JPH0756067B2 - Method for manufacturing aluminum foil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a method for producing an aluminum foil material which is excellent in economic efficiency without deteriorating foil rollability and pinhole characteristics.

[Conventional technology]

Generally, aluminum foil is different depending on the application, but the thickness is 5.
Many of 0-200 μm are used, and usually Cu0.04wt
% Or less (hereinafter wt% is simply abbreviated as%), Si 0.2% or less, Fe
JIS1070 alloy with 0.25% or less, Mn0.03% or less, Mg0.03% or less, Zn0.04% or less, Ti0.03% or less, Al99.7% or more, Cu0.1
JIS1N30 alloy of 0% or less, Si + Fe 0.7% or less, Mn 0.05% or less, Zn 0.05% or less, Al 99.3% or more, Cu 0.05 to 0.20%, Si
JIS3003 alloy with 0.6% or less, Fe 0.7% or less, Mn 1.0 to 1.5%, Zn 0.10% or less, and balance Al is used. These are produced by homogenizing the ingot, hot rolling, and then cold rolling and foil baking. However, if the foil thickness is 25 μm or less, the occurrence of pinholes cannot be avoided and there is a drawback that the moisture permeability (air permeability) increases, which is a serious problem depending on the application. The work hardening properties of foil materials are closely related to the rollability and quality of the foil, and an appropriately large work hardening speed increases the rolling speed of the foil and contributes to improved productivity. If it is too large, not only the thickness cannot be reduced to a predetermined thickness, the number of passes increases, but also problems such as rolling cuts and the number of pinholes increase. Therefore, a material for foil with appropriate work hardening characteristics is required, but one method to adjust this work hardening characteristic is to dissolve solid solution Fe, Si in the foil material into the intermetallic material such as crystallized substances and precipitates. There is a method of reducing work hardening by using a compound. This solid solution Fe, Si
In order to deposit, the foil is baked.

Recently, a method for producing an aluminum foil material having less rolling hardening and excellent foil rollability has been proposed in Japanese Patent Publication No. Sho 60-56786. This method is Fe0.1-0.8%, Ti0.003-0.08%, B0.01
% Or less, Si 0.2% or less, Cu 0.03% as impurities
Below is pure Al with Mn 0.008% or less and Mg 0.008% or less, and the ingot surface layer has a uniform granular crystal structure, and the dendrite arm spacing inside the ingot is 40 μm or more on average. A pure Al ingot is homogenized at 500-600 ℃, hot-rolled, cold-rolled at a working rate of 50% or more, then 280
It is a method of baking the foil at ~ 340 ℃, Fe and Si are crystallized as much as possible from the casting to reduce the amount of solid solution Fe and Si.
By further combining homogenization treatment and foil baking to precipitate solid solution Si as elemental Si, rolling hardening is reduced, and this reduction in rolling hardening makes the combination of rolling conditions slightly gradual. As a result, the number of pinholes can be reduced.

[Problems to be solved by the invention]

From an industrial point of view, not only quality but also economical efficiency and productivity are important in foil. However, in the conventional process, that is, in the process of performing hot rolling, cold rolling, and then foil tempering, and then cold rolling to a predetermined thickness, it is economical and economical to produce the foil. It is disadvantageous in terms of sex. This is because normally the foil is made into a soft material that can be easily rolled, and omitting the foil from the conventional manufacturing process makes the foil too hard and makes it difficult to roll the foil. Not only that, the number of pinholes and the number of rolling cuts are increased.

[Means for solving problems]

As a result of various studies in view of the above, the present invention has developed a method for producing an aluminum foil material having excellent economical efficiency and productivity, omitting the step of baking the foil material without deteriorating the foil rolling property and the pinhole property. Fe0.1-1.0%, Si0.3% or less, C
u0.10% or less as an essential component, Mn0.05% or less, Mg0.01%
Below, Ti is kept to 0.05% or less, or B0.01% or less, Z
Add one or two kinds within the range of r0.05% or less,
After homogenizing the ingot of the alloy consisting of the balance Al and ordinary impurities, hot rolling is performed at an end temperature of 250 ° C or higher, and then cooled at a cooling rate of 50 ° C / hr or lower to form a recrystallized structure. Then, after that, cold rolling is performed to a predetermined foil thickness without performing the foil base baking.

[Action]

The present invention adjusts the work hardening of the material by precipitating solid solution Fe and Si during hot rolling, and omits the subsequent annealing of the foil material to improve the economical efficiency and the productivity.

In the present invention, the end temperature of hot rolling is 250 ° C. or higher,
After hot rolling, by cooling at a cooling rate of 50 ° C / hr or less to form a recrystallized structure, solid solution Fe and Si in the material are sufficiently precipitated,
The work hardening of the material after that is reduced. As a result, the foil can be cold-rolled to a predetermined plate thickness without being subjected to the firing and the strength of the foil is slightly increased, but the rolling speed increases in the initial pass of the foil rolling and the productivity of the foil increases. Contribute to improvement. Further, in the subsequent foil rolling, the material does not work harden so much, so that there is no problem such as rolling cuts and an increase in the number of pinholes, and it is possible to carry out rolling with a predetermined number of passes.

The reason why the alloy structure is limited as described above in the present invention is as follows.

The Fe content is limited to 0.1 to 1.0% because Fe has a moderate increase in strength and refinement hardening of crystal grains, but if less than 0.1%, the hardening is small, and if it exceeds 1.0%, the corrosion resistance decreases. Is. The reason for limiting the Si content to 0.3% or less is that Si
Although the appropriate addition of Al contributes to the improvement of the strength and heat resistance of the material, if it exceeds 0.3%, it not only promotes the crystallization of Al-Fe-based coarse intermetallic compounds, but also precipitates as extremely hard simple substance Si. This is because it is easy to do. The reason for limiting the Cu content to 0.10% or less is that moderate addition of Cu contributes to the improvement of the strength and heat resistance of the foil, but if it exceeds 0.10%, the work hardening accompanying foil rolling becomes extremely large. This is because problems such as rolling cuts and an increase in the number of pinholes are likely to occur when a thin foil is used.

Mn and Mg are elements that increase the work hardening in rolling, and especially Mg has a large degree and needs to be suppressed to 0.01% or less. Although Mn is not as high as Mg, it is preferably suppressed to 0.05% or less. Ti is added usually in the form of Al-Ti or Al-TiB master alloys, in order to ensure the rolling of hot rolling the cast structure as a fine granular crystals, Al ₃ Ti and TiB in master alloys
Compounds such as ₂ are not preferable for a foil material that is rolled to a very thin thickness in terms of pinholes and the like, and it is necessary to suppress the content to 0.05% or less. B is generally added in the form of Al-Ti-B. This is to secure hot rolling property like Ti addition,
0.01% or less is sufficient, and addition of more than 0.01 adversely affects the pinhole characteristics. Similar to Ti and B, Zr is for refining the cast structure and improving the hot rolling property. For that purpose, 0.05% or less is sufficient, and addition of more than that adversely affects the pinhole characteristics. Incidentally, the present invention is various ingots used in the production of a general aluminum foil within the range of the alloy structure, for example, by forming feather crystals in the surface layer,
It can be applied to both ingots having 20% or more feather-like crystals and other ingots.

〔Example〕

Using an Al-based alloy having the composition shown in Table 1, an ingot was manufactured by semi-continuous casting and chamfered to a thickness of 400 mm. After homogenizing the ingot at 560 ° C. for 6 hours, a foil having a plate thickness of 0.45 mm was formed by the steps shown in Table 2.

Next, a foil having a plate thickness of 0.45 mm was rolled to a thickness of 7 μm to obtain a finished foil, and the work hardening during rolling was examined, and the number of rolling cuts and the number of pinholes were measured for the finished foil. Figure 1 shows the work hardening curve during rolling, and Table 3 shows the number of rolling cuts and the number of pinholes.

As is apparent from FIG. 1, the method N of the present invention N in which foil baking is omitted
In all of o.1 to 4, the degree of work hardening in the foil rolling is small, and the tensile strength in the thin foil region is the same as that of the comparative method No.5 to 6 in which the conventional foil baking is performed. It turns out that On the other hand, in the comparative methods Nos. 7 to 8 in which the rising temperature of hot rolling or the cooling rate thereafter is out of the range of the present invention and the tempering of the foil material is omitted, the degree of work hardening is large.

Further, as is clear from Table 3, the method No. 1 of the present invention in which the ingot with the increased proportion of feathery crystals is omitted from the method of the present invention, is the same with the ingot. The method of the present invention Nos. 2 to 4 showing the number of rolling cuts and the number of pinholes which are almost the same as those of the comparative method No. 5 performed, and omitting the refining of the foil using an ordinary ingot having a small proportion of feathery crystals. Shows the number of rolling breaks and the number of pinholes almost the same as Comparative Method No. 6 in which the foil ingot was refined using the same ingot, and according to the present invention, regardless of the proportion of feathery crystals. , It turns out that you can omit the foil baking. On the other hand, the hot rolling rising temperature or the subsequent cooling rate is out of the range of the present invention, and the comparative method No. 7-
In No. 8, the number of rolling cuts and the number of pinholes significantly increase.

〔The invention's effect〕

Thus, according to the present invention, in the production of the aluminum foil, without deteriorating the rollability and pinhole characteristics,
By omitting the foil baking, it is possible to improve economical efficiency and productivity, and to achieve a remarkable industrial effect.

[Brief description of drawings]

FIG. 1 shows a work hardening curve in rolling an aluminum foil.

Claims (1)

[Claims] 1. Fe 0.1 to 1.0 wt%, Si 0.3 wt% or less, Cu 0.10 w
t% or less as an essential component, Mn0.05wt% or less, Mg0.01wt%
Below, Ti is kept to 0.05 wt% or less, or one or two of them is added within the range of B0.01 wt% or less and Zr 0.05 wt% or less, and casting of an alloy consisting of the balance Al and ordinary impurities After the ingot is homogenized, hot rolling is performed at an end temperature of 250 ° C or higher, and then cooled at a cooling rate of 50 ° C / hr or lower to obtain a recrystallized structure, and then a predetermined annealing is not performed on the foil. A method for producing an aluminum foil, which comprises cold rolling to a foil thickness.