Composite material and production method for same

Abstract

Provided is a production technique for a composite material that makes it possible to produce, on demand, a composite material that allows for length and puts few limitations on shape while still having desired properties and also exhibits substantial bonding strength. According to the present invention, a production method for a composite material comprises a shaped material preparation step for preparing a metal shaped material that has a polygonal columnar shape that has surfaces at which grooves are formed in the longitudinal direction, an intermediate material production step for inserting respective cores that have shapes that match the shapes of the grooves into the grooves in the shaped material to produce an intermediate material, and a composite material production step for pressing the intermediate material from side surfaces to plastically work the intermediate material and compound the shaped material and the cores and thereby produce a composite material that has desired properties.

Description

Composite materials and methods for manufacturing the same

[0001] The present invention relates to composite materials and methods for manufacturing the same, and more particularly to a method for efficiently manufacturing a composite material having desired properties in a short time, and to a composite material manufactured by the said manufacturing method.

[0002] In recent years, with the progression of global warming, "multi-material design," a design method that optimizes cost and performance by combining various materials such as metals and fiber-reinforced plastics and placing them in the right places, has been attracting attention in the design of automobiles, aircraft, and other products in order to reduce carbon dioxide emissions.

[0003] However, the aforementioned "multi-material design" approach has drawbacks, such as the need for trial and error and inefficiency, because the shape is determined and performance is verified only after selecting the appropriate material for each component through topology optimization, etc.

[0004] Therefore, the concept of "multi-property design" has been proposed, which involves changing the selected material from a single material with constant material properties to a composite material whose properties can be arbitrarily altered, thereby designing and fixing the shape regardless of the material properties. When this concept is applied, the optimal material solution for a given shape can be determined, reducing the time required for trials, making it easier to conduct comparative verification over a wide range, and enabling the on-demand provision of materials with any desired product properties.

[0005] Based on the concept of "multi-property design" described above, the inventors first proposed a technology for manufacturing composite materials by inserting a core material into a pipe material (sheath material) and then extruding it (multi-core clad extrusion) (Patent Document 1), demonstrating that "multi-property design" is feasible.

[0006] WO2023 / 063185 publication

[0007] However, since the multi-core clad extrusion described above is performed using dies, the product shape is limited by the die shape, and it was necessary to change the die to match different product shapes. Furthermore, because the core material is inserted from the end of the sheath material to form the billet, it was difficult to make the product long. In addition, the filling rate of the core material inside the sheath material was sometimes low, and sufficient joint strength could not be achieved.

[0008] Therefore, the object of the present invention is to provide a composite material manufacturing technology that enables the on-demand production of composite materials that have desired properties, have fewer limitations on product shape, allow for product lengthening, and exhibit sufficient bonding strength.

[0009] The inventors of this invention have diligently studied how to solve the above problems and have found that the above problems can be solved by the invention described below, thus completing the present invention.

[0010] The invention described in claim 1 is a method for manufacturing a composite material, comprising: a profile preparation step of preparing a metal profile in the shape of a polygonal prism having a surface with grooves formed in the longitudinal direction; an intermediate material manufacturing step of inserting core materials shaped to match the shape of the grooves into each of the grooves of the profile to produce an intermediate material; and a composite material manufacturing step of plastically processing the produced intermediate material by pressing it from the side to composite the profile and the core material to produce a composite material with desired properties.

[0011] The invention described in claim 2 is a method for manufacturing a composite material according to claim 1, characterized in that the shape of the groove is a quadrangular prism.

[0012] The invention described in claim 3 is a method for manufacturing a composite material according to claim 1, characterized in that the profile is a swastika-shaped or inverted swastika-shaped material having a cross-sectional shape with four-fold symmetry.

[0013] The invention described in claim 4 is a method for manufacturing a composite material according to claim 3, characterized in that the cross-sectional shape of the intermediate material is square or rectangular.

[0014] The invention described in claim 5 is a method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that the plastic deformation is one of compression, rolling, extrusion, drawing, or forging.

[0015] The invention described in claim 6 is a method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that two or more materials selected from among a plurality of metal materials and a plurality of polymer materials are used as the core material.

[0016] The invention described in claim 7 is a method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that a plurality of the core materials are used and are inserted into grooves at positions that are symmetrical to the line or point of the profile.

[0017] The invention described in claim 8 is a method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that a square wire is used as the core material.

[0018] The invention described in claim 9 is a method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that the core material is a core material formed by combining multiple types of materials in a shape that conforms to the groove shape.

[0019] The invention described in claim 10 is a method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that, based on the characteristics of the profile and the core material, the characteristics of the profile and the core material are used to predict the characteristics of the composite material obtained by the combination of the profile and the core material, the configuration of the intermediate material necessary to obtain a composite material with desired characteristics is determined by referring to the prediction, the intermediate material is manufactured based on the determined configuration, and then plastically processed to manufacture a composite material with desired characteristics.

[0020] The invention described in claim 11 is a method for manufacturing a composite material according to claim 10, characterized in that machine learning is used when predicting the properties of the composite material.

[0021] The invention described in claim 12 is a method for manufacturing a composite material according to claim 11, characterized in that the machine learning is one of a neural network, deep learning, or clustering.

[0022] The invention described in claim 13 is a method for manufacturing a composite material, comprising: a profile preparation step of preparing a metal profile in the shape of a polygonal prism having a surface with grooves formed in the longitudinal direction; an intermediate material manufacturing step of manufacturing an intermediate material by inserting a core material shaped to match the shape of the grooves into each of the grooves of the profile; and a composite material manufacturing step of manufacturing a composite material having desired properties by pressing the manufactured intermediate material from the side to perform plastic deformation and compounding the profile and the core material, wherein the core material is a composite material manufactured by the composite material manufacturing method described in claim 1.

[0023] The invention described in claim 14 is a composite material characterized by being manufactured by the method for manufacturing a composite material described in any one of claims 1 to 4, or claim 13.

[0024] According to the present invention, it is possible to provide a composite material manufacturing technology that enables the on-demand production of composite materials that possess desired properties, have minimal limitations on product shape, allow for product lengthening, and exhibit sufficient bonding strength.

[0025] This is a schematic perspective view and a schematic cross-sectional view illustrating an example of a combination of profile and core material in one embodiment of the present invention. This is a diagram illustrating an example of the manufacturing flow of a composite material in one embodiment of the present invention. This is a schematic cross-sectional view illustrating an example of the arrangement of profile and core material in an embodiment of the present invention. This is a diagram illustrating a cross-section of a compressed clad material in an embodiment of the present invention. This is a diagram illustrating the contact portion between the profile and core material in an embodiment of the present invention. This is a radar chart created based on measured values ​​of the properties of the compressed clad material in an embodiment of the present invention. This is a graph illustrating the relationship between predicted and measured values ​​of density in an embodiment of the present invention. This is a graph illustrating the relationship between predicted and measured values ​​of electrical resistance in an embodiment of the present invention. This is a graph illustrating the relationship between predicted and measured values ​​of bending stiffness in an embodiment of the present invention. This is a graph showing the relationship between density and the reciprocal of electrical resistivity (electrical conductivity) in an embodiment of the present invention. This is a graph showing the relationship between density and bending stiffness in an embodiment of the present invention.

[0026] The present invention will be described below based on embodiments.

[0027] 1. Basic Concept of the Invention First, the basic concept of the present invention will be explained.

[0028] As mentioned above, multi-core clad extrusion technology has several problems, including: (1) the product shape is limited by the die shape because it is performed using a die; (2) the die needs to be changed to match the product shape; (3) it is not easy to insert long core materials from the end of the sheath material; and (4) the core material filling rate may be low, making it impossible to achieve sufficient bonding strength. For these reasons, it has not yet been sufficient as a technology for on-demand manufacturing of composite materials that have the desired properties and can be made into long lengths.

[0029] The inventors conducted thorough research and, as a means of increasing the length of composite materials, first conceived of using a metal profile with an insertion opening on its side, that is, a polygonal prism shape having a surface with grooves formed in the longitudinal direction, instead of a tubular sheath material as the member into which the core material is inserted.

[0030] A metal profile with a polygonal prism shape having a surface with grooves formed in the longitudinal direction can be easily made into a clad material with a polygonal prism shape by easily inserting a core material into the grooves from the side surface of the profile, even if it is long. Therefore, it is possible to easily lengthen the composite material. And by making the shape of the core material match the shape of the groove, the core material can be inserted into the groove at a high filling rate, so that sufficient bonding strength can be exhibited in the obtained composite material.

[0031] Furthermore, as a means for easily corresponding to the product shape, it occurred to adopt plastic processing such as compression processing, rolling processing, extrusion processing, drawing processing, forging processing, etc., and press the clad material from the side surface.

[0032] In the plastic processing of pressing the clad material from the side surface, since the dimensions after compression can be changed by the reduction ratio, it is easy to respond to changes in the shape of the product due to design changes, and it is possible to shorten the time required for prototyping the composite material.

[0033] As a specific example, when a clad material with a square or rectangular cross section is formed by inserting a core material into the groove of a swastika-shaped angle bar described later, processing can be performed from two directions. Therefore, by adjusting the degree of processing for each pass, the width and thickness of the product can be arbitrarily changed, and it is possible to respond to even a slight change in shape. Also, by reducing the cross-sectional area by plastic processing in multiple passes, it becomes possible to use the integrated product as a new core material, and it is considered that the controllable range expands. For example, when a 10×10 mm clad material is reduced to 4×4 mm in cross-sectional area (a 84% reduction in cross-sectional area or a 6.25-fold increase in length) by H-V type (alternating in the longitudinal and transverse directions) rolling or compression, as described later, the obtained composite material can be treated as a core material (nested).

[0034] As a result, it is possible to provide a manufacturing technique for a composite material that can manufacture, on demand, a composite material that has desired properties, has little restriction on the product shape, can be lengthened, and exhibits sufficient bonding strength. In other words, since creation and adjustment of dimensions according to the product shape can be carried out simultaneously, it can be considered to be close to an ideal design method in "multi-property design".

[0035] That is, the present invention includes a shaped material preparation step of preparing a shaped material made of metal in a polygonal prism shape having a surface with a groove formed in the longitudinal direction, an intermediate material production step of inserting a core material having a shape matching the shape of the groove into each of the grooves of the shaped material to produce an intermediate material, and a composite material production step of pressing and plastically processing the produced intermediate material from the side surface to composite the shaped material and the core material to produce a composite material having desired properties. It is a manufacturing method for a composite material characterized by this.

[0036] In the above, the shaped material is not limited as long as it can restrain the inserted core material as much as possible and has a shape to which multi-pass processing can be applied by changing the direction. Also, the shape of the groove is not particularly limited as long as an opening portion serving as an insertion portion and a wall surface portion serving as a restraint portion are formed. However, from the viewpoint of easily inserting the core material at a high filling rate, for example, a triangular groove composed of one opening surface and two wall surfaces, or a quadrangular groove composed of one opening surface and three wall surfaces can be cited as a preferable groove shape. And, from the viewpoint of a high filling rate, the shape of the core material is preferably a shape along the groove shape. In addition, considering the possibility of breakage during processing, the shaped material is preferably a shaped material made of a metal material. On the other hand, the core material is not limited to a metal material and may be a polymer material such as plastic, rubber, or carbon fiber.

[0037] The inventors have come to think that among such shaped materials, a swastika-shaped square bar (hereinafter also referred to as "swastika-shaped material") having a four-fold symmetric cross section shown in FIG. 1 is suitable as the shaped material.

[0038] In other words, the swastika-shaped material has grooves on all four sides, and can be plastically deformed by simultaneously compressing two sides. Furthermore, a clad material can be formed by inserting a thin core material into the grooves of the swastika-shaped material. The core material in contact with the three sides of the swastika-shaped material other than the opening is constrained by the walls of the swastika-shaped material, so that the interface between the core material and the shaped material can be filled with almost no voids. This is also preferable because it enables stable processing during plastic deformation.

[0039] In this case, the filling ratio of the core material can be easily adjusted by thinning the wall portion of the swastika-shaped material or by making the core material thicker. Preferably, the core material is inserted into grooves at positions that are symmetrical to the line or point of the shape. Furthermore, if necessary, different core materials can be inserted and arranged in the longitudinal direction to change the properties in the longitudinal direction, thus allowing for three-dimensional control of the properties. In addition, since the core materials do not come into direct contact with each other, the properties can be predicted more easily.

[0040] Furthermore, as the core material inserted into a single groove, in addition to a core material formed from a single type of metal material to match the groove shape, a core material may be used that is formed by combining two or more materials selected from multiple types of metal materials and multiple types of polymer materials to conform to the groove shape. Also, a composite material manufactured using the manufacturing method of the present invention may be used as the core material, thereby allowing for more precise adjustment of the properties of the composite material.

[0041] Furthermore, the materials of the profiles and core materials can be appropriately selected according to the required product characteristics. For example, in the case of the "manji profile" shown in Figure 1, two different types of core materials, 1 and 2, are arranged diagonally opposite each other. As shown in the examples described later, core materials 1 and 2 may be made of the same material as the profile, or they may be made of different materials. It is also possible for all four core materials to be made of different materials.

[0042] Although the above explanation uses a "swastika-shaped material" as an example, a "reverse swastika-shaped material" would also be acceptable.

[0043] 2. Manufacturing of specific composite materials Next, we will explain the manufacturing of specific composite materials.

[0044] Figure 2 shows an example of the manufacturing flow of the composite material in this embodiment. The following explanation will be given in reference to Figure 2.

[0045] (1) Product Design First, design the product to determine what kind of product (composite material) is required to be manufactured.

[0046] (2) Design of the shape Next, the shape of the product is designed, and at the same time, the dimensions of the components (profiles, core materials) required for the product are determined.

[0047] (3) Determining required characteristics Next, the characteristics required for the product are determined. Based on the determined characteristics, the composition of the clad material, which is an intermediate material, is decided. That is, the material type of the profiles and core material, the shape of the profiles, and the insertion position (placement position) of the core material are determined to decide on the composition of the clad material.

[0048] Furthermore, the properties of the composite material obtained based on the determined cladding configuration should be confirmed to satisfy the specified properties through the composite material property prediction method described later.

[0049] In addition, we will determine the plastic deformation conditions that allow the clad material to be uniformly deformed without fracture.

[0050] (4) Manufacturing of Composite Materials Next, based on the configuration of the clad materials determined above, the clad materials are assembled and plastically processed to manufacture the composite materials.

[0051] Specific plastic deformation processes include rolling processes such as H-V rolling (horizontal and vertical rolling), universal rolling, and four-way roll rolling, as well as extrusion, drawing using bore dies, roller dies, or Turkshead (four-way roller dies), and forging processes such as upsetting and swaging. However, these are not limited to these processes, and other plastic deformation processes may be employed.

[0052] (5) Verification of properties Next, measure the properties of the fabricated composite material and verify that it satisfies the specified properties. At this time, if it does not satisfy the specified properties, return to the above “(2) Shape design” and repeat until it is verified that the specified properties are satisfied.

[0053] (6) Fabrication of the product Finally, in the verification of properties, if it is confirmed that there are no problems, proceed to the fabrication of the actual product.

[0054] 3. Prediction of properties of composite materials As described above, when fabricating a composite material, it is necessary to predict the properties of the composite material in advance.

[0055] Hereinafter, as the properties of the composite material to be predicted, the density, electrical conductivity, and flexural rigidity in the composite metal material shown in the examples described later will be given, and the prediction from the respective property values of the profile material (卍-shaped material) and the core material before processing will be explained. However, for other property predictions, similarly, they can be considered based on the composite rule. Hereinafter, aluminum, copper, and stainless steel are used as the core materials.

[0056] (1) Density The density ρ of the composite metal material can be predicted by an arithmetic mean according to the composite rule as shown in the following formula, corresponding to the cross-sectional area ratio before processing. At this time, it is assumed that no voids remain after processing and there is no density change.

[0057]

[0058] In the above formula, ρ ｓ , f ｓ is the density and cross-sectional area ratio of the 卍-shaped material, ρ Ａｌ , ρ Ｃｕ , ρ Ｆｅ are the densities of aluminum, copper, and stainless steel, respectively, n Ａｌ , n Ｃｕ , n Ｆｅ are the numbers of aluminum, copper, and stainless steel core materials inserted, respectively, and f ｆ indicates the cross-sectional area ratio of one core material.

[0059] As a method for measuring density, the Archimedes method can preferably be used. Specifically, the density of pure water at room temperature is ρ ０ , the weight of the sample in air is w Ａ, the weight underwater lol Ｂ Given this, the density ρ of the sample can be calculated using the following formula.

[0060]

[0061] (2) Electrical conductivity Electrical conductivity is the reciprocal of electrical resistivity, and the composite law holds. Therefore, assuming that the swastika-shaped material and all the core materials are connected in parallel, the electrical resistivity κ and its reciprocal, the electrical conductivity 1 / κ of the composite metal material can be predicted by calculating the harmonic mean of their electrical resistivity from the following formula.

[0062]

[0063] In the above equation, κ ｓ The electrical resistivity of the swastika-shaped material is κ. Ａｌ κ Ｃｕ κ Ｆｅ These represent the electrical resistivity of aluminum, copper, and stainless steel, respectively. Also, as described above, f ｓ n is the cross-sectional area ratio of the swastika-shaped material. Ａｌ , n Ｃｕ , n Ｆｅ The number of aluminum, copper, and stainless steel core materials inserted is f ｆ This indicates the cross-sectional area ratio of a single core material.

[0064] Furthermore, the four-terminal method is preferably used as the method for measuring electrical resistivity. Specifically, in the embodiment described later, an electric current is passed through the swastika-shaped portion of the composite metal material, and voltage terminals are pressed against the center of the swastika-shaped portion on the opposite side at intervals of 20.0 mm to measure the voltage. The current value is set to two levels, 1 A and 2 A, and the resistance R is obtained by dividing each measured voltage value by the current value, and these are averaged to obtain the resistance value. If the resistance of the sample is R, the cross-sectional area is A, and the distance between the voltage terminals is l, the electrical resistivity κ can be calculated from the following formula.

[0065]

[0066] (3) Bending stiffness The bending stiffness can be predicted by determining the cross-sectional area and centroid of the entire clad material and each core material from images of the cross-section taken after cutting and polishing the composite metal material, and then determining the second moment of area of ​​the swastika-shaped material and each core material.

[0067] Furthermore, when predicting bending stiffness, it is assumed that the elongation due to compression is 0, i.e., that the plane strain condition is met, and that the swastika-shaped members and all core materials are uniformly compressed by 5%.

[0068] (4) Others Although the above prediction uses a compound rule, machine learning may also be used. Higher accuracy can be expected by using machine learning. As for machine learning, known methods such as supervised learning such as neural networks and deep learning, and unsupervised learning such as clustering can be used.

[0069] 4. Examples The present invention will be described in more detail below with reference to specific examples.

[0070] (1) Preparation of the swastika-shaped material and core material First, the swastika-shaped material and core material were prepared.

[0071] (i) Preparation of the swastika-shaped material A 50 mm long, square-shaped pure copper (99.8% purity) bar with a cross-section of 10.0 x 10.0 mm [obtained from Nirako Co., Ltd.] was prepared, and grooves with a width of 4.05 mm and a depth of 4.05 mm were made along the entire length of all four sides of this bar by machining, to create a swastika-shaped material. Note that the swastika-shaped material can also be manufactured more cheaply by extrusion instead of processing from a square bar.

[0072] (b) Preparation of core material On the other hand, as core material, square wires with a cross-section of 4.0 x 4.0 mm and a length of 50 mm were prepared from pure aluminum (99%) [obtained from Niraco Co., Ltd.], copper (C1100B-1 / 2H) [obtained from Fujino Metal Co., Ltd.], and stainless steel (SUS304) [obtained from Fujino Metal Co., Ltd.].

[0073] Table 1 shows the electrical resistivity, density, and Young's modulus of the prepared swastika-shaped material and core material. The density and electrical resistivity were measured using the method described above and have been confirmed to be approximately equal to the values ​​reported as physical properties for general aluminum, copper, and SUS304. For Young's modulus, the data for copper was taken from the Copper Alloy Data Book (2nd edition), the data for aluminum from the Aluminum Handbook (6th edition), and the data for stainless steel from the Science Almanac 2022.

[0074]

[0075] (2) Fabrication of Clad Material Next, clad material was fabricated by combining the swastika-shaped material and the core material. At this time, there were three combinations of core material to insert into the swastika-shaped material: three combinations of inserting four of the same type of core material, and three combinations of inserting two different types of core material. For the clad material with two types of core material inserted, two cases were considered in which the surface in which each was inserted was the compression surface, and in the end, a total of nine types of clad material (= 3 + 3 × 2) were fabricated. In addition, in order to ensure that the deformation during compression is the same in the vertical and horizontal directions, when inserting two different types of core material with two of each, the core material of the same type was inserted and arranged diagonally to achieve four-fold symmetry (see Figure 3). This makes it possible to suppress the occurrence of processing defects such as warping, bending, and twisting during compression.

[0076] Table 2 shows the code names for the arrangement in each cladding material. In Table 2, the first letter of each code represents the material of the swastika-shaped material (C: copper), the second letter represents the material of the core material (core material 1) inserted into the grooves on the compression surface that contact the upper and lower tools (A: aluminum, F: stainless steel), and the third letter represents the material of the core material (core material 2) inserted into the grooves on the sides. For example, the code "CAF" indicates that the material of the swastika-shaped material is copper, the material of core material 1 is aluminum, and the material of core material 2 is stainless steel.

[0077]

[0078] (3) Processing of clad materials (fabrication of composite materials) Next, each clad material was subjected to transverse compression processing using a 100t Amsler type universal testing machine (manufactured by Tokyo Testing Machine Works, Ltd., No. 19685).

[0079] Specifically, the clad material was compressed using a universal testing machine, clamped between flat steel tools, until its height decreased by 0.5 mm. During compression, lithium stearate powder, suspended in alcohol, was applied to the compressed surface of the clad material as a lubricant.

[0080] (4) Confirmation of processing results (a) Observation of cross-sectional shape Next, the compressed clad material (compressed material) was cut and its cross-section was observed.

[0081] Specifically, the cut surface of the compressed material was polished with emery paper ranging from #220 to #1200 grit, and then the cut surface was photographed using a single-lens reflex camera (Nikon D7500) equipped with a micro lens. The results are shown in Figure 4.

[0082] Then, based on the photographs taken, the bonding condition of each contact point between the swastika-shaped material and the core material was determined (see Table 3). In Table 3, the contact points between the swastika-shaped material and the core material are labeled 1 to 4 clockwise from the top surface, and a to d clockwise from the top surface (see Figure 5).

[0083]

[0084] In Table 3, the check symbols indicate the degree of the gap at the interface between the profile and the core material, with two checks indicating a larger gap than one. Additionally, an "×" in the "total" column indicates that the core material has come loose.

[0085] As shown in Table 3, in the compression processing method used in this embodiment, the core material did not come off in any of the five combinations, and it was possible to obtain clad square timbers with varying dimensions.

[0086] (b) Dimensional changes and compressive load of the clad material before and after compression Next, the dimensional changes of the clad material before and after compression were measured. Table 4 shows the dimensional changes of the clad material before and after compression and the compressive load. Table 5 shows the rate of dimensional change due to compression and the average compressive stress.

[0087]

[0088]

[0089] Tables 4 and 5 show that in all clad materials, the compression ratio in the height direction and the expansion ratio in the width direction are 2-6%, while the elongation ratio in the length direction is 1%, indicating that there is almost no deformation in the longitudinal direction, i.e., that they are in a plane strain state. Furthermore, it can be seen that in all combinations without aluminum insertion, the compression ratio in the height direction is lower and the compressive stress is higher than in the combination with aluminum insertion.

[0090] (h) Table 6 of the properties of the clad material after compression shows the measured values ​​of the properties of the clad material after compression alongside the values ​​predicted by the method described above.

[0091]

[0092] Figure 6 is a radar chart created based on the measured properties of the compressed cladding material shown in Table 6, where each peak represents the reciprocal of the density. －１ ), bending stiffness, reciprocal of electrical resistivity －１ ) Note that in Figure 6, the properties of copper are normalized to 1.

[0093] Table 6 shows that the density after compression ranges from 4.876 to 8.431 Mg / m³. ３ The electrical resistivity is 21.6–57.3 nΩ·m, and the bending stiffness is 66.4–131.3 N·m. ２ It can be seen that clad lumber with different characteristics can be obtained within this width. Furthermore, from Table 6 and Figure 6, it can be seen that when the same combination of core materials is inserted, there is almost no difference in characteristics between CCF and CFC, but there is a difference of 1.52 times in electrical resistivity between CAC and CCA, and between CFA and CAF.

[0094] Next, we investigated the relationship between the predicted and measured values ​​for each characteristic. Figure 7 shows the relationship for density, Figure 8 for electrical resistivity, and Figure 9 for bending stiffness. In each figure, the vertical axis represents the measured value and the horizontal axis represents the predicted value.

[0095] Regarding density, as shown in Figure 7, the difference between the measured value and the predicted value is 0.7 to 5.4%, indicating that highly accurate predictions have been made.

[0096] Regarding electrical resistivity, as shown in Figure 8, the prediction accuracy was generally poor, with the largest discrepancy being observed in the CCC, where the measured value was 2.56 times the predicted value. This is thought to be due to some current flowing through the core material due to air gaps and contact resistance between dissimilar metals, as well as the effects of increased resistance due to processing and measurement errors.

[0097] Regarding bending stiffness, as shown in Figure 9, the difference between the measured value and the predicted value is 0 to 15.1%, demonstrating high prediction accuracy for the bending stiffness of all compression materials.

[0098] Furthermore, Figure 10 shows a graph with density (which has a small error) on the horizontal axis and the reciprocal of electrical resistivity (corresponding to electrical conductivity) on the vertical axis. The area formed by connecting the predicted values ​​on this graph represents the control range of the theoretical clad timber properties. In this case, the relationship between density and bending stiffness is shown in Figure 11.

[0099] In summary, it was confirmed that by constructing a composite material using swastika-shaped material and a square wire core and then performing compression processing, composite materials with a wide range of different property combinations can be manufactured on demand, and that this can be applied as a new method for realizing multi-property design.

[0100] Although the present invention has been described above based on embodiments, the present invention is not limited to the above embodiments. Various modifications can be made to the above embodiments within the same and equivalent scope as the present invention.

Claims

1. A method for manufacturing a composite material, comprising: a profile preparation step of preparing a metal profile in the shape of a polygonal prism having a surface with grooves formed in the longitudinal direction; an intermediate material manufacturing step of inserting core materials shaped to match the shape of the grooves into each of the grooves of the profile to produce an intermediate material; and a composite material manufacturing step of plastically processing the manufactured intermediate material by pressing it from the side to composite the profile and the core material to produce a composite material with desired properties.

2. The method for manufacturing a composite material according to claim 1, characterized in that the shape of the groove is a quadrangular prism.

3. The method for manufacturing a composite material according to claim 1, characterized in that the profile is a swastika-shaped or inverted swastika-shaped material having a cross-sectional shape with four-fold symmetry.

4. The method for manufacturing a composite material according to claim 3, characterized in that the cross-sectional shape of the intermediate material is square or rectangular.

5. The method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that the plastic deformation is one of compression, rolling, extrusion, drawing, or forging.

6. A method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that two or more materials selected from among multiple types of metal materials and multiple types of polymer materials are used as the core material.

7. A method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that a plurality of the core materials are used and are inserted into grooves at positions that are symmetrical to the line or point of the profile.

8. A method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that a square wire is used as the core material.

9. The method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that the core material is a core material formed by combining multiple types of materials to conform to the groove shape.

10. A method for manufacturing a composite material according to any one of claims 1 to 4, characterized in that, based on the characteristics of the profile and the core material, the characteristics of the composite material obtained by the combination of the profile and the core material are predicted, the configuration of the intermediate material necessary to obtain a composite material with desired characteristics is determined by referring to the prediction, the intermediate material is manufactured based on the determined configuration, and then plastically processed to manufacture a composite material with desired characteristics.

11. The method for manufacturing a composite material according to claim 10, characterized in that machine learning is used when predicting the properties of the composite material.

12. The method for manufacturing a composite material according to claim 11, characterized in that the machine learning is one of a neural network, deep learning, or clustering.

13. A method for manufacturing a composite material, comprising: a profile preparation step of preparing a metal profile in the shape of a polygonal prism having a surface with grooves formed in the longitudinal direction; an intermediate material manufacturing step of inserting a core material shaped to match the shape of the grooves into each of the grooves of the profile to produce an intermediate material; and a composite material manufacturing step of plastically processing the manufactured intermediate material by pressing it from the side to composite the profile and the core material to produce a composite material with desired properties, wherein the core material is a composite material manufactured by the composite material manufacturing method described in claim 1.

14. A composite material characterized by being manufactured by the method for manufacturing a composite material described in any one of claims 1 to 4, or claim 13.

Images