TWI732529B - Titanium alloy plate, titanium alloy plate manufacturing method, copper foil manufacturing roller, and copper foil manufacturing roller manufacturing method - Google Patents

Abstract

The titanium alloy plate of the present invention has the following chemical composition: Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less by mass%. One or more of two types: a total of 0.2% or more and 7.0% or less, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, O: 0.700% or less, and Fe: 0.500% or less, with the remainder The part contains Ti and impurities; the average crystal grain size is 40μm or less; the standard deviation of the particle size distribution according to the logarithm of the crystal grain size (μm) is 0.80 or less; it contains the α phase whose crystal structure is the hexagonal closest-packed structure; and the aforementioned α The area ratio of the crystal grains whose angle formed by the [0001] direction relative to the plate thickness direction is 0° or more and 40° or less is 70% or more.

Description

Titanium alloy plate, titanium alloy plate manufacturing method, copper foil manufacturing roller, and copper foil manufacturing roller manufacturing method

The invention relates to a titanium alloy plate, a method of manufacturing a titanium alloy plate, a roller for manufacturing copper foil, and a method for manufacturing a roller for manufacturing copper foil. This case is based on Special Application No. 2019-078824 filed in Japan on April 17, 2019 and Special Application No. 2019-078828 filed in Japan on April 17, 2019, and its content is cited here.

Background of the invention In most cases, copper foil is used as the raw material for the wiring of wiring substrates such as multilayer wiring boards and flexible wiring boards or the current collectors of lithium-ion batteries and other electronic components.

The copper foil used for the above-mentioned application can be manufactured by an apparatus for manufacturing copper foil, and the apparatus for manufacturing copper foil is provided with a roller for manufacturing copper foil. Fig. 7 is a schematic diagram of an apparatus for manufacturing copper foil. The apparatus 1 for manufacturing copper foil, for example, as shown in FIG. 7 is provided with: an electrolytic cell 10 storing a copper sulfate solution, an electrodeposition drum 2 provided in the electrolytic cell 10 so that a part of it will be immersed in the copper sulfate solution, and In the electrolytic cell 10, an electrode plate 30 which is immersed in a copper sulfate solution and opposed to the outer peripheral surface of the electrodeposition drum 2 at a predetermined interval is provided. By applying a voltage between the electrodeposition roller 2 and the electrode plate 30, the copper foil A is electrodeposited on the outer peripheral surface of the electrodeposition roller 2 to be formed. The copper foil A having a predetermined thickness is peeled from the electrodeposition roller 2 by the winding part 40 and is wound on the winding roller 60 while being guided by the guide roller 50.

As the material of the roller (electrodeposition roller), from the viewpoints of excellent corrosion resistance and excellent peelability of the copper foil, titanium is generally used on the surface (outer peripheral surface). However, even when a titanium material with excellent corrosion resistance is used, if the copper foil is manufactured for a long time, the surface of the titanium material constituting the drum in the copper sulfate solution will gradually be corroded. Then, the state of the corroded roller surface may be transferred to the copper foil when the copper foil is manufactured.

It is known that the corrosion of metal materials is caused by the different internal factors caused by the metal structure, such as the crystal structure, crystal orientation, defects, segregation, processing strain, and residual strain of the metal material, which lead to the corrosion state and corrosion. The degree is different. Rollers using metal materials with inhomogeneous metal structure between parts will not be able to maintain the uniform surface state of the roller when it is corroded with the manufacture of copper foil, and an uneven surface will be produced on the surface of the roller. The uneven surface produced on the surface of the drum can be recognized as a pattern. Among the above-mentioned patterns caused by the inhomogeneous metal structure, the pattern that is caused by the macroscopic structure with a larger area and can be distinguished by the naked eye is called "the macroscopic pattern." In addition, the macro pattern produced on the surface of the roller may be transferred to the copper foil when the copper foil is manufactured.

Therefore, in order to manufacture high-precision and uniform thickness of copper foil, it is important to make the macrostructure of the titanium material constituting the drum homogeneous, and to make the corrosion of the drum surface homogeneous, so as to reduce the macrostructure caused by the inhomogeneity. To the look of the giant view.

Patent Document 1 proposes a titanium plate for use in a roller for producing electrolytic Cu foil, which is characterized in that it contains Cu: 0.15% or more and less than 0.5%, and oxygen: more than 0.05% and less than 0.20% by mass% And Fe: 0.04% or less, and the remainder is composed of titanium and unavoidable impurities, and the titanium plate is composed of an α-phase homogeneous fine recrystallized structure with an average crystal grain size of less than 35μm.

Patent Document 2 proposes a titanium plate used in a roller for producing electrolytic Cu foil, which is characterized in that it contains Cu: 0.3 to 1.1%, Fe: 0.04% or less, oxygen: 0.1% or less, and hydrogen in mass %. : 0.006% or less, the average crystal grain size is 8.2 or more, and the Vickers hardness is 115 or more and 145 or less; in the part parallel to the surface of the titanium plate, the aggregate structure is such that the crystals exist in the following elliptical range When the total area of the grains is A and the total area of the crystal grains outside it is B, the area ratio A/B is 0.3 or more, and the elliptical range is from the rolling surface and from the normal direction (ND axis) In the polar figure of the (0001) plane of the α phase, the inclination angle of the normal line of the (0001) plane is ±45° in the rolling width direction TD as the long axis, and is set to ±25 in the final rolling direction RD. ° is the range of the minor axis.

Patent Document 3 proposes a titanium alloy thick plate, which contains Al: 0.4 to 1.8% and has a plate thickness of 4 mm or more; the average crystallinity is in the 1.0 mm and 1/2 plate thickness part parallel to the plate surface under the surface The particle size is 8.2 or more and the Vickers hardness is 115 or more and 145 or less; and, in the part parallel to the plate surface that spans from 1mm to 1/2 the thickness of the plate below the surface, the aggregate structure is in the final rolling direction Is RD, the normal of the rolling surface is ND, the rolling width direction is TD, and the normal of the (0001) surface is the c-axis, let the total area of the crystal grains with the c-axis in the following elliptical region be A and let The total area of the other crystal grains is B, and the area ratio A/B is 3.0 or more. This elliptical region is in the polar figure of the (0001) plane of the α phase from the rolling plane and from the normal direction, with the c axis The tilting angle to the TD direction is -45~45° and the tilting angle of the c-axis to the RD direction is -25~25°.

Patent Document 4 proposes a method for manufacturing titanium and titanium alloy plates with a uniform and fine macroscopic appearance. The method is characterized in that it includes the steps of sequentially performing block forging, rough hot rolling, and finishing hot rolling. When manufacturing titanium and titanium alloy plates, the heating temperature of block forging and rough hot rolling is set to 950℃ or higher, and the heating temperature of finishing hot rolling is set to 700℃ or lower, and the rough hot rolling and finishing are changed. Cross hot rolling in the rolling direction of the whole hot rolling.

Patent Document 5 proposes a titanium cathode electrode for the production of electrolytic copper foil, which is a titanium cathode electrode made of titanium material used when copper electrolyte is used to obtain electrolytic copper foil; it is characterized by: crystallization of titanium material The particle size number is above 7.0, and the initial hydrogen content is below 35 ppm. Patent Document 5 discloses that if the titanium cathode electrode is used, it can be used for a very long period of time when manufacturing electrolytic copper foil compared with the past, which can effectively reduce the number of maintenance, and can produce high-quality electrolysis for a long time. Copper foil.

Patent Document 6 proposes a titanium plate for rollers for producing electrolytic Cu foil, which is characterized in that it contains Cu: 0.5 to 2.1%, Ru: 0.05 to 1.00%, Fe: 0.04% or less, and oxygen in mass%: 0.10% or less, and the remainder is composed of titanium and unavoidable impurities, and has a homogeneous fine recrystallized structure.

However, with the current miniaturization and high density of electronic components, the copper foil system requires further thinning and improvement of surface quality. Under such circumstances, it is also required to further reduce the above-mentioned macroscopic appearance. With the conventional technologies described in Patent Documents 1 to 6, the macroscopic appearance cannot be sufficiently reduced.

In addition, the roller used for the manufacture of copper foil is manufactured by shrink-fitting a plate of insoluble metal such as a titanium plate on the surface of the core material that becomes the core of the roller for manufacturing copper foil. From the viewpoint of the productivity of the roller, the sheet material that shrink fits on the surface of the core material is preferably a sheet material with excellent shrink fit. However, with the techniques of Patent Documents 1 to 6, labor is required to shrink the core material and the titanium plate, and there is still room for improvement in the productivity of the copper foil roll.

In addition, the roller for manufacturing the copper foil can be manufactured by forging in a ring shape, but also by bending a titanium plate into a cylindrical shape and welding adjacent ends. The latter method is suitable for manufacturing high-quality copper foil rolls because it is easy to control the metal structure of the titanium plate. By homogenizing the macrostructure of the titanium material that constitutes the roller for manufacturing copper foil, the uniform corrosion of the roller is achieved, and the macroscopic appearance caused by the inhomogeneous macrostructure can be reduced. However, regarding the welded part of the roller manufactured by welding, the metal structure will inevitably be different from other parts. Therefore, even if the macrostructure of the titanium material is made homogeneous, the macrostructure caused by the welded part will still be easily generated. As for the problem of the appearance, the titanium material is used as the blank of the surface of the roller for manufacturing the copper foil. Although the proportion of welded parts on the surface of the copper foil roll is not large, the demand for reducing the macroscopic appearance of the welded parts has gradually increased in recent years.

Regarding the welding of titanium materials, Patent Document 7 proposes a Ti-based wire for forming molten metal, which has a predetermined tensile strength in the longitudinal direction of the wire, and the surface of the wire body is formed with Ti with a thickness of 1 μm or more and 5 μm or less. Department of oxide film. In addition, Patent Document 8 proposes a welding wire composed of Ti or Ti alloy, which has an oxygen-concentrated layer on the surface, and further has a metal compound selected from alkali metals and alkaline earth metals. At least one metal of the group.

However, the techniques described in Patent Documents 7 and 8 are not techniques for improving the weld and the structure of the welded portion in the manufacture of a titanium roller for manufacturing copper foil. Therefore, it is difficult to use this technology to suppress the macroscopic appearance. That is, the titanium rod and wire for welding, which is used in the manufacture of a titanium roller for manufacturing copper foil and which can suppress the generation of a macroscopic appearance in the welding part of the titanium roller for manufacturing copper foil, has not been fully studied so far.

Prior art literature Patent literature Patent Document 1: Japanese Patent Application Publication No. 2009-41064 Patent Document 2: Japanese Patent Application Publication No. 2012-112017 Patent Document 3: JP 2013-7063 A Patent Document 4: Japanese Patent Application Laid-Open No. 60-9866 Patent Document 5: Japanese Patent Laid-Open No. 2002-194585 Patent Document 6: Japanese Patent Laid-Open No. 2005-298853 Patent Document 7: Japanese Patent Laid-Open No. 2005-21983 Patent Document 8: Japanese Patent Application Laid-Open No. 2006-291267

Summary of the invention The problem to be solved by the invention The present invention was made in view of the above-mentioned problems. The object of the present invention is to provide a titanium alloy plate and a copper foil roller manufactured using the titanium alloy plate, which can suppress the use of the titanium alloy plate in the copper foil manufacturing roller Produce a giant look. In addition, a preferred object of the present invention is to provide a titanium alloy plate and a copper foil drum manufactured using the titanium alloy plate, which can suppress the appearance of macroscopic appearance when the titanium alloy plate is used in the copper foil manufacturing drum, and Excellent shrink fit.

In addition, another preferred object of the present invention is to provide a method for manufacturing a copper foil roller and a copper foil roller. The method for manufacturing the copper foil roller uses a titanium rod wire for welding, which is used in the manufacture of It is used in the titanium roller for the manufacture of copper foil and can suppress the appearance of macroscopic appearance in the welded part of the titanium roller for the manufacture of copper foil.

Means to solve the problem In order to solve the above-mentioned problems, the inventors of the present invention conducted incisive research. As a result, we have obtained the following knowledge: only by reducing the crystal grain size of the aggregate structure in the titanium plate, or making the normal line of the crystal (0001) plane close to perpendicular to the rolling surface (plate surface), it is impossible to suppress the macroscopic appearance. The level required today.

The inventors of the present invention conducted further studies and found that macroscopic appearance can be suppressed by setting the chemical composition to a chemical composition that can suppress the precipitation of the β phase, making the crystal grains not only fine but also uniform in size, and making the structure Including the α phase whose crystal structure is the hexagonal closest-packed structure, the area ratio of the crystal grains whose angle formed by the [0001] direction (c axis) of the α phase with respect to the plate thickness direction is 0° or more and 40° or less is 70% or more, and it is better to control it in the following way: in the (0001) pole figure from the normal direction of the plate surface, the peak of the degree of aggregation of crystal grains exists from the normal line of the plate surface Within 30° from the direction and the maximum concentration is above 4.0. In addition, a method for manufacturing a titanium alloy plate that can achieve the above-mentioned chemical composition and aggregate structure at the same time was found, and the present invention was finally completed.

In addition, the inventors of the present invention also studied the shrinkage fit of the titanium alloy plate to the core material when manufacturing a copper foil roll. As a result, it was found that the Younger ratio of the titanium alloy sheet affects the shrinkage fit. Based on this knowledge, the inventors of the present invention focused on the hardness, crystal grain size, crystal orientation, second phase, and element distribution of the titanium alloy sheet. As a result, it was found that if the titanium alloy plate used for the copper foil manufacturing roller contains a larger amount of Al, the growth of the crystal grains will be suppressed and it becomes easy to form a fine structure. As a result, the hardness of the titanium alloy plate increases and the titanium alloy plate becomes harder. The Younger rate of alloy plates has been increased.

In addition, the inventors of the present invention conducted studies on suppressing the appearance of macroscopic appearance in the welded portion. As a result, it was found that by making the metal structure of the welded part the main α-phase, and controlling the hardness while making the crystal grains finer, this action can suppress the macroscopic appearance in the welded part. It was also found that in order to obtain the structure of the welded part, it is effective to make the titanium wire for welding contain an appropriate amount of one or more selected from the group consisting of Sn, Zr, and Al, and O.

The gist of the present invention completed based on the above knowledge is as follows. [1] The titanium alloy plate of one aspect of the present invention has the following chemical composition: Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and One or two or more of the group consisting of 7.0% or less: a total of 0.2% or more and 7.0% or less, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, O: 0.700% or less, and Fe : 0.500% or less, and the remainder contains Ti and impurities; the average crystal grain size is 40μm or less; the standard deviation of the particle size distribution according to the logarithm of the crystal grain size in unit μm is 0.80 or less; the crystal structure is the densest hexagon The alpha phase of the stacked structure; and the angle formed by the [0001] direction of the aforementioned alpha phase with respect to the plate thickness direction is 0° or more and 40° or less, and the area ratio of the crystal grains is 70% or more. [2] The titanium alloy plate of [1] above may also have the following aggregate structure: In the (0001) pole figure from the normal direction of the plate surface, the electron backscatter diffraction method is used to obtain the pole by the spherical harmonic function method. When the expansion index of the graph is set to 16 and the Gaussian half-value width is set to 5°, the peak of the concentration calculated by the texture analysis exists within 30° from the normal direction of the aforementioned board surface, and the maximum The aggregation degree is above 4.0. [3] For the titanium alloy plate of [1] or [2] above, when the average crystal grain size is in the unit of μm and is set as D, the standard deviation of the grain size distribution may also be (0.35×lnD-0.42) or less . [4] When observing the cross section of the titanium alloy plate in any one of the above [1] to [3] in the thickness direction, at a position of 1/4 of the plate thickness from the surface, the length of the twin grain boundary is relative to the thickness of the cross section The ratio of the total crystal grain boundary length can also be below 5.0%. [5] The titanium alloy plate of any one of [1] to [4] above may contain 0.2% or more and 5.0% in total in the aforementioned chemical composition of one or two of the following groups The above elements: Sn: 0.2% or more and 2.0% or less, Zr: 0.2% or more and 5.0% or less, and Al: 0.2% or more and 3.0% or less. [6] The titanium alloy plate of any one of the above [1] to [4] may contain Al in the aforementioned chemical composition: more than 1.8% and 7.0% or less, and the Vickers hardness is 350 Hv or less. [7] For the titanium alloy plate of [6] above, when the Al content is [Al%], the Zr content is [Zr%], the Sn content is [Sn%], and the O content is [O%] in terms of mass% , The Al equivalent Aleq represented by the following formula (1) may be 7.0 or less. Aleq=[Al%]+[Zr%]/6+[Sn%]/3+10×[O%]　 formula (1) [8] The titanium alloy plate of [6] or [7] mentioned above uses an electron probe microanalyzer. At a position of 1/4 of the plate thickness from the surface, the surface perpendicular to the plate thickness direction is 20mm×20mm or more. When analyzing the composition of the analysis area, let the average content of Al be [Al%], the Al concentration is ([Al%]-0.2) mass% or more and the area below ([Al%]+0.2) mass% is relative to The area ratio of the aforementioned analysis area can also be above 90%. [9] The titanium alloy sheet of any one of [1] to [8] above may also contain 98.0 vol% or more of the aforementioned α phase. [10] The titanium alloy plate of any one of [1] to [9] above may also be a titanium alloy plate used for a roller for manufacturing copper foil. [11] A roller for manufacturing copper foil in another aspect of the present invention has: a cylindrical inner roller; such as the titanium alloy plate of any one of [1] to [10] attached to the outer circumference of the aforementioned inner roller The surface; and the welded part are set at the butt part of the aforementioned titanium alloy plate; wherein the metal structure of the aforementioned welded part has an alpha phase of 98.0% or more in volume ratio, and is based on the particle size number according to JIS G 0551:2013. 6 or more and 11 or less. [12] A method of manufacturing a copper foil roller according to another aspect of the present invention has a welding step in which a titanium wire for welding is used to weld adjacent two ends of a titanium alloy plate processed into a cylindrical shape ; Wherein the aforementioned titanium wire for welding has the following chemical composition: Contains in mass %: one or more selected from the group consisting of Sn, Zr and Al: a total of 0.2% or more and 6.0% or less, O: 0.01% Above and below 0.70%, N: below 0.100%, C: below 0.080%, H: below 0.015%, and Fe: below 0.500%, and the remainder contains Ti and impurities. [13] The method for manufacturing a copper foil roller of [12], wherein in the titanium wire for welding, at least a part of the O may be selected from the group consisting of Ti, Sn, Zr, and Al Exist in the form of oxides of one or more elements.

Invention effect According to the above aspect of the present invention, it is possible to provide a titanium alloy plate and a copper foil drum manufactured using the titanium alloy plate. The titanium alloy plate can be used in a copper foil manufacturing drum to suppress the appearance of macroscopic appearance. In addition, according to a preferred aspect of the present invention, a titanium alloy plate can be provided, which can suppress the appearance of macroscopic appearance when used in a roll for manufacturing copper foil, and has excellent shrink fit. In addition, according to a preferred aspect of the present invention, it is possible to provide a method for manufacturing a copper foil roller and a copper foil roller, which can suppress the appearance of macroscopic patterns in the welded portion of the copper foil roller.

The form used to implement the invention The preferred embodiments of the present invention will be described in detail below. ＜1. Titanium alloy plate＞ First, the titanium alloy sheet of this embodiment will be described. The titanium alloy plate of this embodiment is supposed to be used as a material for a roller for manufacturing copper foil (a roller for manufacturing copper foil). Therefore, the titanium alloy plate of this embodiment can also be said to be a titanium alloy plate used for a roll for manufacturing copper foil. When used in the production of copper foil rollers, one surface of the titanium alloy plate constitutes the cylindrical surface of the roller.

(1.1　Chemical composition) First, the chemical composition of the titanium alloy sheet of this embodiment will be explained. The titanium alloy plate of this embodiment contains in mass%: 1 of the group consisting of Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less One or two or more types: a total of 0.2% or more and 7.0% or less, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, O: 0.700% or less, and Fe: 0.500% or less, and the remainder contains Ti And impurity. If there is no special indication below, the mark of "%" related to the chemical composition is set to mean "mass%".

Industrial pure titanium has a very small amount of added elements, and its structure is essentially an α-phase single-phase. As long as the titanium alloy plate made of such industrial pure titanium is used for the roller, when the roller is immersed in the copper sulfate solution, the roller will be uniformly corroded. Thereby, the generation of macroscopic appearance due to the different corrosion rates of the α phase and β phase can be suppressed.

The titanium alloy sheet of this embodiment is essentially the following alloy sheet: In the α-phase single-phase industrial pure titanium, Sn: 0% or more is contained in a mass% of 0.2% or more and 7.0% or less in total And 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less in the group consisting of one or more elements. The reasons for limiting the content of each element are explained.

＜Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less in the group consisting of one or two or more types: a total of 0.2% or more and 7.0 % Or less＞ As long as the total content of one or more elements selected from the group consisting of Sn, Zr, and Al is 0.2% or more, the growth of crystal grains can be stably suppressed. On the other hand, by making the total content of one or more elements selected from the group consisting of Sn, Zr, and Al less than 7.0%, it becomes the aforementioned hot-rolled titanium alloy sheet High temperature strength to the extent that it will not deform. From the viewpoint of high temperature strength, it is preferable that the Al content is 0.2% or more and 3.0% or less, and the content of one or more elements selected from the group consisting of Sn, Zr, and Al is added in total 0.5% or more and 5.0% or less. The total content of one or two or more elements selected from the group consisting of Sn, Zr, and Al is more preferably 0.5% or more and 4.0% or less.

Sn is a neutral element and is an element that inhibits the growth of crystal grains by solid solution in titanium. As long as the Sn content is 0.2% or more, the growth of crystal grains can be stably suppressed. Therefore, the Sn content should be 0.2% or more. The Sn content is preferably above 0.3%. In addition, Sn stabilizes each phase by solid dissolving in the α phase and β phase in titanium. If the Sn content is too large, the high-temperature strength becomes high, and the plate shape after the hot rolling is likely to be distorted into a wave shape due to the reaction force of the hot rolling. The wave-shaped titanium alloy plate is given strain due to the processing to correct the shape, so that the crystals of the titanium alloy plate are introduced into the row. This disparity will become the cause, making it easy to produce a macroscopic appearance. In addition, if the Sn content is too large, the toughness of the titanium alloy sheet will decrease, and the shrinkage compatibility during the manufacture of a copper foil roll will decrease, and the productivity will decrease. Therefore, the Sn content is preferably 2.0% or less, preferably 1.5% or less. Sn is not necessarily required in the titanium alloy sheet, so when Zr and/or Al are contained in a total of 0.2% or more, the Sn content may be 0%.

Zr is a neutral element like Sn, and it is an element that inhibits crystal grain growth by being dissolved in titanium. As long as the Zr content is 0.2% or more, the growth of crystal grains can be stably suppressed. Therefore, the Zr content should be 0.2% or more. The Zr content is preferably 0.3% or more. On the other hand, Zr is an element that stabilizes each phase by solid solution in the α phase and β phase in titanium. If the Zr content is too large, the temperature range in which the two phases of the α phase and the β phase are thermally stable becomes wider, and the β phase becomes easy to precipitate during heating. Since the β phase is corroded more preferentially than the α phase, when a roller with a titanium alloy plate containing the β phase on the surface is used to manufacture copper foil, the β phase will corrode preferentially and cause a macroscopic appearance on the surface of the roller. As a result, the macro image may be transferred to the copper foil. In addition, due to solidification segregation, the strength difference between the parts of the titanium alloy plate may occur, and a macroscopic appearance may be produced when the obtained titanium alloy plate is polished. Therefore, the Zr content is 5.0% or less. The Zr content is preferably 4.5% or less, preferably 4.0%. The Zr content is more preferably 2.5% or less, and even more preferably 2.0% or less. Zr is not necessarily required in the titanium alloy sheet, and therefore, when Sn and/or Al are contained in a total of 0.2% or more, the Zr content may be 0%.

Al is an α-phase stabilizing element, and it inhibits crystal grain growth in the same way as Sn or Zr in the heat treatment in the temperature region of the α-phase single phase. As long as the Al content is 0.2% or more, grain growth can be stably suppressed. Therefore, the Al content should be 0.2% or more. The Al content is preferably above 0.5%. In addition, Al is also an element that increases the Young's ratio of the titanium alloy sheet. With the increase in the Young's ratio, the shrink fit of the core material and the titanium alloy plate is improved when manufacturing a copper foil roll. Thereby, the productivity of the roller for manufacturing copper foil is improved. In addition, by increasing the Young's ratio, uniform shrink fit can be achieved, and the abrasiveness of the titanium alloy sheet is improved. As a result, it can be more restrained to produce a macro appearance. From the viewpoint of increasing the Younger ratio to improve the shrinkage compatibility, it is preferable to set the Al content to more than 1.8%. On the other hand, compared to Sn or Zr, Al will increase the high temperature strength of the titanium alloy sheet. As described later, when manufacturing the titanium alloy sheet of the present embodiment, hot rolling is performed to a lower temperature for the purpose of controlling the aggregate structure. Therefore, if the high-temperature strength becomes too high, the reaction force of the hot rolling delay time will become too large, causing the shape of the titanium alloy sheet after hot rolling to be greatly distorted and the titanium alloy sheet to become a wave shape. Therefore, more follow-up corrections are required for the titanium alloy plate, but if strain is applied at this time, many differences will be introduced. As a result, when the titanium alloy plate is used for the drum, it becomes easy to produce a macroscopic appearance. If the Al content is more than 7.0%, toughness and workability are reduced, making it difficult to manufacture the roller. As a result, the productivity of the roller for manufacturing copper foil is reduced. Therefore, the Al content should be 7.0% or less. From the above viewpoint, the Al content is preferably 3.0% or less, and more preferably 2.5% or less. Al is not necessarily required in the titanium alloy sheet, and therefore, when Sn and/or Zr are contained in a total of 0.2% or more, the Al content may be 0%.

In addition, if the Al content is high, there are doubts about Al segregation. If Al segregates, there will be differences in hardness and electrical resistance between parts of the titanium alloy plate. The titanium alloy plate with uneven hardness will form large irregularities on the titanium alloy plate during grinding, and sometimes produce a macroscopic appearance. In addition, the difference in resistance may cause differences in the corrosion rate, sometimes resulting in a macroscopic appearance. Therefore, the Al concentration distribution is preferably small. In the titanium alloy plate of this embodiment, when the Al content is greater than 1.8%, when the Al content (average content) is [Al%], the Al concentration is ([Al%]-0.2) mass% or more and in ([Al %]+0.2) The area ratio of the area below mass% should be 90% or more. Thereby, the macroscopic appearance can be stably suppressed.

The evaluation of Al segregation is carried out by the following method: using an electron probe microanalyzer (EPMA; Electron Probe Microanalyzer), the beam diameter is set to 500 μm, the step size is set to 500 μm, which is the same as the beam diameter. In the 1/4 position of the plate thickness from the surface of the plate thickness direction, the composition analysis is performed on the area of 20mm×20mm or more. In addition, in order to convert the composition analysis results into alloy element concentrations, the average chemical composition and Kα line strength of JIS1 industrial pure titanium and the target titanium alloy plate are analyzed, and the linear approximation is performed based on the results, and the obtained inspection quantity is used. line.

In addition, in the titanium alloy sheet of this embodiment, the Al content is [Al%] (mass%), the Zr content is [Zr%] (mass%), the Sn content is [Sn%] (mass%), and When the O content is [O%] (mass%), the Al equivalent Aleq represented by the following formula (1) is preferably 7.0 (mass%) or less. Aleq=[Al%]+[Zr%]/6+[Sn%]/3+10×[O%]　 formula (1) The Al equivalent is an index indicating the degree of stabilization of the α phase. As the Al equivalent increases, the hardness increases, but on the other hand, the toughness decreases. By setting the Al equivalent to 7.0% by mass or less, toughness can be maintained and shrinkage compatibility can be improved.

＜O: 0.700% or less＞ O series is an element that helps increase the strength of the titanium alloy plate and helps increase the surface hardness. However, if the strength of the titanium alloy plate becomes too high, a large amount of processing is required during correction, and twin crystals are likely to be produced. In addition, if the surface hardness becomes too large, it becomes difficult to polish when the titanium alloy plate is used as a roller. Therefore, when the titanium alloy sheet contains O, the O content is set to 0.700% or less. The O content is preferably 0.400% or less. The O content is preferably 0.150% or less, more preferably 0.120% or less. Since O is not necessarily required in the titanium alloy plate, the lower limit of its content is 0%. However, it is difficult to prevent it from being mixed in from the sponge titanium of the molten raw material or additional elements, and the actual lower limit is 0.020%. When the O content is to be used to increase the strength, the O content should be above 0.030%.

＜Fe: 0.500% or less＞ Fe-based elements strengthen the β phase. In the titanium alloy sheet, if the precipitation amount of the β phase increases, it will affect the formation of the macroscopic appearance. Therefore, when the titanium alloy sheet contains Fe, the upper limit of Fe content is set to 0.500%. The Fe content is preferably 0.100% or less, preferably 0.080% or less. Since Fe is not necessarily required in the titanium alloy plate, the lower limit of its content is 0%. However, it is difficult to prevent Fe from mixing in actual production, and the actual lower limit is 0.001%.

＜N: 0.100% or less＞ ＜C: Below 0.080%＞ ＜H: 0.015% or less＞ The titanium alloy plate of this embodiment may further contain N, C, or H as impurities. N is an element that forms nitrides with Ti. If nitrides are formed, sometimes the titanium alloy plate will harden or become brittle. Therefore, it is advisable to suppress N content as much as possible. In the titanium alloy sheet of this embodiment, the N content is set to 0.100% or less. The N content is preferably 0.080% or less. Since N is not necessarily required in the titanium alloy plate, the lower limit of its content is 0%. However, N is an impurity mixed in during the manufacturing process, and the actual lower limit of the N content can also be set to 0.0001%.

The C series will form carbides with Ti and, like nitrides, will harden or embrittle the titanium alloy plate. In order to suppress the hardening or embrittlement of the titanium alloy plate, it is advisable to reduce the C content as much as possible. In the titanium alloy sheet of this embodiment, the C content is set to 0.080% or less. The content of C is preferably below 0.050%. Since C is not necessarily required in the titanium alloy plate, the lower limit of its content is 0%. However, C is an impurity mixed in during the manufacturing process, and the actual lower limit of the C content can also be set to 0.0005%.

H is an element that forms a hydride with Ti. If a hydride is formed, the titanium alloy plate may become embrittled. And sometimes due to the hydride, it will produce a huge appearance. Therefore, it is advisable to suppress the H content as much as possible. In the titanium alloy sheet of this embodiment, the H content is set to 0.015% or less. The H content is preferably below 0.010%. Since H is not necessarily required in the titanium alloy plate, the lower limit of its content is 0%. However, H is an impurity mixed in during the manufacturing process, and the actual lower limit of the H content can also be set to 0.0005%.

In the chemical composition of the titanium alloy plate of this embodiment, the remainder contains Ti and impurities, and may also be composed of Ti and impurities. In addition to the above elements, specific examples of impurities include Cl, Na, Mg, Si, Ca mixed in the refining step and Mo, Nb, Ta, V, Cr, Mn, Co, Ni, Cu, etc. mixed from scrap . As long as the total content of impurities is less than 0.50%, there is no problem. However, the aforementioned impurities may contain β-phase stabilizing elements. If the amount of precipitation of β phase increases, it will affect the production of macroscopic appearance, so it is better to use less β phase stabilizing elements. Examples of β-phase stabilizing elements include V, Mo, Ta, Nb, Cr, Mn, Co, Ni, and Cu. In the titanium alloy sheet of this embodiment, after the total impurity content is made 0.50% or less, the content of each β-phase stabilizing element contained in the titanium alloy sheet is preferably 0.10% or less.

The chemical composition is calculated by the following method. Β-stabilizing elements such as Al, Zr, Sn or Fe, V, Mo, Ta, Nb, Cr, Mn, Co, Ni, and Cu can be measured by IPC emission spectroscopy. O and N can be measured using an oxygen and nitrogen simultaneous analysis device, using inert gas melting, thermal conductivity, and infrared absorption methods. C can be measured by an infrared absorption method using a simultaneous carbon and sulfur analyzer. H can be measured by inert gas melting and infrared absorption method.

(1.2　Metal structure) Next, the metal structure of the titanium alloy sheet of this embodiment will be described. The titanium alloy plate of this embodiment has an average crystal grain size of 40 μm or less, and the standard deviation of the particle size distribution based on the logarithm of the crystal grain size (μm) is 0.80 or less, and contains the α phase whose crystal structure is the hexagonal closest packing structure. And the area ratio of the crystal grains whose angle formed by the [0001] direction of the α phase with respect to the plate thickness direction is 0° or more and 40° or less is 70% or more. Hereinafter, the metal structure of the titanium alloy sheet of this embodiment will be explained in detail in order.

(1.2.1　 Phase composition of metal structure) The metal structure of the titanium alloy sheet of this embodiment includes an α phase having a hexagonal closest packing structure. The metal structure of the titanium alloy sheet of this embodiment may include a β phase in addition to the α phase. However, the β phase will corrode more preferentially than the α phase. Therefore, when a titanium roller with a titanium alloy plate containing β phase on the surface is used to manufacture copper foil, the β phase will preferentially corrode and cause a macroscopic appearance on the surface of the drum, which may be transferred to the copper foil. In addition, when the β phase is aggregated and formed, the aggregate structure of the titanium alloy sheet may change. Therefore, less β phase is better. In the titanium alloy sheet of this embodiment, the volume ratio of the α phase is preferably 98.0% or more, more preferably 99.0% or more, and more preferably 100% (α-phase single phase).

In addition, the metal structure of the titanium alloy sheet preferably does not include non-recrystallized parts. The unrecrystallized part is generally coarse and may cause the macroscopic appearance. Therefore, the metal structure of the titanium alloy sheet is preferably a completely recrystallized structure. The so-called "recrystallized structure" is defined as a structure composed of crystal grains with an aspect ratio of less than 2.0. The presence or absence of unrecrystallized grains can be confirmed by the following method. That is, crystal grains with an aspect ratio of 2.0 or more are regarded as unrecrystallized crystal grains and the presence or absence of the crystal grains is confirmed. Specifically, the cross section of the titanium alloy plate is chemically polished, and then the electron backscattering diffraction method (EBSD (Electron Back Scattering Diffraction Pattern)) is used in the area of 1~2mm×1~2mm. Measured in 1~2µm steps and measured about 2~10 field of view. Then, the boundary of the upper level difference of 5° measured by EBSD is used as the crystal grain boundary, and the range surrounded by the crystal grain boundary is used as the crystal grain. After calculating the long axis and the short axis of the crystal grain, the long axis is calculated The value obtained by dividing by the minor axis (major axis/minor axis) is used as the aspect ratio. The long axis refers to the longest line connecting any two points on the grain boundary of the α phase, and the short axis refers to the longest line perpendicular to the long axis and connecting any two points on the crystal boundary. The α-phase single-phase metal structure as described above can be achieved by the chemical composition of the titanium alloy plate as described above.

The volume ratio of each phase of the metal structure constituting the titanium alloy plate can be easily measured and calculated using EPMA (Electron Probe Microanalyzer) (SEM/EPMA) attached to SEM (Scaning Electron Microscopy). In detail, for any section of the board, after grinding to the mirror surface, use SEM/EPMA at a magnification of 100 times in the area of 1mm×1mm at the 1/4 position of the board thickness from the surface in 1~2μm steps. Measure and measure around 2~5 fields of view to determine the concentration distribution of Fe or other β-phase stabilizing elements. The point (concentrated part) where the Fe concentration or the total concentration of β-phase stabilizing elements is higher than the average concentration of the measurement range by 1% by mass or more is defined as the β phase, and the area ratio is calculated. The area ratio and the volume ratio are considered equal, and the obtained area ratio is taken as the volume ratio of the β phase, and the area ratio of the portion where the β phase stabilizing element is not concentrated (other than the concentrated part) is taken as the volume ratio of the α phase .

(1.2.2 ``Average particle size and particle size distribution of crystal grains) Next, the average particle size and particle size distribution of the crystal grains contained in the metallic structure of the titanium alloy sheet of this embodiment will be described. First, if the grain size (crystal grain size) of the crystal grains in the metallic structure of the titanium alloy sheet is coarse, the grain itself will become a pattern and the pattern will be transferred to the copper foil, so the crystal grain size is preferably fine. If the average crystal grain size of the crystal grains in the metallic structure of the titanium alloy plate is greater than 40 µm, the crystal grains themselves become a pattern and the pattern is transferred to the copper foil. Therefore, the average crystal grain size of the crystal grains in the metallic structure of the titanium alloy sheet is set to 40 µm or less. In this way, the crystal grains become fine enough to suppress the appearance of macroscopic appearance. The average crystal grain size of the crystal grains in the metallic structure of the titanium alloy plate is preferably 38 µm or less, preferably 35 µm or less. On the other hand, the lower limit of the average crystal grain size of the crystal grains in the metallic structure of the titanium alloy sheet is not particularly limited. However, in the case where the crystal grains are very small, unrecrystallized parts may be generated during the heat treatment. Therefore, the average crystal grain size of the crystal grains is preferably 3 μm or more, preferably 5 μm or more, and more preferably 10 μm or more.

In addition, when the β phase is present in the metal structure, the average crystal grain size of the β phase is preferably 0.5 μm or less. When the β phase particle size is large, the titanium alloy plate may form large unevenness due to corrosion or grinding. By setting the average crystal grain size of the β phase to 0.5 μm or less, the formation of unevenness due to corrosion or polishing can be suppressed.

In addition, the inventors of the present invention have understood that the fine crystal grains of the metallic structure of the titanium alloy sheet alone cannot sufficiently suppress the macroscopic appearance. That is, even if the crystal grains of the metallic structure of the titanium alloy sheet are fine, coarse crystal grains still exist when the particle size distribution is wide. If there are places where the coarse crystal grains and the fine crystal grains are mixed as described above, a macroscopic appearance may be produced due to the difference in particle size. Therefore, the inventors of the present invention found that in order to suppress the generation of macroscopic appearances, it is important that the crystal grains of the metallic structure of the titanium alloy plate should not only be fine, but also have a narrow particle size distribution, that is, a uniform crystal grain size.

Specifically, in the titanium alloy sheet of this embodiment, the standard deviation of the particle size distribution based on the logarithm of each crystal particle size (µm) is 0.80 or less. As the crystal grains satisfy the above-mentioned average particle size and the standard deviation of the particle size distribution, the crystal grains in the metal structure become sufficiently fine and uniform. As a result, when the titanium alloy plate is used for the drum, the macroscopic appearance is suppressed.

On the other hand, if the standard deviation of the particle size distribution based on the logarithm of the crystal grain size (µm) is greater than 0.80, coarse crystal grains will still be produced even when the average crystal grain size as described above is satisfied, and the titanium alloy When the plate is used in the roller, it becomes easy to produce a macro look.

According to the standard deviation of the logarithm of the crystal grain size (µm), when the average grain size is D (µm), it should be less than the limit value (0.35×lnD-0.42).

The average crystal grain size and the standard deviation of the grain size distribution of the crystals in the metallic structure of the titanium alloy sheet can be measured and calculated as follows. Specifically, the cross-section of the titanium alloy plate is chemically polished, and the electron backscattering diffraction method (EBSD (Electron Back Scattering Diffraction Pattern)) is used in the area of 1~2mm×1~2mm. Measured in 1~2µm steps and measured about 2~10 field of view. Regarding the crystal grain size, the boundary of 5° above the height difference measured by EBSD is used as the grain boundary, and the range surrounded by the grain boundary is taken as the crystal grain, and the circle equivalent grain size (area A) is calculated from the grain area. =π×(particle diameter D/2) ² ), and the average value based on the number is regarded as the average crystal particle diameter. In addition, the standard deviation σ of the logarithmic normal distribution can be calculated from the crystal particle size distribution. At this time, the circle-equivalent particle diameter D of each crystal grain is converted into a natural logarithm lnD, and the standard deviation σ of the distribution of the obtained conversion value is calculated. It is generally known that the crystal particle size distribution of metallic materials follows a logarithmic normal distribution. Therefore, when calculating the standard deviation of the particle size distribution as described above, the obtained particle size distribution can also be normalized to a logarithmic normal distribution, and then the standard deviation can be calculated from the normalized logarithmic normal distribution.

(1.2.3 　 collective organization) <The area ratio of the crystal grains whose angle formed by the [0001] direction of the α phase with respect to the plate thickness direction is 0° or more and 40° or less is 70% or more> The crystal structure of the α phase of titanium has a hexagonal close-packed structure (hexagonal close-packed; hcp). Regarding titanium of the hcp structure, the physical anisotropy due to the crystal orientation is large. Specifically, in titanium with the hcp structure, the strength is high in the direction parallel to the [0001] direction (hereinafter also referred to as the c-axis direction), and the closer to the direction perpendicular to the c-axis direction, the lower the strength. Therefore, even if the titanium alloy plate satisfies the above-mentioned crystal grain size distribution, for example, if an aggregate of crystals with different crystal orientations is produced, the workability between the two aggregates is different, so it is still possible to manufacture a roll for manufacturing copper foil. The workability during grinding may be different. In this case, it may be recognized in the resulting roller as a macroscopic appearance close to the size of the crystal grain. Therefore, it is advisable to gather the crystal orientation of the assembled structure of the titanium alloy plate as much as possible to suppress the macroscopic appearance.

In addition, titanium with the hcp structure has high strength in a direction parallel to the c-axis direction. Therefore, if a surface that is perpendicular to the c-axis is polished, it is difficult to produce a polished appearance. From the above point of view, for the crystal orientation of the aggregate structure of the titanium alloy plate, it is advisable to arrange the c-axis of the crystal lattice of the titanium alloy plate to be perpendicular to the polishing surface, that is, to arrange it to be perpendicular to the thickness direction of the surface of the titanium alloy plate ( The normal direction of the board surface: ND) parallel.

In the titanium alloy plate of this embodiment, the area ratio of crystal grains whose angle θ formed by the normal direction (ND) of the plate surface and the c-axis ([0001] direction) of the α phase is 40° or less is relative to all The area of the crystal grain is more than 70%. The angle θ is the angle shown in FIG. 4. The area ratio of crystal grains with an angle θ of 40° or less formed by the ND and the c-axis of the α phase is 70% or more, and the crystal orientations are gathered, and the crystal orientation difference between adjacent crystals can be reduced. As a result, macroscopic appearance can be suppressed. The area ratio of crystal grains with an angle θ of 40° or less is preferably 72% or more relative to the area ratio of all crystal grains. The higher the above-mentioned area ratio, the better. Therefore, the upper limit of the area ratio is not specifically set, but it can be manufactured to about 95%.

The angle θ formed by the c-axis of the α phase with respect to the plate thickness direction can be calculated from the (0001) pole figure in the normal direction (ND) of the plate surface. The (0001) pole figure can be obtained by chemically polishing the observation surface of a titanium alloy plate sample, and then performing crystal orientation analysis using EBSD. Specifically, for example, using EBSD to scan an area of 1~2mm×1~2mm at intervals of 1~2μm, thereby obtaining the crystal orientation distribution map as shown in FIG. 5. For example, the white area G1 in FIG. 5 shows crystal grains whose angle θ formed by the ND and the c axis of the α phase is less than 40°, and the black area G2 shows the angle θ formed by the c axis of the α phase greater than 40°. ° and less than 60°, the gray area G3 shows the angle θ formed by the c axis of the α phase is greater than 60° and less than 90°. Then, the (0001) pole figure can be created by analyzing the crystal orientation. As shown in Figure 6, in the (0001) pole figure, the area R1 surrounded by the dotted line b1 is the area where the angle θ formed by the thickness direction (ND) and the c-axis of the crystal grain is less than 40°, the dotted line b1 and the dotted line The area R2 surrounded by b2 is an area where the angle θ is greater than 40° and less than 60°, and the area outside of the dotted line b2 is an area where the angle θ is 60° or more and 90° or less.

The area ratio of crystal grains where the angle θ formed by the thickness direction (ND) of the titanium alloy sheet and the c axis of the α phase is 40° or less can be calculated as follows. After chemically polishing the cross section of the cut titanium alloy plate, EBSD is used to analyze the crystal orientation. And for the lower part of the surface of the titanium alloy plate and the central part of the thickness of the titanium alloy plate, the measurement is performed in a 1~2mm×1~2mm area with a step of 1~2μm and a field of view of about 2~10 is measured. Regarding the data, use OIM Analysis software manufactured by TSL Solutions to select the measurement point data whose angle formed by the ND and the c axis is below 40°. Based on the above, the area ratio of crystal grains where the angle θ formed by the thickness direction (ND) of the titanium alloy sheet and the c axis of the α phase is 40° or less is calculated.

＜With in the (0001) pole figure from the normal direction of the plate surface, the peak of the concentration exists within 30° from the normal direction of the plate surface and the maximum concentration of the (0001) surface is 4.0 or more. , The concentration peak is calculated by the texture analysis of the pole figure obtained by the spherical harmonic function method of the electron backscatter diffraction (EBSD) method (expansion index=16, Gaussian half-value width=5°) ＞

The titanium alloy sheet of this embodiment preferably has the following aggregate structure: in the (0001) pole figure from the normal direction (ND) of the sheet surface (or the rolled surface if it is a rolled material), the degree of aggregation of crystal grains The sharp peaks exist in the collective tissue within 30° from the normal direction (TD) of the board surface, and the maximum concentration is above 4.0. As a result, the c-axis of the crystal grains can be more concentrated in the part close to the thickness direction (ND) of the titanium alloy plate, and when the titanium alloy plate is used for the production of copper foil rolls, the occurrence of crystal orientation differences can be more suppressed. What it looks like. By rolling or the like, the peak of the degree of aggregation of crystal grains tends to be inclined in a direction (final rolling width direction (TD)) at right angles to the final rolling direction. Therefore, when the final rolling direction is clear, in the (0001) pole figure from the normal direction (ND) of the plate surface, the peak of the degree of crystal grain aggregation only needs to be calculated from the normal direction (ND) of the plate surface. It is sufficient to exist within 30° in the final rolling width direction (TD).

The (0001) pole figure can be obtained by chemically polishing the observation surface of a titanium alloy plate sample, and then performing crystal orientation analysis using EBSD. For example, you can scan an area of 1~2mm×1~2mm at 1~2µm intervals (steps) as described above to create a (0001) pole figure. At this time, the position with the highest contour line is the peak position of the concentration degree, and the maximum concentration value among the peak positions is taken as the maximum concentration degree.

Fig. 1 shows an example of the (0001) pole figure from the rolling surface of the titanium alloy sheet of this embodiment and from the normal direction (ND). In Figure 1, the detected poles will be gathered according to the final rolling direction (RD) and the inclination to the final rolling width direction (TD), and a contour line of concentration is drawn in the (0001) pole map. In addition, in FIG. 1, the locations where the contour lines become the highest are the peaks P1 and P2 of the degree of aggregation of crystal grains. Therefore, in this embodiment, the peaks P1 and P2 of the crystal grains respectively exist within 30° from ND (center). For example, when the peak is P1, a in the figure is within 30° (P1 in Figure 1, sometimes the peak position will deviate slightly from the TD direction, but as long as the deviation is within 10°, it can be tolerated, and a is within 30°. can). In addition, the maximum aggregation degree is 4.0 or more. Generally, the maximum degree of aggregation will be the degree of aggregation of the peaks P1 or P2 of the crystal grains.

In contrast, in the (0001) pole figure, when the peak of the degree of crystal grain aggregation does not exist within 30° with respect to the final rolling width direction (TD), the crystal grains with different crystal orientations are likely to be adjacent to each other. And it becomes easy to produce a visually distinguishable look. Specifically, for example, in the normal uniaxially rolled titanium hot-rolled sheet, the aggregate structure is usually formed with the concentration reaching the peak at the following position: relative to ND, the c-axis of the hcp structure is in the final rolling width direction ( TD) The position with an upward incline of about 35~40°. However, when the peak is at this position, the crystal orientation will be more inclined by 15-20°, so there will be cases where crystal grains with different crystal orientations are adjacent to each other, and it becomes easy to produce a macroscopic appearance.

Preferably, the maximum degree of aggregation is 4.0 or more. In this way, the crystal orientations are fully gathered, and the crystal orientation difference between adjacent crystals can be reduced. The maximum aggregation degree is preferably 4.0 or more, and for the purpose of suppressing the generation of macroscopic appearance, it is preferably 5.0 or more, and more preferably 6.0 or more. The larger the maximum degree of aggregation, the better, so the upper limit is not limited, and for example, about 15-20 may be the upper limit when the crystal orientation is controlled by hot rolling.

(0001) The degree of aggregation of a specific orientation of the pole figure indicates: how many times the frequency of existence of crystal grains with this orientation is relative to the organization with a completely random orientation distribution (degree of aggregation 1). The degree of aggregation can be calculated using the texture analysis of the pole figure obtained by the spherical harmonic function method of the electron backscatter diffraction (EBSD) method (expansion index=16, Gaussian half-value width=5°). Specifically, after chemically polishing the cross section of the cut titanium alloy plate, the EBSD method is used to measure in a 1~2mm×1~2mm area with a step of 1~2μm, and the field of view is about 2~10. . Use the OIM Analysis software manufactured by TSL Solutions to calculate the data by analyzing the texture of the pole figure using the spherical harmonic function method.

(1.2.4　Double crystal) Titanium sometimes undergoes twin-crystal deformation during plastic deformation. In addition to the chemical composition, twin deformation is also related to the crystal grain size, and the larger the grain size, the more likely it is to occur. Therefore, by generating twin crystals, the grain distribution of the appearance may become uniform. On the other hand, if the twin crystals are deformed, the crystal orientation difference will increase, and the crystal grains with a large difference in crystal orientation will be adjacent, and the abrasiveness will be changed at the boundary, and the pattern will be recognized. Therefore, it is advisable to suppress twin crystals as much as possible.

Specifically, regarding the titanium alloy plate of the present embodiment, when observing the cross section in the thickness direction, the double crystal grain boundary length is relative to the total crystal grain boundary length of the plate thickness section at a position of 1/4 of the plate thickness from the surface The ratio should be less than 5.0%. In this way, the macroscopic appearance caused by the twin crystals can be reduced to an unrecognizable level. The ratio of the twin grain boundary length to the total crystal grain boundary length is preferably 3.0% or less, and more preferably 1.0% or less. The lower limit of the above ratio can be 0%, but due to the correction of the titanium alloy plate and other processing, the twin crystal deformation will inevitably occur, so it is difficult to completely eliminate the twin crystal. In order to reduce twin crystals, it is important to reduce the amount of correction. For example, it is effective to make the finished plate shape as flat as possible.

To calculate the above ratio, the total crystal grain boundary length and the twin crystal grain boundary length of the thickness section can be calculated as follows. First, after chemically polishing the observation cross section (thickness direction cross section) of the sample of the titanium alloy plate, the crystal orientation analysis was performed using the electron backscatter diffraction method. Scan the area of 1~2mm×1~2mm at intervals of 1~2μm in the 1/4 position of the plate thickness from the surface of the titanium alloy plate of the sample, and use the OIM Analysis software made by TSL Solutions to create the inverse pole map distribution Figure (IPF: inverse pole figure). At this time, consider the following as the twin crystal interface: the rotation axis of (10-12) twin crystal, (10-11) twin crystal, (11-21) twin crystal and (11-22) twin crystal produced in titanium, And within 2° from the theoretical value of the crystal orientation difference (rotation angle) (for example, if it is a (10-12) twin crystal, the theoretical values of the rotation axis and the crystal orientation difference (rotation angle)) are respectively <11-20> and 85°). Then, the grain boundary with a crystal orientation difference (rotation angle) of 2° or more was taken as the total crystal grain boundary length, and the ratio of the twin grain boundary length to the total crystal grain boundary length was calculated. The reason for observing the twin grain boundary in the 1/4 position of the plate thickness from the surface is that the position can fully represent the structure of the titanium alloy plate. And because the surface of the titanium alloy plate may not be able to fully represent the structure due to grinding or the like.

(1.3　surface hardness) The surface hardness (Vickers hardness) of the surface of the titanium alloy plate that becomes the surface of the drum is not particularly limited, but HV110 or more is preferred. Thereby, when the titanium alloy plate is used to manufacture the drum and polish the surface, uniform polishing can be performed, and the macroscopic appearance can be more suppressed. The surface hardness (Vickers hardness) of the titanium alloy plate is preferably above HV112, and more preferably above HV115. In addition, the upper limit of the surface hardness (Vickers hardness) of the surface of the titanium alloy plate that becomes the surface of the drum is not particularly limited. However, if the surface hardness is greater than HV350, the number of polishing times will increase and it will take more time, thereby reducing the productivity of the drum. Therefore, it should be below 350HV. It is preferably below 300 HV, more preferably below 250 HV. In addition, when the amount of processing required to correct the titanium alloy plate is sufficiently reduced, it is better to be HV160 or less. It is preferably HV155 or less, more preferably HV150 or less.

The surface hardness of the titanium alloy plate can be measured at 3 to 5 points with a load of 1 kg using a Vickers hardness tester in accordance with JIS Z 2244:2009 after polishing the surface of the titanium alloy plate to a mirror surface, and set it as an average value.

(1.4　 thickness) The thickness of the titanium alloy plate of the present embodiment is not particularly limited, and can be appropriately set according to the purpose, specifications, and the like of the roller to be manufactured. When used as a material for a roller for manufacturing copper foil, since the plate thickness decreases with the use of the roller for manufacturing copper foil, the thickness of the titanium alloy plate is preferably 4.0 mm or more, and may also be 6.0 mm or more. The upper limit of the thickness of the titanium alloy plate is not particularly limited, and is, for example, 15.0 mm.

In the embodiment described above, the chemical composition of the titanium alloy sheet is set to suppress the growth of crystal grains and reduce the deformation after hot rolling, so that the crystals are not only fine, but also fall within a predetermined standard deviation. The uniform size within, including the crystal structure of the α phase of the hexagonal closest-packed structure, and the angle formed by the [0001] direction of the α phase with respect to the thickness direction of the plate is 0° or more and the area of the crystal grains below 40° The rate is above 70%. Therefore, when it is used in a roll for manufacturing copper foil, the appearance of a macroscopic appearance can be sufficiently suppressed.

In addition, when the titanium alloy sheet of the present embodiment contains more than 1.8% and 7.0% or less of Al, the Younger ratio of the titanium alloy sheet increases. As a result, when manufacturing a copper foil roller, the shrink fit of the titanium alloy plate to the surface of the core material is improved, and the productivity of the copper foil roller is improved.

As an example, Fig. 2 shows a photograph of the macroscopic appearance of the surface of the titanium alloy plate. The so-called "macro-view" is shown in Figure 2, which refers to the part of ribs with a length of several mm and different colors generated in a manner parallel to the rolling direction (for reference, it is shown in Figure 3 to see that Figure 2 The location of the macro view emphasizes the map of the macro view). If a large amount of the above-mentioned pattern is produced, the pattern will finally be transferred to the manufactured copper foil. Although the macro pattern is produced in the copper foil manufacturing process, the titanium alloy plate is prone to produce the macro pattern (the rate of generation of the macro pattern under the same conditions), and the titanium alloy can be polished with #800 sandpaper After the surface of the board, use 10% nitric acid and 5% hydrofluoric acid to corrode the surface and observe for evaluation.

＜Copper foil rolls＞ As explained above, the titanium alloy plate of the present embodiment can sufficiently suppress the appearance of macroscopic appearance when used in a roller for manufacturing copper foil, and is suitable as a material for a roller for manufacturing copper foil. 8, the copper foil manufacturing roller 20 of this embodiment has: an inner roller 21 that is a part of the electrodeposition roller and is cylindrical, a titanium alloy plate 22 attached to the outer peripheral surface of the inner roller 21, and a device The welding part 23 of the butting part of the titanium alloy plate 22, and the titanium alloy plate 22 is the titanium alloy plate of the above-mentioned present embodiment. That is, the copper foil manufacturing roller 20 of this embodiment is a copper foil manufacturing roller manufactured using the titanium alloy plate of this embodiment. The roller 20 for manufacturing copper foil of the present embodiment uses the titanium alloy plate of the present embodiment on the surface of the roller where the copper foil is deposited. Therefore, it is possible to suppress the appearance of macroscopic appearance and to manufacture high-quality copper foil. The size of the copper foil roll of this embodiment is not particularly limited, and the roll diameter is, for example, 1 to 5 m. The inner drum 21 may be a well-known thing, and its blank may not be a titanium alloy plate, and may be, for example, mild steel or stainless steel. The titanium alloy plate 22 is wound around the outer peripheral surface of the cylindrical inner drum 21 and welded to the abutting part, thereby adhering to the inner drum. Therefore, there is a welded portion 23 at the butted portion.

In the copper foil manufacturing roller of this embodiment, the metal structure of the welded portion has an α phase of 98.0% or more in volume ratio, and is 6 or more and 11 or less in terms of the particle size number in accordance with JIS G 0551:2013. In addition, the particle size number is preferably 7 or more and 10 or less. If the grain size (crystal grain size) of the crystal grains in the metal structure of the welded portion is coarse, the crystal grains themselves become a pattern and the pattern is transferred to the copper foil. As the crystal grains in the metal structure of the welded portion are as fine as described above, the appearance due to the crystal grains can be suppressed.

The grain size number of the crystal grains in the metal structure of the welded part can be measured by the comparison method, the counting method and the cutting method in accordance with JIS G 0551:2013.

In the roller 20 for manufacturing copper foil of the present embodiment, the welded portion 23 has, for example, the following metal structure. The metal structure of the welded part is the main α phase, that is, it mainly contains the α phase. The β phase will corrode more preferentially than the α phase. Therefore, from the viewpoint of achieving uniform corrosion and suppressing macroscopic appearance, the smaller the β phase, the better. On the other hand, when a small amount of β phase is present, the growth of crystal grains during heat treatment can be suppressed, and a uniform and fine crystal grain size can be obtained. From the above point of view, the volume ratio of the β phase in the metal structure of the welded portion is preferably 2.0% or less. In this case, the remainder of the metallic structure of the titanium alloy sheet is the α phase. The volume ratio of the β phase is preferably 1.0% or less, and it is more preferable that the aggregate structure of the welded portion is an α single phase. In addition, in the metal structure of the welded portion of the present embodiment, the volume ratio of the α phase is preferably 98.0% or more, more preferably 99.0% or more, and more preferably 100%.

The volume fraction of each phase in the metal structure constituting the welded portion can be calculated by the same method as the base material portion.

In addition, if the hardness difference between the welded portion and the base material of the drum is large, a difference in height may occur during polishing. Therefore, the difference between the hardness (Vickers hardness) of the welded part and the base material of the drum is preferably ±25 or less. More preferably, it is below ±15. Thereby, when the titanium alloy plate is used to manufacture the drum and polish the surface, uniform polishing can be performed, and the macroscopic appearance can be more suppressed. The hardness of the welded portion is, for example, HV110 or higher, preferably HV112 or higher, and more preferably HV115 or higher.

The hardness of the welded portion can be measured at 3 to 5 points with a load of 1 kg using a Vickers hardness tester in accordance with JIS Z 2244:2009 after polishing the surface of the welded portion to a mirror surface, and set it as an average value.

In addition, the difference between the crystal grain size of the formed welded portion and the crystal grain size of the titanium alloy plate (the difference in the grain size number) is preferably -1.0 or more and 1.0 or less. By reducing the difference in the crystal grain size between the welded part and other parts, it is possible to more reliably suppress the appearance of macroscopic appearance.

<2. The manufacturing method of the titanium alloy plate of this embodiment> The titanium alloy plate of the present embodiment described above can be manufactured by any method, for example, it can be manufactured by the method of manufacturing the titanium alloy plate of the present embodiment described below. The preferred manufacturing method of the titanium alloy plate of this embodiment has the following steps: (I) The first step (heating step), heating the titanium alloy with the above chemical composition to a temperature above 750°C and below 950°C; (II) In the second step (rolling step), rolling is performed after the heating step to produce a titanium alloy plate; and (III) The third step (annealing step), annealing the titanium alloy after the rolling step. Hereinafter, each step will be explained.

(2.1　Prepare titanium alloy sheet blank) First, before the above steps, prepare titanium alloy sheet blanks. The blank can be made of the above-mentioned chemical composition and can be made by a well-known method. For example, ingots are produced from sponge titanium by various melting methods such as a furnace melting method such as a vacuum arc remelting method, an electron beam melting method, or a plasma melting method. Then, the obtained ingot is hot forged or rolled at the temperature of the α-phase high-temperature zone or the β-phase single-phase zone, thereby obtaining a blank. The blank may also be subjected to pre-processing such as washing and cutting as needed. In addition, when a rectangular flat blank shape that can be hot-rolled is manufactured by the furnace melting method, it may be directly supplied to the following first step and second step (heating, hot rolling) without hot forging or the like.

(2.2　Step 1) This step is a heating step performed before the hot rolling of the titanium material. In this step, the titanium alloy plate blank is heated to a temperature above 750°C and below 950°C. With the heating temperature above 750°C, the titanium alloy sheet can be prevented from cracking during the hot rolling in the second step. In addition, by heating the temperature below 950°C, it is possible to prevent the formation of a T-texture in which the c-axis of the hcp structure is oriented in the width direction of the plate during the hot rolling in the second step. On the other hand, if the heating temperature is lower than 750°C, for example, when coarse particles are generated during hot forging, casting, etc., the coarse particles may be generated in the titanium alloy sheet starting from the coarse particles in the second step of hot rolling. rupture.

In addition, if the heating temperature exceeds 950°C, a coarse aggregate structure (T-texture) with the c-axis of the hcp structure oriented in the width direction of the sheet will be generated during the hot rolling in the second step. In this case, it is impossible to obtain a structure in which the angle formed by the [0001] direction of the α phase with respect to the plate thickness direction is 0° or more and 40° or less and the area ratio of the crystal grains is 70% or more. By heating the temperature below 950℃, the formation of T-texture can be prevented. Therefore, the heating temperature is 950°C or less. The heating temperature is preferably below the β transformation point, and preferably below 900°C or (β transformation point-10°C) or less. And, in order to obtain the (0001) pole figure from the normal direction of the plate surface, the peak of the crystal grain aggregation degree exists within 30° with respect to the final rolling width direction, and the aggregation structure with the maximum aggregation degree above 4.0 , The heating temperature should be below 900℃, especially when the Al content is below 3.0%, the heating temperature should be below 880℃.

In the present embodiment, the "β transformation point" means the boundary temperature at which the α phase starts to be generated when the titanium alloy is cooled from the β phase single-phase region. The β metamorphosis point can be obtained from the state diagram. The state diagram can be obtained by, for example, the CALPHAD (Computer Coupling of Phase Diagrams and Thermochemistry) method. Specifically, Thermo-Calc Sotware AB's integrated thermodynamic calculation system Thermo-Calc and a predetermined database (TI3) can be used to obtain the state diagram of the titanium alloy by the CALPHAD method to calculate the β transformation point.

(2.3　 Step 2) In this step, the heated titanium alloy sheet blank is rolled (hot rolled). Also, in this step, it is advisable to set the total reduction ratio to 80% or more, and set the ratio of the rolling reduction ratio at 200°C or higher and 650°C or less to 5% or more in the total rolling reduction ratio. And below 70%. Thereby, an aggregate structure in which the crystal grains are uniformly refined as described above and the c-axis of the hcp structure is highly concentrated in the plate thickness direction can be obtained. The start temperature of hot rolling in this step is basically the above heating temperature. With a total reduction ratio of 80% or more, the coarse grains produced in hot forging, casting, etc. can be sufficiently refined, and at the same time, T-texture can be prevented. If the total reduction ratio is less than 80%, the structure produced in hot forging, casting, etc. will remain, and coarse grains may be formed or T-texture may be formed. If this kind of structure is produced, a huge appearance will be produced in the manufactured roller. When the Al content is 3.0% or less, the total rolling reduction ratio in this step is preferably 85% or more. In addition, the higher the reduction ratio, the better the structure, so it only needs to be determined in accordance with the required product size and the characteristics of the manufacturing mill.

In addition, in the method of manufacturing the titanium alloy of this embodiment, among the total rolling reduction ratios, the ratio of the rolling reduction ratio of the titanium alloy sheet at 200°C or more and 650°C or less is preferably set to 5% or more and Below 70%. In particular, when the Al content is small (for example, 3.0% or less), it is better to satisfy the above. If it is the case where all rolling is performed at a temperature higher than 650°C, etc., the rolling shrinkage ratio of the titanium alloy sheet at 200°C or higher and 650°C or lower among the total rolling shrinkage ratio is less than 5%, Therefore, the amount of shrinkage in this temperature zone is insufficient, and recovery occurs during subsequent cooling, resulting in a portion with a smaller amount of strain. Therefore, through the heat treatment after hot rolling, the crystal grain size variation becomes larger. Variations in crystal grain size are particularly likely to occur when the Al content that can suppress the growth of crystal grains is small. In addition, by setting the rolling reduction ratio of the titanium alloy sheet at 200°C or higher and 650°C or lower to 5% or more and 70% or less, it becomes easy to obtain the following structures and/or aggregates Microstructure: Including the α phase whose crystal structure is the most densely packed hexagonal structure, and the angle formed by the [0001] direction of the α phase with respect to the plate thickness direction is 0° or more and 40° or less, and the area ratio of the crystal grains is 70% The above structure; in the (0001) pole figure from the normal direction of the plate surface, the peak of the crystal grain aggregation degree exists within 30° relative to the final rolling width direction, and the aggregation structure with the maximum aggregation degree above 4.0 . On the other hand, if all rolling and the like are carried out at less than 200°C, and the total rolling shrinkage ratio is between 200°C and 650°C, the rolling shrinkage ratio of the titanium alloy sheet is less than 5% In the case, the shape of the board becomes unstable. In this case, in the subsequent correction, the amount of processing becomes large and strain is introduced, and the difference in the amount of strain between the corrected portion and the other parts becomes larger, and further, the variation in the crystal grain size in the subsequent heat treatment becomes larger. In addition, if correction is performed after the heat treatment, the strain will be affected and only this part will be easily corroded, which may be the cause of the macroscopic appearance. Among the total rolling reduction ratios, the rolling reduction ratio of the titanium alloy sheet at 200° C. or more and 650° C. or less is preferably 10% or more, and more preferably 15% or more.

On the other hand, all rolling and the like are performed below 650°C, and if the total rolling reduction ratio is between 200°C and 650°C, the rolling reduction ratio of the titanium alloy sheet is greater than 70%, the plate shape will be Unstable. In this case, in the subsequent correction, the amount of processing becomes large and strain is introduced, and the difference in the amount of strain between the corrected portion and the other parts becomes larger, and further, the variation in the crystal grain size in the subsequent heat treatment becomes larger. In addition, if correction is performed after the heat treatment, the strain will be affected and only this part will be easily corroded, which may be the cause of the macroscopic appearance. Therefore, it is preferable that the rolling reduction ratio of the titanium alloy sheet when the rolling reduction ratio is between 200° C. and 650° C. be 70% or less in the total rolling reduction ratio. Preferably it is 65% or less, more preferably 60% or less.

The surface temperature of the hot-rolled delayed titanium alloy sheet after this step should be above 200°C. By setting the surface temperature of the titanium alloy sheet after the completion of the hot rolling to 200°C or higher, the unstable shape of the titanium alloy sheet can be suppressed, and the amount of processing caused by the subsequent correction can be reduced. As a result, the amount of strain introduced into the titanium alloy sheet is reduced, and the crystal grain size variation that may occur in the subsequent heat treatment is reduced. In addition, if strain is introduced, only this part becomes easy to be corroded, which may cause the macroscopic appearance. However, by making the surface temperature of the titanium alloy sheet after the completion of the hot rolling to be 200°C or more, the amount of processing during correction can be reduced. , The amount of strain introduced into the titanium alloy plate is reduced and the macroscopic appearance can be suppressed. The surface temperature of the titanium alloy sheet after the completion of the hot rolling is preferably above 300°C.

In addition, in this step, rolling can be unidirectional rolling extending along the long side direction of the titanium alloy sheet, and in addition to rolling in the long side direction, it can also be perpendicular to the long side direction. Rolling in the direction of. Thereby, the degree of aggregation of the aggregate structure can be further improved in the obtained titanium alloy sheet. Specifically, when the rolling reduction ratio in the final rolling direction is L (%), and the rolling reduction ratio in the direction orthogonal to the final rolling direction is T (%), L/ T is preferably 1.0 or more and 10.0 or less. Thereby, the degree of aggregation of the aggregate structure can be further improved in the obtained titanium alloy sheet. L/T is 1.0 or more and more preferably 5.0 or less.

In this step, the rolling delay is performed when the temperature is above 200°C and below 650°C, and it can also be maintained for a period of time to wait for the titanium alloy plate to cool.

In the manufacturing method of the titanium alloy sheet of this embodiment, it is preferable not to perform reheating and rolling in the second step. Thereby, the strain generated during rolling can be prevented from being released by reheating, and the strain can be stably applied to the titanium alloy sheet. As a result, the degree of aggregation of the aggregate structure of the titanium alloy sheet can be increased, and local abnormal grain growth during the heat treatment described later can be suppressed.

Cold rolling can also be performed after the second step. Cold rolling is rolling at a temperature below 200°C and can be performed by unidirectional rolling or cross rolling. The reduction ratio is preferably set to 10% or more. The strain can be introduced uniformly by making the rolling shrinkage rate above 10%, and the crystal grain size variation that may be generated in the subsequent heat treatment can be reduced. If cold rolling is required, the oxide film on the surface of the hot rolled titanium alloy sheet will be removed in advance. The oxide film can be removed by, for example, bead spraying followed by pickling, or machining such as cutting. Before removing the oxide film, annealing may be performed at a temperature lower than the β transformation point if necessary. The annealing is preferably performed at (β transformation point-50)°C or lower. When the cold rolling is delayed, if the Al content of the titanium alloy sheet is too large, the cold rollability is poor and the titanium alloy sheet may be cracked. Therefore, the Al content of the titanium alloy sheet after cold rolling is preferably 3.5% or less. In addition, to reduce the ratio of the twin grain boundary length to the total crystal grain boundary length, cold rolling should not be performed.

(2.4　Step 3) In this step, the titanium alloy sheet is heat-treated (annealed) at a temperature of 600°C or higher and β transformation point°C or lower for 20 minutes or longer. Thereby, the non-recrystallized crystal grains can be precipitated as fine recrystallized crystal grains, and the crystals in the metallic structure of the obtained titanium alloy sheet can be made uniform and become fine particles. As a result, it is possible to more reliably suppress the appearance of macroscopic appearance.

Specifically, by heat-treating the titanium alloy plate at a temperature of 600° C. or higher for 20 minutes or longer, the unrecrystallized grains can be fully analyzed into recrystallized grains. The annealing temperature is preferably above 650°C. In addition, from the viewpoint of suppressing the coarsening of crystal grains, it is preferable to set the annealing temperature to be below the β transformation point. Preferably it is below 800°C. The upper limit of the annealing time is not particularly limited, and may be, for example, 5 hours or less. In particular, when the Al content that has the effect of suppressing the growth of crystal grains is small, etc., from the viewpoint of suppressing the coarsening of crystal grains, the annealing time is preferably set to 90 minutes or less.

The heat treatment can be performed in any of an atmospheric environment, an inert gas environment, or a vacuum environment. However, if an oxide film is formed on the titanium alloy plate, the oxide film must be removed. The removal of the oxide film is not particularly limited, and it can be performed by, for example, bead spraying followed by pickling, or machining such as cutting. However, bead spraying may introduce strain into the titanium alloy plate, so it is advisable to avoid removing the oxide film by bead spraying. In addition, the annealing method is not particularly limited, and it may be a continuous heating method or a batch heating method.

(2.5　Post-processing steps) The post-treatment can be, for example, pickling or cutting to remove oxide film, etc., or washing treatment, etc., and can be appropriately applied as needed. Alternatively, the correction processing of the titanium alloy plate may be performed as a post-processing. The correction processing can be performed by, for example, vacuum creep flattening (VCF; Vacuum creep flattening). In the above, the manufacturing method of the titanium alloy sheet of this embodiment has been demonstrated.

Next, the manufacturing method of the roll for manufacturing copper foil of this embodiment is demonstrated. The method of manufacturing the copper foil roller of the present embodiment has the following steps: use the titanium wire for welding (the titanium wire for welding of this embodiment) to be described later to weld the adjacent titanium alloy plate of the present embodiment that has been processed into a cylindrical shape. Two end steps (welding step). The method of processing the titanium alloy plate into a cylindrical shape, welding conditions, etc. can be known methods. At the time of welding, for example, the two adjacent ends of the titanium alloy plate processed into a cylindrical shape are surfacing and fused using the titanium wire for welding described above to form a welded portion (surfacing welded portion). Here, since cold or warm processing is performed on the welded part, it is advisable to pile up the welded part. The stack height can be set to, for example, 10 to 50% of the thickness of the titanium alloy plate. In addition, the surfacing welded part may be rolled in a cold state or a temperature of 200°C or less. Thereby, the solidified structure of the surfacing part can be made into a uniform fine equiaxed structure. In order to prevent the occurrence of cracks due to the high processing rate and ensure that the solidified structure becomes a uniform fine equiaxed structure, the rolling reduction ratio is preferably 10% or more and 50% or less. In addition, heat treatment (annealing) may be performed after welding. The heat treatment can be performed, for example, at a temperature of 500° C. or more and 850° C. or less for 1 minute or more and 10 minutes or less. By performing the heat treatment at 850°C or less for 10 minutes or less, coarsening of crystal grains or part of the crystal grains can be prevented, and a uniform fine grain crystal structure can be obtained.

Next, a description will be given of the titanium wire for welding of this embodiment, which is used to manufacture a roll for manufacturing copper foil.

＜Titanium wire for welding＞ The titanium wire for welding of this embodiment can be used to manufacture a titanium roller for making copper foil, and more specifically, to weld adjacent ends of a titanium alloy plate that has been bent into a cylindrical shape.

The titanium wire for welding of this embodiment should have the following chemical composition: Contains in mass%: One or more selected from the group consisting of Sn, Zr and Al: a total of 0.2% or more and 6.0% or less, O: 0.01% or more and 0.70% or less, N: 0.100% or less, C: Below 0.080%, H: 0.015% or less and Fe: 0.500% or less, and The remainder contains Ti and impurities.

The total content of one or more elements selected from the group consisting of Sn, Zr, and Al is 0.2% by mass or more and 6.0% by mass or less. Thereby, the metal structure of the obtained welded part can be made into an α-phase main body and the generation of β phase can be suppressed, so that the corrosion resistance of the welded part can be improved. In addition, the crystal grains in the metal structure of the obtained welded portion can be sufficiently fined, and the generation of macroscopic appearance due to the crystal grains can be suppressed.

On the other hand, when the total content of one or more elements selected from the group consisting of Sn, Zr, and Al is less than 0.2% by mass, the resulting metal structure of the welded part may produce coarse particles in the crystal grains, which may not Suppresses the appearance of a giant. The content of one or more elements selected from the group consisting of Sn, Zr, and Al is preferably 0.3% by mass or more in total, and more preferably 0.4% by mass or more in total.

In addition, if the total content of one or more elements selected from the group consisting of Sn, Zr, and Al is greater than 6.0% by mass, the above-mentioned excessive Sn, Zr, and Al content may cause adverse effects, and the adverse effects The influence makes it impossible to suppress the macroscopic appearance in the resulting welded portion. The total content of one or more elements selected from the group consisting of Sn, Zr, and Al is preferably 5.5% by mass or less, and more preferably 5.0% by mass or less in total.

Among the above-mentioned elements, Sn is a neutral element and is an element that can suppress the growth of crystal grains in the welded portion by being contained in the titanium wire for welding. In order to stably suppress the growth of crystal grains, the Sn content is preferably 0.2% by mass or more, preferably 0.3% by mass or more. On the other hand, if too much Sn is added, depending on the chemical composition, it may segregate in the longitudinal direction of the titanium wire for welding and form a macroscopic pattern caused by the concentration in the welded part of the bead. Therefore, the Sn content is preferably 6.0% by mass or less, and more preferably 5.5% by mass or less.

Zr is also a neutral element, and is an element that can suppress crystal grain growth by being contained in the titanium wire for welding. In order to stably suppress the growth of crystal grains, the Zr content is preferably 0.2% by mass or more, preferably 0.3% by mass or more. On the other hand, if too much Zr is added, depending on the chemical composition, the α+β region near the transformation temperature will be widened, and the β phase will be easily precipitated during the heat treatment when manufacturing a titanium roll for manufacturing copper foil. In addition, the surface strength is different due to solidification segregation, and as a result, a large appearance may be produced when the surface is polished on a titanium roller for manufacturing copper foil. Therefore, the Zr content is preferably 5.5% by mass or less, and more preferably 5.0% by mass or less.

Al is an α-stabilizing element. Like Sn and Zr, it can suppress crystal grain growth by being contained in the titanium wire for welding, and contributes to enhancing the strength of the titanium wire for welding and the welded part formed using it. In order to stably suppress the growth of crystal grains, the Al content is preferably 0.2% by mass or more, preferably 0.3% by mass or more. On the other hand, if the Al content is too large, depending on the chemical composition, the increase in high temperature strength increases, and the solidified structure (welded portion) of the titanium wire for welding becomes too large in the processing before heat treatment, and processing cracks may occur. And the difference in hardness between the welded part and the base material becomes larger, and the height difference may occur during the polishing and the whole surface of the titanium roller used to manufacture the copper foil. Therefore, the Al content is preferably 5.0% by mass or less, and more preferably 4.5% by mass or less.

As described above, Al-based elements can contribute to increasing the strength of the welded portion, and increase the hardness of the welded portion. Therefore, in order to suppress the increase in the hardness of the welded part, it is preferable to contain Sn and/or Zr together. In this case, for example, the total content of Sn and Al is 0.2% by mass or more and 6.0% by mass or less, preferably 0.3% by mass or more and 5.5% by mass or less. Moreover, for example, the total content of Zr and Al is 0.2% by mass or more and 6.0% by mass or less, preferably 0.3% by mass or more and 5.5% by mass or less.

The above-mentioned Sn, Zr, and Al may be contained in the above-mentioned amounts in total, and any one or two of them may not be included in the titanium wire for welding.

O is an alpha stabilizing element, which can suppress the increase in high temperature strength and increase the strength at room temperature, and can increase the hardness of the welded part. In order to obtain this effect, the O content is set to 0.01% by mass or more. From the viewpoint of controlling the hardness of the welded portion, the O content is preferably 0.015 mass% or more, and more preferably 0.02 mass% or more. On the other hand, if the O content is greater than 0.70% by mass, cracks will occur during the surfacing process during welding. Therefore, the O content is 0.70% by mass or less. The O content is preferably 0.60% by mass or less, and more preferably 0.50% by mass or less.

At least a part of O is preferably present in the form of granular oxides of Ti, Sn, Zr and/or Al in the titanium wire for welding, for example, in the form of TiO ₂ , SnO, SnO ₂ , ZrO ₂ , Al ₂ O ₃ . These oxides are dissociated by the arc during welding, and the dissociated O forms an oxide film on the welded part, which prevents the arc from locally impacting and stabilizes, and the welded part will be homogenized. Thereby, the surfacing shape and workability can be improved during welding. O is considered to be homogeneously dissolved in the welded part of the roller.

More specifically, let the peak intensity of α-titanium obtained by the X-ray diffraction method for the titanium wire for welding be A, and let TiO ₂ (110), ZrO ₂ (111), SnO ₂ (110) and Al _{The sum of the peak intensities of 2} O ₃ (104) is B. In this case, B/A (radiation intensity ratio) should be 0.01 or more. Thereby, a sufficient amount of oxide is contained in the titanium wire for welding, and the above-mentioned effects can be sufficiently obtained. B/A is preferably greater than 0.015 and less than 0.10, more preferably greater than 0.02 and less than 0.09.

The X-ray diffraction of the titanium wire for welding of this embodiment is implemented using a Cu tube for a cross section perpendicular to the longitudinal direction at a current of 40 mA, a voltage of 40 kV, and a range of 2θ from 10 to 110°. The measurement is performed at 0.01° intervals, 1 s/point, and can be performed by rotating the sample 360° at each measurement point.

Fe-based elements strengthen the β phase. In the welded part, an increase in the precipitation amount of the β phase will affect the formation of a macroscopic pattern, so the upper limit of Fe content in the titanium wire for welding is set to 0.500%. The Fe content is preferably 0.100% or less, preferably 0.080% or less.

N, C, and H are all elements that reduce ductility and workability if contained in large amounts. Therefore, the N content is limited to 0.100% or less, the C content is limited to 0.080% or less, and the H content is limited to 0.015% or less. N, C, and H are impurities, and the lower the content, the better. However, these elements may be mixed during the manufacturing process, and the actual lower limits of the content may be set to 0.0001% for N, 0.0005% for C, and 0.0005% for H.

In the chemical composition of the titanium wire for welding of this embodiment, the remainder contains titanium (Ti) and impurities, and may be composed of Ti and impurities. If the impurity needs to be specifically exemplified, there are Cl, Na, Mg, Si, and Ca mixed in the refining step, and Cu, Mo, Nb, Ta, and V mixed from scrap. When these impurity elements are contained, for example, as long as the content is each 0.10% by mass or less and the total amount is 0.50% by mass or less, it is a level of no problem.

The wire diameter of the titanium wire for welding of this embodiment is not particularly limited, and for example, it is 0.8 mm or more and 3.4 mm or less. The cross-sectional shape of the titanium wire for welding of this embodiment is not particularly limited as long as it can be used for welding, and can be any shape.

The production of the titanium wire for welding can be carried out by, for example, the following methods: cold, warm and hot plastic processing and powder metallurgy using hole die drawing, drum die drawing, and caliber rolling.

As described above, according to the present embodiment, by making the titanium wire for welding contain at least one element selected from the group consisting of Sn, Zr, and Al in an appropriate amount, the structure of the welded part can be made into the α-phase main body and the crystal grains can be fine.化. In addition, by containing a proper amount of O in the titanium wire for welding, the hardness of the welded portion can be controlled. As a result, in the titanium roller for manufacturing copper foil, the appearance of the macroscopic appearance due to the welded portion is suppressed.

In particular, when the titanium wire for welding contains granular oxides of Ti, Sn, Zr, and/or Al, the following method can be used to manufacture the titanium wire for welding: a method of making it into the wire by powder metallurgy , By attaching oxides to the surface of the rod and wire, the oxide is crimped on the surface, and the oxide is attached to the surface of the rod and wire is vacuum-annealed at 750~1000℃ to make it Diffusion and bonding methods, etc. Although there is also a method of inserting powdered oxide into a hollow titanium tube to manufacture titanium wire for welding, the distribution of oxides is prone to unevenness. In this case, it will become a factor in the composition change in the welded part, and the hardness at this part And the crystal grain size changes. Therefore, this embodiment does not adopt the method of inserting powdery oxide into the titanium tube, and is regarded as an unsuitable method. Example

Hereinafter, examples are shown and embodiments of the present invention are specifically described. The embodiment shown below is only one case of the present invention, and the present invention is not limited to the following cases.

1. Manufacturing Titanium Alloy Plate First, an ingot with the chemical composition of Table 1 and Table 2 is produced by the vacuum arc remelting method, and then it is hot forged to obtain a titanium alloy sheet stock with a predetermined composition.

Next, the obtained titanium alloy sheet blank was heated to the temperature shown in Table 3 and Table 4 (first step), and then hot rolled under the conditions shown in Table 3 and Table 4 (second step). In the table, "Ratio of rolling reduction ratio at 200~650℃" refers to the ratio of rolling reduction ratio of titanium alloy sheet when the total rolling reduction ratio is above 200℃ and below 650℃. "Rolling ratio (L /T)” when the reduction ratio of rolling in the final rolling direction is L (%), and the reduction ratio of rolling in the direction orthogonal to the final rolling direction is T (%), Indicates the value of L/T. In addition, in each of the invention examples and comparative examples shown in Table 1 and Table 2, except for Comparative Example 1, in order to roll the titanium alloy sheet at 200°C or higher and 650°C or lower, the hot rolling was temporarily stopped and waited until cooling. After the temperature is below 650°C, the hot rolling is started again. In some cases, annealing before cold rolling and cold rolling were carried out.

Next, in an atmospheric environment, heat treatment is performed at the temperature and time described in Table 3 and Table 4 (the third step) to produce a titanium alloy plate with a thickness of 8.0 to 15.0 mm.

[Table 1]

[Table 2]

[table 3]

[Table 4]

2. 　Analysis and Evaluation The following items were analyzed and evaluated for the titanium alloy sheets of the invention examples and comparative examples.

2.1 Crystal grain size The average crystal grain size D and the standard deviation of the grain size distribution of the crystals in the metallic structure of the titanium alloy plates of the invention examples and comparative examples are measured and calculated as follows. After chemically polishing the cross section of the cut titanium alloy plate, the electron backscattering diffraction method is used to measure in a 2mm×2mm area with 2μm steps and measure 10 fields of view. Then, for the crystal grain size, calculate the equivalent circle size (area A=π×(grain size D/2) ² ) based on the crystal grain area measured by EBSD, and take the average value based on the number as the average crystal Particle size D, and calculate the standard deviation σ of the logarithmic normal distribution based on the crystal size distribution.

2.2　 Collective Organization According to the following method, calculate the area ratio of crystal grains whose angle θ formed by the thickness direction (ND) of the titanium alloy plate and the [0001] direction (c-axis) of the α phase is 40° or less. After chemically polishing the cross section of the cut titanium alloy plate, EBSD is used to analyze the crystal orientation. In addition, the lower part of the surface of the titanium alloy plate and the central part of the thickness of the titanium alloy plate were measured in a 2 mm×2 mm area with a step of 2 μm, and 10 fields of view were measured. Regarding the data, use OIM Analysis software manufactured by TSL Solutions to select the measurement point data whose angle formed by the ND and the c axis is below 40°.

After chemically polishing the observation surface of the titanium material sample of each invention example and comparative example, the crystal orientation analysis was performed using the electron backscatter diffraction method to obtain a (0001) pole figure. More specifically, a 2mm×2mm area was scanned at 2μm intervals, and a (0001) pole figure was created using OIM Analysis software manufactured by TSL Solutions. At this time, the position with the highest contour line is taken as the peak position of the concentration degree, and the value of the maximum concentration degree among the peak positions is taken as the maximum concentration degree. The maximum concentration is calculated by using the texture analysis of the pole figure obtained by the spherical harmonic function method (expansion index=16, Gaussian half-value width=5°).

2.3　Al segregation The presence or absence of Al segregation (Al uniformity) was confirmed as follows. Use EPMA and set the beam diameter to 500μm and the step size to 500μm, which is the same as the beam diameter. In the 1/4 position of the plate thickness from the surface of the titanium alloy plate, the surface perpendicular to the plate thickness direction is 20mm×20mm or more Analysis of the composition of the area. In addition, in order to convert the composition analysis results into alloy element concentrations, JIS1 industrial pure titanium and target titanium alloy plates are analyzed, and linear approximation is performed based on the results, and the obtained calibration curve is adopted. Then, the area ratio of the region where the Al concentration is ([Al%]-0.2) mass% or more and ([Al%]+0.2) mass% or less is calculated.

2.4　Double crystal After chemically polishing the thickness-direction cross-sections of the titanium alloy plate samples of the respective invention examples and comparative examples, the crystal orientation analysis was performed using the electron backscatter diffraction method. Specifically, in the 1/4 position of the plate thickness from the surface of the titanium alloy plate of the sample, an area of 2mm×2mm was scanned at 2μm intervals, and an inverse pole figure (IPF: inverse pole figure) was created. At this time, consider the following as the twin crystal interface: the rotation axis of the (10-12) twin crystal, (10-11) twin crystal, (11-21) twin crystal and (11-22) twin crystal produced, and Within 2° from the theoretical value of the crystal orientation difference (rotation angle). Then, the grain boundary with a crystal orientation difference (rotation angle) of 2° or more was taken as the total crystal grain boundary length, and the ratio of the twin grain boundary length to the total crystal grain boundary length was calculated.

2.5　α phase area ratio After mirror-polishing the thickness-direction cross-sections of the titanium alloy plates of each invention example and comparative example, the concentration distribution of β-phase stabilizing elements in the cross-section was measured by SEM/EPMA at a position of 1/4 of the plate thickness from the surface. And calculate the area ratio of the α phase where the β phase stabilizing element is not concentrated.

2.6　surface hardness Regarding the surface hardness of the titanium alloy plate of each invention example and comparative example, after the surface of the titanium alloy plate is polished to a mirror surface, 3 to 5 points are measured using a Vickers hardness tester with a load of 1 kg in accordance with JIS Z 2244:2009. The obtained value is averaged as the surface hardness.

2.7　Major appearance Regarding the macroscopic appearance, the surface of the titanium alloy plate of each invention example and comparative example with a size of about 5 to 10 pieces of 50×100mm each was polished with #800 sandpaper, and then a solution of 10% nitric acid and 5% hydrofluoric acid was used. Corroded the surface and observed it. Next, a rib-like pattern with a length of 3 mm or more was used as a macro pattern, and the average of the generation ratio was evaluated in the following manner.

A: The production ratio is 1.0 pieces/piece or less (very good, 1.0 pieces or less in 50×100mm) B: The production ratio is greater than 1.0 pcs/sheet and 5.0 pcs/sheet or less (good, greater than 1.0 and 5.0 pcs or less in 50×100mm) C: The production ratio is more than 5.0 pieces/piece and 10.0 pieces/piece or less (slightly good, more than 5.0 pieces and 10.0 pieces or less in 50×100mm) D: The production ratio is greater than 10.0 pieces/piece (unqualified, more than 10.0 pieces in 50×100mm) The obtained analysis results and evaluation results are shown in Table 5 and Table 6.

2.8　 abrasiveness In the above-mentioned grinding with #800 sandpaper for observing the macroscopic appearance, the grinding time was set to 1 minute for grinding. When the surface layer is removed within 1 minute of the polishing time, it is judged that the productivity of the manufacturing drum can be maintained and the abrasiveness is evaluated as good (OK), and when the surface layer cannot be removed within 1 minute, it is judged that the productivity of the manufacturing drum is reduced. And rated as bad (NG).

2.9　 shrink fit The shrink fit was evaluated in the following manner. The shrink fit will affect the Young's ratio and shape ratio (for example, if it is a tube sheet, it is the ratio of the outer diameter of the inner tube to the inner diameter of the outer tube). In particular, in order to obtain the stress required to fix the titanium, the larger the Young's rate of titanium, the smaller the amount of deformation can be achieved, so the heating temperature can be lowered and the workability can be improved. Therefore, the case where the Younger ratio is 135 GPa or more is rated as excellent in shrinkage compatibility.

The obtained analysis results and evaluation results are shown in Table 5 and Table 6. The "area ratio (%) of crystal grains with an angle θ of 0° or more and 40° or less" shown in Table 5 and Table 6 means that the angle formed by the c axis of the α phase with respect to the thickness direction is 0° or more and The area ratio of crystal grains below 40°. In addition, the "Al uniformity (%)" shown in Table 2 refers to the area ratio of a region where the Al concentration is ([Al%]-0.2) mass% or more and ([Al%]+0.2) mass% or less. In addition, the "RT" in the "cold rolling step" shown in Table 2 means room temperature.

[table 5]

[Table 6]

As shown in Table 5 and Table 6, the titanium alloy plates of Invention Examples 1 to 16 and Invention Examples 101 to 115 have suppressed the macroscopic appearance. In contrast, the titanium alloy plates of Comparative Examples 1 to 5 produced many macroscopic appearances. In addition, compared with Invention Examples 101 to 115 with a high Al content, Invention Examples 1 to 16 with a low Al content suppressed the occurrence of macroscopic appearance. On the other hand, Inventive Example 101 to Inventive Example 115 having a high Al content had a high Younger ratio and excellent shrinkage compatibility.

<Example 2> The titanium alloy plate is used as the base material and processed into a cylindrical shape with a diameter of 1m, and then the butting parts (two adjacent ends) are welded using the titanium wire for welding shown in Table 7. This titanium alloy plate system is expected to be used in manufacturing The copper foil roll is obtained by the same method as the invention example of the above-mentioned Example 1 as shown in Table 7. The welding system sets the stack height to 25% or less of the base material thickness. Then, after the stacking, the thickness of only the stacking height is reduced to the thickness of the base material at a temperature below 200°C. Finally, the welding part was heat-treated under the conditions of 600 to 800°C for 20 to 90 minutes to obtain welding samples of the titanium wires for welding using the invention examples and the comparative examples.

[Table 7]

According to JIS G 0551:2013, the crystal grain size in the metal structure of the obtained welded part was measured according to the comparative method, and the grain size number (GSN) was obtained. In addition, SEM/EPMA was used to measure the concentration distribution of Fe or β-phase stabilizing elements on the metal structure of the welded part, and the total concentration of Fe or β-phase stabilizing elements was higher than the average concentration of the measurement range by 1% by mass or more. The point (concentrated part) is defined as the β phase, and the area ratio is calculated. The area ratio and the volume ratio are considered equal, and the obtained area ratio is taken as the volume ratio of the β phase, and the area ratio of the portion where the β phase stabilizing element is not concentrated (other than the concentrated part) is taken as the volume ratio of the α phase , Calculate the volume ratio of α phase. In addition, the Vickers hardness (Hv) of the welded portion and the base material in the welded samples of each invention example and each comparative example was calculated by measuring 3 to 5 points with a load of 1 kg and calculating the average value. In addition, a contact roughness meter was used to measure the height difference (μm) of the boundary between the welded part and the base material part in accordance with JISB0633:2001 with λc: 0.8 mm, λs: 2.5 μm, and rtip: 2 μm. For the macroscopic appearance of the welded part in each welded sample, the surface of each titanium alloy plate with a size of about 5-10 pieces of 50×100mm was polished with a #800 buffing wheel, and 10% nitric acid and hydrofluoric acid were used. After the% solution corrodes the surface, observe it. Next, a rib-like pattern with a length of 3 mm or more was generated as a macro pattern, and the average of the generation ratio was evaluated in the following manner.

A: The production ratio is 1.0 pieces/piece or less (very good, 1.0 pieces or less in 50×100mm) B: The production ratio is greater than 1.0 pcs/sheet and 5.0 pcs/sheet or less (good, greater than 1.0 and 5.0 pcs or less in 50×100mm) C: The production ratio is more than 5.0 pieces/piece and 10.0 pieces/piece or less (slightly good, more than 5.0 pieces and 10.0 pieces or less in 50×100mm) D: The production ratio is greater than 10.0 pieces/piece (unqualified, more than 10.0 pieces in 50×100mm) In addition, when there is a height difference of 5 μm or more between the welded part and the base material part, it is also rated as D in the macro pattern column.

In addition, use a depth gauge to measure 10 points each of the convex and concave parts of any 50cm interval in the welded bead obtained by welding, and make the average height of the top 3 points of the convex part be h, and the average height of the bottom 3 points of the concave part as D And when the average height of the 20 measuring points is A, if the values of (hA)/A and (AD)/A are all below 0.3, it is rated as OK, and when the value is below 0.1, it is rated as Ex. The results are shown in Table 8.

[Table 8]

As shown in Table 8, Inventive Examples 201 to 205 suppressed the formation of the macroscopic appearance of the welded part. On the other hand, Comparative Examples 201 and 202 produced many macroscopic appearances of welded parts.

Industrial availability According to the present invention, it is possible to provide a titanium alloy plate and a copper foil roll manufactured by using the titanium alloy plate. When the titanium alloy plate is used in a copper foil manufacturing roll, it is possible to suppress the appearance of macroscopic appearance.

1: Device for manufacturing copper foil 2: Electrodeposition roller 10: Electrolyzer 20: Roller for manufacturing copper foil 21: inner drum 22: Titanium alloy plate 23: Welding part 30: Electrode plate 40: Coiling section 50: guide roller 60: take-up roller A: Copper foil b, b1, b2: dotted line G1, G2, G3, R1, R2: area ND, RD, TD: direction P1, P2: spikes θ: Angle

Fig. 1 is an example of the (0001) pole figure from the rolling surface of a titanium alloy sheet according to an embodiment of the present invention and from the normal direction (ND). Figure 2 is a micrograph showing an example of the macroscopic appearance observed on the surface of the corroded titanium alloy plate. Fig. 3 is a reference diagram, which emphasizes the macro appearance in order to show the position of the macro appearance. Fig. 4 is an explanatory diagram for explaining the crystal orientation of the α phase. Fig. 5 is an example of a crystal orientation distribution map, which shows an example of crystal orientation analysis. 6 is an explanatory diagram of the (0001) pole figure from the normal direction (ND) of the rolling surface, which is used to illustrate the crystal orientation of the titanium alloy sheet according to an embodiment of the present invention. Fig. 7 is a schematic diagram of an apparatus for manufacturing copper foil. Fig. 8 is a schematic diagram of the roller for manufacturing copper foil of the present embodiment.

P1, P2: spikes

RD, TD: direction

b: dotted line

Claims (14)

A titanium alloy plate with the following chemical composition: Contained by mass%: Sn: 0% or more and 2.0% or less, Zr: 0% or more and 5.0% or less, and Al: 0% or more and 7.0% or less. One or more of two types: a total of 0.2% or more and 7.0% or less, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, O: 0.700% or less, and Fe: 0.500% or less, with the remainder The part contains Ti and impurities; the average crystal grain size is 40μm or less; the standard deviation of the particle size distribution according to the logarithm of the crystal grain size in unit μm is 0.80 or less; it contains the alpha phase whose crystal structure is the hexagonal closest-packed structure; and The area ratio of crystal grains where the angle formed by the [0001] direction of the aforementioned α phase with respect to the plate thickness direction is 0° or more and 40° or less is 70% or more. For example, the titanium alloy plate of claim 1, which has the following collective structure: in the (0001) pole figure from the normal direction of the plate surface, the pole figure obtained by the spherical harmonic function method of the electron backscatter diffraction method will be expanded When the exponent is set to 16 and the Gaussian half-value width is set to 5°, the peak of the aggregation degree calculated by the texture analysis exists within 30° from the aforementioned normal direction of the plate surface, and the maximum aggregation degree is 4.0 or above. For the titanium alloy plate of claim 1 or 2, in which the aforementioned average crystal grain size is measured in a unit of μm and is set as D, the standard deviation of the aforementioned grain size distribution is (0.35×lnD-0.42) or less. For the titanium alloy plate of claim 1 or 2, when observing the cross section in the thickness direction, the length of the double crystal grain boundary relative to the total crystal grain boundary length of the thickness section at a position of 1/4 of the plate thickness from the surface ratio The rate is below 5.0%. For example, the titanium alloy plate of claim 1 or 2, in the aforementioned chemical composition, contains a total of 0.2% or more and 5.0% or more of one or two or more elements in the group consisting of: Sn: 0.2% or more and 2.0% or less, Zr: 0.2% or more and 5.0% or less, and Al: 0.2% or more and 3.0% or less. Such as the titanium alloy plate of claim 1 or 2, wherein the aforementioned chemical composition contains Al: greater than 1.8% and less than 7.0%; and the Vickers hardness is less than 350Hv. For the titanium alloy plate of claim 6, when the Al content is [Al%], the Zr content is [Zr%], the Sn content is [Sn%] and the O content is [O%] in terms of mass%, the following The Al equivalent Aleq shown in the formula (1) is below 7.0; Aleq=[Al%]+[Zr%]/6+[Sn%]/3+10×[O%] formula (1). Such as the titanium alloy plate of claim 6, which uses an electron probe microanalyzer to analyze the composition of an analysis area of 20mm×20mm or more on the surface perpendicular to the thickness direction at a position of 1/4 of the plate thickness from the surface. When, let the average content of Al be [Al%], the Al concentration is the area of ([Al%]-0.2) mass% or more and below ([Al%]+0.2) mass% relative to the area of the aforementioned analysis area The rate is above 90%. Such as the titanium alloy plate of claim 7, which uses an electron probe microanalyzer to analyze the composition of an analysis area of 20mm×20mm or more perpendicular to the thickness of the plate at a position of 1/4 of the plate thickness from the surface. When, let the average content of Al be [Al%], the Al concentration is the area of ([Al%]-0.2) mass% or more and below ([Al%]+0.2) mass% relative to the area of the aforementioned analysis area The rate is above 90%. Such as the titanium alloy plate of claim 1 or 2, which contains 98.0% by volume or more of the aforementioned α phase. For example, the titanium alloy plate of claim 1 or 2 is the titanium alloy used in a roller for making copper foil Gold plate. A roller for manufacturing copper foil, comprising: a cylindrical inner roller; a titanium alloy plate as claimed in any one of claims 1 to 11 attached to the outer peripheral surface of the inner roller; and a welding part, which is provided on the titanium The butt portion of the alloy plate; wherein the metal structure of the aforementioned welded portion has an alpha phase of 98.0% or more in volume ratio, and is 6 or more and 11 or less in accordance with the particle size number of JIS G 0551:2013. A method for manufacturing a copper foil roller, comprising a welding step of using a titanium wire for welding to weld two adjacent ends of the titanium alloy plate processed into a cylindrical shape such as claims 1 to 11; wherein The aforementioned titanium wire for welding has the following chemical composition: Contains in mass %: one or more selected from the group consisting of Sn, Zr, and Al: a total of 0.2% or more and 6.0% or less, O: 0.01% or more and 0.70% or less, N: 0.100% or less, C: 0.080% or less, H: 0.015% or less, and Fe: 0.500% or less, and the remainder contains Ti and impurities. The method for manufacturing a copper foil roller according to claim 13, wherein in the titanium wire for welding, at least a part of the O is selected from at least one of the group consisting of Ti, Sn, Zr, and Al The element's oxide form exists.

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