramics).

As described above, although the ceramic structure disclosed in the present specification is an integrally molded product in which each truss structure is integrated, the through holes formed in each truss structure are formed in the thickness direction. It extends in two or more orthogonal directions. In such a ceramic structure, for example, after forming a desired shape with a flammable material, an intermediate is formed by impregnating this material with a ceramic material (ceramic slurry), and the intermediate is fired. Can be manufactured. Examples of flammable materials include paper, cloth, and resin. Depending on the flammable material used, the material components of the porous material tend to remain inside the skeleton as compared with the surface layer portion of the skeleton constituting each truss structure. Therefore, at least one element of carbon and calcium (an element typically contained in a flammable porous material) is contained inside the skeleton as compared with the surface layer portion of the skeleton constituting each truss structure. May be included in large quantities. For example, when the ceramic structure (each truss structure) is made of SiC material, the main component (more than 50 wt% of the whole) of the surface layer of the skeleton is SiC and the rest is metallic Si, and the inside of the skeleton. The main component may be metallic Si and the balance may be carbon and / or calcium.

As described above, in the ceramic structure disclosed in the present specification, truss structures having a plurality of through holes are laminated in the thickness direction. Therefore, the weight of the ceramic structure can be reduced, and the heat insulating property in the thickness direction can be increased (the thermal conductivity between the front and back surfaces can be reduced). Further, since the truss structures are laminated so that the through holes extend in a plurality of directions, the strength balance in the surface direction can be improved. Taking advantage of these characteristics, the ceramic structure can be suitably used as a heat insulating member (or a constituent member of the heat insulating member). Further, the ceramic structure can be suitably used as a heat exchange member of a heat exchanger by taking advantage of the feature that the through holes extend in a plurality of directions even though it is an integrally molded product. When used as a heat exchange member, the through hole of the first truss structure is used as a flow path for passing the first heat medium, and the through hole of the second truss structure is used as a flow path for passing the second heat medium. By using it as a path, heat exchange between the first heat medium and the second heat medium can be performed. When the ceramic structure is used as the heat exchange member, the material of the ceramic structure is preferably SiC or SiC material having high thermal conductivity.

(First Example)
The ceramic structure 100 will be described with reference to FIGS. 1 to 4. Although FIG. 1 shows a substantially cubic ceramic structure 100, the ceramic structure 100 has a thickness (Z-axis) of the front surface 2 and the back surface 4 (length in the X-axis direction and length in the Y-axis direction). In some cases, it is a flat plate that is much larger than the length in the direction.

As shown in FIG. 1, the ceramic structure 100 includes a first truss structure 10 and a second truss structure 20. The first truss structure 10 and the second truss structure 20 are alternately laminated in the thickness direction (Z-axis direction). That is, except for the truss structure located at the end in the thickness direction, the second truss structure 20 is laminated on both sides of the first truss structure 10, and the first truss structure 10 is laminated on both sides of the second truss structure 20. Are stacked. The first truss structure 10 and the second truss structure 20 have substantially the same structure except for the direction in which the through hole extends. The first truss structure 10 has a plurality of first through holes 14 extending in the Y-axis direction (an example of the first direction). The first through hole 14 is defined by a surface layer of the first truss structure 10, a back layer, and a partition wall 12 provided between the surface layer and the back layer. The second truss structure 20 has a plurality of second through holes 24 extending in the X-axis direction (an example of the second direction) orthogonal to the Y-axis direction and the Z-axis direction. The third through hole 24 is defined by a surface layer of the second truss structure 20, a back layer, and a partition wall 22 provided between the surface layer and the back layer.

As shown in FIG. 2, in each truss structure 10 and 20,

partition walls

12 and 22 are connected to the surface layer 16 and the back layer 18, and a plurality of through holes 14 (24) are formed. As described above, the first truss structure 10 and the second truss structure 20 have substantially the same structure. Therefore, the first truss structure 10 will be described below. The partition wall 12 is connected to the surface layer 16 and the back layer 18 in an inclined state to realize a truss structure (first truss structure 10). The surface layer 16, the back layer 18, and the partition wall 12 are integrally molded, and there is no clear boundary between the surface layer 16 and the partition wall 12, and the back layer 18 and the partition wall 12. It is also clear between the surface layer 16 of the first truss structure 10 and the back layer 18 of the second truss structure 20, and the back layer 18 of the first truss structure 10 and the surface layer 16 of the second truss structure 20. There is no boundary. That is, the ceramic structure 100 shown in FIG. 1 is an integrally molded product in which the first truss structure 10 and the second truss structure 20 are integrated. When the truss structures 10 and 20 shown in FIG. 2 are located on the outermost surface layer (Z-axis direction + side end portion) of the ceramic structure 100, the surface layer 16 is the surface 2 of the ceramic structure 100. Similarly, when the truss structures 10 and 20 are located in the innermost layer (Z-axis direction-side end) of the ceramic structure 100, the back layer 18 is the back surface 4 of the ceramic structure 100.

The ceramic structure 100 is manufactured by forming an intermediate body in which a flammable base material such as paper is impregnated with a SiC slurry, and then firing the metal Si in contact with the metal Si. Therefore, the surface portion of the skeleton (surface layer 16, back layer 18, partition wall 12) constituting the ceramic structure 100 is mainly composed of SiC and the rest is metallic Si. The inside of the skeleton is mainly composed of metallic Si and the rest is elements (carbon and / or calcium) contained in the base material. The open porosity on the surface of the skeleton is 1% or less.

FIG. 3 shows the concentration distribution of the components of the base material contained in the skeleton constituting the ceramic structure 100. The horizontal axis of the graph indicates the thickness of the skeleton (for example, the thickness 31 of the surface layer 16 and the thickness 32 of the partition wall 12 shown in FIG. 2) in terms of the distance (%) from one end to the other end. The vertical axis shows the ratio of elements (C, Ca) derived from the base material. As shown in FIG. 3, the surface portion of the aggregate contains almost no “C” or “Ca”. "C" and "Ca" begin to appear after a predetermined depth has passed from the surface of the skeleton and increase toward the center of the skeleton.

(Modification example of ceramic structure 100)
As shown in FIG. 1, in the ceramic structure 100, the first through hole 14 extends in the Y-axis direction, and the second through hole 24 extends in the X-axis direction. That is, in the ceramic structure 100, the angle formed by the direction in which the first through hole 14 extends (first direction) and the direction in which the second direction extends (second direction) is 90 degrees. However, the angle formed by the first direction and the second direction does not have to be 90 degrees. As shown in FIG. 4, the angle formed by the second direction (direction 24 in which the second through hole extends) with respect to the first direction (direction in which the first through hole 14 extends) is in the range α1 of 10 degrees or more and 90 degrees or less. For example, the strengths of the first truss structure 10 and the second truss structure 20 can be complemented with each other. If the angle formed by the second direction with respect to the first direction is in the range α2 (that is, substantially right angle) of 80 degrees or more and 90 degrees or less, the first truss structure 10 and the second truss structure 20 are mutually. The reinforcing effect is maximized.

In the ceramic structure 100, truss structures having through holes extending in the same direction in the thickness direction may be continuously laminated. That is, the first truss structure 10 (or the second truss structure 20) may be continuously laminated twice or more in the thickness direction. In this case, the thickness and / or the through-hole size of the first truss structure 10 (or the second truss structure 20) to be continuously laminated may be different.

(Second Example)
The ceramic structure 200 will be described with reference to FIG. The ceramic structure 200 is a modification of the ceramic structure 100, and a third truss structure 30 is provided between the first truss structure 10 and the second truss structure 20. Regarding the ceramic structure 200, the same structure as that of the ceramic structure 100 may be omitted by assigning the same reference number as the reference number assigned to the ceramic structure 100.

The third truss structure 30 includes a plurality of third through holes 34 extending in the third direction. The direction in which the third through hole 34 extends (third direction) is the direction in which the first through hole 14 extends (first direction: Y-axis direction) and the direction in which the second through hole 24 extends (second direction: X-axis direction). Different from. In the ceramic structure 200, the angle formed by the third through hole 34 and the first through hole 14 is 45 degrees, and the angle formed by the third through hole 34 and the second through hole 24 is also 45 degrees.

(Modified example of the second embodiment)
In the ceramic structure 200, the stacking order of the truss structures 10, 20, and 30 can be changed. In the ceramic structure 200 as well, similarly to the ceramic structure 100, truss structures having through holes extending in the same direction in the thickness direction may be continuously laminated. For example, the first truss structures 10 may be continuously laminated in the thickness direction. In this case, the thickness and / or through-hole size of the truss structures 10 that are continuously laminated may be different.

Further, also in the ceramic structure 200, the direction in which the first through hole 14 extends (first direction), the direction in which the second through hole 24 extends (second direction), and the direction in which the third through hole 34 extends (third direction). Can be changed. However, the total angle (θ1 + θ2 + θ3) of the angle θ1 formed by the first direction and the third direction, the angle θ2 formed by the second direction and the third direction, and the angle θ3 formed by the first direction and the second direction is 180 degrees. Adjust each direction so that. Further, as shown in FIG. 6, the angle θ1 is adjusted to 50 degrees or less, and the angle θ2 is adjusted to 70 degrees or less. The angle θ3 is adjusted to 60 degrees or more. That is, the directions in which the through

holes

14, 24 and 34 extend are adjusted so as to satisfy the following equations (1) and (2). By satisfying the following equations (1) and (2), at least the angle θ3 is adjusted to 60 degrees or more, so that the truss structures 10, 20, and 30 can be reinforced with each other.
50 degrees ≤ θ1, θ2 ≤ 70 degrees ... (1)
θ1 + θ2 + θ3 = 180 degrees ... (2)

(Third Example)
The ceramic structure 300 will be described with reference to FIGS. 7A and 7B. FIG. 7B shows a perspective view (showing the surface 50) observed from the side opposite to that of FIG. 7A. The ceramic structure 300 is a modification of the

ceramic structures

100 and 200, and like the ceramic structure 200, the third truss structure 330 is provided between the first truss structure 310 and the second truss structure 320. Has been done. Regarding the ceramic structure 300, the same configuration as the

ceramic structures

100 and 200 may be omitted by assigning the same reference number as the reference number attached to the

ceramic structures

100 and 200 and the last two digits. ..

The ceramic structure 300 has an equilateral triangle shape on the front surface 302 and the back surface 304. The ceramic structure 300 includes

truss structures

310, 320, and 330 in which the through holes extend in different directions. The angle formed by the direction in which the through hole 14 of the first truss structure 310 extends (first direction) and the direction in which the through hole 24 of the second truss structure 320 extends (second direction) is 60 degrees. Further, the angle formed by the direction in which the through hole 14 of the first truss structure 310 extends (first direction) and the direction in which the through hole 34 of the third truss structure 330 extends (third direction) is also 60 degrees. Therefore, the angle formed by the second direction and the third direction is also 60 degrees. The ceramic structure 300 satisfies the above formula (2). In the ceramic structure 300, the through holes can be arranged so as to be orthogonal to the side surface of the ceramic structure 300. Therefore, for example, when the ceramic structure 300 is used as a heat exchange member for circulating a fluid (heat medium) through each through hole, the movement resistance of the fluid can be reduced.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above. In addition, the technical elements described in the present specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the techniques illustrated in the present specification or drawings can achieve a plurality of purposes at the same time, and achieving one of the purposes itself has technical usefulness.

10: First truss structure 14: Through hole of the first truss structure 20: Second truss structure 24: Through hole of the second truss structure 100: Ceramic structure

Claims

A first truss structure made of ceramics provided with a plurality of through holes extending in the first direction orthogonal to the thickness direction, and
It is provided with a second truss structure made of ceramics, which is orthogonal to the thickness direction and is provided with a plurality of through holes extending in a second direction different from the first direction.
A ceramic structure in which a first truss structure and a second truss structure are integrally molded products in which they are laminated in the thickness direction.
The ceramic structure according to claim 1, wherein the second truss structure is laminated on both sides of the first truss structure in the thickness direction.
The ceramic structure according to claim 1 or 2, wherein the angle formed by the first direction and the second direction is 10 degrees or more and 90 degrees or less.
The ceramic structure according to claim 3, wherein the angle formed by the first direction and the second direction is 80 degrees or more and 90 degrees or less.
The ceramics according to any one of claims 1 to 4, wherein the material of the first truss structure and the second truss structure is a SiC material mainly composed of SiC particles and containing metallic Si between the SiC particles. Structure.
The ceramic structure according to any one of 1 to 5, wherein the surface layer portion of the skeleton constituting the first truss structure and the second truss structure has an open porosity of less than 5%.
Further provided with a third truss structure made of ceramics, which is orthogonal to the thickness direction and is provided with a plurality of through holes extending in a third direction different from the first direction and the second direction.
When the angle θ1 formed by the first direction and the third direction, the angle θ2 formed by the second direction and the third direction, and the angle θ3 formed by the first direction and the second direction, the following equations (1) and (2) are used. The ceramic structure according to any one of claims 1 to 6.
50 degrees ≤ θ1, θ2 ≤ 70 degrees ... (1)
θ1 + θ2 + θ3 = 180 degrees ... (2)
A ceramic truss structure provided with a plurality of through holes extending in one direction orthogonal to the thickness direction is an integrally molded ceramic structure in which a plurality of ceramic truss structures are laminated in the thickness direction.
A ceramic structure in which each truss structure is laminated so that the through holes extend in two or more directions orthogonal to the thickness direction.
A heat exchange member provided with the ceramic structure according to any one of claims 1 to 8.
The through hole of the first truss structure is a flow path for passing the first heat medium.
A heat exchange member in which the through hole of the second truss structure is a flow path for passing the second heat medium.
A heat insulating member provided with the ceramic structure according to any one of claims 1 to 8.