Method for producing forged aluminum alloy cladding material, and forged aluminum alloy cladding material

Abstract

This method for producing a forged aluminum alloy cladding material forms a multilayer body that includes a first member and a second member by superposing the first member, which is formed of a first aluminum alloy, and a second member, which is formed of a second aluminum alloy, and pressurizing the first member and second member in the superposing direction. Subsequently, the multilayer body is die-forged by being pressurized in the superposing direction with use of a die. For example, after the die-forging, the forged aluminum alloy cladding material is subjected to a heat treatment.

Description

Manufacturing method of forged aluminum alloy clad material, and forged aluminum alloy clad material CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This international application claims priority based on Japanese Patent Application No. 2024-097553, filed with the Japan Patent Office on June 17, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a method for manufacturing an aluminum alloy forged clad material, and to an aluminum alloy forged clad material.

[0003] Patent Document 1 describes a dissimilar material forging method. In the dissimilar material forging method, a first metal-based member and a second metal-based member are joined to obtain a first material. The first material is then forged to obtain a forged product. Examples of the first metal-based member include a member made of chromium steel, carbon steel for mechanical structures, and boron steel. Examples of the second metal-based member include a member made of nickel-chromium-molybdenum steel.

[0004] JP 2014-65052 A

[0005] Conventionally, an aluminum alloy forged clad material in which aluminum alloy members are joined together has not been known. In one aspect of the present disclosure, it is preferable to provide an aluminum alloy forged clad material in which aluminum alloy members are joined together, and a method for manufacturing the same.

[0006] One aspect of the present disclosure is a method for producing an aluminum alloy forged clad material, which includes stacking a first member made of a first aluminum alloy and a second member made of a second aluminum alloy, applying pressure in the stacking direction to form a laminate including the first member and the second member, and then die forging the laminate by applying pressure in the stacking direction using a die.

[0007] According to a method for manufacturing an aluminum alloy forged clad material that is one aspect of the present disclosure, an aluminum alloy forged clad material can be obtained in which a first member made of a first aluminum alloy and a second member made of a second aluminum alloy are joined together.

[0008] Another aspect of the present disclosure is an aluminum alloy forged clad material including a first member made of a first aluminum alloy and a second member made of a second aluminum alloy and joined to the first member.

[0009] According to another aspect of the present disclosure, an aluminum alloy forged clad material can be obtained in which a first member made of a first aluminum alloy and a second member made of a second aluminum alloy are joined together.

[0010] FIG. 7A is a perspective view showing the configuration of a first member and a second member. FIG. 7B is a graph showing the measurement results of Zn in a sample after heat treatment. FIG. 8A is a graph showing the measurement results of Mg in a sample before heat treatment. FIG. 8B is a graph showing the measurement results of Mg in a sample after heat treatment.

[0011] Exemplary embodiments of the present disclosure will now be described with reference to the drawings.

[0012] 1. Manufacturing Method of Aluminum Alloy Forged Clad Material 1 The aluminum alloy forged clad material 1 can be manufactured, for example, by the following method: As shown in Figure 1, a first member 3 made of a first aluminum alloy and a second member 5 made of a second aluminum alloy are prepared.

[0013] The first aluminum alloy is not particularly limited as long as it is within the range of aluminum alloys. Examples of the first aluminum alloy include JIS A5052 and JIS A7050. The second aluminum alloy is not particularly limited as long as it is within the range of aluminum alloys. Examples of the second aluminum alloy include JIS A5052 and JIS A7050. However, it is preferable that the type of the second aluminum alloy is different from the type of the first aluminum alloy.

[0014] There are no particular limitations on the shapes of the first member 3 and the second member 5. Examples of the shapes of the first member 3 and the second member 5 include a cylindrical shape, a plate shape, a rod shape, a block shape, a spherical shape, and an irregular shape. The shapes of the first member 3 and the second member 5 shown in Fig. 1 are cylindrical.

[0015] The thickness of each of the first member 3 and the second member 5 in the overlapping direction X is, for example, 20 mm or more and 500 mm or less. The overlapping direction X is the direction in which the first member 3 and the second member 5 are later overlapped. In the first member 3 and the second member 5 shown in FIG. 1 , the overlapping direction X is parallel to the axial direction of the cylinder.

[0016] The size of each of the first member 3 and the second member 5 in the orthogonal direction Y is, for example, 100 mm or more and 1000 mm or less. The orthogonal direction Y is a direction perpendicular to the stacking direction X.

[0017] Next, as shown in Fig. 2, the first members 3 and the second members 5 are stacked. For example, one to three first members 3 and one to three second members 5 can be stacked alternately in the stacking direction X. For example, as shown in Fig. 2, one second member 5 can be sandwiched between two first members 3 in the stacking direction X.

[0018] The thickness of the set of the stacked first members 3 and second members 5 in the stacking direction X is, for example, 100 mm or more and 1500 mm or less. The size of the set of the stacked first members 3 and second members 5 in the orthogonal direction Y is, for example, 100 mm or more and 1000 mm or less.

[0019] Next, the set of stacked first members 3 and second members 5 is pressed in the stacking direction X. As a result, a stack 7 including the first members 3 and the second members 5 is formed. The maximum load when pressing is, for example, 1,000 tons or more and 15,000 tons or less. When the maximum load when pressing is within the above range, the bonding strength between the first member 3 and the second member 5 is further increased.

[0020] An example of a device used for pressurization is a hydraulic forging press, etc. Examples of a method for pressurizing the overlapping first member 3 and second member 5 include upset forging, die forging, etc.

[0021] The thickness of the laminate 7 in the stacking direction X is, for example, 50 mm or more and 500 mm or less. The size of the laminate 7 in the orthogonal direction Y is, for example, 200 mm or more and 1000 mm or less.

[0022] Next, the laminate 7 is die-forged by applying pressure in the stacking direction X using a die. As a result, an aluminum alloy forged clad material 1 is obtained as shown in Figures 3 and 4. An example of a device used for die-forging is a hydraulic forging press.

[0023] Die forging can be performed, for example, as shown in Fig. 5. In S1 of Fig. 5, an upper die 21 is placed above the laminate 7, and a lower die 23 is placed below the laminate 7. The upper die 21 and the lower die 23 each have a product portion 25, which is a space corresponding to the shape of the aluminum alloy forged clad material 1, on the side facing the laminate 7.

[0024] Next, as shown in S2 of Fig. 5, the laminate 7 is pressed in the stacking direction X using the upper die 21 and the lower die 23. The laminate 7 deforms according to the shapes of the upper die 21 and the lower die 23. When the laminate 7 is further pressed, the laminate 7 deforms further as shown in S3 of Fig. 5, and the filling of the laminate 7 into the product portion 25 is completed. By the above steps, the aluminum alloy forged clad material 1 is obtained.

[0025] After die forging, the aluminum alloy forged clad material 1 may be subjected to heat treatment. Examples of heat treatment include solution treatment and aging treatment. For example, solution treatment can be performed, followed by aging treatment. The heat treatment temperature is preferably 100°C or higher and 600°C or lower. The heat treatment time is preferably 1 hour or higher and 48 hours or lower. When heat treatment is performed, the bonding strength between the first member 3 and the second member 5 is further increased. When the heat treatment temperature and time are within the above ranges, the bonding strength between the first member 3 and the second member 5 is particularly high.

[0026] 2. Structure of Aluminum Alloy Forged Clad Material 1 As shown in Fig. 4, the aluminum alloy forged clad material 1 includes a first member 3 and a second member 5. The second member 5 is joined to the first member 3. For example, in the aluminum alloy forged clad material 1, one to three first members 3 and one to three second members 5 are alternately stacked. For example, one second member 5 is sandwiched between two first members 3.

[0027] For example, as shown in Figure 6, when the concentration of Zn or Mg is continuously measured along a 0.5 mm long line 10 that is perpendicular to the joining surface 6 between the first member 3 and the second member 5 and is bisected by the joining surface 6, the concentration of Zn or Mg remains constant or changes continuously depending on the position on the line 10, except for local increases and decreases. In this case, the joining strength between the first member 3 and the second member 5 is further increased. The concentration of Zn or Mg is measured using an electron probe microanalyzer (EPMA).

[0028] For example, a graph is created with the horizontal axis representing the position on line segment 10 and the vertical axis representing the Zn or Mg concentration. A case in which the Zn or Mg concentration measured on line segment 10 is constant except for local increases or decreases means that the curve of the graph is horizontal over the entire line segment 10 except for local increases or decreases. A case in which the Zn or Mg concentration measured on line segment 10 changes continuously depending on the position on line segment 10 except for local increases or decreases means that the curve of the graph is continuous (i.e., has no discontinuously changing portions) over the entire line segment 10 except for local increases or decreases.

[0029] For example, the concentration of Zn or Mg may be constant on one part of the line segment 10, except for local increases or decreases, and the concentration of Zn or Mg may vary continuously depending on the position on the line segment 10, except for local increases or decreases, on another part of the line segment 10. The local increases or decreases are, for example, increases or decreases within a range of about 10 μm or less on the line segment 10. Zn and Mg are additive elements to the first aluminum alloy and the second aluminum alloy.

[0030] After die forging, the aluminum alloy forged clad material 1 is subjected to heat treatment, so that the Zn or Mg concentration measured on the line segment 10 can be made constant or change continuously depending on the position on the line segment 10, except for local increases and decreases. The heat treatment temperature is preferably 320°C or higher and 470°C or lower. The heat treatment time is preferably 1 hour or higher and 48 hours or lower. Before the heat treatment, when the Zn and Mg concentrations are measured on the line segment 10, the Zn and Mg concentrations change discontinuously near the joining surface 6.

[0031] For example, as shown in Figure 3, the surface of the aluminum alloy forged clad material 1 has a portion 11 having a non-planar shape. A non-planar shape means a shape that is not flat. For example, the joining surface 6 (hereinafter referred to as a curved joining surface 6A) located at the back of the portion 11 having a non-planar shape has a curved shape that follows the non-planar shape. In the aluminum alloy forged clad material 1, even at the curved joining surface 6A, the second member 5 is unlikely to peel from the first member 3. Therefore, the aluminum alloy forged clad material 1 may have the portion 11 having a non-planar shape, which provides a high degree of freedom in terms of shape.

[0032] 3. Effects of the Aluminum Alloy Forged Clad Material 1 and Its Manufacturing Method (1A) According to the manufacturing method of the aluminum alloy forged clad material disclosed herein, it is possible to obtain an aluminum alloy forged clad material 1 in which the first member 3 and the second member 5 are joined together.

[0033] (1B) After die forging, the aluminum alloy forged clad material 1 can be heat treated. In this case, the bonding strength between the first member 3 and the second member 5 is further increased.

[0034] (1C) For example, the concentration of Zn or Mg measured on the line segment 10 is constant, except for local increases and decreases, or changes continuously depending on the position on the line segment 10. In this case, the bonding strength between the first member 3 and the second member 5 is further increased.

[0035] 4. Examples (4-1) Manufacturing of aluminum alloy forged clad material 1 A first member 3 and a second member 5 shown in FIG. 1 were prepared. Two first members 3 were prepared. The first member 3 was made of JIS A5052. JIS A5052 corresponds to the first aluminum alloy. The second member 5 was made of JIS A7050. JIS A7050 corresponds to the second aluminum alloy.

[0036] The first member 3 had a cylindrical shape. The diameter of the cylinder was 470 mm. The height of the first member 3 was 50 mm. The stacking direction X was parallel to the axial direction of the cylinder (i.e., the height direction).

[0037] The second member 5 had a cylindrical shape. The diameter of the cylinder was 470 mm. The height of the second member 5 was 315 mm. The stacking direction X was parallel to the axial direction (i.e., height direction) of the cylinder.

[0038] 2, the first member 3, the second member 5, and the first member 3 were stacked in this order in the stacking direction X. Next, the assembly of the stacked first member 3, the second member 5, and the first member 3 (hereinafter referred to as the laminated material) was heated to 400 to 440°C.

[0039] Next, the laminated material was pressed at a maximum pressure of 3000 tons. The direction in which pressure was applied during the press working was the stacking direction X. The press working was performed by upset forging. As a result, a laminated body 7 was obtained. The height of the laminated body 7 in the stacking direction X was 200 mm. The temperature of the laminated material was maintained at 330°C or higher until the press working was completed.

[0040] Next, as shown in S1 of FIG. 5, an upper die 21 was placed above the laminate 7, and a lower die 23 was placed below the laminate 7. Next, the laminate 7 was heated to 380 to 440°C. Next, the upper die 21 and the lower die 23 were used to pressurize the laminate 7 in the stacking direction X. The pressing was performed by die forging. The maximum pressure during pressing was 15,000 tons. During die forging, the first member 3 and the second member 5 were deformed, as shown in S2 and S3 of FIG. 5. Through the above steps, the aluminum alloy forged clad material 1 shown in FIGS. 3 and 4 was obtained.

[0041] Next, the aluminum alloy forged clad material 1 was subjected to a solution treatment. The solution treatment corresponds to a heat treatment. In the solution treatment, the aluminum alloy forged clad material 1 was heated and held at 477°C for 9 hours, then held at 465°C for 1 hour, and then cooled in hot water at 63°C.

[0042] Next, the aluminum alloy forged clad material 1 was subjected to aging treatment. The aging treatment corresponds to heat treatment. In the aging treatment, the aluminum alloy forged clad material 1 was held in a heat treatment device at 177°C for 9 hours. Next, the aluminum alloy forged clad material 1 was taken out of the heat treatment device and air-cooled in the atmosphere.

[0043] As shown in Figure 4, a portion 11 having a non-planar shape was present on the surface of the aluminum alloy forged clad material 1. Of the joining surfaces 6, a curved joining surface 6A located on the rear side of the non-planar portion 11 had a curved shape that followed the non-planar shape. The first member 3 and the second member 5 were also joined at the curved joining surface 6A.

[0044] (4-2) Evaluation of aluminum alloy forged clad material 1 In the aluminum alloy forged clad material 1 produced in (4-1) above, which was not subjected to solution treatment and aging treatment (hereinafter referred to as the pre-heat-treated product), the first member 3 and the second member 5 were joined together.

[0045] Furthermore, in the aluminum alloy forged clad material 1 manufactured in the above (4-1) and subjected to solution treatment and aging treatment (hereinafter referred to as the post-heat treatment product), the first member 3 and the second member 5 were also joined.

[0046] (4-3) Analysis of aluminum alloy forged clad material 1 A sample was obtained from the product before heat treatment. This sample was used as the sample before heat treatment. A sample was also obtained from the product after heat treatment. This sample was used as the sample after heat treatment.

[0047] The sample before and the sample after the heat treatment each had a bonding surface 6 shown in Figure 6 at the center. Each of the sample before and the sample after the heat treatment was analyzed using an electron probe microanalyzer (EPMA). Specifically, the concentrations of Zn and Mg were measured on a 0.5 mm long line segment 10 that was perpendicular to the bonding surface 6 and bisected by the bonding surface 6. The measurement positions for the concentrations of Zn and Mg covered the entire area from one end of the line segment 10 to the opposite end.

[0048] The measurement results of Zn in the sample before heat treatment are shown in FIG. 7A. The horizontal axis in FIG. 7A represents the position on line segment 10. The unit of the horizontal axis is mm. The joining surface 6 is at a position of 0.25 mm on the horizontal axis. On the horizontal axis, the right side of the 0.25 mm position is the inside of the first member 3. On the horizontal axis, the left side of the 0.25 mm position is the inside of the second member 5. The horizontal axes in FIGS. 7B, 8A, and 8B are the same as the horizontal axis in FIG. 7A.

[0049] The measurement results of Zn in the heat-treated sample are shown in Figure 7B. The measurement results of Mg in the sample before heat treatment are shown in Figure 8A. The measurement results of Mg in the heat-treated sample are shown in Figure 8B.

[0050] 7B and 8B , in the heat-treated sample, the Zn and Mg concentrations measured on the line segment 10 changed continuously depending on the position on the line segment 10, except for local increases and decreases. In the heat-treated sample, the Zn and Mg concentrations also changed continuously near the joining surface 6.

[0051] In contrast, in the sample before the heat treatment, the concentrations of Zn and Mg measured on the line segment 10 changed discontinuously near the bonding surface 6, as shown in FIGS. 7A and 8A.

[0052] 5. Other Embodiments Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modifications.

[0053] (1) The laminate 7 may be composed of two layers. Alternatively, the laminate 7 may include four or more layers. For example, each of the four or more layers may be a first member 3 or a second member 5. For example, the laminate 7 may include a layer that is neither a first member 3 nor a second member 5, in addition to a layer that is a first member 3 and a layer that is a second member 5.

[0054] (2) The concentrations of Zn and Mg measured on the line segment 10 may vary discontinuously near the joining surface 6 .

[0055] (3) The function of one component in each of the above embodiments may be shared among multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0056] (4) In addition to the above-described aluminum alloy forged clad material 1, the present disclosure can also be realized in various forms, such as a system including the aluminum alloy forged clad material 1 as a component, a heat treatment method for the aluminum alloy forged clad material 1, etc.

[0057] Reference Signs List 1...Aluminum alloy forged clad material, 3...First member, 5...Second member, 6...Joint surface, 6A...Curved joint surface, 7...Laminate, 21...Upper die, 23...Lower die, 25...Product part

Claims

1. A method for manufacturing an aluminum alloy forged clad material, comprising stacking a first member made of a first aluminum alloy and a second member made of a second aluminum alloy, and applying pressure in the stacking direction to form a laminate including the first member and the second member, and then die forging the laminate by applying pressure in the stacking direction using a die.

2. A method for producing an aluminum alloy forged clad material according to claim 1, wherein after die forging, the aluminum alloy forged clad material is subjected to heat treatment.

3. An aluminum alloy forged clad material comprising: a first member made of a first aluminum alloy; and a second member made of a second aluminum alloy and joined to the first member.

4. An aluminum alloy forged clad material according to claim 3, wherein the Zn or Mg concentration measured on a 0.5 mm long line segment that is perpendicular to the joint surface between the first member and the second member and that is bisected by the joint surface is constant or changes continuously depending on the position on the line segment, except for local increases or decreases.

5. An aluminum alloy forged clad material according to claim 3 or 4, wherein a portion having a non-planar shape is present on the surface of said aluminum alloy forged clad material, and a portion of the joining surface between said first member and said second member that is located behind said portion having a non-planar shape has a curved shape that follows the non-planar shape.

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