WO2023063185A1 - Composite metal material and production method therefor - Google Patents

Abstract

Provided is a technology whereby different types of material are appropriately arranged and a composite metal material having desired characteristics can be produced in a short time by extrusion. The production method comprises: an intermediate material creation step in which a core material is inserted inside a cylindrical tube material and an intermediate material is created; and a composite metal material production step in which the created intermediate material is extruded and a tube material and a core material and/or core materials are composited to produce a composite metal material. The core material inserted inside the tube material comprises a plurality of core materials and the cross-sectional shape of the plurality of core materials and the cross-sectional dimensions are the same for all. At least one core material among the plurality of core materials is a different type of material from the tube material. A composite metal material having the desired characteristics is produced by adjusting the combination of tube material and plurality of core materials, creating the intermediate material, and then extruding same.

Description

Composite metal material and its manufacturing method

TECHNICAL FIELD The present invention relates to a composite metal material and a method for producing the same, and more particularly to a method for efficiently producing a composite metal material having desired properties in a short time by extrusion, and a composite metal material produced by the above production method. .

In recent years, many products and parts are not made of a single material, but are made of different materials. For example, in the case of automobiles, various materials such as steel materials, copper alloys, and aluminum alloys are used. For this reason, optimization of material arrangement (topology optimization) is being carried out for the purpose of improving fuel efficiency, collision safety, and reducing manufacturing costs.

A clad material is attracting attention as a composite metal material (Patent Document 1). The material properties of the clad material can be changed by changing the types and ratios of the constituent materials, and it is possible to relatively easily produce a material having a combination of properties not found in a single material.

For the clad material, there is a rolled type that is produced by laminating and rolling flat materials and bonding the materials together, and a billet (intermediate material) that is made by inserting a core material into a sheath (tube material). After that, there is an extrusion type in which the sheath and core and/or multiple core members are joined by extrusion.

In this case, the rolling type requires large-scale equipment for laminating and rolling flat materials, but the degree of processing that can be applied at one time is small, and it cannot be said that productivity is high.

On the other hand, the extrusion type generally does not require as large equipment as the rolling type, and the degree of processing is large, so the process is short and productivity is high. Moreover, since high pressure acts, it is also advantageous in terms of bonding.

JP 2013-40370 A

However, in the case of the extrusion type, it is difficult to produce a composite metal material with the desired characteristics by arranging dissimilar materials in appropriate positions and obtaining the desired properties in a short period of time.

For this reason, dissimilar materials, especially dissimilar metal materials, are arranged in appropriate positions and extruded to manufacture a composite metal material. Then, the composite metal material is manufactured again by extrusion, and then the characteristics of the manufactured composite metal material are analyzed again, and modifications such as rearrangement are considered. Therefore, it is difficult to manufacture a composite metal material with the properties of

However, in the case of extrusion-type clad materials, even if it takes a lot of time and money to repeat trial and error as described above, once the appropriate conditions are determined, a large amount of products can be manufactured under the same conditions for a long period of time. Since it is manufactured over a long period of time, the time and cost required for repeating trial and error did not pose a big problem.

On the other hand, today, there are more and more occasions where it is required to manufacture materials with desired properties in short time, on demand, in suitable quantities and with high accuracy, instead of mass-produced products. However, until now, there has been no technology capable of coping with such a case.

Therefore, an object of the present invention is to provide a technique for appropriately arranging dissimilar metal materials and manufacturing a composite metal material with desired properties in a short time and with high accuracy in properties by extrusion.

The present inventors have diligently studied how to solve the above problems, found that the above problems can be solved by the invention described below, and completed the present invention.

The invention according to claim 1,
an intermediate material manufacturing step of inserting a core material inside a cylindrical tubular material to create an intermediate material;
a composite metal material manufacturing step of manufacturing a composite metal material by extruding the produced intermediate material to composite the pipe material and the core material and/or the core materials together,
The core material inserted inside the pipe material is a plurality of core materials,
The cross-sectional shape and cross-sectional dimensions of the plurality of core materials are all the same,
At least one core material among the plurality of core materials is a core material of a material type different from the material type of the pipe material,
A composite metal material having desired characteristics is manufactured by extruding after manufacturing the intermediate material by adjusting the content of the combination of the pipe material and the plurality of core materials. manufacturing method.

The invention according to claim 2,
The contents of the combination of the pipe material and the plurality of core materials are the material type of the pipe material, the number of the core materials, the material type of each of the plurality of core materials, and each of the plurality of core materials. 2. The method of manufacturing a composite metal material according to claim 1, wherein the content of combination with the insertion position into the pipe material.

The invention according to claim 3,
3. The method for producing a composite metal material according to claim 1, wherein the plurality of core members are inserted at positions that are axially symmetrical.

The invention according to claim 4,
The manufacturing of the composite metal material according to any one of claims 1 to 3, wherein the number of the plurality of core members is equal to or greater than the number of desired properties of the composite metal material. The method.

The invention according to claim 5,
an intermediate material manufacturing step of inserting a core material inside a cylindrical tubular material to create an intermediate material;
a composite metal material manufacturing step of manufacturing a composite metal material by extruding the produced intermediate material to combine the pipe material and the core material,
The core material inserted inside the tubular material is a single core material,
The material type of the core material is a material type different from the material type of the tube material,
A method for producing a composite metal material, wherein the combination of the pipe material and the core material is adjusted to prepare the intermediate material, and then the composite metal material having desired characteristics is produced by extrusion. be.

The invention according to claim 6,
6. The method for producing a composite metal material according to any one of claims 1 to 5, wherein the cross-sectional shape of the core material is circular or polygonal.

The invention according to claim 7,
7. The method for producing a composite metal material according to any one of claims 1 to 6, wherein the tubular member is a tubular member with one end closed.

The invention according to claim 8,
8. The method for producing a composite metal material according to any one of claims 1 to 7, wherein a wire rod is used as the core material.

The invention according to claim 9,
9. The method for producing a composite metal material according to any one of claims 1 to 8, wherein a tube material having a deformation resistance greater than the deformation resistance of at least one core material is used as the tube material. be.

The invention according to claim 10,
10. The intermediate material is manufactured by sequentially inserting the core materials of a plurality of material types shorter than the length of the pipe into the same cross-sectional position inside the pipe. 1. A method for producing a composite metal material according to claim 1.

The invention according to claim 11,
11. The method for producing a composite metal material according to any one of claims 1 to 10, wherein the extrusion process is cold extrusion process or hot extrusion process.

The invention according to claim 12,
Based on the characteristics of the pipe material and the characteristics of the core material, the characteristics of the composite metal material obtained by combining the pipe material and the core material are predicted, and the composite metal material with desired characteristics is obtained by referring to the predicted contents. After determining the configuration of the intermediate material necessary to obtain the intermediate material, the intermediate material is produced based on the determined configuration, and then extruded to produce a composite metal material with desired characteristics. A method for producing a composite metal material according to any one of claims 1 to 11.

The invention according to claim 13,
Analyzing the characteristics of the composite metal material manufactured based on the method for manufacturing a composite metal material according to any one of claims 1 to 12, and analyzing the obtained composite metal material based on the contents of the analysis It is possible to manufacture a composite metal material having desired characteristics by changing the combination of the pipe material and the core material used in the production, producing the intermediate material based on the changed content, and then extruding it. A method for producing a composite metal material according to any one of claims 1 to 12.

The invention according to claim 14,
Preparing in advance a plurality of core materials having the same cross-sectional shape, cross-sectional dimensions and length and made of a plurality of material types,
Using a plurality of core materials prepared in advance, by appropriately changing one or more of the material type, insertion position, and number of insertion of the core materials, the content of the combination of the pipe material and the core material is adjusted. 14. The method for manufacturing a composite metal material according to any one of claims 1 to 13, wherein the composite metal material having desired properties is manufactured by extruding the intermediate material after manufacturing the intermediate material. is.

The invention according to claim 15,
Preparing in advance a plurality of pipe members having the same cross-sectional shape, cross-sectional dimensions and length and made of a plurality of material types,
Using a plurality of previously prepared pipe materials and appropriately changing the material type of the pipe materials to adjust the content of the combination of the pipe materials and the core material to prepare the intermediate material, and then extruding. 15. The method for producing a composite metal material according to any one of claims 1 to 14, wherein the composite metal material having desired properties is produced by

The invention according to claim 16,
A composite metal material manufactured by the method for manufacturing a composite metal material according to any one of claims 1 to 15.

According to the present invention, it is possible to provide a technology for appropriately arranging dissimilar metal materials and manufacturing a composite metal material with desired properties in a short time and with high accuracy in properties by extrusion.

1 is a diagram showing an example of a manufacturing flow of a composite metal material according to one embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram conceptually showing a manufacturing method of a multifilamentary composite metal material according to an embodiment of the present invention; 1 is a cross-sectional view showing a configuration example of an intermediate material in one embodiment of the present invention; FIG. 1 is a longitudinal sectional view showing the configuration of an extrusion device used in one embodiment of the present invention; FIG. FIG. 4 is a diagram showing an example of a cut surface of a sample after extrusion of the present invention; FIG. 4 is a diagram showing experimental results of product density in Example 1 of the present invention. FIG. 2 is a diagram showing experimental results of yield strength of a product in Example 1 of the present invention; FIG. 2 is a diagram showing experimental results of the electrical resistivity of the product in Example 1 of the present invention; FIG. 4 is a diagram illustrating a combination of material types for the core material in the example of the present invention; It is a figure showing (a) Al, Fe, Cu and (b) Mg, Ag, Ti, each density, yield strength, and electrical resistivity. It is a figure which shows the cut surface of each sample before extrusion in Example 2 of this invention. It is a figure which shows the cut surface of each sample after extrusion in Example 2 of this invention. It is the figure which compared the measurement result in the Example of this invention.

The present invention will be described below based on embodiments.

1. Circumstances of the Study of the Present Invention The present inventors have conventionally found it difficult to properly arrange dissimilar metal materials and manufacture a composite metal material with desired characteristics in a short period of time and with high accuracy by extrusion. I considered the reason.

As a result, it was found that one of the causes was uneven deformation during extrusion. When an intermediate material (billet) is produced by inserting a core material into a tube material and then extruding the intermediate material, uneven deformation such as constriction or breakage tends to occur in the tube material or the core material.

For this reason, as described above, after dissimilar metal materials are arranged in positions considered appropriate to produce a composite metal material, the characteristics of the produced composite metal material are analyzed, and modifications such as rearrangement are made as appropriate. However, each time a composite metal material is manufactured, uneven deformation often occurs, and correction methods such as rearrangement are even more complicated. It became, and repetition of trial and error increased.

For this reason, in order to produce a composite metal material with desired properties, it is necessary to devise ways to prevent non-uniform deformation. Errors were to be claimed.

Therefore, the present inventors first examined the conditions under which uniform deformation is possible. As a result, it was found that uniform deformation can be achieved by using a soft core material whose deformation resistance is lower than that of the tube material and by preventing relative slippage at the interface between the core material and the tube material. (Daiso Taniguchi et al.: Copper and Copper Alloys, Vol. 60, No. 1, 280-284)

Next, the present inventors studied a method of improving the prediction accuracy so that a composite metal material with properties as predicted can be obtained, even if only a little, during manufacturing through trial and error. However, pipes have various conditions such as the diameter, length, and material of the pipes. In addition, since the core material has various conditions such as thickness, length, material, and number, it is not easy to improve the prediction accuracy.

For this reason, while studying methods to improve the prediction accuracy, we will analyze the characteristics of the composite metal material that was manufactured in advance, make corrections such as rearrangement as appropriate, and manufacture the composite metal material again. In the repetitive method, a method for producing a composite metal material in a short period of time by repeating these operations in a short period of time was investigated.

As a result of intensive studies, the inventors of the present invention have found that after manufacturing a composite metal material, as a method of making necessary corrections in a short time, the cross-sectional shape and cross-sectional dimensions of the core material are all made the same, and the previously manufactured composite Based on the characteristics of the metal material, the inventors came up with a method of replacing the core material in a short time and changing the material and arrangement position of the core material in a short time.

That is, by making the cross-sectional shape and cross-sectional dimensions of the core material the same, it is easy to replace the core material for each pass of extrusion. etc., and it is thought that the composite metal material can be manufactured repeatedly in a short period of time.

In addition, since the cross-sectional shape and cross-sectional dimensions of the core material are all the same, it is possible to predict the properties of the finished composite metal material more easily than before, and it is thought that the prediction accuracy will be improved.

Then, based on the above idea, we conducted an experiment to manufacture the clad material by extrusion, and as a result, we were able to confirm that the composite metal material almost exactly as predicted could be manufactured in a short period of time with high accuracy.

In today's world where multi-material design, in which dissimilar materials are placed in the right place, is attracting attention, there is a strong demand for chance-free, in other words, on-demand manufacturing of materials that meet various required properties as multi-property design. However, the present invention is a technique that can meet such a strong demand in recent years, and its effect is great.

In the above, as techniques for avoiding uneven deformation, techniques such as using a soft core material whose deformation resistance is lower than that of the tube material and preventing relative slippage at the interface between the core material and the tube material have been described. Alternatively, even in the case of non-uniform deformation, by applying the present invention, a composite metal material having properties close to the desired properties can be produced in as short a time as possible.

Further, in the above description, the method of analyzing the characteristics of the previously manufactured composite metal material, appropriately correcting such as rearrangement, and manufacturing the composite metal material again has been described. It is not limited to such cases.

In the present invention, since the cross-sectional shape and cross-sectional dimensions of the core material are all the same, as described above, the prediction accuracy is improved. , it is also possible to produce a composite metal material with desired properties without repeated operations.

In addition, when the composite metal material is manufactured by predicting the characteristics of the composite metal material from the characteristics of the intermediate material and setting the manufacturing conditions at the stage where the intermediate material is manufactured without manufacturing the composite metal material in advance It is possible to exhibit the effects of the present invention.

2. Contents of the Present Invention Next, the above-described present invention will be described in order.

<1> Main Constituent Elements of the Present Invention The main constituent elements of the present invention are as follows.
[1] When there are a plurality of core members First, the case where there are a plurality of core members in the cross section of the pipe member will be described.

(1) An intermediate material producing step of inserting a core material into the inside of a cylindrical tubular material to produce an intermediate material, extruding the produced intermediate material, and extruding the tubular material and the core material, and/or between the core materials. and a composite metal material manufacturing step of manufacturing a composite metal material by combining the.
(2) A plurality of core members are inserted inside the pipe member.
(3) The cross-sectional shape and cross-sectional dimensions of the plurality of core members are all the same.
(4) Among the plurality of core members, at least one core member is of a material type different from that of the tube member.
(5) After preparing an intermediate material by adjusting the combination of the tube material and a plurality of core materials, the intermediate material is extruded to manufacture a composite metal material having desired properties.

As described above, all of the core materials have the same cross-sectional shape and cross-sectional dimensions, and the intermediate material is manufactured by appropriately replacing the plurality of core materials and adjusting the combination of the pipe material and the plurality of core materials. Therefore, it is possible to easily combine core materials of a plurality of types of materials without changing the shape and dimensions of the cross section of the intermediate material in the process of manufacturing the intermediate material. Also, the characteristics can be easily predicted.

Therefore, it is possible to easily change the composition of the intermediate material, and to manufacture a composite metal material with desired properties in a short period of time.

[2] When there is one core material The only difference from the case of a plurality of core materials is that they are different material types.

Because there is only one core material, there is a limit to the desired properties, but because of the simple structure, a composite metal material with the required properties can be produced in a short period of time. In addition, by inserting the manufactured composite metal material into a pipe material as a core material, it is possible to easily obtain a multi-property design composite metal material that can satisfy more properties.

<2> Preferred Embodiments of the Present Invention Next, preferred embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

(1) Prediction based on physical properties of tube and core material Based on the physical properties of the tube material and the physical properties of the core material, the properties of the composite metal material obtained by combining the tube material and multiple core materials are predicted. By referring to the above, the composition of the intermediate material necessary to obtain the composite metal material with the desired properties is determined, and the intermediate material is produced based on the determined composition, and then extruded to obtain the composite metal with the desired properties. It is preferred to manufacture materials.

In this way, the properties of the composite metal material are predicted based on the physical properties of the tube material and the core material, and by referring to the predicted content and determining the composition of the intermediate material, the composite metal material with the desired properties can be produced efficiently. Generally, it can be manufactured with high accuracy. Further, as described above, in the case of the present invention, since the cross-sectional shape and cross-sectional dimensions of the core material are all the same, it is possible to refer to the predicted content with improved accuracy.

As a specific prediction method, it is preferable to use a rule of mixture (compound rule) that can be easily predicted, but prediction by machine learning may also be used.

(2) Prediction based on analysis of the properties of the composite metal material manufactured in advance When manufacturing the composite metal material by the manufacturing method of the present invention, the properties of the composite metal material manufactured prior to the manufacturing method of the present invention is analyzed, and based on the analysis content, the content of the combination of the pipe material and multiple core materials used in the manufacture of the composite metal material manufactured in advance is changed, and the intermediate material is produced based on the changed content. , preferably by extrusion to produce a composite metal material of desired properties.

By analyzing the characteristics of the composite metal material manufactured in advance, it is possible to easily determine the composition of the intermediate material for manufacturing the composite metal material with the desired characteristics. Since the cross-sectional dimensions are the same, it is possible to quickly change the combination of the tube material and the plurality of core materials in a short time. Then, after manufacturing an intermediate material based on the changed contents, by extruding it, a composite metal material having desired properties can be rapidly manufactured in a short time.

In addition, in the present invention, as described above, since the cross-sectional shape and cross-sectional dimensions of the plurality of core materials are all the same, it is easy to analyze the characteristics, and even if a composite metal material with desired characteristics cannot be obtained, It is also possible to easily analyze the factors that caused the difference between the predicted value and the measured value in .

(3) Advance preparation of pipe materials and core materials In carrying out the above-described present invention, a plurality of pipe materials and core materials having the same cross-sectional shape, cross-sectional dimensions and length and made of a plurality of material types are prepared in advance. It is preferable to keep

The pipe materials and core materials that are prepared in advance can be prepared efficiently because they have the same cross-sectional shape, cross-sectional dimensions, and length.

Then, by using a plurality of tubes and core materials prepared in advance and having the same cross-sectional shape, cross-sectional dimension and length and made of a plurality of material types, in the intermediate material manufacturing process, the material types of the tube materials and the core materials It is possible to quickly change the combination of the material type, insertion position, number of insertions, etc. in a short time. As a result, a composite metal material having desired properties can be produced in a short period of time, improving productivity.

(4) Contents of combination of tube material and multiple core materials , and insertion positions of a plurality of core members into respective pipe members.

Most of the composite metal materials with desired characteristics can be handled by combining the type of tube material, the number of cores, the type of core material, and the insertion position of the core material. This allows prediction, design and manufacturing to proceed quickly and efficiently.

(5) Insertion position of core material It is preferable that the insertion positions of a plurality of core materials are symmetrical with respect to the center of the pipe material. Since the tube member is usually cylindrical, it is preferable to insert a plurality of core members concentrically around the same position as the center of the tube member. This suppresses the occurrence of non-uniform deformation in the extrusion process. In addition, a composite metal material with uniform properties can be easily produced.

(6) Desired Number of Properties and Number of Types of Core Materials The number of core materials is preferably equal to or greater than the number of desired properties of the composite metal material. For example, when three characteristics of density, yield strength, and electrical resistivity are specified as a desired composite metal material, at least three types of core materials, such as Al, Fe, and Cu, are used as the core material. is preferred. This makes it easier to respond to each desired characteristic.

The properties of composite metal materials are generally determined by the law of mixture, and the regression formula for determining each property is determined by a regression formula that uses the individual physical properties of the material types that make up the composite metal material and their ratios as factors. be done. Therefore, in order to achieve highly accurate optimization, it is necessary to increase the number of factors used in the design. can be optimized.

(7) Cross-Sectional Shape of Core Material The cross-sectional shape of the core material is preferably circular or polygonal.

It is preferable to insert as many core materials as possible into the pipe material without any gaps. Moreover, it is preferable that the core material has a simple cross-sectional shape and is easy to manufacture. Considering this, the cross-sectional shape of the core material is preferably circular or polygonal. Polygons include triangles, quadrilaterals, hexagons, and the like. In the case of a polygon, it is preferably a regular polygon.

(8) Use of tube material with one end closed As the tube material, it is preferable to use a tube material with one end closed.

By using a tubular material with one end closed, it becomes easier to fix the inserted core material and manage its position.

(9) Use of wire A wire is preferably used as the core material.

By inserting a large number of small-diameter core materials, it becomes easier to obtain characteristics close to the required characteristics. For this reason, a wire rod is preferable as the core material. Wire rods also have the advantage of being easy to manufacture and readily available from the outside. As the wire, a round wire is particularly preferable, but a wire having a triangular, quadrangular, hexagonal cross section, or the like may also be used.

(10) Deformation resistance of tube material As the tube material, it is preferable to use a tube material whose deformation resistance is greater than the deformation resistance of at least one of the core members.

By using such a pipe material, it is possible to suppress the breakage of the pipe material and to uniformly deform it in the extrusion process.

(11) Insertion of Multiple Core Materials in Longitudinal Direction of Tube Material It is preferable to prepare an intermediate material by sequentially inserting core materials of a plurality of material types shorter than the length of the tube material at the same cross-sectional position inside the tube material.

By doing so, a composite metal material with different properties in the longitudinal direction can be easily obtained in a single pass.

(12) Cold working and hot working

The extrusion process may be cold extrusion process or hot extrusion process.

Cold extrusion processing does not require material temperature control, so production efficiency is high. Moreover, when hot extruding a composite material consisting of a large number of materials, such as a multifilamentary material, the temperature dependence of the deformation resistance of each material differs depending on the type of material, so that each material does not always deform uniformly. In this regard, cold extrusion is preferable as a method for extruding a multifilamentary material because it is not affected by temperature dependence of deformation resistance.

However, hot extrusion can be used with a small extrusion force to achieve a large degree of processing, that is, a large processing ratio.

3. Specific Manufacturing Method of Composite Metal Material <1> Manufacturing Flow of Composite Metal Material First, an example of a manufacturing flow of a composite metal material will be described. FIG. 1 is a diagram showing an example of a production flow of a composite metal material according to this embodiment.

(1) Basic design of the product First, perform the basic design of the product.

(2) Designation of dimensions and properties of parts Next, the dimensions and properties of parts required for the product are specified.

(3) Determination of Extrusion Conditions and Configuration of Intermediate Material Next, the extrusion conditions and the configuration of the intermediate material for producing each member are determined.

Regarding the extrusion conditions, the external dimensions of the intermediate material are selected, and the extruder, extrusion ratio, speed, lubrication, die angle, etc. are set to determine the extrusion conditions.

Regarding the composition of the intermediate material, based on the specified characteristics and the outer diameter of the intermediate material, selection of the inner diameter of the tube material, selection of the wire diameter and number of insertions of the core material, selection of the material type of the tube material and the core material, And the insertion position (arrangement position) of the core material is determined to determine the configuration of the intermediate material.

(4) Judgment of Manufacturability Next, the characteristics of the composite metal material obtained based on the determined configuration of the intermediate material are predicted. In addition, it is predicted whether or not uniform deformation without breakage is possible based on the composition of the intermediate material and the extrusion conditions such as the extrusion ratio.

Then, if the prediction result satisfies the specified characteristics and uniform deformation is possible without breakage, proceed to the next intermediate material assembly process. On the other hand, if the predicted result does not satisfy the specified characteristics, or if uniform deformation without breakage cannot be achieved, the design is redesigned.

In addition, in the present invention, since the cross-sectional shape and cross-sectional dimensions of the core material are all the same, it is easy to predict the characteristics of the composite metal material and whether uniform deformation without breakage is possible.

(5) Manufacture of Composite Metal Material Next, the intermediate material is assembled based on the configuration of the intermediate material determined above. After that, the intermediate materials are extruded and joined to produce a composite metal material.

(6) Confirmation of Dimensions and Characteristics of Composite Metal Material Finally, confirm dimensions and characteristics of the manufactured composite metal material. Then, if there is no problem, the product is shipped, and the composite metal material is secondary-processed at the shipping destination and used for various purposes.

<2> Characteristic Prediction of Composite Metal Material As described above, in manufacturing the composite metal material, it is preferable to predict the characteristics of the composite metal material. Methods for predicting the density, yield strength, and electrical resistivity of composite metal materials are described below. In the following, the core material _F1 of the first layer is made of aluminum (Al), the core material _F2 of the second layer is made of iron (Fe), and the core material _F3 of the third layer is made of copper (Cu). Suppose you are

(1) Area Ratio Generally, the weighted arithmetic mean (rule of mixture) of the area of the cross section before extrusion is used to predict the properties of the composite metal material.

Assuming that the tube material and the core material deform uniformly during extrusion, the area ratio of the tube material after extrusion f _s , the area ratio of the core material after extrusion f _c , and the area ratio of one core material after extrusion f _f is the number of cores, _d0 is the outer diameter (mm) of the sheath (pipe), _d is the inner diameter (mm) of the sheath (pipe), and _df is the diameter of the core (mm). Each is obtained by the following formula.
f _s =(d ₀ ² −d _i ² )/(d ₀ ² −d _i ² +nd _f ² )
f _c =nd _f ² /(d ₀ ² −d _i ² +nd _f ² )
f _f =d _f ² /(d ₀ ² −d _i ² +nd _f ² )

(2) Density Then, the density ρ of the composite metal material is such that ρ _s is the density of the tube material, ρ _c is the density of the core material, _fc is the area ratio of one core material, ρ _Al , ρ _Fe , ρ _Cu , When the densities of Al, Fe, and Cu, n _Al , n _Fe , and n _Cu are respectively the numbers of the Al core material, the Fe core material, and the Cu core material, they are predicted by the following formulas.
ρ = ρ _s · f _s + ρ _c · f _c
= ρ _s · f _s + ρ _Al · n _Al · _ff + ρ _Fe · n _Fe · _ff + ρ _Cu · n _Cu · _ff

(3) Yield strength In addition, the yield strength σ of the composite metal material is such that σ _s is the yield strength of the tube material, σ _c is the yield strength of the core material, and σ _Al , σ _Fe , and σ _Cu are the respective amounts of Al, Fe, and Cu. Yield strength is predicted by the following formula.
σ = σ _s · f _s + σ _c · f _c
= σ _s · f _s + σ _Al · n _Al · _ff + σ _Fe · n _Fe · _ff + σ _Cu · n _Cu · _ff

(4) Electrical resistivity In addition, the _electrical resistivity κ of the composite metal material is defined as the electrical resistivity of the tube material, κ _Al , κ _Fe , κ _Cu , assuming that the tube material and all the core materials are connected in parallel. are the electrical resistivities of Al, Fe, and Cu, respectively, are predicted by the following equations.
1/κ= _fs / _κs +( _nAl / _κAl + _nFe / _κFe + _nCu / _κCu ) _ff

(5) Others In addition, although the rule of mixture was used in the above prediction, machine learning may be used. Highly accurate prediction is expected by using machine learning. As machine learning, known methods such as supervised learning such as neural network and deep learning, and unsupervised learning such as clustering can be used.

<3> Specific Example of Manufacturing Method Next, a specific manufacturing method will be described with reference to manufacturing of a multifilamentary composite metal material as an example.

(1) Assembly of Intermediate Material FIG. 2 is a view conceptually showing a method of manufacturing a multifilamentary composite metal material according to an embodiment of the present invention. In FIG. 2, C is a core (core material), S is a sheath (tube material), IM is an intermediate material, and P is a composite metal material as a product. D is the diameter of the die and also the outer diameter of the composite metal material.

The core (core material) C is composed of three types of core materials with different material types, that is, a first layer core material F ₁ , a second layer core material F ₂ and a third layer core material F ₃ in order from the center. Consists of For example, the core material _F1 of the first layer is made of aluminum (Al), the core material _F2 of the second layer is made of iron (Fe), and the core material _F3 of the third layer is made of copper (Cu).

Then, the intermediate material is assembled by inserting each core material into the pipe material.

FIG. 3 is a cross-sectional view showing a configuration example of the intermediate material IM. The sheath (tubing material) S has a cylindrical shape, _d0 is the outer diameter (mm) of the sheath (tubing material), and d _i is the inner diameter (mm). The core material has a circular cross section, and the core material F ₁ of the first layer, the core material F ₂ of the second layer, and the core material F ₃ of the third layer all have the same diameter of d _f mm.

The core materials are inserted in a close-packed state, and the numbers of the core material F ₁ in the first layer, the core material F ₂ in the second layer, and the core material F ₃ in the third layer are 1 and 6, respectively. 12, which are arranged concentrically and axially symmetrically.

(2) Manufacture of Composite Metal Material FIG. 4 is a vertical cross-sectional view showing the configuration of an extrusion device. D is the die diameter (mm) and also the outer diameter of the composite metal material.

Then, the intermediate material IM is inserted into the container 12, the punch 11 is lowered, and the material is passed through the die 14 and extruded to manufacture a composite metal material as a product.

The present invention will be described more specifically below based on examples. In Example 1, a multifilamentary composite metal material was produced, and the density, yield strength, and electrical resistivity were compared with the predicted values based on the prediction method described above and the measured values of the produced composite metal material. , it was evaluated whether or not a composite metal material having properties as expected could be produced by the production method of the present invention. In consideration of cost, Al, Fe, and Cu are suitable materials for composite metal materials that require lightness (low density), high yield strength, and high electrical conductivity (low electrical resistivity). It was used as a core material. As a result of the experiment, as shown below, a composite metal material having excellent properties as expected was obtained.

Next, whether or not a composite metal material having excellent properties equivalent to those of the composite metal material of Al, Fe, and Cu used in Example 1 can be easily manufactured from other metals using the manufacturing method of the present invention. , confirmed by experiments as Example 2. In the experiments, Mg, Ag and Ti were used as core materials. The density of Mg is lower than that of Al, the electrical conductivity of Ag is higher than that of Cu, and the specific strength (strength/density) of Ti is higher than that of Fe. It is a combination of high-quality materials. As a result, as shown below, it was confirmed that a composite metal material having excellent properties equivalent to those of a composite metal material of Al, Fe, and Cu can be easily obtained by the production method of the present invention.

[Example 1]
1. Composition of Materials (1) Tubing As the tubing, pure copper (C1020) having an outer diameter d ₀ of 10.9 mm and a length of 35.0 mm with one end closed was used. The hole for inserting the core material had an inner diameter d _i of 7.5 mm and a depth of 30 mm.

(2) Core Material Three types of core materials, pure copper (C1020), pure aluminum (A1070), and pure iron (purity 99.65%) having a diameter d _f of 1.45 mm and a length of 30 mm were prepared.

(3) Arrangement position of core material The position where each core material is inserted into the pipe material and arranged is the position shown in FIG. 3 . Specifically, one core material _F1 of the first layer is arranged in the center of the tube material, six core materials F2 of the second layer are arranged around the core material of the first layer, and the core material _F2 of the second layer is arranged around the first layer core material. Twelve core members _F3 of the third layer are arranged around the core member.

(4) Combination of Material Types of Core Materials The combination of material types of the core material F ₁ of the first layer, the core material F ₂ of the second layer, and the core material F ₃ of the third layer is CCC, FFF, AAA, AFC. , ACF, FAC, FCA, CAF, and CFA. In the above, C, F, and A represent pure copper (Cu), pure iron (Fe), and pure aluminum (Al), respectively, and from the left, the core material F ₁ of the first layer and the core of the second layer. The material types of the material F ₂ and the core material F ₃ of the third layer are shown. For example, FCA indicates an arrangement with a first layer of pure iron (Fe), a second layer of pure copper (Cu), and a third layer of pure aluminum (Al).

(5) Preparation of Intermediate Material According to the combination of the core materials described above, each core material was inserted into the pipe material described above to prepare an intermediate material.

2. Extrusion Using the extrusion device 1 shown in FIG. 4, the prepared intermediate material is inserted into the container 12, the punch 11 is lowered, and the composite metal material is manufactured by extruding through the die 14. . As the die, a tool steel die with a hole diameter (die diameter) of 6 mm and a half angle of 60° was used. At this time, the extrusion _ratio er defined by the ratio of the cross-sectional area of the entire intermediate material to the area of the die hole is 3.30, and the net extrusion ratio excluding the voids in the intermediate material is 2.85. .

3. Method of Measuring Characteristics (1) Electrical Resistivity The electrical resistivity was measured by a four-probe method in which voltage terminals were attached at positions of 20 mm and 60 mm from the tip of the extruded material.

(2) Density Density was measured by the Archimedes method using a cylindrical test piece sampled at a position of 20 mm to 30 mm from the tip of the extruded material.

(3) Yield Strength As the yield strength, a 0.2% yield strength obtained by axially uniaxially compressing a cylindrical test piece sampled at a position of 60 mm to 69 mm from the tip of the extruded material was used. Compression was performed at a speed of 1.0 mm/min with the end face lubricated with a Teflon sheet (registered trademark).

4, Density, yield strength, and electrical resistivity of copper, aluminum, and iron From the measurement results of the extruded material when copper was used for both the core material and the tube material, the density, yield strength, and electrical resistivity of copper were first calculated by back calculation. . Next, from the measurement results of the extruded materials using only aluminum (AAA) and only iron (FFF) as core materials, the densities, yield strengths, and electrical resistivities of aluminum and iron were obtained by back calculation. Table 1 summarizes the characteristic values of the three types of materials obtained in this way.

5. Property Prediction of Composite Metal Material Density and yield strength were predicted using the property values of each material type in Table 1, and the weighted arithmetic mean (rule of mixture) of the cross-sectional area before extrusion. It was assumed that no voids remained after extrusion. The electrical resistivity of the extruded material was predicted by the harmonic mean of the tube and all cores assuming they were connected in parallel.

6. Experimental Results (1) Uniform Deformation Observation of the appearance and the cut surface of the sample after extrusion showed no breakage in both the tube material and the core material, confirming uniform deformation. FIG. 5 shows an example of a cut surface of the sample after extrusion.

(2) Predicted Values and Measured Values of Density, Yield Strength, and Electrical Resistivity Experimental results of density, yield strength, and electrical resistivity are shown in FIGS. 6, 7, and 8, respectively. In these figures, the horizontal axis is the predicted value and the vertical axis is the measured value.

　In Figures 6, 7, and 8, the correlation coefficients between the predicted values and the actual measurements were calculated as density: 0.996, yield strength: 0.983, and electrical resistivity: 0.967, respectively. From these results, it was confirmed that each of the composite metal materials prepared had three types of characteristics, ie, density, yield strength, and electrical resistivity, which were almost as predicted.

From the above, the method of manufacturing a composite metal material of the present invention is a rational manufacturing method, and by predicting the characteristics of the composite metal material, it is possible to narrow down the configuration of the intermediate material at the design stage. , the fabrication method of the present invention, and the prediction of properties in the present invention have been found to be sufficiently effective in optimizing material placement, ie speeding up topology optimization.

[Example 2]
Next, as described above, a composite metal material having excellent properties equivalent to those of the composite metal material of Al, Fe, and Cu used in Example 1 can be easily produced using other metals using the production method of the present invention. Experiments were conducted using Mg, Ag, and Ti in order to confirm by experiments whether they could be produced.

1. Composition of materials (1) Tubing The tubing is made of pure copper (C1020) with an outer diameter d ₀ of 10.9 mm and a length of 35.0 mm with one end closed, in the same manner as in Example 1, and a core material is inserted. A hole having an inner diameter d _i of 7.5 mm and a depth of 30 mm was provided as a hole for this purpose.

(2) Core material Pure titanium (purity 99.5%), pure magnesium (purity 99.95%), and pure silver of the same size (diameter d _f 1.45 mm, length 30 mm) as in Example 1 were used as the core material. (Purity 99.99%) was prepared.

(3) Arrangement position of the core material The position where each core material is inserted and arranged in the pipe material is the same as in Example 1, one core material of the first layer is arranged in the center of the pipe material, and the core of the first layer is arranged. Six core members of the second layer are arranged around the core member, and 12 core members of the third layer are arranged around the core member of the second layer.

(4) Combination of material types of core material In this embodiment, as shown in FIG. 9B, the combination of material types of the core material is as follows: , (b) a combination of 3 Mg, 6 Ti and 10 Ag (MTA), and (c) a combination of 1 Ti, 4 Ag and 14 Mg (TAM).

It should be noted that the above TMA is an example of a combination assumed to obtain characteristics equivalent to those of the FAC in Example 1, the MTA to the FCA, and the TAM to the CAF. In order to show the correspondence between the two, FIG. 9A shows the corresponding combinations of material types for the core materials of FAC, FCA, and CAF.

FIG. 10 is a diagram (radar chart) showing the density, yield strength, and electrical resistivity of (a) Al, Fe, and Cu, and (b) Mg, Ag, and Ti. In order to indicate that the characteristics become more excellent as the distance from the center point increases, the density is expressed by the reciprocal of the density, and the electrical resistivity is expressed by the reciprocal of the electrical resistivity (electrical conductivity).

From FIG. 10, it can be seen that the use of Mg, Ag, and Ti makes it easier to obtain better characteristics and has a higher degree of freedom in design. Then, in order to obtain a composite metal material corresponding to FAC, FCA, and CAF, considering the characteristics of each of Mg, Ag, and Ti, the number and arrangement positions of Mg, Ag, and Ti are determined as shown in FIG. b).

(5) Preparation of Intermediate Material According to the combination of the core materials described above, each core material was inserted into the pipe material described above to prepare an intermediate material. FIG. 11 shows a cut surface of each sample before extrusion.

2. Extrusion Processing and Measurement of Properties A composite metal material was manufactured by extrusion processing in the same manner as in Example 1 using the produced intermediate material. After that, the electrical resistivity, density and yield strength were measured in the same manner as in Example 1.

3. Experimental Results (1) Uniform Deformation Observation of the external appearance and the cut surface of each sample after extrusion showed no breakage in both the tube material and the core material, confirming uniform deformation. FIG. 12 shows a cut surface of each sample after extrusion.

(2) Comparison of measurement results In order to compare the results of electrical resistivity, density, and yield strength of FAC, FCA, and CAF in Example 1 and TMA, MTA, and TAM in Example 2, both results are superimposed on each other. Radar charts shown in 13(a) to (c) were prepared.

As a result, in any of FIG. 13, substantially the same characteristics were obtained for both, and the combination of Mg, Ti, and Ag also produced a composite metal material with substantially the same characteristics as the combination of Al, Fe, and Cu. It has been confirmed that it can be realized by applying the manufacturing method of the present invention.

As described above, the present invention has a great effect, but although it is an invention that does not require a complicated method, the reason why such a technology has not been developed for many years is the extrusion process. In , research has mainly been carried out on hard core materials, in which non-uniform deformation occurs remarkably, and in the field of manufacturing technology for clad materials by extrusion, there is a practice that the arrangement of core materials should not be changed easily. This seems to have been a major factor.

In this respect, as described above, the present inventors first investigated a method for preventing non-uniform deformation during extrusion and clarified the conditions for uniform deformation. As a result, the characteristics of the previously manufactured composite metal material are analyzed, the arrangement is appropriately modified, etc., and the problem of uneven deformation in the repeated work of manufacturing the composite metal material again is resolved, and the repeated work is performed. time can be shortened.

Then, since the conditions for uniform deformation could be clarified, it was possible to concentrate on studying a method for producing a composite metal material in a short time without being bound by the practice that the arrangement of the core material should not be changed easily. I was able to reach

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

1 extrusion device 11 punch 12 container 13 die holder 14 die C core (core material)
D Die diameter (outer diameter of composite metal material)
_F1 Core material of the first layer _F2 Core material of the second layer _F3 Core material of the third layer IM Intermediate material P Composite metal material S Sheath (tube material)
d _f diameter of core material d _i inner diameter of tube material d ₀ outer diameter of tube material

Claims (16)

1. an intermediate material manufacturing step of inserting a core material inside a cylindrical tubular material to create an intermediate material;
   a composite metal material manufacturing step of manufacturing a composite metal material by extruding the produced intermediate material to composite the pipe material and the core material and/or the core materials together,
   The core material inserted inside the pipe material is a plurality of core materials,
   The cross-sectional shape and cross-sectional dimensions of the plurality of core materials are all the same,
   At least one core material among the plurality of core materials is a core material of a material type different from the material type of the pipe material,
   A composite metal material having desired characteristics is manufactured by extruding after manufacturing the intermediate material by adjusting the combination of the pipe material and the plurality of core materials. Production method.
2. The contents of the combination of the pipe material and the plurality of core materials are the material type of the pipe material, the number of the core materials, the material type of each of the plurality of core materials, and each of the plurality of core materials. 2. The method for manufacturing a composite metal material according to claim 1, wherein the content of the combination with the insertion position into the pipe material.
3. The method for producing a composite metal material according to claim 1 or 2, characterized in that the plurality of core members are inserted at axially symmetrical positions.
4. The manufacturing of the composite metal material according to any one of claims 1 to 3, wherein the number of the plurality of core members is equal to or greater than the number of desired properties of the composite metal material. Method.
5. an intermediate material manufacturing step of inserting a core material inside a cylindrical tubular material to create an intermediate material;
   a composite metal material manufacturing step of manufacturing a composite metal material by extruding the produced intermediate material to combine the pipe material and the core material,
   The core material inserted inside the tubular material is one core material in the cross section of the tubular material,
   The material type of the core material is a material type different from the material type of the tube material,
   A method for manufacturing a composite metal material, comprising: manufacturing a composite metal material having desired characteristics by adjusting the content of the combination of the pipe material and the core material to prepare the intermediate material, and then extruding the intermediate material.
6. The method for producing a composite metal material according to any one of claims 1 to 5, wherein the cross-sectional shape of the core material is circular or polygonal.
7. The method for producing a composite metal material according to any one of claims 1 to 6, characterized in that the tubular member is a tubular member with one end closed.
8. The method for producing a composite metal material according to any one of claims 1 to 7, wherein a wire rod is used as the core material.
9. The method for producing a composite metal material according to any one of claims 1 to 8, wherein a tube material having deformation resistance greater than that of at least one core material is used as the tube material.
10. 10. The intermediate material is manufactured by sequentially inserting the core materials of a plurality of material types shorter than the length of the pipe into the same cross-sectional position inside the pipe. 2. A method for producing a composite metal material according to claim 1.
11. The method for producing a composite metal material according to any one of claims 1 to 10, wherein the extrusion is cold extrusion or hot extrusion.
12. Based on the characteristics of the pipe material and the characteristics of the core material, the characteristics of the composite metal material obtained by combining the pipe material and the core material are predicted, and the composite metal material with desired characteristics is obtained by referring to the predicted contents. After determining the configuration of the intermediate material necessary to obtain the intermediate material, the intermediate material is produced based on the determined configuration, and then extruded to produce a composite metal material with desired characteristics. A method for manufacturing a composite metal material according to any one of claims 1 to 11.
13. The characteristics of the composite metal material manufactured based on the method for manufacturing a composite metal material according to any one of claims 1 to 12 are analyzed, and based on the analysis content, the obtained composite metal material It is possible to manufacture a composite metal material having desired characteristics by changing the combination of the pipe material and the core material used in the production, producing the intermediate material based on the changed content, and then extruding it. 13. A method for producing a composite metal material according to any one of claims 1 to 12.
14. Preparing in advance a plurality of core materials having the same cross-sectional shape, cross-sectional dimensions and length and made of a plurality of material types,
    Using a plurality of core materials prepared in advance, by appropriately changing one or more of the material type, insertion position, and number of insertion of the core materials, the content of the combination of the pipe material and the core material is adjusted. 14. The method for manufacturing a composite metal material according to any one of claims 1 to 13, wherein the composite metal material having desired properties is manufactured by extruding the intermediate material after manufacturing the intermediate material. .
15. Preparing in advance a plurality of pipe members having the same cross-sectional shape, cross-sectional dimensions and length and made of a plurality of material types,
    Using a plurality of previously prepared pipe materials and appropriately changing the material type of the pipe materials to adjust the content of the combination of the pipe materials and the core material to prepare the intermediate material, and then extruding. 15. The method for manufacturing a composite metal material according to any one of claims 1 to 14, wherein the composite metal material having desired properties is manufactured by
16. A composite metal material manufactured by the method for manufacturing a composite metal material according to any one of claims 1 to 15.

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