JPH0920990A - Titanium material for electrodeposition drum for producing electrodeposited metal foil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably and surely obtain the material in which any irregular surface polishing marks are inhibited from being generated by specifying thickness of the material and the hardness distribution of its surface that is polished and finished to have a specified roughness. SOLUTION: The thickness of the material is adjusted to 4 to 30mm and in the surface of the material, that is polished and finished so as to have a <=0.3μm average roughness (Ra), the maximum and minimum of Vickers hardness measured values with a <=1kg load at positions of points of >=10, which are selected at intervals of 0.3 to 1mm in an arbitrary direction on the surface are adjusted to <=10. The titanium material having this hardness distribution is obtained by cooling it at an about >=1,000 deg.C/hr cooling rate so as to pass the temp. through the β-transformation point in the process from the casting of a molten titanium material into an ingot to the forming of the ingot into a platelike or ringlike shape and thereafter, performing working treatment, etc., of the resulting formed material in a temp. region lower than the β-transformation point. Thus, the objective titanium material in which even very slight visual irregular polishing marks such as simple bright and dark marks are inhibited from being generated can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a titanium material for an electrodeposition drum used for producing electrolytically deposited metal foil (electrodeposited foil).

[0002]

2. Description of the Related Art In recent years, the demand for electrodeposited foils has rapidly increased with the remarkable progress of electronic devices, and the demand for copper foils in particular has shown signs of increasing. By the way, electrodeposited foils such as copper foils used for such applications are currently in the form of roll-shaped electrolytic deposition electrodes (electrodeposition drums) from the viewpoint of productivity and the like.
Generally, the method of depositing on the electrode is used, but this electrodeposition drum is required to have sufficient corrosion resistance because it is used in the environment where it is exposed to the electrolytic solution. A composite of titanium rings, which is the material, is applied.

The titanium ring is a) a plate-shaped titanium material is rolled to have a predetermined outer diameter, and the abutting ends thereof are welded together. B) A titanium perforated material obtained by forging an ingot is used as a ring ring. -It is generally prepared by one of two methods of ring rolling to a predetermined outer diameter by a ring mill, and an electrodeposition drum for producing electrodeposited foil is prepared in this way. The titanium ring is assembled by shrink fitting on an inner drum made of carbon steel or the like, and subjected to a surface polishing step to be used for producing an electrodeposited foil.

However, when the surface of the titanium ring is polished as described above for use in the production of electrodeposited foil, the surface of the titanium ring that has been polished to a greater or lesser degree has a visually irregular polishing pattern (brightness and darkness). Pattern) tends to appear,
There was a problem that this polishing pattern was printed on the electrodeposited foil.

Incidentally, it is known that a relatively remarkable irregular polishing pattern appears due to the structural nonuniformity of the titanium material.
It is well known as described in Japanese Patent Publication No. 9866, and therefore, a titanium ring material for an electrodeposition drum has been selected so far that a macro structure or a micro structure is as uniform and fine as possible. The pattern has been improved. For this reason, the conventional titanium ring, though not completely free of visual polishing patterns, is extremely slight and has been used as a practically satisfactory one for electrodeposition drums.

Recently, however, the consumers' eyes on the product quality have become more severe, and even the "extremely slight and slightly visible light-dark pattern" which has not been a problem in the past, is electrodeposited. There is a growing concern that it will cause a significant decline in the value of titanium ring materials for drums.

In view of the above, the object of the present invention is to provide an electrodeposition drum which does not even generate the above-mentioned "very slight visually irregular polishing pattern such as a mere light and dark pattern" even if the surface is polished. It is to provide a titanium ring material for use.

[0008]

As a result of intensive studies to achieve the above object, the present inventor was able to obtain the following series of findings. (a) Even if the macrostructure and microstructure are made sufficiently uniform and fine by structural adjustment such as recrystallization annealing, the titanium ring material for electrodeposition drum is subjected to surface polishing, resulting in very slight visual irregular polishing. A pattern may occur, but this visually polished pattern is a glossy pattern caused by the difference in glossiness on the surface of the material. The reason why such a pattern occurs during surface polishing is that "hexagonal C There is an aggregate of crystal grains whose axial direction is close to the direction perpendicular to the plate surface, and there is a slight difference in polishability due to the fact that this part is harder than other parts. ，

(B) However, when the surface hardness distributions of various titanium materials that have undergone various processing and heat histories are measured under certain conditions, "the presence or absence of the above-mentioned visual polishing pattern" and "hardness distribution" are measured. , And there is a clear relationship with ", and when the difference between the maximum hardness and the minimum hardness in the hardness distribution is 10 or less, the polishing pattern is substantially absent. (c) Moreover, there is a treatment method capable of stably and reliably realizing a titanium material having a difference between the maximum hardness and the minimum hardness in the hardness distribution of 10 or less.

The present invention has been made on the basis of the above findings and the like. "A titanium material for an electrodeposition drum for producing an electrodeposited foil has a thickness of 4 to 30 mm and an average surface roughness. (R
a): the maximum hardness of "Vickers hardness measurement value under a load of 1 kg or less carried out at a position of 10 points or more at 0.3 to 1 mm pitch in an arbitrary direction on the surface" when polished to 0.3 μm or less By configuring the difference in the minimum hardness to be 10 or less, it is possible to impart a good surface property that does not cause even a very slight irregular surface polishing pattern ”. .

The titanium referred to in the present invention means not only industrial pure titanium specified in JIS H4600 but also Pd, Ru, Pt, Ta, Ni, Co, Mo and W of several wt% or less.
This is a general term for α-type titanium alloys added with, and the titanium material may be plate-shaped or ring-shaped.

[0012]

Next, the reason why the thickness, surface roughness and surface hardness distribution of the titanium material for electrodeposition drum according to the present invention are limited as described above will be explained together with its operation. First, the reason for limiting the thickness of the titanium material to 4 to 30 mm is that the thickness is 4 mm.
If it is less than mm, sufficient current density cannot be given during electrodeposition due to heat generation, etc., and efficient electrodeposition cannot be performed.
On the other hand, if the thickness exceeds 30 mm, sufficient workability cannot be obtained, and it becomes difficult to prevent the uneven polishing pattern due to the uneven structure, and therefore it is judged that they are all unsuitable as electrodeposition drum materials. is there.

Next, regarding the hardness distribution of the titanium material for an electrodeposition drum according to the present invention, the surface has an average roughness (Ra): 0.3 μm.
Maximum and minimum hardness of "Vickers hardness measurement value under load of 1 kg or less carried out at 10 or more points at 0.3 to 1 mm pitch on the surface in an arbitrary direction on the surface" The difference in hardness is adjusted to be 10 or less, but this is only when the difference between the maximum hardness and the minimum hardness is 10 or less, and even an extremely slight irregular light-dark polishing pattern on the surface is generated. This is because it is stably suppressed and a polishing pattern is substantially not generated.

The conditions for measuring the surface hardness distribution are defined as above for the following reason. That is, when the surface roughness of the titanium material exceeds 0.3 μm in average roughness (Ra), the measurement error increases due to the influence of the roughness, and the pitch of the measurement points is 0.3 mm.
If it is less than 1, the indentations during Vickers hardness measurement may overlap with each other or the indentations may be too close to each other, resulting in work hardening, resulting in inaccurate measurement. On the other hand, the pitch of measurement points may exceed 1 mm, Alternatively, if the number of measurement points (measurement positions) is less than 10, the probability of avoiding the hard “aggregate of crystal grains” is increased, and accurate measurement cannot be performed. In addition, if the measured load exceeds 1 kg, the indentation will become too large, and it will tend to result in the simultaneous measurement of the hard “grain aggregate” part and other parts. In this case as well, the hardness distribution can be accurately measured. Can not be.

By the way, the "titanium material according to the present invention having an extremely uniform hardness distribution" in which the difference between the maximum hardness and the minimum hardness determined by the above-mentioned hardness distribution measuring method is 10 or less is "from the casting of the ingot. During the process of manufacturing the plate-shaped or ring-shaped titanium material, the β transformation point (depending on the existence and type of the additional element, usually 950 to 8 at a cooling rate of 1000 ° C / h or more)
(50 ° C.) is ensured and a treatment (processing or heat treatment) after the cooling step is carried out in a temperature range below the β transformation point. ”

For example, an intermediate material formed into a slab or a perforated material by forging from an ingot is heated to a β transformation point or higher and then water-cooled, and thereafter, plate rolling or annular rolling and heat treatment in an α temperature range lower than the β transformation point. The step of producing a plate-shaped or ring-shaped titanium material by the above method can be recommended as a specific method that satisfies the above conditions and can be adopted in actual production.

Here, all the reasons why a plate-shaped or ring-shaped titanium material having a uniform hardness distribution on the surface can be obtained by a manufacturing process satisfying the above-mentioned conditions are not fully clear, but it is considered to be the largest reason. Is a martensitic transformation of titanium when the cooling rate when passing through the β transformation point is 1000 ° C / h or more, and the crystal orientation is randomized accordingly, and the above-mentioned "hexagonal C-axis direction is the plate surface". It means that the formation of aggregates of crystal grains "oriented in the direction close to the perpendicular may be suppressed.

Next, the present invention will be described in more detail with reference to Examples and comparison with Comparative Examples.

【Example】

[Example 1] First, C: 0.01% or less (% representing a component ratio)
%), H: 0.001% or less, N: 0.01% or less, O: 0.03 to 0.07%, Fe: 0.02 to 0.05%, and the balance being substantially equivalent to JIS H4600 specified by JIS H4600. The relationship between the surface hardness distribution and the surface irregular polishing pattern was investigated for a pure titanium plate (plate thickness: 4.5 to 18 mm).

In this investigation, the "inventive titanium plate" and the "comparative titanium plate" which had undergone the following manufacturing steps were used as test materials. The titanium plate of the present invention: ingot → slab forging (heating at 1000 ° C) → 150
mm thick slab → 950 ℃ heating / water cooling → rolling (800 ℃ heating) → heat treatment (670 ℃ x 15 minutes hold), comparative titanium plate: ingot → slab forging (1000 ℃ heating) → 150
mm thick slab → rolling (heating at 800 ℃) → heat treatment (holding at 670 ℃ for 15 minutes).

That is, the titanium plate of the present invention was heated to 950 ° C. in the slab stage and then water-cooled (average cooling rate: 1100).
C./h) is heat-treated while the comparative titanium plate is not subjected to this treatment, and this is the only difference between the two manufacturing processes.

The hardness distribution is measured by cutting a 30 mm × 30 mm test piece from each titanium plate and finishing the surface by wet polishing to an average roughness (Ra) of about 0.2 μm.
A Vickers hardness tester with a load of 1 kg was used under the conditions of a measurement pitch of 0.5 mm and 20 measurement points, and the difference between the maximum value and the minimum value in the hardness distribution was obtained. Then, following this, the surface of each plate was polished by a PVA grindstone to an area of about 150 mm × 300 mm up to # 600, and then the presence or absence of an irregular polishing pattern was visually observed. Table 1 shows the results.

[0022]

[Table 1]

As is clear from Table 1, the comparative titanium plates (test numbers 5, 6, 7 and 8) in which the difference between the maximum value and the minimum value in the hardness distribution exceeds 10 have a visually irregular polishing pattern. On the other hand, in the titanium plate of the present invention having a difference of 10 or less (test numbers 1, 2, 3, 4), no irregular polishing pattern occurs at all.

Example 2 A test similar to that of Example 1 was conducted.
C: 0.01% or less, H: 0.002% or less, N: 0.01% or less,
O: 0.04 to 0.06%, Fe: 0.04 to 0.07%, Pd: 0.16 to 0.18
% Titanium alloy plate (plate thickness: 8 to 16 mm) specified in JIS H4605 with the balance being substantially Ti, and C: 0.
01% or less, H: 0.001% or less, N: 0.01% or less, O: 0.
10 to 0.12%, Fe: 0.07 to 0.09%, Mo: 0.26 to 0.30%, N
i: AST containing 0.70 to 0.80% and the balance being substantially Ti
It was carried out on a titanium alloy plate (plate thickness: 5 to 16 mm) equivalent to M. Gr.12. The manufacturing steps of the applied "titanium plate of the present invention" and "comparison titanium plate" are exactly the same as in the case of Example 1.

In this test, exactly the same conditions as in Example 1 were adopted except for the measurement of hardness distribution, but for the measurement of hardness distribution, the test piece was adjusted in the same manner as in Example 1. The load of the Vickers hardness tester was 500 g, and the measurement pitch was 1 mm and the number of measurement points was 15. Table 2 shows the difference between the maximum value and the minimum value in the hardness distribution measured in this manner and the result of the visual judgment for the presence or absence of the irregular polishing pattern.
Shown in

[0026]

[Table 2]

From the results shown in Table 2, the difference between the maximum value and the minimum value in the hardness distribution is 10 and the irregular polishing pattern is exceeded in the comparative examples (Test Nos. 13, 14, 15, 16) that exceed this value. Of the present invention (test number 9, 1)
It can be seen that the irregular polishing pattern does not occur in 0, 11, 12).

[Embodiment 3] Here, the wall thickness corresponding to one kind specified in JIS H4600 having the same composition as in Embodiment 1 is as follows:
The relationship between the surface hardness distribution and the surface irregular polishing pattern was investigated for 7.5 to 28 mm pure titanium annular rolled material.

In this investigation, the “annular rolled material of the present invention” and the “comparative titanium annular rolled material” which have undergone the following manufacturing processes were used as test materials. The titanium annular rolled material of the present invention: ingot → forging (heating at 1050 ° C) →
Perforated material (outer diameter: 580 mm, wall thickness: 95 mm) → heated at 950 ° C
Water-cooled → annular rolling (700 ℃ heating) → heat treatment (670 ℃ × 15 minutes hold), comparative titanium annular rolling material: ingot → forging (1050 ℃ heating) → perforated material (outer diameter: 580mm, wall thickness: 95mm) → Annular rolling (700 ℃
Heating) → heat treatment (670 ℃ x 15 minutes hold).

That is, in the titanium annular rolled material of the present invention, the perforated material (outer diameter: 580 mm, wall thickness: 95 mm) forged from the ingot was heated to 950 ° C. and then water-cooled (average cooling rate: 1500 ° C.). While the heat treatment of / h) is carried out, this treatment is not applied to the comparative titanium annular rolled material, and this is the only difference between the manufacturing processes.

The hardness distribution was measured by cutting out a 30 mm × 30 mm test piece from each titanium annular rolled material, and the measuring method was exactly the same as in Example 1. Then, subsequently, similarly to the case of Example 1, the surface of each titanium annular rolled material was polished up to # 600 with a PVA grindstone by an area of about 150 mm × 300 mm, and then visually observed for the presence or absence of an irregular polishing pattern. did. Table 3 shows the results.

[0032]

[Table 3]

From the results shown in Table 3, as with the strip rolled material, the rolled rolled material has a difference in hardness distribution between the maximum value and the minimum value of more than 10, which is a comparative titanium annular rolled material (test numbers 21, 22,
23, 24) an irregular polished pattern is generated, whereas the difference between the present invention is 10 or less.
It can be seen that the polishing pattern does not occur in 9, 20, 21, 22).

[0034]

[Summary of Effects] As described above, according to the present invention, electrodeposition for the production of extremely high-quality electrodeposited foils in which even a very slight visual irregular polishing pattern does not occur even if surface polishing is performed. Industrially useful effects such as stable and reliable supply of titanium material for drums can be achieved.

Claims (1)

[Claims] 1. When the surface has a thickness of 4 to 30 mm and the surface is polished to an average roughness (Ra) of 0.3 μm or less, “a position of 10 points or more at 0.3 to 1 mm pitch in an arbitrary direction of the surface” Of the Vickers hardness measurement value under a load of 1 kg or less, the difference between the maximum hardness and the minimum hardness being 10 or less, Titanium material for electrodeposition drums.