Method for producing Si-SiC composite structure

Abstract

The present invention provides a method for manufacturing a Si-SiC composite structure capable of improving the manufacturing efficiency of the Si-SiC composite structure. The method for manufacturing a Si-SiC composite structure according to an embodiment of the present invention comprises the following steps: in a state where a supply body containing Si is in contact with a molded body containing SiC, the supply body is heated so that a molten metal containing Si is impregnated into the molded body, and the contact portion of the supply body that contacts the molded body is a portion of the surface opposite to the molded body.

Description

Technical Field

[0001] The present invention relates to a method for producing a Si-SiC based composite structure. Background Art

[0002] Si-SiC composite materials have excellent thermal conductivity and are expected to be used in various industrial products. As a method for manufacturing such a structure formed by Si-SiC composite materials (hereinafter referred to as Si-SiC composite structure), for example, the following technical scheme is proposed: after placing an impregnated metal supplier containing Si on an impregnated body containing SiC, the impregnated body is heated to a temperature of 1200°C to 1600°C, thereby impregnating the impregnated body with molten metal containing Si (see Patent Document 1).

[0003] However, regarding this technology, since the impregnation process is carried out in a state where the entire lower surface of the impregnated metal supplier is in contact with the impregnated body, the impregnated metal supplier is sometimes attached (adhered) to the impregnated body. If the impregnated metal supplier is attached (adhered) to the impregnated body, the quality, size, performance, etc. of the Si-SiC composite material may deviate from the allowable range. Therefore, it is necessary to eliminate the excessive adhesion of the impregnated metal supplier to the impregnated body, and products that cannot fully eliminate the adhesion of the impregnated metal supplier have to be discarded. Therefore, the yield of the Si-SiC composite structure may be reduced.

[0004] In addition, the attachment position of the impregnated metal supplier to the impregnated body may be different each time the Si-SiC composite structure is manufactured, so it is difficult to predict the attachment position of the impregnated metal supplier. Therefore, the process of removing the attachment portion of the impregnated metal supplier to the impregnated body may become complicated. As such, regarding the technology described in Patent Document 1, there is room for improvement in terms of improving the manufacturing efficiency of Si-SiC composite structures.

[0005] Patent Document 1: International Publication No. 2011 / 145387 Summary of the invention

[0006] A main object of the present invention is to provide a method for producing a Si—SiC based composite structure capable of improving the production efficiency of the Si—SiC based composite structure.

[0007] The method for manufacturing a Si-SiC composite structure involved in an embodiment of the present invention includes the following steps: while a supply body containing Si is in contact with a molded body containing SiC, the supply body is heated to impregnate the molded body with molten metal containing Si, and the contact portion of the supply body with the molded body is a portion of the surface opposite to the molded body.

[0008] In one embodiment, a convex portion that protrudes toward the molded body is provided on a surface of the supply body that faces the molded body, and the convex portion is in contact with the molded body.

[0009] In one embodiment, the cross section of the convex portion includes an arc shape.

[0010] In one embodiment, the convex portion has a pyramid shape.

[0011] In one embodiment, the supply body contacts the molded body at a plurality of locations. In this case, the interval between mutually adjacent contact portions of the supply body in the plurality of contact portions with the molded body is 78.5 mm or less.

[0012] In one embodiment, the contact portion of the supply body with the molded body extends linearly.

[0013] In one embodiment, the molded body has a honeycomb structure.

[0014] Effects of the Invention

[0015] According to the embodiment of the present invention, it is possible to realize a method for producing a Si—SiC based composite structure capable of improving the production efficiency of the Si—SiC based composite structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a top view of a molded body according to a method for producing a Si—SiC based composite structure according to one embodiment of the present invention.

[0017] Figure 2 This is a perspective view of a supply body involved in a method for producing a Si—SiC based composite structure according to one embodiment of the present invention.

[0018] Figure 3 yes Figure 2 Bottom view of the supply body.

[0019] Figure 4 It shows that Figure 2 The supplier and Figure 1 A schematic cross-sectional view of a state in which the molded bodies are in contact.

[0020] Figure 5 (a) is a bottom view of a supply body according to another embodiment of the present invention. Figure 5 (b) is to show that Figure 5 (a) is a schematic cross-sectional view showing a state in which a supply body and a molded body are in contact with each other.

[0021] Figure 6 (a) is a bottom view of a supply body according to still another embodiment of the present invention. Figure 6(b) is to show that Figure 6 (a) is a schematic cross-sectional view showing a state in which a supply body and a molded body are in contact with each other.

[0022] Figure 7 (a) is a bottom view of a supply body according to still another embodiment of the present invention. Figure 7 (b) is to show that Figure 7 (a) is a schematic cross-sectional view showing a state in which a supply body and a molded body are in contact with each other.

[0023] Figure 8 This is a schematic plan view showing a state in which a supply body and a molded body according to still another embodiment of the present invention are brought into contact with each other.

[0024] Fig. 9 (a) is a bottom view of a supply body according to still another embodiment of the present invention. Fig. 9 (b) is to show that Fig. 9 (a) is a schematic cross-sectional view showing a state in which a supply body and a molded body are in contact with each other.

[0025] Fig.10 (a) is a bottom view of a supply body according to still another embodiment of the present invention. Fig.10 (b) is to show that Fig.10 (a) is a schematic cross-sectional view showing a state in which a supply body and a molded body are in contact with each other.

[0026] Fig.11 (a) is a bottom view of a supply body according to still another embodiment of the present invention. Fig.11 (b) is to show that Fig.11 (a) is a schematic cross-sectional view showing a state in which a supply body and a molded body are in contact with each other.

[0027] Fig.12 A top view photograph of the honeycomb structure obtained in Example 1 is shown.

[0028] Fig.13 A top view photograph of the honeycomb structure obtained in Comparative Example 1 is shown.

[0029] Description of Reference Numerals

[0030] 1 ... formed body; 1a ... honeycomb formed body; 2 ... supply body; 21 ... convex portion. DETAILED DESCRIPTION

[0031] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

[0032] A. Overview of the method for producing Si-SiC composite structure

[0033] Figure 1is a top view of a molded body involved in a method for producing a Si-SiC composite structure according to one embodiment of the present invention; Figure 2 is a perspective view of a supply body involved in a method for producing a Si-SiC composite structure according to one embodiment of the present invention; Figure 3 yes Figure 2 A bottom view of a supply body; Figure 4 It shows that Figure 2 The supplier and Figure 1 A schematic cross-sectional view of a state in which the molded bodies are in contact.

[0034] A method for producing a Si-SiC composite structure according to one embodiment of the present invention includes the following step (impregnation step): in a state where a supply body 2 containing Si is in contact with a molded body 1 containing SiC, the supply body 2 is heated so that a molten metal containing Si is impregnated into the molded body 1. In the impregnation step, the contact portion of the supply body 2 with the molded body 1 is a portion of the surface facing the molded body 1.

[0035] The inventors of the present invention have discovered that if a portion of the supply body contacts the molded body during the impregnation process, the molten metal containing Si can be impregnated into the entire molded body by means of the contact portion, thereby completing the present invention. According to the above method, during the impregnation process, a portion of the surface of the supply body opposite to the molded body contacts the molded body, so the amount of supply body attached to the molded body can be reduced compared to the case where the entire surface of the supply body opposite to the molded body contacts the molded body. Therefore, the attachment of the supply body can be easily eliminated, and the yield of the Si-SiC composite structure can be improved. In addition, the portion to which the supply body may be attached can be limited, so the process of eliminating the supply body attached to the molded body can be smoothly implemented. As a result, the manufacturing efficiency of the Si-SiC composite structure can be improved.

[0036] The molded body is an impregnated body in which the molten metal containing Si is impregnated in the impregnation process. As described above, the molded body contains SiC as a main component. In addition, in this specification, markings such as "SiC" are intended to include not only pure SiC, but also SiC containing inevitable impurities. In addition to SiC, the constituent materials of the molded body may also contain Al and / or Si. In addition, the constituent materials of the molded body may also contain a molding aid. The proportion of SiC contained in the molded body is, for example, more than 50% by mass, preferably more than 85% by mass, for example, less than 100% by mass, preferably less than 95% by mass.

[0037] As described above, the supply body contains Si as a main component. In addition to Si, the constituent material of the supply body may contain Al. In addition, the constituent material of the supply body may further contain a molding aid.

[0038] The proportion of Si contained in the supply body is, for example, 50 mass % or more, preferably 90 mass % or more, more preferably 95 mass % or more, for example, 100 mass % or less, preferably 97 mass % or less, more preferably 96 mass % or less. If the proportion of Si contained in the supply body is within this range, the entire molded body can be uniformly impregnated with the molten metal containing Si in the impregnation step, and the Si impregnation amount of the Si-SiC composite structure can be uniform.

[0039] In one embodiment, the supply body 2 contacts the molded body 1 at multiple locations. The interval L between the contact portions adjacent to each other in the multiple contact portions of the supply body 2 in contact with the molded body 1 is 78.5 mm or less, preferably 70 mm or less, and more preferably 60 mm or less. If the interval L between the contact portions adjacent to each other is below the above upper limit, the entire molded body can be uniformly impregnated with the molten metal containing Si in the impregnation process, and the Si-SiC composite structure can suppress the occurrence of insufficient Si impregnation (Si impregnation omission). As a result, the deviation of the performance of the Si-SiC composite structure can be suppressed, and a Si-SiC composite structure with excellent performance can be stably manufactured. In particular, if the proportion of Si contained in the supply body is within the above range and the interval L between the contact portions adjacent to each other is below the above upper limit, the Si impregnation amount of the Si-SiC composite structure can be further uniformized. In addition, the lower limit of the interval L between the contact portions adjacent to each other is typically 10 mm or more.

[0040] In one embodiment, the distance between the contact portion between the supply body and the molded body and the end surface of the molded body is equal to or less than 1 / 2 of the distance L. According to this structure, in the impregnation step, the entire molded body can be more uniformly impregnated with the molten metal containing Si.

[0041] The contact between the supply body 2 and the molded body 1 can be point contact, line contact, or surface contact. When the supply body 2 contacts the molded body 1 at multiple locations, all of the multiple contact portions can be any one of point contact, line contact, or surface contact, or can include two or more of point contact, line contact, or surface contact. In the case where the supply body 2 is in surface contact with the molded body 1, the interval L between the adjacent contact portions and the distance between the contact portion and the end face of the molded body are measured based on the end (end edge) of the surface contact portion. For example, the interval L between adjacent surface contact portions refers to the distance from the end (end edge) of the surface contact portion to the end (end edge) of other surface contact portions, and the interval L between adjacent surface contact portions and point contact portions refers to the distance from the end (end edge) of the surface contact portion to the point contact portion.

[0042] The area of ​​the contact portion between the supply body and the molded body (the sum of the areas of the multiple contact portions when there are multiple contact portions) is, for example, 40% or less, preferably 30% or less, when the area of ​​the surface of the supply body facing the molded body is set to 100%. If the area of ​​the contact portion is below the above upper limit, the amount of the supply body attached to the molded body can be further reduced, and the manufacturing efficiency of the Si-SiC composite structure can be further improved. In addition, the lower limit of the area of ​​the contact portion is typically 1% or more.

[0043] In the impregnation process, typically, the molded body 1 and the supplier 2 are heated in a state where the supplier 2 containing Si is in contact with the molded body 1 containing SiC. The heating temperature is, for example, above 1200°C, preferably above 1300°C, for example below 1600°C, preferably below 1500°C. The heating time is, for example, above 10 minutes, preferably above 1 hour. If the heating temperature is within the above range and / or the heating time is above the above lower limit, the molten metal containing Si can be smoothly impregnated into the molded body. In addition, the upper limit of the heating time is typically below 10 hours, preferably below 5 hours. If the heating time is below the above upper limit, the manufacturing efficiency of the Si-SiC composite structure can be further improved.

[0044] Preferably, the impregnation process is carried out under reduced pressure. If the impregnation process is carried out under reduced pressure, the molded body can be further smoothly impregnated with the molten metal containing Si. The pressure of the impregnation process is, for example, 500 Pa or less, preferably 300 Pa or less, more preferably 200 Pa or less, and typically 10 Pa or more. In addition, the impregnation process can also be carried out under normal pressure (0.1 MPa).

[0045] Hereinafter, a molded body and a supply body involved in the method for producing a Si—SiC based composite structure will be described.

[0046] B. Molded body (honeycomb molded body)

[0047] As a molded body, any appropriate shape can be adopted according to the purpose of the Si-SiC composite structure. As the shape of the molded body, for example, a cylindrical shape, an elliptical cylindrical shape, and a prism shape can be cited. In addition, the molded body can have a hollow area in its center in a cross section in a direction orthogonal to the axial direction (length direction) of the molded body.

[0048] In one embodiment, the molded body is a honeycomb molded body having a honeycomb structure. When the molded body is a honeycomb molded body, the Si-SiC composite structure can be a honeycomb structure. The honeycomb molded body has a plurality of compartments. The compartment extends from the first end face of the honeycomb molded body to the second end face in the axial direction (length direction) of the honeycomb molded body. The compartment has any appropriate shape in the cross section in a direction orthogonal to the axial direction of the honeycomb molded body. As the cross-sectional shape of the compartment, for example, a triangle, a quadrilateral, a pentagon, a polygon above a hexagon can be cited. The cross-sectional shape and size of the compartment can be all the same, or at least a part can be different.

[0049] Figure 1 1 embodiment of a honeycomb formed body is shown in FIG. The honeycomb formed body 1a has a cylindrical shape and has a hollow area in its center. The first end face (upper surface) and the second end face (lower surface) of the honeycomb formed body 1a are planes perpendicular to the axial direction of the honeycomb formed body, respectively. The outer diameter of the honeycomb formed body can be appropriately set according to the purpose. The outer diameter of the honeycomb formed body can be, for example, 20 mm to 200 mm, and can also be, for example, 30 mm to 100 mm. In addition, when the cross-sectional shape of the honeycomb formed body is not circular, the diameter of the maximum inscribed circle inscribed in the cross-sectional shape (for example, a polygon) of the honeycomb formed body can be set as the outer diameter of the honeycomb structure. The length of the honeycomb formed body can be appropriately set according to the purpose. The length of the honeycomb formed body can be, for example, 3 mm to 200 mm, and can also be, for example, 5 mm to 100 mm, and can also be, for example, 10 mm to 50 mm.

[0050] The honeycomb formed body 1 a includes an outer peripheral wall 11 , an inner peripheral wall 12 located inside the outer peripheral wall 11 , and partition walls 13 located between the outer peripheral wall 11 and the inner peripheral wall 12 .

[0051] The outer peripheral wall 11 has a cylindrical shape. The inner peripheral wall 12 has a cylindrical shape with a diameter smaller than the diameter of the outer peripheral wall 11. The outer peripheral wall 11 and the inner peripheral wall 12 share a common axis. The thickness of each of the outer peripheral wall 11 and the inner peripheral wall 12 can be appropriately set according to the purpose of the honeycomb structure. The thickness of each of the outer peripheral wall 11 and the inner peripheral wall 12 can be, for example, 0.3 mm to 10 mm, and can be, for example, 0.5 mm to 5 mm. If the thickness of the outer peripheral wall and / or the inner peripheral wall is within this range, damage to the wall by external force (such as cracks, fissures) can be suppressed.

[0052] The partition wall 13 defines a plurality of cells 14. More specifically, the partition wall 13 includes: a first partition wall 13a extending from the inner peripheral wall 12 to the outer peripheral wall 11 in a radial direction; and a second partition wall 13b extending in a circumferential direction, and the first partition wall 13a and the second partition wall 13b define a plurality of cells 14. The cross-sectional shape of the cell 14 is a quadrilateral (a rectangle that is longer in the radial direction of the honeycomb formed body).

[0053] Although not shown, the first partition wall 13 a and the second partition wall 13 b may be orthogonal to each other and define a cell 14 having a quadrilateral (square) cross-sectional shape except for portions in contact with the inner peripheral wall 12 and the outer peripheral wall 11 .

[0054] The cell density (that is, the number of cells 14 per unit area) in the cross section in the direction perpendicular to the axial direction of the honeycomb formed body can be appropriately set according to the purpose. For example, the cell density can be 4 cells / cm 2 ~320 compartments / cm 2 When the cell density is within such a range, the strength and effective GSA (geometric surface area) of the honeycomb structure can be sufficiently ensured.

[0055] The thickness of the partition wall 13 can be appropriately set according to the purpose of the honeycomb structure. Typically, the thickness of the partition wall 13 is thinner than the thickness of the outer peripheral wall 11 and the inner peripheral wall 12. The thickness of the partition wall 13 can be, for example, 0.1 mm to 1.0 mm, and can be, for example, 0.2 mm to 0.6 mm. If the thickness of the partition wall is within this range, the mechanical strength of the honeycomb structure can be sufficiently ensured, and the opening area (the total area of ​​the cells in the cross section) can be sufficiently ensured.

[0056] The porosity of each of the outer peripheral wall 11, the inner peripheral wall 12 and the partition wall 13 can be appropriately set according to the purpose. The above-mentioned porosity is, for example, 15% or more, preferably 20% or more, for example, 50% or less, preferably 45% or less. In addition, the porosity can be measured by, for example, mercury intrusion method. If the porosity of the outer peripheral wall, the inner peripheral wall and the partition wall is within this range, the molten metal can be impregnated into the honeycomb molded body by using capillary force in the impregnation process.

[0057] The density of each of the outer peripheral wall 11, the inner peripheral wall 12, and the partition wall 13 (density of the molded body) can be appropriately set according to the purpose. For example, the density is 1.7 g / cm 3 Above, preferably 1.8 g / cm 3 Above, for example, 2.6 g / cm 3 Below, preferably 2.8 g / cm 3In addition, the density can be measured, for example, by mercury penetration. If the density of each of the outer peripheral wall, the inner peripheral wall, and the partition wall is within this range, voids can be formed inside the outer peripheral wall, the inner peripheral wall, and the partition wall at the above-mentioned porosity.

[0058] Such a molded body (honeycomb molded body) can be produced by the following method. First, a binder and water or an organic solvent are added to an inorganic material powder containing SiC powder, and the obtained mixture is kneaded to form a blank, and the blank is molded (typically extrusion molded) into a desired shape and dried to produce a dried body (honeycomb dried body). Next, the dried body (honeycomb dried body) is subjected to a predetermined outer shape processing to obtain a molded body (honeycomb molded body) of a desired shape.

[0059] C.Supply

[0060] The supply body may be in any appropriate shape according to the shape of the formed body. The supply body may be, for example, in the form of a plate having a predetermined thickness. The cross-sectional shape in a direction perpendicular to the thickness direction of the supply body may be, for example, a circle, an ellipse, or a polygon. In addition, the supply body may have a hollow region in the center of its cross section. A supply body having a hollow region is a so-called doughnut shape.

[0061] In one embodiment, the supply body has a convex portion. Figures 2 to 8 A supply body having a convex portion is shown in FIG.

[0062] like Figure 2 and Figure 3 As shown, the supply body 2 includes: a main body 21 having a disk shape (circular ring plate shape) having a hollow area in the center; and a plurality of convex portions 22 protruding from the main body 21 .

[0063] The thickness of the main body 21 can be appropriately set according to the purpose. The thickness of the main body 21 can be, for example, 5 mm to 25 mm, and can be, for example, 8 mm to 15 mm.

[0064] A plurality of protrusions 22 are provided on a surface in the thickness direction of the main body 21. Typically, the plurality of protrusions 22 are arranged at equal intervals from each other in the circumferential direction of the main body 21. In the illustrated example, the number of protrusions 22 is 4, but is not limited thereto. The number of protrusions 22 may be, for example, more than 4 and less than 20, or, for example, more than 4 and less than 10. The protruding length of the protrusion 22 (the dimension in the thickness direction of the main body) may be appropriately set according to the purpose. The protruding length of the protrusion 22 may be, for example, 0.5 mm to 5 mm, or, for example, 1 mm to 3 mm. As Figure 4As shown, the cross section of the protrusion 22 in the thickness direction of the main body 21 includes an arc shape (the cross section is an arc shape). In one embodiment, the protrusion may be hemispherical. If the protrusion has an arc-shaped cross section, it is difficult to cause the protrusion to break when manufacturing the supply body (especially stamping). Therefore, shape stability when manufacturing the supply body can be expected.

[0065] In the impregnation step, the supply body 2 is placed on the molded body 1 (honeycomb molded body 1a) in such a manner that the convex portion 22 contacts the first end surface of the molded body 1 (honeycomb molded body 1a). In this state, the surface of the supply body 2 including the convex portion 22 faces the molded body 1 (honeycomb molded body 1a), and the convex portion 22 protrudes from the main body 21 toward the molded body 1. A portion of the convex portion 22 (specifically, the vertex portion of the arc) contacts the first end surface of the molded body 1 (honeycomb molded body 1a).

[0066] like Figure 5 As shown, the main body 21 may not have a hollow area. In addition, the size of the protrusion 22 is not particularly limited.

[0067] like Figure 6 and Figure 7 As shown, the convex portion 22 may have a pyramidal shape. If the convex portion has a pyramidal shape, the contact position with the molded body can be set with high precision compared to the case where the cross section of the convex portion is in an arc shape. Therefore, the portion to which the supply body may adhere can be controlled with high precision, and the process of eliminating the supply body attached to the molded body can be implemented more smoothly. Examples of the pyramidal shape include a triangular pyramid, a quadrangular pyramid, a pentagonal pyramid or more. The angle of the vertex of the pyramidal convex portion can be set to any appropriate value.

[0068] like Figure 8 As shown, the main body 21 may have a cylindrical shape (cylindrical shape) having a hollow region in the center, and the convex portion 22 may be provided on the outer peripheral surface of the main body 21. In this case, the molded body 1 (honeycomb molded body 1a) has a hollow region. In the impregnation step, the supply body 2 is arranged in the hollow region of the molded body 1 (honeycomb molded body 1a), and the convex portion 22 contacts the inner peripheral surface of the molded body 1 (honeycomb molded body 1a).

[0069] In one embodiment, the contact portion of the supply body with the molded body extends in a linear shape. Figures 9 to 11 A supply body that can be in contact with a molded body in a linear shape is shown in FIG. If the contact portion of the supply body relative to the molded body extends in a linear shape, even if a portion of the contact portion is broken or damaged, the contact area between the supply body and the molded body can be sufficiently ensured, and the Si impregnation leakage of the Si-SiC composite structure can be stably suppressed.

[0070] like Fig. 9As shown, the supply body 2 has a so-called donut shape. The cross section in the thickness direction of the surface of the supply body 2 facing the forming body 1 has an arc shape (the cross section is an arc shape). The surface with an arc shape in cross section extends in the entire circumference of the supply body 2. In the impregnation step, a part of the surface with an arc shape in cross section of the supply body 2 (specifically, the vertex part) contacts the forming body 1 (honeycomb formed body 1a) in a line extending in the circumferential direction of the supply body.

[0071] In addition, if Fig.10 As shown, the supply body 2 may have a V-shaped cross section in the thickness direction of the surface facing the molded body 1. The angle of the top of the surface having the V-shaped cross section may be set to any appropriate value.

[0072] In addition, regarding Fig. 9 and Fig.10 In the structure shown, the supply body 2 has a hollow area, but it may not have a hollow area. In this case, although not shown in the figure, the portion of the supply body including the surface having the above-mentioned specific cross-sectional shape (arc-shaped cross section, V-shaped cross section) protrudes from the peripheral end of the main body having a circular plate shape, which is equivalent to a convex portion. In addition, as shown in FIG. Fig.11 As shown, the cross section of the supply body 2 may be circular.

[0073] Such a supply body can be produced by the following method: Material powder containing Si powder is molded (typically, press-molded) into a desired shape and then dried to obtain a supply body of the desired shape.

[0074] In the above embodiment, the supply body having the above specific structure (convex portion, arc-shaped cross section, V-shaped cross section) contacts the flat first end surface of the molded body, but the present invention is not limited to this. For example, a convex portion may be provided on the molded body and made to contact the flat end surface of the supply body. In this way, a part of the surface of the supply body facing the molded body may also contact the molded body.

[0075] In addition, in the above-mentioned embodiment, the supply body is in direct contact with the molded body, but the supply body and the molded body may be in contact with each other via a relay component. In this case, the contact portion of the supply body that is in contact with the molded body refers to the contact portion of the supply body that is in contact with the relay component. This can also reduce the amount of adhesion of the supply body to the molded body. The relay component is formed as a separate structure with respect to the supply body and the molded body, respectively, and typically has the same shape as the above-mentioned convex portion. In one embodiment, the relay component is sandwiched between the flat first end face of the molded body and the flat end face of the supply body during the impregnation process. As the constituent material of the relay component, for example, the constituent material of the above-mentioned molded body, the constituent material of the above-mentioned supply body, and the precursor material of SiC (such as carbon) can be cited.

[0076] [Example]

[0077] Hereinafter, the present invention will be specifically described using examples, but the present invention is not limited to these examples.

[0078] <Example 1>

[0079] 1. Preparation of honeycomb molded body

[0080] The blank containing SiC powder and molding auxiliary powder is extruded to form Figure 1 The honeycomb is formed into the shape shown, and then dried to obtain a honeycomb dried body. Next, the outer surface of the honeycomb dried body is processed to obtain a honeycomb formed body. The honeycomb formed body comprises: an outer peripheral wall (outer diameter of 86 mm); an inner peripheral wall (inner diameter of 66 mm), which is located inside the outer peripheral wall; and a partition wall, which is located between the outer peripheral wall and the inner peripheral wall and defines a plurality of cells. The cell density of the honeycomb formed body is 56 cells / cm 2 The thickness of the partition wall is 0.3 mm, and the thickness of the outer wall and the inner wall are each 2 mm.

[0081] 2. Preparation of the donor

[0082] The material powder containing Si powder and molding auxiliary powder is pressed and molded into Figure 2 The supply body is formed into the shape shown in the figure, and then dried to obtain the supply body. The supply body has a main body (41 mm in inner diameter, 73 mm in outer diameter, and 10 mm in thickness) having a circular ring plate shape, and four convex parts protruding from the main body.

[0083] 3. Impregnation process

[0084] Next, if Figure 4 As shown in FIG. 1 , the supply body is placed on the honeycomb formed body in such a manner that the convex portion of the supply body contacts the honeycomb formed body, and then heated at a temperature of 1500° C. for 4 hours under reduced pressure conditions (200 Pa), thereby impregnating the honeycomb formed body with the molten metal containing Si. In addition, the interval between the contact portions of the convex portion and the honeycomb formed body, which are adjacent to each other, is 54 mm.

[0085] A honeycomb structure (Si—SiC based composite structure) was obtained in the above manner. Then, the honeycomb structure was cooled to room temperature (23° C.), and the adhesion state of the supply body to the honeycomb structure was confirmed. Fig.12 A top view photograph of the honeycomb structure obtained in Example 1 is shown in FIG.

[0086] <Comparative Example 1>

[0087] A honeycomb structure (Si-SiC composite structure) was obtained in the same manner as in Example 1, except that the supply body had no convex portion and the entire lower surface of the supply body was in contact with the honeycomb formed body during the impregnation step. Then, the honeycomb structure was cooled to room temperature (23° C.), and the adhesion state of the supply body to the honeycomb structure was confirmed. Fig.13 A top view photograph of the honeycomb structure obtained in Comparative Example 1 is shown in FIG.

[0088] according to Fig.12 and Fig.13 It is clear that in the impregnation step, by making the contact portion of the supply body with the honeycomb formed body a part of the surface facing the formed body, the adhesion amount of the supply body to the honeycomb structure can be reduced and the adhesion location can be limited.

[0089] [Industrial Application Possibility]

[0090] The method for producing a Si—SiC-based composite structure according to the embodiment of the present invention can be used for the production of various industrial products, and is particularly preferably applied to the production of a heat exchanger.

Claims

1. A method for producing a Si-SiC composite structure, comprising the steps of: heating a supply body containing Si and a molded body containing SiC in a state where the supply body is in contact with the molded body so that a molten metal containing Si is impregnated into the molded body; A convex portion protruding toward the molded body is provided on the surface of the supply body opposite to the molded body, and the convex portion is in contact with the molded body, or a convex portion protruding toward the supply body is provided on the surface of the molded body opposite to the supply body, and the convex portion is in contact with the supply body, thereby making the contact portion of the supply body that contacts the molded body a part of the surface opposite to the molded body.

2. The method for producing a Si-SiC composite structure according to claim 1, characterized in that: The cross section of the convex portion includes an arc shape.

3. The method for producing a Si-SiC composite structure according to claim 1, characterized in that: The convex portion has a pyramid shape.

4. The method for producing a Si-SiC composite structure according to any one of claims 1 to 3, characterized in that: The supply body contacts the molded body at multiple locations. Among the plurality of contact portions of the supply body that are in contact with the molded body, an interval between mutually adjacent contact portions is 78.5 mm or less.

5. The method for producing a Si-SiC composite structure according to any one of claims 1 to 3, characterized in that: A contact portion of the supply body with the molded body extends in a linear shape.

6. The method for producing a Si-SiC composite structure according to any one of claims 1 to 3, characterized in that: The molded body has a honeycomb structure.

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