Titanium electroplated drum and method for manufacturing the same

Abstract

The object of the present invention is to provide a titanium electroplated drum and a method for manufacturing the same that can be manufactured stably without relying on personal know-how and have a longer service life than conventional drums. [Solution] The electrodeposition drum 1 of the present invention has a joint 9 (friction stir joint). With this electrodeposition drum 1, the joint 9 (friction stir joint) approximates the metal crystal structure of the base material portion other than the joint 9, so the transfer of traces of the joint 9 to the manufactured copper foil is prevented. Furthermore, with the electrodeposition drum 1, unlike conventional electrodeposition drums, there is no need to perform recrystallization treatment on the joint 9 (friction stir joint).

Description

Technical Field

[0001] The present invention relates to a titanium electroplating drum used in the production of metal foils and a method for manufacturing the same.

Background Art

[0002] Conventionally, an electroplating drum in which the joints (butt joints) between the ends of a titanium plate roll-formed into a cylindrical shape are joined by welding is known (for example, see Patent Document 1). The joint portion of this electroplating drum is subjected to a recrystallization treatment by forging and heating. As a result, the electroplating drum has a reduced change in partial electrical characteristics at the joint portion caused by the transformation of the metal structure due to welding heat. According to such an electroplating drum, it is possible to reduce the quality gap between the metal foil electroplated on the joint portion based on the change in electrical characteristics and the metal foil electroplated on the portion other than the joint portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the recrystallization process in conventional electrodeposition drums (see, for example, Patent Document 1) requires the expertise of the operator and depends on their skill level. As a result, it has been difficult to stably manufacture conventional electrodeposition drums that meet predetermined quality standards. Furthermore, conventional electrodeposition drums have the problem of difficulty in completely recrystallizing the inside of the joint in the thickness direction. Consequently, conventional electrodeposition drums have the problem of having to be discarded early, even when they are still sufficiently thick, in order to maintain the quality of the resulting metal foil, as their thickness gradually decreases with repeated use in metal foil manufacturing. Therefore, there has been a demand for titanium electrodeposition drums that can be stably manufactured without relying on expert know-how and have a longer service life than conventional drums.

[0005] The object of the present invention is to provide a titanium electroplated drum and a method for manufacturing the same that can be manufactured stably without relying on personal know-how and have a longer service life than conventional drums. [Means for solving the problem]

[0006] The titanium electrodeposited drum of the present invention, which solves the aforementioned problems, has a friction stir joint.

[0007] Furthermore, the present invention, which solves the above-mentioned problems, is a method for manufacturing a titanium electrodeposited drum, comprising the steps of forming a titanium plate into a cylindrical shape and performing friction stir welding at the joint of the cylindrical titanium plate. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a titanium electroplated drum and a method for manufacturing the same that can be stably manufactured without relying on personal know-how and have a longer service life than conventional drums. [Brief explanation of the drawing]

[0009] [Figure 1] This is an explanatory diagram of the configuration of a metal foil manufacturing apparatus using a titanium electrodeposition drum according to an embodiment of the present invention. [Figure 2] This is an overall perspective view of a titanium electroplating drum according to an embodiment of the present invention. [Figure 3] Figure 2 is an explanatory diagram of the configuration of a friction stir welding apparatus used in the manufacture of titanium electrodeposition drums. [Figure 4A] Figure 3 is a partially enlarged side view of the tip of a tool used in a friction stir welding apparatus. [Figure 4B] This is a plan view of the tip surface of the tool as seen from the direction indicated by the arrow IV in Figure 4A. [Figure 5A] (a) to (f) are backscattered electron images of the metallic structure in the titanium electrodeposited drum obtained in Example 1. [Figure 5B] This is a schematic plan view showing a metal foil manufactured using the titanium electrodeposition drum obtained in Example 1 of the present invention. [Figure 5C] This is a magnified photograph of a sample created by cutting out the metal foil corresponding to the area indicated by the arrow V in Figure 5B. [Figure 6A] This is a schematic plan view showing a metal foil manufactured using the titanium electrodeposition drum obtained in Comparative Example 1 of the present invention. [Figure 6B] This is a magnified photograph of a sample created by cutting out the metal foil corresponding to the area indicated by the arrow in Figure 6A, VI. [Modes for carrying out the invention]

[0010] The embodiments for implementing the titanium electroplating drum of the present invention (hereinafter simply referred to as the electroplating drum) will be described in detail below, with reference to the drawings as appropriate. First, before describing the electrodeposition drum, we will explain the metal foil manufacturing apparatus that uses this electrodeposition drum. Here, we will use the example of manufacturing electrolytic copper foil as the metal foil, but the metal foil to be manufactured is not limited to copper foil. The electrodeposition drum of this embodiment can also be applied to the manufacture of other electrolytic metal foils such as nickel and silver.

[0011] Figure 1 is an explanatory diagram of the configuration of the metal foil manufacturing apparatus 10. As shown in Fig. 1, the metal foil manufacturing apparatus 10 mainly includes a cathode drum 4, an anode 5, an electrolytic cell 6, and a winding roll 7. The cathode drum 4 includes an inner drum 3 that rotates about a shaft 2, and an electrodeposition drum 1 of the present embodiment, which is an outer drum attached to the outer peripheral surface of the inner drum 3 by shrink fitting or the like.

[0012] Although not shown in the figure, the inner drum 3 is assumed to be, for example, a copper conductive cylinder adhered to the outer peripheral surface of an inner support drum made of carbon steel or stainless steel, and further silver-plated or tin-plated on its outer peripheral surface. However, the inner drum 3 is not limited thereto. The electrodeposition drum 1 will be described in detail later.

[0013] About half of the cathode drum 4 is accommodated in the electrolytic cell 6 so as to be immersed in the electrolytic solution 6a. The electrolytic solution 6a in the present embodiment is assumed to be a sulfuric acid-based copper electrolytic solution with a copper concentration of about 60 to 90 g / L, but is not limited thereto.

[0014] The anode 5 is composed of a curved plate arranged at a predetermined interval with respect to the peripheral surface of the cathode drum 4 in the electrolytic solution 6a. The anode 5 in the present embodiment is assumed to be composed of, for example, lead, platinum-coated titanium, iridium-coated titanium, etc., but is not limited thereto. The anode 5 is provided with an opening 5a through which the electrolytic solution 6a can flow between the anode 5 and the cathode drum 4.

[0015] In such a metal foil manufacturing apparatus 10, in an electrolytic cell 6 filled with an electrolytic solution 6a, a cathode drum 4 arranged at a predetermined interval from an anode 5 rotates. An electric current is passed between the anode 5 and the cathode drum 4 at a predetermined current density. On the outer peripheral surface of the rotating cathode drum 4, an electrolytic copper foil is formed by depositing metallic copper due to the electrolytic reaction of the electrolytic solution 6a. At this time, the electrolytic solution 6a is supplied from an opening 5a of the anode 5 between the cathode drum 4 and the anode 5. Then, the copper foil 8 having a predetermined thickness is peeled off from the cathode drum 4 by a guide roller (not shown). The peeled copper foil 8 is wound up by a take-up roll 7.

[0016] The metal foil manufacturing apparatus 10 continuously manufactures a long copper foil 8 in the winding direction. The copper foil 8 manufactured in this way has a cathode surface with a luster on the side of the cathode drum 4 and a crystal deposition surface of copper on the side of the electrolytic solution 6a. Note that the cathode drum 4 in this embodiment is assumed to have a diameter of 1 to 3 m and an axial length of about 1 to 3 m, but the size of the cathode drum 4 is not limited to this.

[0017] FIG. 2 is an overall perspective view of the electrodeposition drum 1 of this embodiment. As shown in FIG. 2, the electrodeposition drum 1 has a cylindrical shape. The electrodeposition drum 1 of this embodiment is assumed to have a diameter of 1 to 3 m and an axial length of about 1 to 3 m corresponding to the cathode drum 4 (see FIG. 1), but the electrodeposition drum 1 can be appropriately changed according to the size of the cathode drum 4.

[0018] The thickness of the electrodeposition drum 1 can be set to, for example, about 5 mm to 8 mm according to the diameter of the electrodeposition drum 1, but is not limited to this. The electrodeposition drum 1 of this embodiment is formed by roll-forming a plate made of pure titanium (for example, TP270, TP340, etc.) and friction stir welding the joint (butt joint). However, the electrodeposition drum 1 is not excluded from those formed of titanium alloy materials. In Figure 2, reference numeral 9 denotes a friction stir joint (hereinafter sometimes simply referred to as "joint") where the joint (butt joint) is friction stir-welded.

[0019] The metal crystals in the joint 9 of the electrodeposited drum 1 constitute a so-called equiaxed structure. Unlike the coarse-grained structure of pure titanium, which grows when heated to high temperatures near the β-transformation point during welding, this equiaxed structure has a fine structure in which the average grain size of the crystals is 3.0 μm or less and the average aspect ratio is 1.5 or less in any cross-section arbitrarily set in the welded part 9. In other words, the metal crystal structure of the joint 9 approximates the metal crystal structure of the base material portion of the electrodeposited drum 1 outside of the joint 9.

[0020] Figure 3 is an explanatory diagram of the configuration of the friction stir welding apparatus 20 used in the manufacture of the electrodeposition drum 1 shown in Figure 2. As shown in Figure 3, the friction stir welding apparatus 20 comprises a backing material 21, a pressing jig 22, a cover 23, a tool 24, and a tool driving mechanism 25. In Figure 3, reference numeral 27 denotes a cylindrical titanium plate supported on a support base (not shown), and reference numeral 27a denotes the unjointed joint (butt joint) of the cylindrical titanium plate 27.

[0021] In this embodiment, the backing material 21 is a long member that extends in the axial direction of the cylindrical titanium plate material 27 and is positioned on the inner circumference side of the cylindrical titanium plate material 27. The backing material 21 consists of a backing body 21a and a support portion 21b for the backing body 21a. The backing body 21a and the support part 21b are integrated to form a T-shaped cross-section. The backing body 21a has a curved surface that matches the curvature of the cylindrical titanium plate 27 so as to adhere closely to the inner circumferential surface of the cylindrical titanium plate 27.

[0022] The support portion 21b is fixed to a suitable location on a support base (not shown) of the cylindrical titanium plate material 27. This allows the support portion 21b to position the backing body 21a along the joint 27a (butt joint). Furthermore, a heater 21c is provided on the backing body 21a. The heater 21c is configured to heat the cylindrical titanium plate material 27 near the joint 27a (butt joint) to a predetermined temperature, which will be described later.

[0023] The clamping jig 22 is an elongated member that extends in the axial direction of the cylindrical titanium plate material 27 and is positioned on the outer circumference of the cylindrical titanium plate material 27. The pressing jig 22 fixes the cylindrical titanium plate material 27 between itself and the backing body 21a.

[0024] The pressing jig 22 has a pair of pressing parts 22a. In this embodiment, the pressing portion 22a is formed from a member with a rectangular cross-section (including a square). The pair of pressing portions 22a are positioned on the outer circumference of the cylindrical titanium plate material 27, with a predetermined distance between them, so as to sandwich the joint 27a (butt joint) in the circumferential direction of the cylindrical titanium plate material 27.

[0025] In this embodiment, the pressing jig 22 is fastened and secured at both ends in the longitudinal direction to the respective ends in the longitudinal direction of the backing body 21a using a fastening device (not shown), so that the pressing portion 22a presses the cylindrical titanium plate material 27 toward the backing body 21a.

[0026] In this embodiment, the cover 23 forms a space (inert gas introduction space 26) that partially creates an inert gas atmosphere around the joint 27a (butt joint) which will be joined by the tool 24, which will be described in detail later. Specifically, the cover 23 is made up of a flexible cylindrical body that is attached to the tip of the outer cylinder 25d, which constitutes part of the tool drive mechanism 25 described later. In this embodiment, the cover 23 is assumed to be made of aluminum tape, but is not limited to this.

[0027] The tip of the cover 23, which extends from the outer cylinder 25d to cover the outer circumference of the tool 24, contacts the outer surface of the titanium plate 27 when the tool 24 accesses the joint 27a (butt joint). Inside the cylindrical cover 23, an inert gas introduction space 26 is formed, as shown by the shading in Figure 3. Then, as the tool 24 moves along the joint 27a (butt joint) as described later, the tip of the cover 23 moves together with the tool 24, sliding in contact with the outer surface of the titanium plate 27. The area around the joint 27a (butt joint) joined by tool 24 will always be kept in an inert gas atmosphere.

[0028] Incidentally, inert gas is supplied at a predetermined flow rate from an inert gas supply mechanism (not shown) to the inert gas introduction space 26 formed by the cover 23. In this embodiment, the inert gas is assumed to be argon gas, but it is not limited to this. Furthermore, by introducing such an inert gas, the atmosphere during friction stir welding at the joint 27a (butt joint) will be set to an oxygen concentration below the predetermined value described later.

[0029] Next, we will explain tool 24 (see Figure 3). Figure 4A is a magnified side view of the tip of tool 24. Figure 4B is a plan view of the tip surface of tool 24 as seen from direction IV in Figure 4A. As shown in Figures 4A and 4B, the tool 24 (a tool for friction stir welding) has a main body 24a having a shoulder portion 24a1 and a probe portion 24b provided on the bottom surface of the main body 24a.

[0030] The main body 24a has a cylindrical shape. The probe portion 24b has a cylindrical shape with a hemispherical tip. However, the shape of the probe portion 24b is not limited to this. In this embodiment, the tool 24 is assumed to be made of cemented carbide, cermet, silicon nitride, sialon, pc-BN, tungsten alloy, etc., but the material of the tool 24 is not limited to these.

[0031] The tool drive mechanism 25 is configured to friction stir-bond the joint 27a (butt joint) of the cylindrical titanium plate material 27 from the radially outer side using a rotating tool 24. Specifically, the tool drive mechanism 25 moves a tool 24, which rotates at a predetermined rotational speed while maintaining a predetermined forward angle, along the joint 27a with a predetermined amount of indentation and a predetermined feed rate, thereby friction stir welding the joint 27a. The forward angle, rotational speed, indentation amount, and feed rate of the tool 24 as performed by the tool drive mechanism 25 in this embodiment will be described in detail later.

[0032] As shown in Figure 3, such a tool drive mechanism 25 has a spindle portion 25b with a tool holder 25a at its tip, and a rotation drive portion 25c for the spindle portion 25b. The tool drive mechanism 25 also includes, although not shown in the figure, a displacement device that displaces the rotation drive portion 25c in the axial direction of the spindle portion 25b, and a displacement device that displaces the rotation drive portion 25c along the joint 27a. Incidentally, these displacement devices can be configured, for example, with a ball screw that expands and contracts in the direction of displacement, and a rotation drive portion that rotates this ball screw in both forward and reverse directions, but are not limited to this.

[0033] Next, we will explain the manufacturing method of the electrodeposition drum 1 (see Figure 2). The manufacturing method for the electrodeposited drum 1 in this embodiment includes the steps of forming a titanium plate into a cylindrical shape and applying friction stir welding to the joints between the cylindrical titanium plates, that is, the unjointed joints 27a (see Figure 3) of the cylindrical titanium plate material 27 (see Figure 3). In this manufacturing method, a sheet material made of pure titanium is first formed into a cylindrical shape by roll forming or the like.

[0034] Next, in this manufacturing method, the cylindrical titanium plate material 27 is set in the friction stir welding apparatus 20. As shown in Figure 3, the cylindrical titanium plate material 27 is fixed on the backing body 21a with a pressing jig 22. Specifically, the cylindrical titanium plate material 27 is fixed so that its joint 27a (butt joint) faces the inert gas introduction space 26.

[0035] Then, as shown in Figure 3, when the tool 24 is brought into the inert gas introduction space 26 via the main spindle portion 25b of the tool drive mechanism 25, heat input to the cylindrical titanium plate material 27 by the heater 21c and the supply of inert gas to the introduction space 26 from an inert gas supply mechanism (not shown) begin.

[0036] As a result, the temperature of the cylindrical titanium plate material 27 around the joint 27a (butt joint) is set to a range of 150°C to 400°C. In addition, the oxygen concentration in the inert gas introduction space 26 is set to 0.5 volume% or less in the area where friction stir welding is performed. The oxygen concentration here is the oxygen concentration when the oxygen concentration around the joint 27a (see Figure 3) to be joined is reduced by introducing an inert gas (argon gas) into the cover 23 (see Figure 3). Specifically, this oxygen concentration is measured by inserting the probe of an oxygen concentration meter into the introduction space 26 (see Figure 3) through a small hole (not shown) formed in the cover 23 (see Figure 3). Furthermore, the temperature of the cylindrical titanium plate material 27 can be controlled based on the temperature measured by, for example, a thermocouple. In addition, the oxygen concentration in the area where friction stir welding is performed can be controlled based on the relationship between the supply amount of inert gas and the oxygen concentration, which is determined in advance by, for example, CAE (Computer-Aided Engineering).

[0037] The conditions for friction stir welding of the cylindrical titanium plate material 27 are as follows: Tool 24 rotation speed: 100 rpm or more, 250 rpm or less Tool 24 feed rate: 10 mm / min or more, 50 mm / min or less Tool 24 indentation amount: -0.4mm or more, 0.1mm or less Tool 24 advance angle: 2 degrees or more, 4 degrees or less In this embodiment, the indentation amount [mm] of the tool 24 is expressed as the relative distance between the center of the base of the probe portion 24b extending from the main body portion 24a of the tool 24 and the surface of the cylindrical titanium plate material 27. That is, the lower limit of the indentation amount -0.4 mm means that the center of the base of the probe portion 24b is located 0.4 mm above the surface of the cylindrical titanium plate material 27, and the upper limit of the indentation amount 0.1 mm means that the center of the base of the probe portion 24b is pushed in 0.1 mm below the surface of the cylindrical titanium plate material 27.

[0038] <Effects> Next, the effects and advantages of the electrodeposition drum 1 (titanium electrodeposition drum) and its manufacturing method according to this embodiment will be described. The electrodeposited drum 1 (titanium electrodeposited drum) of this embodiment has a friction stir joint. The metal crystals in the friction stir joint form an equiaxed structure.

[0039] Generally, the equiaxed α-crystal structure in pure titanium and titanium alloys undergoes transformation when heated to temperatures exceeding the β-transformation point, or when crystals grow at high temperatures close to the β-transformation point, resulting in a coarse-grained structure. In conventional titanium electrodeposition drums with welded sections, there was a problem in that traces of the welded section were transferred to the manufactured metal foil due to the difference in crystal structure between the welded section and the base material outside the welded section.

[0040] To address these challenges, an electroplated drum has been proposed in which the welded portion (joint) is subjected to recrystallization treatment by forging and heating (see, for example, Patent Document 1). This electroplating drum makes it possible to reduce the difference in quality between the metal foil electroplated at the joint and the metal foil electroplated on areas other than the joint. However, conventional electroplating drums (see, for example, Patent Document 1) could not be manufactured reliably without personal know-how, as mentioned above, and did not have a sufficient service life.

[0041] In contrast, with the electrodeposition drum 1 of this embodiment, the joint portion 9 (friction stir joint portion) approximates the metal crystal structure of the base material portion other than the joint portion 9, thus preventing the transfer of traces of the joint portion 9 to the manufactured copper foil 8. Furthermore, unlike conventional electrodeposition drums (see, for example, Patent Document 1), the electrodeposition drum 1 of this embodiment does not require recrystallization treatment of the joint portion 9 (friction stir joint portion), so it can be manufactured stably without relying on personal know-how. Furthermore, the electrodeposition drum 1 of this embodiment can be used to manufacture copper foil 8 without recrystallization treatment, thus avoiding the problem of reduced service life caused by the aforementioned recrystallization treatment. In other words, unlike conventional electrodeposition drums (see, for example, Patent Document 1), the electrodeposition drum 1 of this embodiment can be used up to the limit of the titanium plate thickness, resulting in a longer service life than conventional drums.

[0042] The manufacturing method for the electrodeposited drum 1 of this embodiment includes the steps of forming a titanium plate into a cylindrical shape and performing friction stir welding on the joint of the cylindrical titanium plate. According to the manufacturing method of the electroplated drum 1 of this embodiment, the dimensional accuracy of the electroplated drum 1 is excellent because the titanium structure is not altered during mechanical joining. Furthermore, because the electroplated drum 1 can be manufactured by mechanical joining, it is possible to shorten the manufacturing time, improve work efficiency, and establish a mass production system.

[0043] Furthermore, in this manufacturing method, the friction stir welding is carried out under an inert gas atmosphere with an oxygen concentration of 0.5 volume% or less. This manufacturing method makes it possible to more reliably prevent the formation of titanium oxide in the joint 9 (friction stir joint). The change in electrical properties between the joint 9 and the base material parts other than the joint 9 is more reliably mitigated. With such an electrodeposition drum, the difference in quality between the metal foil electrodeposited on the joint 9 and the metal foil electrodeposited on the parts other than the joint 9, based on the change in electrical properties, can be more reliably reduced.

[0044] Furthermore, in this manufacturing method, the heat input temperature to the titanium plate before friction stir welding is 400°C or less. This manufacturing method allows for more reliable prevention of metal crystal structure transformation in the joint 9 while promoting plastic flow of titanium, thereby enabling efficient friction stir welding.

[0045] Furthermore, in this manufacturing method, the rotational speed of the friction stir welding tool is 250 rpm or less, the feed rate of the friction stir welding tool is 50 mm / min or less, and the indentation amount of the friction stir welding tool is 0.4 mm or less. This manufacturing method allows for even more efficient friction stir welding.

[0046] Although the electrodeposited tram 1 and its manufacturing method according to this embodiment have been described above, the present invention is not limited to the above-described embodiment and can be implemented in various forms. [Examples]

[0047] Next, the present invention will be described in more detail based on examples and comparative examples of the present invention. (Example 1) In this embodiment, an electrodeposited drum 1 was manufactured by friction stir welding at the joint 27a (butt joint) of a cylindrical titanium plate material 27 made of pure titanium, which has an outer diameter of 2700 mm and a plate thickness of 7 mm, using a friction stir welding apparatus 20. Friction stir welding was performed under the following conditions. Inert gas used: Argon gas Oxygen concentration in the friction stir joint: 0.1% by volume Heat input from heater 21c: 350℃ Tool 24 rotation speed: 150 rpm Tool 24 feed rate: 15 mm / min Tool 24 indentation amount: -0.25mm Tool 24 advance angle: 3 degrees Tool 24 probe length: 6.75mm

[0048] Figures 5A(a) to (f) show backscattered electron images of the metallic structure in the titanium electrodeposited drum obtained in Example 1. (a) is a backscattered electron image of the metal structure at a depth of 500 μm from the outer surface of the friction stir joint. (b) is a backscattered electron image of the metal structure at a depth of 1 mm from the outer surface of the friction stir joint. (c) is a backscattered electron image of the metal structure near the center in the thickness direction of the friction stir joint. (d) is a backscattered electron image of the metal structure at a depth of 1 mm from the inner surface (back surface) of the friction stir joint. (e) is a backscattered electron image of the metal structure at a depth of 500 μm from the inner surface (back surface) of the friction stir joint. (f) is a backscattered electron image of the metal structure in the base material, which is the part other than the friction stir joint.

[0049] As shown in Figures 5A(a) to (e), the microstructure in the friction stir-welded portion had a fine structure throughout the entire thickness direction of the cylindrical titanium plate 27. Furthermore, the microstructure in the friction stir-welded portion did not contain needle-like crystals or coarse-grained structures. In addition, as is clear from the comparison between Figures 5A(a) to (e) and Figure 5A(f), it was found that the friction stir-welded portion had a finer structure compared to the portion made of the base material.

[0050] Next, copper foil 8 with a thickness of 7 μm was manufactured using a metal foil manufacturing apparatus 10 that utilizes an electrodeposition drum 1. Figure 5B is a plan view of the cathode side (Sc) of the copper foil 8 manufactured using the titanium electrodeposition drum obtained in Example 1 of the present invention. Figure 5C is a magnified photograph of a sample created by cutting out the metal foil corresponding to the portion indicated by the arrow V in Figure 5B. As shown in Figures 5B and 5C, the cathode surface Sc of the copper foil 8 had a uniform glossy surface along the longitudinal direction Ld corresponding to the winding direction of the winding roll 7 of the metal foil manufacturing apparatus 10.

[0051] (Comparative Example 1) In Comparative Example 1, an electroplated drum was fabricated by TIG (Tungsten Inert Gas) welding to the joint 27a (butt joint) of a cylindrical titanium plate material 27. Next, a copper foil 8 with a thickness of 50 μm was manufactured in the same manner as in Example 1, except that the electrodeposited tram prepared in Comparative Example 1 was used. Figure 6A is a plan view of the cathode side (Sc) of the copper foil 8 manufactured using the titanium electrodeposition drum obtained in Comparative Example 1. Figure 6B is a magnified photograph of a sample created by cutting out the metal foil corresponding to the area indicated by the arrow VI in Figure 6A. As shown in Figure 6A, traces of the welded portion Tr of the electrodeposition drum were repeatedly transferred to the cathode surface Sc of the copper foil 8 in the longitudinal direction Ld. Furthermore, the trace Tr was formed to extend in the width direction of the copper foil 8 (left-right direction on the paper in Figure 6B), with a width indicated between the pair of white arrows in Figure 6B. [Explanation of Symbols]

[0052] 1. Electroplated drum (titanium electroplated drum) 9 Joint (friction stir joint) 27. Cylindrical titanium plate material (titanium plate formed into a cylindrical shape)

Claims

1. A titanium electroplated drum with friction stir bonding.

2. The titanium electrodeposited drum according to claim 1, characterized in that the metal crystals in the friction stir-bonded portion constitute an equiaxed structure.

3. The process of forming a titanium plate into a cylindrical shape, A step of applying friction stir welding to the joint of the cylindrical titanium plate, A method for manufacturing a titanium electroplated drum having [the specified characteristic].

4. The aforementioned friction stir welding is The method for manufacturing a titanium electrodeposited drum according to claim 3, characterized in that it is carried out in an inert gas atmosphere with an oxygen concentration of 0.5 volume% or less.

5. The method for manufacturing a titanium electrodeposited drum according to claim 3, characterized in that the heat input temperature to the titanium plate before the friction stir welding is 400°C or less.

6. The rotational speed of the tool for the friction stir welding is 250 rpm or less. The feed rate of the tool for the friction stir welding is 50 mm / min or less. The method for manufacturing a titanium electrodeposited drum according to claim 3, characterized in that the amount of indentation of the friction stir welding tool is 0.1 mm or less.

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