Method for manufacturing clad material

Abstract

The present invention provides a manufacturing method in which a means that is capable of highly accurately predicting the thickness of an aluminum layer after rolling and joining is introduced, and with which it is possible to reduce the design man-hours and the cost of experiment and trial manufacture of a novel clad material which has no manufacturing performance data, and to which an aluminum material is applied.　The present invention provides a method for manufacturing a clad material to which an aluminum material is applied, the method including: a process for forming a clad material, which has an aluminum layer having a thickness T2Al and a high stress metal layer, by rolling and joining an aluminum material and a high stress metal material; and a prediction process for setting a target thickness of the aluminum material and a total rolling ratio of the rolling and joining. In the prediction process, if an assumed thickness of the aluminum material is taken as an independent variable t1Al and a predicted thickness of the aluminum layer is taken as a dependent variable t2Al, a t1Al value at which the t2A1 value obtained by a specific prediction formula satisfies relational expression (t2Al - T2Al) / T2Al ≤ |0.05| is set as the thickness T1Al of the aluminum material.

Description

Clad material manufacturing method

[0001] The present invention relates to a method for manufacturing a clad material, and more particularly to a method for manufacturing a clad material using an aluminum material.

[0002] Conventionally, clad materials using aluminum materials include, for example, clad materials formed by roll-bonding an aluminum material and a copper material (hereinafter referred to as "Al / Cu clad materials") and clad materials formed by roll-bonding an aluminum material and a stainless steel material (hereinafter referred to as "Al / SUS clad materials").

[0003] Al / Cu clad materials are widely used as conductive parts, and have recently been used, for example, in terminals of lithium-ion batteries (LIBs) for vehicles such as hybrid electric vehicles (HEVs) and electric vehicles (EVs) (see Japanese Patent No. 6070490), and conductive members connecting terminals and bus bars (see Japanese Patent No. 6071990).Al / SUS clad materials are also widely used as structural parts that achieve weight reduction while maintaining mechanical strength, and have recently been used, for example, in chassis for smart devices (see Japanese Patent No. 6070490).

[0004] For example, Japanese Patent No. 6070490 discloses an example of a battery terminal made of an Al / Cu clad material, Japanese Patent No. 6071990 discloses an example of a connecting conductive member made of an Al / Cu clad material, and Japanese Patent No. 7067151 discloses an example of a chassis for a mobile device that uses a composite material made of an Al / SUS clad material in which stainless steel materials are roll-bonded to both sides of an aluminum material.

[0005] Patent No. 6070490 Patent No. 6071990 Patent No. 7067151

[0006] Although not disclosed in the above-mentioned Japanese Patent Publications No. 6070490, 6071990, and 7067151, in clad materials using aluminum, the thickness ratio of the aluminum material to other metal materials may differ before and after roll joining. This phenomenon of difference in thickness ratio before and after roll joining is thought to be due to the fact that during roll joining, plastic deformation of the aluminum material proceeds preferentially over other metal materials that have a larger equivalent stress for the same equivalent strain. If this phenomenon occurs, the thickness of the aluminum layer constituting the clad material will be smaller than the design value (target value), which is undesirable.

[0007] To date, there have been no known documents disclosing a method for accurately predicting or forecasting the thickness of the aluminum layer that constitutes a clad material, which is characterized by a difference in thickness ratio before and after roll bonding observed in clad materials using aluminum materials. Therefore, for clad materials using aluminum materials, it has generally been necessary to predict the thickness of the aluminum layer after roll bonding based on manufacturing history data. However, when developing new products without manufacturing history data, it has been necessary to conduct repeated experiments and prototypes to find appropriate manufacturing conditions. Therefore, for new products without manufacturing history data, the increased design time and costs of experiments and prototypes make it difficult to bring them to market quickly and affordably.

[0008] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a method for manufacturing clad materials that introduces a process for predicting with high accuracy the thickness of the aluminum layer after roll bonding, and that makes it possible to reduce design man-hours and costs for experiments and prototyping in the development of new clad materials that use aluminum materials.

[0009] The inventors thoroughly investigated the mechanical properties of clad materials (aluminum and other metals) and the behavior of clad materials during roll bonding. They then focused on the strain energy of the clad materials during roll bonding and discovered a process for predicting the thickness of the aluminum layer after roll bonding with high accuracy, which led to the invention.

[0010] The method for producing a clad material according to the present invention includes a roll-joining process in which an aluminum material made of aluminum or an aluminum alloy and a high-stress metal material made of a metal having a higher equivalent stress for an equivalent strain than the aluminum material are laminated in the thickness direction and roll-joined to form a clad material having an aluminum layer made of the aluminum material and a high-stress metal layer made of the high-stress metal material; and a prediction process in which a target thickness of the aluminum material and a total rolling reduction ratio of the roll-joining are set, and in the prediction process, an estimated thickness of the aluminum material is set as an independent variable t1. Ａｌ and the predicted thickness of the aluminum layer is the dependent variable t2 Ａｌ t2 calculated by Equation 1, Equation 2 and Equation 3 Ａｌ The value is (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ t1 that satisfies ≦|0.05| Ａｌ The value is the target thickness T1 of the aluminum material. Ａｌ The RL value obtained by Equation 4 is set as the total rolling reduction ratio of the roll joining. Ａｌ = (T2 Ａｌ +T2 ＨＳ )×(A+τ) / (A+τ+1) Formula 2: A=(t1 Ａｌ ×U Ａｌ ) / (T1 ＨＳ ×U ＨＳ ) Equation 3: τ=3 ０．５ / 2×(t1 Ａｌ / T1 ＨＳ ) × (1-U Ａｌ / U ＨＳ ) Formula 4: RL=1-(T2 Ａｌ +T2 ＨＳ ) / (T1 Ａｌ +T1 ＨＳ ) and T1 ＨＳ : Thickness of high stress metal material before roll joining T2 Ａｌ : Thickness of aluminum layer after roll bonding T2 ＨＳ : Thickness of the highly stressed metal layer after roll bonding U Ａｌ : Equivalent strain energy density of aluminum material during roll joining U ＨＳ: Equivalent strain energy density of high stress metal material during roll joining

[0011] In the method for producing a clad material according to the present invention, preferably, in the prediction process, t2 calculated by the formula 1 and the formula 2 is Ａｌ The value is (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ t1 that satisfies ≦|0.03| Ａｌ The value is the target thickness T1 of the aluminum material. Ａｌ Set as.

[0012] According to this invention, a process for predicting with high accuracy the thickness of the aluminum layer after roll bonding is introduced, and a method for manufacturing clad materials can be provided that enables reduction in design labor and experimental / prototype costs in the development of new clad materials using aluminum materials.

[0013] Hereinafter, an embodiment of the method for manufacturing a clad material according to the present invention will be described with respect to a clad material using an aluminum material. Note that the method for manufacturing a clad material according to the present invention is not limited to the content of the embodiment exemplified here, but is defined by the claims, and includes all modifications within the meaning and scope equivalent to the claims.

[0014] The method for manufacturing a clad material according to the present invention includes a roll-joining process in which an aluminum material (hereinafter simply referred to as "aluminum material") made of aluminum or an aluminum alloy and a high-stress metal material (hereinafter simply referred to as "high-stress metal material") made of a metal whose equivalent stress for the same equivalent strain is greater than that of the aluminum material are stacked in the thickness direction and roll-joined to form a clad material having an aluminum layer made of the aluminum material and a high-stress metal layer made of the high-stress metal material; and a prediction process in which the target thickness of the aluminum material and the total rolling reduction ratio of the roll-joining are set.

[0015] In the method for manufacturing a clad material according to the present invention, in the above-mentioned prediction process, the estimated thickness of the aluminum material is set as an independent variable t1 Ａｌ and the predicted thickness of the aluminum layer is the dependent variable t2 Ａｌt2 calculated by Equation 1, Equation 2 and Equation 3 Ａｌ The value is (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ t1 that satisfies ≦|0.05| Ａｌ The value is the target thickness T1 of the aluminum material. Ａｌ and the RL value calculated by Equation 4 is set as the total rolling reduction of the roll joining. Ａｌ The value is (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ t1 that satisfies ≦|0.03| Ａｌ The value is the target thickness T1 of the aluminum material. Ａｌ Set as.

[0016] However, Formula 1: t2 Ａｌ = (T2 Ａｌ +T2 ＨＳ )×(A+τ) / (A+τ+1) Formula 2: A=(t1 Ａｌ ×U Ａｌ ) / (T1 ＨＳ ×U ＨＳ ) Equation 3: τ=3 ０．５ / 2×(t1 Ａｌ / T1 ＨＳ ) × (1-U Ａｌ / U ＨＳ ) Formula 4: RL=1-(T2 Ａｌ +T2 ＨＳ ) / (T1 Ａｌ +T1 ＨＳ ) and T1 ＨＳ : Thickness of high stress metal material before roll joining T2 Ａｌ : Thickness of aluminum layer after roll bonding T2 ＨＳ : Thickness of the highly stressed metal layer after roll bonding U Ａｌ : Equivalent strain energy density of aluminum material during roll joining U ＨＳ : Equivalent strain energy density of high stress metal material during roll joining

[0017] In the present invention, before the roll bonding is performed in the roll bonding process, the thickness of the aluminum material before the roll bonding is estimated in the prediction process, and the thickness of the aluminum layer constituting the clad material after the roll bonding is estimated. Specifically, the estimated thickness of the aluminum material is used as an independent variable t1 Ａｌ and the predicted thickness of the aluminum layer is the dependent variable t2 Ａｌ The expected thickness of the aluminum layer is t2 Ａｌ and the thickness of the aluminum layer is the dependent variable when predicting the thickness of the aluminum layer. Ａｌ The input value (t1 Ａｌ value) according to a particular prediction equation, i.e., Equation 1, Equation 2, and Equation 3 above, the dependent variable t Ａｌ The output value (t Ａｌ value).

[0018] And the independent variable t1 Ａｌ Enter the dependent variable t2 Ａｌ The process of outputting the output value (t Ａｌ value) satisfies the above-mentioned specific condition, i.e., (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ This is repeated until the condition ≦|0.05| is satisfied. As a result, the output value (t Ａｌ The input value (t1 Ａｌ value) to the target thickness T1 of the aluminum material prepared to actually form the clad material. Ａｌ Set as.

[0019] In addition, in the above prediction process, the output value (t2 Ａｌ The target thickness T1 of the aluminum material when the Ａｌ and the thickness of the aluminum layer T2 Ａｌ The RL value is calculated using the above-mentioned specific calculation formula, that is, the above-mentioned formula 4, using the above-mentioned (design value). The RL value is set as the total rolling reduction ratio when actually performing roll joining to form a clad material.

[0020] By the above-mentioned prediction process, the desired thickness T2 ＡｌA predetermined target thickness T1 that can form an aluminum layer of (design value) Ａｌ It is possible to prepare an aluminum material having a thickness T2 ＨＳ A predetermined thickness T1 that allows forming a high stress metal layer of (design value) ＨＳ Then, in the above-described roll joining process, a high-stress metal material having a predetermined target thickness T1 can be prepared. Ａｌ and a predetermined thickness T1 ＨＳ The high stress metal material is laminated in the thickness direction and roll-joined at a total rolling reduction rate RL, thereby forming a thickness T2 Ａｌ (design value) aluminum layer and high stress metal material thickness T2 ＨＳ As a result, it is highly likely that a clad material having a high-stress metal layer with a thickness of the aluminum layer constituting the clad material (design value T2 Ａｌ ) is the expected thickness of the aluminum layer (t Ａｌ ) is likely to be easily formed within a range of ±5%.

[0021] In this invention, the aluminum material for forming the clad material may be appropriately selected from aluminum and aluminum alloys having the desired properties according to the purpose, such as aluminum A1050, aluminum A1100, and aluminum alloys A3003, A5052, etc.

[0022] Furthermore, a high-stress metal material to be combined with an aluminum material to form a clad material can be appropriately selected by comparing the stress-strain data of candidate metals having the desired properties for the purpose with the stress-strain data of an appropriately selected aluminum material. Examples of high-stress metal materials include oxygen-free copper (e.g., C1020) with a copper content of 99.9% or more, tough pitch copper (e.g., C1100), phosphorus-deoxidized copper (e.g., C1220), various stainless steels, nickel, nickel alloys, and other metals.

[0023] In the present invention, the above-mentioned specific prediction formulas, i.e., the above-mentioned formulas 1, 2 and 3, are based on the assumed thickness t1 of the aluminum material before roll joining. Ａｌ Given the expected thickness t2 of the aluminum layer that constitutes the clad material after roll bonding Ａｌ The inventor has devised a method for obtaining the expected thickness t2 of the aluminum layer. Ａｌ (t2 Ａｌ In Equation 1, T2 Ａｌ (T2 Ａｌ value) is the target thickness (design value) of the aluminum layer that constitutes the clad material after roll bonding. ＨＳ (T2 ＨＳ The τ value) is the target thickness (design value) of the high-stress metal layer that constitutes the clad material after roll bonding. A (A value) is a calculated value obtained by Equation 2, and is the ratio of the equivalent strain energy of the aluminum material to the equivalent strain energy of the high-stress metal material (equivalent strain energy ratio of the aluminum material). τ (τ value) is a calculated value obtained by Equation 3.

[0024] Assumed thickness t1 of aluminum material Ａｌ (t1 Ａｌ In Equation 2, T1 is used to calculate the A value. ＨＳ (T1 ＨＳ value) is the thickness (design value or actual measurement value) of the high-stress metal material before roll bonding. Ａｌ (U Ａｌ value) is the equivalent strain energy density of the aluminum material during roll joining. ＨＳ (U ＨＳ The value of U is the equivalent strain energy density of the high stress metal material during roll joining. Ａｌ (U Ａｌ value) and U ＨＳ (U ＨＳ The method for determining the assumed thickness t1 of the aluminum material will be described later. Ａｌ (t1 ＡｌRegarding the τ value calculated by Equation 3 by applying τ (value) to the aluminum material and the high-stress metal material during roll joining, the inventors believe that the difference in equivalent strain energy between the aluminum material and the high-stress metal material during roll joining corresponds to the energy caused by the shear stress acting on the interface between the aluminum material (aluminum layer) and the high-stress metal material (high-stress metal layer) during roll joining. From this perspective, the above τ value corresponds to the shear strain energy of the aluminum material and the high-stress metal material during roll joining.

[0025] As described above, the A value is the ratio of the equivalent strain energy of the aluminum material during roll joining. In the predicted process described above, the equivalent strain energy of the aluminum material during roll joining is calculated by multiplying the assumed thickness t1 of the aluminum material before roll joining by 1 / 2. Ａｌ and the equivalent strain energy density U of the aluminum material during roll joining. Ａｌ The equivalent strain energy of the high stress metal material during roll joining is the product of the thickness T1 of the high stress metal material before roll joining. ＨＳ (design value or actual measurement value) and the equivalent strain energy density U of the high stress metal material during roll joining ＨＳ It is the product of

[0026] In the roll joining process described above, a large amount of strain energy is stored in the clad material (aluminum material and high-stress metal material) due to the large deformation during roll joining. If the energy loss due to heat generation during roll joining is sufficiently smaller than the strain energy, the equivalent strain energy stored in the aluminum material is calculated based on the estimated thickness t1 of the aluminum material in the above-mentioned prediction process. Ａｌ and the equivalent strain energy density U Ａｌ Similarly, the equivalent strain energy stored in the high stress metal material during roll joining can be calculated by multiplying the thickness T1 of the high stress metal material by the ＨＳ and the equivalent strain energy density U ＨＳ Therefore, if there is no energy loss as described above, the equivalent strain energy stored in the clad material during roll joining is the sum of the equivalent strain energy stored in the aluminum material and the high-stress metal material (t1 Ａｌ ×U Ａｌ +T1ＨＳ ×U ＨＳ ) can be calculated.

[0027] Here, the ratio of the equivalent strain energy of the aluminum material to the equivalent strain energy of the clad material is called RU. Ａｌ As R.U. Ａｌ = (t Ａｌ ×U Ａｌ ) / (t1 Ａｌ ×U Ａｌ +T1 ＨＳ ×U ＨＳ Consider the equation A = (t1 Ａｌ ×U Ａｌ ) / (T1 ＨＳ ×U ＨＳ ) as (T1 ＨＳ ×U ＨＳ ) = (t1 Ａｌ ×U Ａｌ ) / A, then RU Ａｌ = A / (A+1). By focusing on the term in the form of A / (A+1) on the right side of this equation and adding a term equivalent to shear strain energy (the τ value obtained by Equation 3) to the A value, we obtain a term in the form of (A+τ) / (A+τ+1). The term in the form of adding the τ value is then multiplied by the thickness of the clad material after roll bonding (T2 Ａｌ +T2 ＨＳ ) to obtain the above-mentioned formula 1. From this viewpoint, in this invention, the above-mentioned formula 1 is calculated by multiplying the expected thickness t2 of the aluminum layer constituting the clad material after roll bonding. Ａｌ The formula is as follows:

[0028] The above U Ａｌ (U Ａｌ value) and U ＨＳ (U ＨＳ The equivalent strain energy density U of aluminum material during roll joining is Ａｌ can be determined based on data showing the relationship between the equivalent stress (σ) and equivalent strain (ε) of the aluminum material (hereinafter referred to as "stress-strain data"). Similarly, the equivalent strain energy density U of a high-stress metal material during roll joining can be determined based on data showing the relationship between the equivalent stress (σ) and equivalent strain (ε) of the aluminum material (hereinafter referred to as "stress-strain data"). ＨＳ can be calculated based on the stress-strain data of the high-stress metal material. ＨＳ(U ＨＳ value) is the U value of aluminum material Ａｌ (U Ａｌ Since it can be obtained in the same way as the U value of aluminum material, Ａｌ (U Ａｌ This section explains the case where the value of

[0029] U of the desired aluminum material Ａｌ (U Ａｌ When determining the stress-strain value, stress-strain data for the aluminum material is prepared. Stress-strain data for general aluminum materials can be determined based on the results of a tensile test of the aluminum material conducted in accordance with the metallic material tensile test method specified in JIS-Z2241:2022. If known stress-strain data is available for the desired aluminum material, the known stress-strain data can be used.

[0030] Next, based on the stress-strain data of the desired aluminum material, stress-strain function data is created that expresses the equivalent stress σ as a function of the equivalent strain ε. Then, using this function data, the equivalent stress σ is integrated in the interval from ε1 to ε2 using the equivalent strain ε. The starting point ε1 of the integration interval is the equivalent strain applied to the aluminum material immediately before roll-joining. Normally, ε1 = 0. Furthermore, the end point ε2 of the integration interval is the equivalent strain applied to the aluminum material during roll-joining, and is ε2 = -1 × LN(1 - Rp) × (2 / 3 ０．５ ) can be calculated. Usually, ε2>ε1. In the above formula for calculating ε2, Rp is the assumed processing rate, and Rp={(t1 Ａｌ +T1 ＨＳ ) - (T2 Ａｌ +T2 ＨＳ )} / (t1 Ａｌ +T1 ＨＳ ) In the above formula for calculating Rp, the denominator (t1 Ａｌ +T1 ＨＳ ) is the assumed thickness t1 of the aluminum material Ａｌ and the thickness T1 of the high stress metal material ＨＳ (design value or actual measurement value) and is the assumed thickness of the clad material before roll bonding.

[0031] Using the above-described method, the value obtained by integrating the equivalent stress σ with the equivalent strain ε over the range from ε1 to ε2 based on the stress-strain data of the desired aluminum material is the equivalent strain energy density U of the aluminum material during roll joining. Ａｌ (U Ａｌ Furthermore, using the same method as in the case of the aluminum material described above, the equivalent stress σ is integrated over the range from ε1 to ε2 based on the stress-strain data of the desired high-stress metal material, and the value obtained is the equivalent strain energy density U of the high-stress metal material during roll joining. ＨＳ (U ＨＳ value).

[0032] In this invention, the t2 calculated by the above-mentioned specific prediction formula, i.e., the above-mentioned formula 1, formula 2 and formula 3 Ａｌ The value satisfies the above-mentioned specific condition, i.e., (t Ａｌ -T2 Ａｌ ) / T2 Ａｌ Preferably, (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ ≦|0.03| until the assumed thickness t1 of the aluminum material before roll joining is satisfied. Ａｌ Given the expected thickness t2 of the aluminum layer after roll bonding Ａｌ By repeating this trial, t2 Ａｌ Appropriate t1 values ​​that satisfy the above-mentioned specific conditions Ａｌ Then, an appropriate t1 value that satisfies the above-mentioned specific conditions can be obtained. Ａｌ The value is the target thickness T2 Ａｌ The target thickness T1 of the aluminum material for forming the aluminum layer Ａｌ Set as.

[0033] In the present invention, the RL value calculated by the above-mentioned specific calculation formula, that is, the above-mentioned (Formula 4), is set as the total rolling ratio.

[0034] By the above-mentioned prediction process, the thickness of the aluminum layer constituting the clad material (design value T2 Ａｌ ) is the expected thickness of the aluminum layer (t Ａｌ) and is preferably within ±5% of the expected thickness (t2 Ａｌ ) is likely to be formed within a range of ±3% of the calculated value. By using the above-mentioned prediction process that involves repeated numerical calculation trials, it is possible to significantly reduce the design man-hours and development costs involved in developing new clad materials that use aluminum materials, compared to the case where repeated experiments and prototype trials are used.

[0035] Below, we will explain experimental trials using the above roll joining process and prediction trials using the above prediction process, which were conducted to confirm the effectiveness of the manufacturing method of clad material using aluminum material according to the present invention.

[0036] <Experimental Trials> In the experimental trials, the following Experiments 1 to 4 were conducted. In Experiments 1 to 4, roll bonding of an aluminum material and a high-stress metal material was actually carried out to produce clad materials having an aluminum layer and a high-stress metal layer. The aluminum material and high-stress metal material shown in Table 1 were prepared as clad materials before roll bonding. In each of Experiments 1 to 4 shown in Table 1, the high-stress metal material has a larger equivalent stress for the same equivalent strain than the aluminum material. In the roll bonding process, Ａｌ (Actual measurement) Aluminum material and thickness T1 ＨＳ The high stress metal material (actual measurement value) was laminated in the thickness direction and roll-bonded at the total rolling reduction shown in Table 2. Ａｌ (Measured value) aluminum layer and thickness T2 ＨＳ A clad material shown in Table 2 was formed having a high stress metal layer of (actual measured value).

[0037]

[0038]

[0039] In Experiment 1, a clad material was fabricated with a thickness ratio (design value) of aluminum layer:high-stress metal layer = 0.600:0.400. To achieve this, an aluminum material with a thickness of 4.96 mm and a high-stress metal material with a thickness of 3.30 mm were prepared, with a thickness ratio of aluminum material:high-stress metal material = 0.600:0.400. Then, roll bonding was performed using the aluminum material and the high-stress metal material. The total rolling reduction during this roll bonding was 63.1% (see Table 2). In this case, since the thickness ratio was 0.600, the thickness of the aluminum layer was approximately 1.83 mm (design value). In contrast, the clad material fabricated by the above roll bonding process had a thickness of 3.05 mm, an aluminum layer thickness of 1.67 mm, and a high-stress metal layer thickness of 1.38 mm. Therefore, the thickness ratio of aluminum layer:high stress metal layer=0.548:0.452, and the thickness ratio of the aluminum layer after roll bonding was smaller than the design value by 0.052 (=0.600-0.548).

[0040] In Experiment 2, a clad material was fabricated with a thickness ratio (design value) of aluminum layer:high-stress metal layer = 0.566:0.434. To this end, an aluminum material with a thickness of 4.30 mm and a high-stress metal material with a thickness of 3.30 mm were prepared, with a thickness ratio of aluminum material:high-stress metal material = 0.566:0.434. Then, roll bonding was performed using the aluminum material and the high-stress metal material. The total rolling reduction during this roll bonding was 59.9% (see Table 2). In this case, since the thickness ratio was 0.566, the thickness of the aluminum layer was approximately 1.73 mm (design value). In contrast, the clad material fabricated by the above roll bonding process had a thickness of 3.05 mm, an aluminum layer thickness of 1.58 mm, and a high-stress metal layer thickness of 1.47 mm. Therefore, the thickness ratio of aluminum layer:high stress metal layer=0.518:0.482, and the thickness ratio of the aluminum layer after roll bonding was smaller than the design value by 0.048 (=0.566-0.518).

[0041] In Experiment 3, a clad material was fabricated with a thickness ratio (design value) of aluminum layer:high-stress metal layer = 0.547:0.453. To this end, an aluminum material with a thickness of 3.98 mm and a high-stress metal material with a thickness of 3.30 mm were prepared, with a thickness ratio of aluminum material:high-stress metal material = 0.547:0.453. Then, roll bonding was performed using the aluminum material and the high-stress metal material. The total rolling reduction during this roll bonding was 58.0% (see Table 2). In this case, since the thickness ratio was 0.547, the thickness of the aluminum layer was approximately 1.67 mm (design value). In contrast, the clad material fabricated by the above roll bonding process had a thickness of 3.06 mm, an aluminum layer thickness of 1.54 mm, and a high-stress metal layer thickness of 1.52 mm. Therefore, the thickness ratio of aluminum layer:high stress metal layer=0.503:0.497, and the thickness ratio of the aluminum layer after roll bonding was smaller than the design value by 0.044 (=0.547-0.503).

[0042] In Experiment 4, a clad material was fabricated with a thickness ratio (design value) of aluminum layer:high-stress metal layer = 0.530:0.470. To achieve this, an aluminum material with a thickness of 3.72 mm and a high-stress metal material with a thickness of 3.30 mm were prepared, with a thickness ratio of aluminum material:high-stress metal material = 0.530:0.470. Then, roll bonding was performed using the aluminum material and the high-stress metal material. The total rolling reduction during this roll bonding was 56.4% (see Table 2). In this case, since the thickness ratio was 0.530, the thickness of the aluminum layer was approximately 1.62 mm (design value). In contrast, the clad material fabricated by the above roll bonding process had a thickness of 3.06 mm, an aluminum layer thickness of 1.49 mm, and a high-stress metal layer thickness of 1.57 mm. Therefore, the thickness ratio of aluminum layer:high stress metal layer=0.487:0.513, and the thickness ratio of the aluminum layer after roll bonding was smaller than the design value by 0.043 (=0.530-0.487).

[0043] <Prediction trial> In the prediction trial, information on the clad material used in the experimental trial was shared, and the experiment and manufacturing predictions described below were made. In the prediction trial, first, the equivalent strain energy density U of the aluminum material during roll joining was calculated for the aluminum material and high-stress metal material used in the experimental trial. Ａｌ and the equivalent strain energy density U of high-stress metal materials ＨＳ was calculated based on the respective stress-strain data. Specifically, as shown in Table 3, for Predictions 1 to 4 corresponding to Experiments 1 to 4, the true strain corresponding to the total rolling reduction ratio (see Table 2) during roll joining performed in Experiments 1 to 4 was calculated, and the equivalent strain corresponding to that true strain was calculated. Next, in the stress-strain data of the aluminum material, the start point ε1 of the integral interval was set to zero (ε1 = 0), and the value corresponding to that equivalent strain was set to the end point ε2 of the integral interval, and an integral value was calculated. The integral value was used as the equivalent strain energy density U of the aluminum material during roll joining. Ａｌ Similarly, the equivalent strain energy density U of the high stress metal material during roll joining is ＨＳ is an integral value calculated based on the stress-strain data of the high-stress metal material, as in the case of the aluminum material described above.

[0044]

[0045] <Experimental Predictions> Next, the information from Experiments 1 to 4 was shared, and Experimental Predictions 1 to 4 corresponding to Experiments 1 to 4 were carried out. The results are summarized in Table 4.

[0046]

[0047] In Experiment 1, for the clad material of Experiment 1 described above, the thickness of the aluminum material, 4.96 mm (measured value), was used as the independent variable (t1 Ａｌ ), and the thickness of the aluminum layer is the dependent variable (t Ａｌ) were predicted. As shown in Table 4, the design values ​​(target values) corresponding to Experiment 1 were a clad material thickness of 3.05 mm, an aluminum layer thickness ratio of 0.600, an aluminum layer thickness of 1.83 mm, and a high-stress metal layer thickness of 1.22 mm. As shown in Table 1, the materials used for Experiment 1 were an aluminum material with a thickness of 4.96 mm (actual measurement value) and a high-stress metal material with a thickness of 3.30 mm (actual measurement value). As shown in Table 3, the equivalent strain energy density was 112.5 for the aluminum material and 459.9 for the high-stress metal material. As a result of the prediction, the predicted thickness of the aluminum layer (t2 Ａｌ ) was 1.75 mm, which was the target thickness of the aluminum layer corresponding to Experiment 1 (T2 Ａｌ ) was smaller than 1.83 mm. Ａｌ -T2 Ａｌ ) is -0.08 mm. Ａｌ -T2 Ａｌ ) / T2 Ａｌ is found to be −0.044, so the error in this prediction is approximately 4.4%.

[0048] In Experiment 2, for the clad material of Experiment 2 described above, the thickness of the aluminum material was 4.30 mm (measured value) as the independent variable (t1 Ａｌ ), and the thickness of the aluminum layer is the dependent variable (t Ａｌ ) was predicted. As shown in Table 4, the design values ​​(target values) corresponding to Experiment 2 are a clad material thickness of 3.05 mm, an aluminum layer thickness ratio of 0.566, an aluminum layer thickness of 1.73 mm, and a high stress metal layer thickness of 1.32 mm. As shown in Table 1, the materials used for Experiment 2 are an aluminum material with a thickness of 4.30 mm (actual measurement value) and a high stress metal material with a thickness of 3.30 mm (actual measurement value). As shown in Table 3, the equivalent strain energy density is 101.2 for the aluminum material and 404.4 for the high stress metal material. As a result of the prediction, the predicted thickness of the aluminum layer (t2 Ａｌ ) was 1.65 mm, and the target thickness of the aluminum layer corresponding to Experiment 2 (T2 Ａｌ ) was smaller than 1.73 mm. Ａｌ -T2 Ａｌ) is -0.08 mm. Ａｌ -T2 Ａｌ ) / T2 Ａｌ is found to be −0.046, so the error in this prediction is approximately 4.6%.

[0049] In Experiment 3, for the clad material of Experiment 3 described above, the thickness of the aluminum material was 3.98 mm (measured value) as the independent variable (t1 Ａｌ ), and the thickness of the aluminum layer is the dependent variable (t Ａｌ ) was predicted. As shown in Table 4, the design values ​​(target values) corresponding to Experiment 3 are a clad material thickness of 3.06 mm, an aluminum layer thickness ratio of 0.547, an aluminum layer thickness of 1.67 mm, and a high stress metal layer thickness of 1.39 mm. As shown in Table 1, the materials used for Experiment 3 are an aluminum material with a thickness of 3.98 mm (measured value) and a high stress metal material with a thickness of 3.30 mm (measured value). As shown in Table 3, the equivalent strain energy density is 95.0 for the aluminum material and 374.5 for the high stress metal material. As a result of the prediction, the predicted thickness of the aluminum layer (t2 Ａｌ ) was 1.59 mm, which was the target thickness of the aluminum layer corresponding to Experiment 3 (T2 Ａｌ ) of 1.67 mm. Ａｌ -T2 Ａｌ ) is -0.08 mm. Ａｌ -T2 Ａｌ ) / T2 Ａｌ is found to be −0.048, so the error in this prediction is approximately 4.8%.

[0050] In Experiment 4, for the clad material of Experiment 4 described above, the thickness of the aluminum material, 3.72 mm (measured value), was used as the independent variable (t1 Ａｌ ), and the thickness of the aluminum layer is the dependent variable (t Ａｌ) was predicted. As shown in Table 4, the design values ​​(target values) corresponding to Experiment 4 are a clad material thickness of 3.06 mm, an aluminum layer thickness ratio of 0.530, an aluminum layer thickness of 1.62 mm, and a high stress metal layer thickness of 1.44 mm. As shown in Table 1, the materials used for Experiment 4 are an aluminum material with a thickness of 3.72 mm (measured value) and a high stress metal material with a thickness of 3.30 mm (measured value). As shown in Table 3, the equivalent strain energy density is 90.2 for the aluminum material and 351.6 for the high stress metal material. As a result of the prediction, the predicted thickness of the aluminum layer (t2 Ａｌ ) was 1.54 mm, which was the target thickness of the aluminum layer corresponding to Experiment 4 (T2 Ａｌ ) of 1.62 mm. Ａｌ -T2 Ａｌ ) is -0.08 mm. Ａｌ -T2 Ａｌ ) / T2 Ａｌ is found to be −0.049, so the error in this prediction is approximately 4.9%.

[0051] <Production prediction> Next, the information from Experiments 1 to 4 was shared, and the predicted thickness of the aluminum layer (t2 Ａｌ ) to the target thickness of the aluminum layer (T2 Ａｌ ) In order to approach the above, Production Predictions 1 to 4 corresponding to Experiments 1 to 4 were carried out.

[0052] <Manufacturing Forecast 1> In Manufacturing Forecast 1, as shown in Table 5, the information on the clad material (thickness 3.05 mm) of Experiment 1 is shared, and the predicted thickness of the aluminum layer (t2 Ａｌ In order to bring the thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ ≦|0.05| when the assumed thickness (t1 Ａｌ value), i.e., the appropriate thickness (T1 ＡｌThe thickness (T1 Ａｌ The appropriate total rolling reduction ratio for roll bonding corresponding to the predicted thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ Appropriate thickness (T1 Ａｌ The thickness (T1 Ａｌ The appropriate total rolling ratio for roll bonding corresponding to the value of the rolling resistance was 63.7% to 67.0%.

[0053] The results of Production Prediction 1 revealed that a clad material having an aluminum layer thickness of 1.83 mm ± 5% is likely to be formed by roll-joining aluminum materials having thicknesses of 4.87 mm to 6.25 mm with a total rolling reduction of 62.7% to 68.1% corresponding to each aluminum material. It was also found that a clad material having an aluminum layer thickness of 1.83 mm ± 3% is likely to be formed by roll-joining aluminum materials having thicknesses of 5.11 mm to 5.94 mm with a total rolling reduction of 63.7% to 67.0% corresponding to each aluminum material. It was also found that the results of Production Prediction 1E revealed that a clad material having an aluminum layer thickness of 1.83 mm is likely to be formed by roll-joining aluminum materials having thicknesses of 5.51 mm with a total rolling reduction of 65.4%.

[0054]

[0055]

[0056] <Manufacturing Forecast 2> In Manufacturing Forecast 2, as shown in Table 7, the information on the clad material (thickness 3.05 mm) of Experiment 2 was shared, and the predicted thickness of the aluminum layer (t2 Ａｌ In order to bring the thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ-T2 Ａｌ ) / T2 Ａｌ ≦|0.05| when the assumed thickness (t1 Ａｌ value), i.e., the appropriate thickness (T1 Ａｌ The thickness (T1 Ａｌ The appropriate total rolling reduction ratio for roll bonding corresponding to the predicted thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ Appropriate thickness (T1 Ａｌ The thickness (T1 Ａｌ The appropriate total rolling ratio for roll bonding corresponding to the value of the rolling resistance was 60.8% to 63.9%.

[0057] The results of Production Prediction 2 revealed that a clad material having an aluminum layer thickness of 1.73 mm ± 5% is likely to be formed by roll-joining aluminum materials having thicknesses of 4.29 mm to 5.40 mm with a total rolling reduction of 59.8% to 64.9% corresponding to each aluminum material. It was also found that a clad material having an aluminum layer thickness of 1.73 mm ± 3% is likely to be formed by roll-joining aluminum materials having thicknesses of 4.49 mm to 5.16 mm with a total rolling reduction of 60.8% to 63.9% corresponding to each aluminum material. The results of Production Prediction 2E revealed that a clad material having an aluminum layer thickness of 1.73 mm is likely to be formed by roll-joining aluminum materials having thicknesses of 4.81 mm with a total rolling reduction of 62.4%.

[0058]

[0059]

[0060] <Manufacturing Forecast 3> In Manufacturing Forecast 3, as shown in Table 9, the information on the clad material (thickness 3.06 mm) of Experiment 3 was shared, and the predicted thickness of the aluminum layer (t2 ＡｌIn order to bring the thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ ≦|0.05| when the assumed thickness (t1 Ａｌ value), i.e., the appropriate thickness (T1 Ａｌ The thickness (T1 Ａｌ The appropriate total rolling reduction ratio for roll bonding corresponding to the predicted thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ Appropriate thickness (T1 Ａｌ The thickness (T1 Ａｌ The appropriate total rolling ratio for roll bonding corresponding to the value of the rolling resistance was 58.8% to 61.8%.

[0061] The results of Production Prediction 3 revealed that a clad material having an aluminum layer thickness of 1.67 mm ± 5% is likely to be formed by roll-joining aluminum materials having thicknesses of 3.95 mm to 4.92 mm with a total rolling reduction of 57.8% to 62.8% corresponding to each aluminum material. It was also found that a clad material having an aluminum layer thickness of 1.67 mm ± 3% is likely to be formed by roll-joining aluminum materials having thicknesses of 4.12 mm to 4.71 mm with a total rolling reduction of 58.8% to 61.8% corresponding to each aluminum material. It was also found that the results of Production Prediction 3E revealed that a clad material having an aluminum layer thickness of 1.67 mm is likely to be formed by roll-joining aluminum materials having thicknesses of 4.41 mm with a total rolling reduction of 60.3%.

[0062]

[0063]

[0064] <Manufacturing Forecast 4> In Manufacturing Forecast 4, as shown in Table 11, the information on the clad material (thickness 3.06 mm) of Experiment 4 is shared, and the predicted thickness of the aluminum layer (t2 Ａｌ In order to bring the thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ ≦|0.05| when the assumed thickness (t1 Ａｌ value), i.e., the appropriate thickness (T1 Ａｌ The thickness (T1 Ａｌ The appropriate total rolling reduction ratio for roll bonding corresponding to the predicted thickness (t2 Ａｌ value) is a specific condition (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ Appropriate thickness (T1 Ａｌ The thickness (T1 Ａｌ The appropriate total rolling reduction ratio for roll bonding corresponding to the value of the rolling resistance was 57.3% to 60.2%.

[0065] The results of Production Prediction 4 revealed that a clad material having an aluminum layer thickness of 1.62 mm ± 5% is likely to be formed by roll-joining aluminum materials having thicknesses of 3.71 mm to 4.58 mm with a total rolling reduction of 56.3% to 61.2% corresponding to each aluminum material. It was also found that a clad material having an aluminum layer thickness of 1.62 mm ± 3% is likely to be formed by roll-joining aluminum materials having thicknesses of 3.87 mm to 4.39 mm with a total rolling reduction of 57.3% to 60.2% corresponding to each aluminum material. The results of Production Prediction 4E revealed that a clad material having an aluminum layer thickness of 1.62 mm is likely to be formed by roll-joining aluminum materials having thicknesses of 4.12 mm with a total rolling reduction of 58.8%.

[0066]

[0067]

[0068] From the above, considering the results of the above-mentioned experimental trials (Experiments 1 to 4) and predicted trials (experimental prediction, production prediction), the effectiveness of the manufacturing method of the clad material using aluminum material according to the present invention can be confirmed. Therefore, by applying this invention, it becomes possible to predict with high accuracy the thickness of the aluminum layer after roll bonding, and therefore it is possible to provide a manufacturing method of clad material that enables reduction in design man-hours and costs of experiments and prototypes in the development of new clad materials using aluminum material.

Claims

1. A method for manufacturing a clad material having an aluminum layer made of the aluminum material and a high stress metal layer made of the high stress metal material, the high stress metal layer being made of the high stress metal material, by performing roll joining in a state where the aluminum material made of aluminum or an aluminum alloy and the high stress metal material made of a metal having a higher equivalent stress for an equivalent strain than the aluminum material are laminated in the thickness direction, comprising: a roll joining process; and a prediction process for setting a target thickness of the aluminum material and a total rolling ratio of the roll joining, wherein in the prediction process, an expected thickness of the aluminum material is set as an independent variable t1. Ａｌ and the predicted thickness of the aluminum layer is the dependent variable t2 Ａｌ t2 calculated by Equation 1, Equation 2 and Equation 3 Ａｌ The value is (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ t1 that satisfies ≦|0.05| Ａｌ The value is the target thickness T1 of the aluminum material. Ａｌ and the RL value calculated by the formula 4 is set as the total rolling ratio of the roll joining. Ａｌ = (T2 Ａｌ +T2 ＨＳ )×(A+τ) / (A+τ+1) Formula 2: A=(t1 Ａｌ ×U Ａｌ ) / (T1 ＨＳ ×U ＨＳ ) Equation 3: τ=3 ０．５ / 2×(t Ａｌ / T1 ＨＳ ) × (1-U Ａｌ / U ＨＳ ) Formula 4: RL=1-(T2 Ａｌ +T2 ＨＳ ) / (T1 Ａｌ +T1 ＨＳ ) and T1 ＨＳ : Thickness of high stress metal material before roll joining T2 Ａｌ : Thickness of aluminum layer after roll bonding T2 ＨＳ : Thickness of the highly stressed metal layer after roll bonding U Ａｌ : Equivalent strain energy density of aluminum material during roll joining U ＨＳ : Equivalent strain energy density of high stress metal material during roll joining 2. In the prediction process, t2 calculated by the formula 1, the formula 2 and the formula 3 Ａｌ The value is (t2 Ａｌ -T2 Ａｌ ) / T2 Ａｌ t1 that satisfies ≦|0.03| Ａｌ The value is the target thickness T1 of the aluminum material. Ａｌ A method for manufacturing a clad material using the aluminum material according to claim 1, wherein

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