Manufacturing method for Si-SiC composite structure

Abstract

To provide a production method of Si-SiC-based composite structure capable of improving producibility of Si-SiC-based composite structure.SOLUTION: A production method of Si-SiC-based composite structure includes a step in which, in the state where a donor containing Si is brought into contact with a compact containing SiC, the donor is heated, and a molten metal containing Si is impregnated into the compact. A contact part with the compact of the donor is a part of a surface facing to the compact.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] Si-SiC composite materials have excellent thermal conductivity and are expected to be used in various industrial products. As a method for producing a structure formed from such a Si-SiC composite material (hereinafter referred to as a Si-SiC composite structure), for example, a technique has been proposed in which an impregnation metal supply body containing Si is placed on an impregnation body containing SiC, and then heated to 1200°C or higher and 1600°C or lower, so that the molten metal containing Si is impregnated into the impregnation body (see Patent Document 1).

[0003] However, in this technique, the impregnation process is carried out with the entire lower surface of the impregnation metal supplier in contact with the body to be impregnated, which can result in the impregnation metal supplier adhering (sticking) to the body to be impregnated. If the impregnation metal supplier adheres (sticks) to the body to be impregnated, the mass, dimensions, performance, and other properties of the Si-SiC composite material may fall outside of the acceptable range. Therefore, any excess impregnation metal supplier adhering to the body to be impregnated must be removed, and products from which the impregnation metal supplier cannot be sufficiently removed must be discarded. This can result in a decrease in the yield of Si-SiC composite structures. Furthermore, the location where the impregnation metal supplier adheres to the body to be impregnated may vary for each production of a Si-SiC composite structure, making it difficult to predict the location where the impregnation metal supplier will adhere. Therefore, the process of removing the portion of the impregnation metal supplier adhering to the body to be impregnated may be complicated. As such, the technology described in Patent Document 1 leaves room for improvement in the production efficiency of Si-SiC composite structures. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2011 / 145387 Summary of the Invention [Problem to be solved by the invention]

[0005] A primary object of the present invention is to provide a method for manufacturing a Si-SiC composite structure that can improve the manufacturing efficiency of the Si-SiC composite structure. [Means for solving the problem]

[0006] A method for manufacturing a Si-SiC composite structure according to an embodiment of the present invention includes a step of heating a Si-containing supply body in contact with a SiC-containing compact to impregnate the compact with molten metal containing Si, wherein the contact portion of the supply body with the compact is a part of the surface facing the compact. In one embodiment, a convex portion that protrudes toward the molded body is provided on a surface of the supplier that faces the molded body, and the convex portion comes into contact with the molded body. In one embodiment, the convex portion has a cross-sectional shape of an arc. In one embodiment, the convex portion has a pyramidal shape. In one embodiment, the supply body is in contact with the compact at a plurality of locations, and in this case, the distance between adjacent contact points of the supply body with the compact is 78.5 mm or less. In one embodiment, the contact portion of the supply body with the compact extends linearly. In one embodiment, the molded body has a honeycomb structure. [Effects of the Invention]

[0007] According to the embodiments of the present invention, it is possible to realize a method for manufacturing a Si-SiC composite structure that can improve the manufacturing efficiency of the Si-SiC composite structure. [Brief explanation of the drawings]

[0008] [Figure 1]FIG. 1 is a plan view of a compact according to a method for producing a Si—SiC composite structure in accordance with one embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of a feed body in a method for producing a Si—SiC composite structure according to one embodiment of the present invention. [Figure 3] FIG. 3 is a bottom view of the supply body of FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a state in which the supply body of FIG. 2 is brought into contact with the molded body of FIG. [Figure 5] Fig. 5(a) is a bottom view of a supply body according to another embodiment of the present invention, and Fig. 5(b) is a schematic cross-sectional view showing a state in which the supply body of Fig. 5(a) is in contact with a molded body. [Figure 6] Fig. 6(a) is a bottom view of a supply body according to yet another embodiment of the present invention, and Fig. 6(b) is a schematic cross-sectional view showing a state in which the supply body of Fig. 6(a) is in contact with a molded body. [Figure 7] Fig. 7(a) is a bottom view of a supply body according to yet another embodiment of the present invention, and Fig. 7(b) is a schematic cross-sectional view showing a state in which the supply body of Fig. 7(a) is in contact with a compact. [Figure 8] FIG. 8 is a schematic plan view showing a state in which a supply body according to still another embodiment of the present invention is brought into contact with a compact. [Figure 9] Fig. 9(a) is a bottom view of a supply body according to yet another embodiment of the present invention, and Fig. 9(b) is a schematic cross-sectional view showing a state in which the supply body of Fig. 9(a) is in contact with a molded body. [Figure 10] Fig. 10(a) is a bottom view of a supply body according to yet another embodiment of the present invention, and Fig. 10(b) is a schematic cross-sectional view showing a state in which the supply body of Fig. 10(a) is in contact with a compact. [Figure 11] Fig. 11(a) is a bottom view of a supply body according to yet another embodiment of the present invention, and Fig. 11(b) is a schematic cross-sectional view showing a state in which the supply body of Fig. 11(a) is in contact with a compact. [Figure 12] FIG. 12 shows a plan photograph of the honeycomb structure obtained in Example 1. [Figure 13]FIG. 13 shows a plan photograph of the honeycomb structure obtained in Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

[0010] A. Overview of manufacturing methods for Si-SiC composite structures Figure 1 is a plan view of a molded body in a method for manufacturing a Si-SiC composite structure according to one embodiment of the present invention; Figure 2 is a perspective view of a feed body in a method for manufacturing a Si-SiC composite structure according to one embodiment of the present invention; Figure 3 is a bottom view of the feed body of Figure 2; and Figure 4 is a schematic cross-sectional view showing the state in which the feed body of Figure 2 is in contact with the molded body of Figure 1. A method for producing a Si-SiC composite structure according to one embodiment of the present invention includes a step (impregnation step) of heating a supply body 2 containing Si while bringing the supply body 2 into contact with a compact 1 containing SiC, and impregnating the compact 1 with molten metal containing Si. In the impregnation step, the contact portion of the supply body 2 with the compact 1 is a part of the surface facing the compact 1. The present inventors discovered that if a portion of the supply body is in contact with the compact during the impregnation process, the entire compact can be impregnated with molten metal containing Si through the contact portion, leading to the completion of the present invention. According to the above method, since a portion of the surface of the supply body facing the compact is in contact with the compact during the impregnation process, the amount of supply body adhering to the compact can be reduced compared to when the entire surface of the supply body facing the compact is in contact with the compact. This allows for easy removal of the supply body, improving the yield of Si-SiC composite structures. Furthermore, since the locations where the supply body can adhere can be limited, the process of removing the supply body adhering to the compact can be smoothly carried out. As a result, the manufacturing efficiency of Si-SiC composite structures can be improved.

[0011] The compact is an object to be impregnated with the molten metal containing Si in the impregnation step. As described above, the compact contains SiC as a main component. In this specification, the term "SiC" is intended to encompass not only pure SiC but also SiC containing unavoidable impurities. The constituent material of the compact may contain Al and / or Si in addition to SiC. The constituent material of the compact may also contain a molding aid. The SiC content in the compact is, for example, 50% by mass or more, preferably 85% by mass or more, and, for example, 100% by mass or less, preferably 95% by mass or less.

[0012] As described above, the supply body contains Si as a main component. The supply body constituent material may contain Al in addition to Si. The supply body constituent material may further contain a molding aid. The Si content in the supply body is, for example, 50 mass% or more, preferably 90 mass% or more, and more preferably 95 mass% or more, and is, for example, 100 mass% or less, preferably 97 mass% or less, and more preferably 96 mass% or less. If the Si content in the supply body is within this range, the Si-containing molten metal can be uniformly impregnated into the entire compact in the impregnation step, and the amount of Si impregnated in the Si-SiC composite structure can be made uniform.

[0013] In one embodiment, the supply body 2 contacts the compact 1 at multiple locations. Among the multiple contact portions of the supply body 2 with the compact 1, the distance L between adjacent contact portions is 78.5 mm or less, preferably 70 mm or less, and more preferably 60 mm or less. When the distance L between adjacent contact portions is equal to or less than the above-mentioned upper limit, the entire compact can be more uniformly impregnated with the Si-containing molten metal in the impregnation step, and the occurrence of insufficiently impregnated portions of the Si-SiC composite structure (lack of Si impregnation) can be suppressed. As a result, the variation in performance of the Si-SiC composite structure can be suppressed, and Si-SiC composite structures with excellent performance can be stably manufactured. In particular, when the Si content in the supply body is within the above-mentioned range and the distance L between adjacent contact portions is equal to or less than the above-mentioned upper limit, the amount of Si impregnation in the Si-SiC composite structure can be further uniform. The lower limit of the distance L between adjacent contact portions is typically 10 mm or more. In one embodiment, the distance between the contact portion between the supply body and the compact and the end face of the compact is equal to or less than half of the distance L. With this configuration, the entire compact can be more uniformly impregnated with the molten metal containing Si in the impregnation step.

[0014] The contact of the supply body 2 with the molded body 1 may be point contact, line contact, or surface contact. When the supply body 2 is in contact with the molded body 1 at multiple locations, all of the multiple contact portions may be point contact, line contact, or surface contact, or may include two or more of point contact, line contact, and surface contact. When the supply body 2 and the molded body 1 are in surface contact, the spacing L between adjacent contact portions and the distance between the contact portion and the end face of the molded body are measured based on the end (edge) of the surface contact portion. For example, the spacing L between adjacent surface contact portions means the distance from the end (edge) of one surface contact portion to the end (edge) of the other surface contact portion, and the spacing L between adjacent surface contact portions and point contact portions means the distance from the end (edge) of the surface contact portion to the point contact portion.

[0015] The area of ​​the contact portion between the supply body and the compact (if there are multiple contact portions, the total area of ​​the 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 compact is taken as 100%. If the area of ​​the contact portion is not more than the above upper limit, the amount of the supply body adhering to the compact can be further reduced, and the production efficiency of the Si-SiC composite structure can be further improved. The lower limit of the area of ​​the contact portion is typically 1% or more.

[0016] In the impregnation step, typically, the molded body 1 containing SiC is brought into contact with the supply body 2 containing Si, and the molded body 1 and the supply body 2 are heated. The heating temperature is, for example, 1200°C or higher, preferably 1300°C or higher, and, for example, 1600°C or lower, preferably 1500°C or lower. The heating time is, for example, 10 minutes or longer, preferably 1 hour or longer. When the heating temperature is within the above range and / or the heating time is equal to or longer than the lower limit, the molded body can be smoothly impregnated with the molten metal containing Si. The upper limit of the heating time is typically 10 hours or shorter, preferably 5 hours or shorter. When the heating time is equal to or shorter than the upper limit, the production efficiency of the Si-SiC composite structure can be further improved. The impregnation step is preferably carried out under reduced pressure. When the impregnation step is carried out under reduced pressure, the molten metal containing Si can be more smoothly impregnated into the molded body. The pressure in the impregnation step is, for example, 500 Pa or less, preferably 300 Pa or less, more preferably 200 Pa or less, and typically 10 Pa or more. The impregnation step can also be carried out under normal pressure (0.1 MPa).

[0017] The following describes the compact and the feed material used in the method for producing a Si-SiC composite structure.

[0018] B. Molded body (honeycomb molded body) The molded body may have any suitable shape depending on the application of the Si-SiC composite structure. Examples of the molded body shape include a cylindrical shape, an elliptical cylindrical shape, and a rectangular prism shape. Furthermore, the molded body may have a hollow region at the center in a cross section perpendicular to the axial direction (lengthwise direction) of the molded body. In one embodiment, the formed body is a honeycomb formed body having a honeycomb structure. When the formed body is a honeycomb formed body, the Si-SiC composite structure can be a honeycomb structure. The honeycomb formed body has a plurality of cells. The cells extend from a first end face to a second end face of the honeycomb formed body in the axial direction (length direction) of the honeycomb formed body. The cells have any appropriate shape in a cross section in a direction perpendicular to the axial direction of the honeycomb formed body. Examples of the cross-sectional shape of the cells include triangles, rectangles, pentagons, hexagons, and other polygons. The cross-sectional shapes and sizes of the cells may all be the same, or at least some may be different.

[0019] One embodiment of a honeycomb formed body is shown in FIG. 1. The honeycomb formed body 1a has a cylindrical shape and has a hollow region at its center. The first end face (upper face) and the second end face (lower face) of the honeycomb formed body 1a are each flat surfaces perpendicular to the axial direction of the honeycomb formed body. The outer diameter of the honeycomb formed body can be appropriately set depending on the purpose. The outer diameter of the honeycomb formed body can be, for example, 20 mm to 200 mm, or can be, for example, 30 mm to 100 mm. Note that when the cross-sectional shape of the honeycomb formed body is not circular, the diameter of the largest inscribed circle inscribed in the cross-sectional shape (e.g., polygonal) 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 depending on the purpose. The length of the honeycomb formed body can be, for example, 3 mm to 200 mm, or can be, for example, 5 mm to 100 mm, or can be, for example, 10 mm to 50 mm. 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 .

[0020] The outer peripheral wall 11 has a cylindrical shape. The inner peripheral wall 12 has a cylindrical shape with a smaller diameter than the outer peripheral wall 11. The outer peripheral wall 11 and the inner peripheral wall 12 share an axis. The thickness of each of the outer peripheral wall 11 and the inner peripheral wall 12 can be appropriately set depending on the application 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, or 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 walls (e.g., cracks, breakage) due to external forces can be suppressed.

[0021] The partition walls 13 define a plurality of cells 14. More specifically, the partition walls 13 have first partition walls 13a extending in the radial direction from the inner peripheral wall 12 to the outer peripheral wall 11 and second partition walls 13b extending in the circumferential direction, and the first partition walls 13a and the second partition walls 13b define a plurality of cells 14. The cross-sectional shape of the cells 14 is quadrilateral (a rectangle whose length is in the radial direction of the honeycomb molded body). Furthermore, although not shown, the first partition wall 13a and the second partition wall 13b may be perpendicular to each other and define cells 14 having a quadrangular (square) cross-sectional shape except for the portions in contact with the inner peripheral wall 12 and the outer peripheral wall 11. The cell density (i.e., 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 depending on the purpose. The cell density is, for example, 4 cells / cm 2 ~320 cells / cm 2 If the cell density is in this range, the strength and effective GSA (geometric surface area) of the honeycomb structure can be sufficiently ensured. The thickness of the partition walls 13 can be appropriately set depending on the application of the honeycomb structure. The thickness of the partition walls 13 is typically thinner than the thickness of each of the outer peripheral wall 11 and the inner peripheral wall 12. The thickness of the partition walls 13 can be, for example, 0.1 mm to 1.0 mm, or can be, for example, 0.2 mm to 0.6 mm. When the thickness of the partition walls is within this range, the mechanical strength of the honeycomb structure can be made sufficient, and the opening area (the total area of ​​the cells in the cross section) can be made sufficient.

[0022] The porosity of each of the outer peripheral wall 11, the inner peripheral wall 12, and the partition walls 13 can be appropriately set depending on the purpose. The porosity is, for example, 15% or more, preferably 20% or more, and for example, 50% or less, preferably 45% or less. The porosity can be measured, for example, by mercury porosimetry. If the porosity of the outer peripheral wall, the inner peripheral wall, and the partition walls is within such range, the molten metal can be impregnated into the honeycomb formed body by utilizing capillary force in the impregnation step. The densities of the outer peripheral wall 11, the inner peripheral wall 12, and the partition walls 13 (densities of the compacts) can be appropriately set depending on the purpose. 3 or more, preferably 1.8 g / cm 3 or more, for example, 2.6 g / cm 3 or less, preferably 2.8 g / cm 3 The density can be measured by, for example, mercury intrusion porosimetry. When the densities of the outer peripheral wall, the inner peripheral wall, and the partition walls are within such ranges, voids can be formed inside the outer peripheral wall, the inner peripheral wall, and the partition walls with the above-mentioned porosity.

[0023] 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 resulting mixture is kneaded to form a clay. The clay is then molded (typically by extrusion molding) into a desired shape and dried to produce a dried body (honeycomb dried body). Next, the dried body (honeycomb dried body) is processed to a predetermined shape, thereby obtaining a molded body (honeycomb molded body) of the desired shape.

[0024] C. Supply body The supply body may have any appropriate shape depending on the shape of the molded body. The supply body may have, for example, a plate shape having a predetermined thickness. Examples of the cross-sectional shape of the supply body in a direction perpendicular to the thickness direction include a circle, an ellipse, and a polygon. The supply body may also have a hollow region in the center of its cross section. A supply body having a hollow region is a so-called donut shape.

[0025] In one embodiment, the supply body has a protrusion. A supply body having a protrusion is shown in Figures 2 to 8. As shown in FIGS. 2 and 3, the supplier 2 includes a main body 21 having a disk shape (annular disk shape) with a hollow region in the center; and a plurality of protrusions 22 protruding from the main body 21. The thickness of the main body 21 can be set appropriately depending on the purpose. The thickness of the main body 21 can be, for example, 5 mm to 25 mm, or can be, for example, 8 mm to 15 mm. The plurality of protrusions 22 are provided on one surface in the thickness direction of the main body 21. The plurality of protrusions 22 are typically arranged at equal intervals in the circumferential direction of the main body 21. The number of protrusions 22 is four in the illustrated example, but is not limited thereto. The number of protrusions 22 may be, for example, 4 to 20, or may be, for example, 4 to 10. The protrusion length of the protrusions 22 (the dimension in the thickness direction of the main body) may be appropriately set depending on the purpose. The protrusion length of the protrusions 22 may be, for example, 0.5 mm to 5 mm, or may be, for example, 1 mm to 3 mm. As shown in FIG. 4 , the protrusions 22 have an arc-shaped cross section in the thickness direction of the main body 21 (arc-shaped cross section). In one embodiment, the protrusions may be hemispherical. When the protrusions have an arc-shaped cross section, chipping is less likely to occur in the protrusions during production of the supply body (particularly press molding). Therefore, shape stability during production of the supply body can be expected.

[0026] In the impregnation step, such a supply body 2 is placed on the formed body 1 (honeycomb formed body 1a) so that the protrusions 22 come into contact with the first end face of the formed body 1 (honeycomb formed body 1a). In this state, the surface of the supply body 2 including the protrusions 22 faces the formed body 1 (honeycomb formed body 1a), and the protrusions 22 protrude from the main body 21 toward the formed body 1. A part of the protrusions 22 (more specifically, the apex of the arc) comes into contact with the first end face of the formed body 1 (honeycomb formed body 1a).

[0027] 5, the main body 21 does not have to have a hollow region. Furthermore, the size of the protrusion 22 is not particularly limited. As shown in Figures 6 and 7, the protrusions 22 may have a pyramidal shape. When the protrusions have a pyramidal shape, the contact position with the compact can be set with greater precision than when the protrusions have an arc-shaped cross section. This allows for more precise control of the location where the supply material may adhere, and the process of removing the supply material adhered to the compact can be carried out more smoothly. Examples of pyramidal shapes include triangular pyramids, quadrangular pyramids, and polygonal pyramids with pentagonal or higher angles. The angle of the apex of the pyramidal protrusions can be set to any appropriate value. 8, the main body 21 may have a columnar (cylindrical) shape with a hollow region in the center, and the protrusions 22 may be provided on the outer peripheral surface of the main body 21. In this case, the formed body 1 (honeycomb formed body 1a) has a hollow region. In the impregnation step, the supply body 2 is placed in the hollow region of the formed body 1 (honeycomb formed body 1a), and the protrusions 22 come into contact with the inner peripheral surface of the formed body 1 (honeycomb formed body 1a).

[0028] In one embodiment, the contact portion of the supply body with the compact extends linearly. Supply bodies that can be in linear contact with the compact are shown in Figures 9 to 11. When the contact portion of the supply body with the compact extends linearly, even if damage such as chipping occurs in part of the contact portion, a sufficient contact area between the supply body and the compact can be ensured, and loss of Si impregnation in the Si-SiC composite structure can be stably suppressed.

[0029] As shown in Fig. 9, the supply body 2 has a so-called doughnut shape. The surface of the supply body 2 facing the molded body 1 has an arc-shaped cross section in the thickness direction (arc-shaped cross section). The arc-shaped cross section surface extends over the entire circumferential direction of the supply body 2. In the impregnation step, a part of the arc-shaped cross section surface of the supply body 2 (more specifically, the vertex portion) comes into contact with the molded body 1 (honeycomb molded body 1a) in a line extending in the circumferential direction of the supply body. 10, the surface of the supply body 2 facing the formed body 1 may have a V-shaped cross section in the thickness direction (V-shaped cross section). The angle of the vertex of the V-shaped cross section may be set to any appropriate value. 9 and 10, the supply body 2 has a hollow region, but it may not have a hollow region. In this case, although not shown, 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 edge of the disk-shaped main body and may correspond to a convex portion. Also, as shown in FIG. 11, the supply body 2 may have a circular cross-section.

[0030] Such a supply body can be produced by the following method: A material powder containing Si powder is molded into a desired shape (typically by press molding), and then dried to obtain a supply body of the desired shape.

[0031] In the above-described embodiment, the supply body having the specific structure (protrusion, 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, the molded body may be provided with a protrusion, which is brought into contact with the flat end surface of the supply body. This also allows a portion of the surface of the supply body facing the molded body to come into contact with the molded body.

[0032] Furthermore, in the above-described embodiment, the supply body and the compact are in direct contact with each other. However, the supply body and the compact may be in contact with each other via a relay member. In this case, the contact portion of the supply body with the compact refers to the contact portion of the supply body with the relay member. This also reduces the amount of supply body attached to the compact. The relay member is separate from the supply body and the compact, and typically has a shape similar to the convex portion. In one embodiment, the relay member is sandwiched between the flat first end surface of the compact and the flat end surface of the supply body during the impregnation process. Examples of materials constituting the relay member include the above-described materials constituting the compact, the above-described materials constituting the supply body, and SiC precursor materials (e.g., carbon). [Example]

[0033] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. Example 1 1. Preparation of honeycomb molded body A clay containing SiC powder and molding aid powder was extruded into the shape shown in Figure 1 and then dried to obtain a dried honeycomb body. Next, the outer surface of the dried honeycomb body was processed to obtain a honeycomb formed body. The honeycomb formed body had an outer peripheral wall (outer diameter 86 mm), an inner peripheral wall (inner diameter 66 mm) located inside the outer peripheral wall, and partition walls located between the outer peripheral wall and the inner peripheral wall to define a plurality of cells. The cell density of the honeycomb formed body was 56 cells / cm. 2 The thickness of the partition wall was 0.3 mm, and the thickness of each of the outer peripheral wall and the inner peripheral wall was 2 mm.

[0034] 2. Preparation of Donor Bodies A material powder containing Si powder and molding aid powder was press-molded into the shape shown in Fig. 2 and then dried to obtain a supply body. The supply body had a main body in the shape of an annular disk (inner diameter 41 mm, outer diameter 73 mm, thickness 10 mm) and four protrusions protruding from the main body.

[0035] 3.Impregnation process Next, as shown in Fig. 4, the supply body was placed on the honeycomb formed body so that the convex portions of the supply body were in contact with the honeycomb formed body, and then heated at 1500°C for 4 hours under reduced pressure (200 Pa) to impregnate the honeycomb formed body with the molten metal containing Si. The distance between adjacent contact portions between the convex portions and the honeycomb formed body was 54 mm. In this way, a honeycomb structure (Si-SiC composite structure) was obtained. After that, the honeycomb structure was cooled to room temperature (23°C), and the state of adhesion of the supply body to the honeycomb structure was confirmed. Fig. 12 shows a plan view of the honeycomb structure obtained in Example 1.

[0036] <Comparative Example 1> A honeycomb structure (Si-SiC composite structure) was obtained in the same manner as in Example 1, except that the supply body did not have any protrusions and the entire lower surface of the supply body was brought into contact with the honeycomb formed body in the impregnation process. Thereafter, 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 shows a plan photograph of the honeycomb structure obtained in Comparative Example 1.

[0037] As is clear from Figures 12 and 13, in the impregnation process, by making the contact portion of the supply body with the honeycomb molded body part of the surface facing the molded body, the amount of adhesion (sticking) of the supply body to the honeycomb structure can be reduced and the areas of adhesion (sticking) can be limited. [Industrial Applicability]

[0038] The method for manufacturing a Si-SiC composite structure according to an embodiment of the present invention can be used to manufacture various industrial products, and can be particularly suitably used to manufacture heat exchangers. [Explanation of symbols]

[0039] 1. Molded body 1a Honeycomb molded body 2 supply body 21 Convex part

Claims

1. a step of heating a supply body containing Si in a state in which the supply body is brought into contact with a compact containing SiC, thereby impregnating the compact with molten metal containing Si, the contact portion of the supply body with the compact is a part of a surface facing the compact, an area of ​​the contact portion of the supply body with the molded body is 40% or less when an area of ​​a surface of the supply body facing the molded body is 100%; the supply body is a solidified body of a material powder containing Si powder, In the method for producing a Si-SiC composite structure, the Si content in the supply body is 90 mass % or more.

2. 2. The method for producing a Si-SiC composite structure according to claim 1, wherein a surface of the supply body facing the compact is provided with a protrusion that protrudes toward the compact, and the protrusion comes into contact with the compact.

3. The method for producing a Si-SiC composite structure according to claim 2, wherein the protrusions have a cross-sectional shape of an arc.

4. The method for producing a Si-SiC composite structure according to claim 2, wherein the protrusions have a pyramidal shape.

5. the supply body is in contact with the compact at a plurality of points, 5. The method for producing a Si-SiC composite structure according to claim 1, wherein, of the plurality of contact portions of the supply body with the compact, the distance between adjacent contact portions is 78.5 mm or less.

6. 6. The method for producing a Si-SiC composite structure according to claim 1, wherein the contact portion of said supply body with said compact extends linearly.

7. The method for producing a Si-SiC composite structure according to any one of claims 1 to 6, wherein the formed body has a honeycomb structure.

Images