CN101789314A - Aluminum foil for low-voltage electrolytic capacitor anode and production method thereof - Google Patents

Abstract

The invention relates to an aluminum foil and a production method thereof, in particular to an aluminum foil for producing a low-voltage electrolytic capacitor anode by adopting a casting and rolling method, which belongs to the technical field of production of aluminum plates, bands and foils. By controlling the purity of Al and the contents of Cu, Fe, Si, Mg, Zn, Ga, Mn, Ce, B, Ti, Zr and V, excessive dissolution cannot be generated, etch pits are uniformly formed at high density and the surface expanding rate is increased, thereby the corrosive electrostatic capacity is increased; cold rolling plates with uniform components and uniform organization structure can be directly provided by adopting a casting and rolling method; component homogenizing and soaking treatments which are essential before the conventional hot rolling method are omitted, thereby shortening production procedures, reducing the energy consumption and improving the finished product rate; and the aluminum foil not only can meet the performance requirements of the low-voltage electrolytic capacitor anode, but also can save energy sources for subsequent corrosive processing.

Description

Aluminum foil for low-voltage electrolytic capacitor anode and production method thereof

 

Technical field

The invention belongs to metallurgical technology, belong to the production technology category of aluminium sheet, band, paper tinsel, particularly the manufacturing of aluminum foil for low-voltage electrolytic capacitor anode.

Background technology

Along with the development of electronic industrial technology, the miniaturization of the expansion of application, particularly complete machine has proposed new requirement to the static capacity and the manufacturing cost of wherein secondary capacitor, for example requires its static capacity big, and with low cost.Satisfying the demand side of this respect, the aluminum foil for capacitor anode material plays leading role.Nowadays, the common semicontinuous ingot casting that adopts, gradually ripe through the aluminium foil that homogenizing annealing, hot rolling, technology cold rolling, that paper tinsel rolls are made high specific capacitance, but because operation is many, energy consumption is big, efficient is low and rate of finished products is low, and can not satisfy the requirement of electrolytic capacitor miniaturization fully.For example described in 2008 disclosed patent application 200710142166.7 on April 16, " aluminium foil for electrode of electrolytic capacitor ", carry out the molten system of aluminium alloy earlier and make ingot casting, homogenize with heating furnace then and handle and the evenly heating processing, carry out hot rolling then, carry out intermediate annealing in addition when cold rolling, last paper tinsel rolls into type.When adopting similar hot rolling technology, because ingot casting cooled and solidified time in casting mold is long, there is more large dendritic crystal in the ingot casting, and component segregation, this not only made before hot rolling ingot casting homogenized and is treated as an inevitable operation, increased energy consumption, and made compositional modulation difficulty more.

Summary of the invention

The present invention seeks to by a kind of material of producing aluminum foil for low-voltage electrolytic capacitor anode that is exclusively used in is provided, and adopt casting-rolling method to produce, realized that operation is few, energy consumption is low, the aluminium loss is few, the effect that lumber recovery is high, and the gained aluminium foil has higher ratio electric capacity than hot rolling method.

Product of the present invention in chemical composition in chemical composition, Al purity 〉=99.99%, Cu:7-57ppm, Fe:5-55ppm, Si:5-55ppm, Zn:1-40ppm, Mg:0.5-40ppm, Ga:0.5-40ppm, Mn:0.5-12ppm, Ce:0.5-12ppm, B :≤1.5ppm, Ti :≤1.5ppm, Zr :≤1.5ppm, V :≤1.5ppm, and unavoidable impurities; Further preferred: in chemical composition, Al: Cu:26-33ppm, Fe:16-25ppm, Si:19-27ppm, Zn:2-8ppm, Mg:15-35ppm, Ga:1-20ppm, Mn:1-10ppm, Ce:1-10ppm, B :≤1.5ppm, Ti :≤1.5ppm, Zr :≤1.5ppm, V :≤1.5ppm 〉=99.99%,, and unavoidable impurities;

Aluminum foil for low-voltage electrolytic capacitor anode with said components, make by the casting-rolling method that comprises the following steps:

1) aluminium alloy melting is prepared: with high-purity aluminium ingot fusing, add and adjust alloying element content, slagging-off, degasification, detect and control aluminium water elemental constituent, and in the control aluminium water air content below 0.12 milliliter/100 gram aluminium water;

2) aluminium alloy melting of preparing is filtered;

3) will be directly inputted in the casting and rolling machine through the aluminium alloy melting of filtering, and the coiled sheet of the thickness of casting one-tenth between the 8-9.5 millimeter, and be cooled to normal temperature;

4) the casting coiled sheet is cold-rolled to thickness between the 4.0-5.0 millimeter;

5) homogenizing annealing between 450-570 ℃ temperature retention time 18-26 hour, is cooled to normal temperature then;

6) the casting plate is cold-rolled to a predetermined thickness, this thickness is that further paper tinsel rolls the reduction ratio of reserving 18-30%; By controlled rolling speed, the aluminium sheet temperature is controlled at below 75 ℃;

7) continue paper tinsel and be rolled to predetermined aluminum foil thickness; Roll speed by the control paper tinsel, the aluminium sheet temperature is controlled at below 75 ℃.

Advantage of the present invention is, by in aluminium, adding various coherent elements and adopting casting-rolling method, can directly provide composition the even and uniform cold rolled sheet of institutional framework, necessary homogenization of composition and evenly heating handled before having saved conventional hot-rolling method, thereby production process is shortened, and energy consumption reduces, and has improved lumber recovery, prepared aluminium foil not only can satisfy the performance requirement of low-voltage electrolytic capacitor anode, can also process energy savings for subsequent corrosion.

Description of drawings

Fig. 1 is the process flow diagram of casting-rolling method of the present invention.

Embodiment

Below in conjunction with accompanying drawing feature of the present invention and correlated characteristic thereof are described further:

To make thickness is 0.12, and width is the aluminum foil for low-voltage electrolytic capacitor anode of 10mm

Al purity is 99.991% in chemical composition, Cu:27ppm, Fe:17ppm, Si:24ppm, Mg:17ppm, Zn:4ppm, Ga:6ppm, Mn:4ppm, Ce:3ppm, B:0.8ppm, Ti:0.6ppm, Zr:0.5ppm, V:0.9ppm.

As shown in Figure 1, with high-purity aluminium ingot heating and melting, add alloying element, adjust elemental composition, concise then, put only, slagging-off, degasification, make al alloy component in the target component scope of setting, the air content in the aluminium water restrains under the aluminium water the qualified aluminium alloy melting of promptly concise one-tenth 0.12 milliliter/100;

After then prepared qualified aluminium alloy melting being filtered through filter, directly deliver to the coiled sheet that rolls into the thickness of thickness between the 8-9.5 millimeter in the casting and rolling machine, for example 8.5 millimeters thick;

Be cooled to be further cold rolled to thickness between the 4-5 millimeter behind the normal temperature, for example 4.5 millimeters, to advance stove then and carry out homogenizing annealing, annealing temperature is between 450-570 ℃, and temperature retention time was at 18-26 hour; For example annealing temperature is set in 540 ℃, and temperature retention time is set at 20 hours; Be cooled to normal temperature then;

Then the casting plate is cold-rolled to a predetermined thickness, this thickness is that further paper tinsel rolls the reduction ratio of reserving 18-30%; By controlled rolling speed, the aluminium sheet temperature is controlled at below 75 ℃ for example 70 ℃;

Continue paper tinsel and be rolled to predetermined aluminum foil thickness, the thickness that makes paper tinsel is within the deviation range of design; Roll speed by the control paper tinsel, the aluminium sheet temperature is controlled at below 75 ℃ for example 70 ℃;

With the finished product paper tinsel of gained, grab sample after the corrosion and the processing of energizing, detects the characteristic of gained aluminium foil with its method than electric capacity of measurement.After the aluminium foil corrosion of this component energized, the ratio electric capacity during actual measurement 25V was 79 μ F/cm ²

The following describes the reason that composition limits in the aluminium foil for electrode of electrolytic capacitor of the present invention:

Cu：7ppm-57ppm

Cu exists with solid solution condition in aluminium, improves the spot corrosion of aluminum foil material, makes the etch uniformity of main body improve, and the effect that improves the strength of materials is arranged in addition.But when if content is lower than 7ppm, then above-mentioned effect is insufficient; And content produced dissolving, uneven distribution when surpassing 100ppm, and can bring the problems such as reprocessing of fail safe hidden danger such as capacitor short-circuit and corrosive liquid; Based on same reason, preferred Cu content range is at 7-57ppm.

Fe：5ppm-55ppm

Fe has the effect of the precipitate that forms the etching starting point for to contain element indispensably in aluminium.If content is less than 5ppm, then can not play one's part to the full; Owing to high-purityization, cost increases in addition.On the other hand, if content surpasses 55ppm, when final annealing, can produce excessive Al-Fe is precipitate, will produce dissolving when corrosion, causes the pit skewness that produces, thereby makes the static capacity reduction.Based on same reason, preferred Fe content range is at 5-55ppm.

Si：5ppm-55ppm

It is precipitate that Si can form Al-Fe-Ni-Si with Fe, Ni, Al, purifies the rafifinal matrix, increases the ratio of (100)＜001〉texture, has the effect of the overgrowth of crystals when preventing recrystallization again.If content is less than 5ppm, then the absolute magnitude of Si is few, can not bring into play above-mentioned effect; If when surpassing 55ppm, then produce excessive separating out, the pit skewness of generation caused dissolving during corrosion, and static capacity is reduced.Based on same reason, preferred Si content range is at 5-55ppm;

Zn：1ppm-40ppm

Zn exists with solid solution condition in Al, has the main body of making current potential and reduces, and increase is precipitate and Al-(Fe, Ni with Al-Fe) be the effect of the potential difference of precipitate, make the easier and surperficial etching of corrosion more even.If content then lacks this effect less than 1ppm, surface dissolution increases when surpassing 40ppm.Based on same reason, preferred Zn content range is between 1-40ppm;

Ga：0.5ppm-40ppm

Identical with the effect of Zn element, in Al, exist with solid solution condition, having the main body of making current potential reduces, increase is precipitate and Al-(Fe, Ni with Al-Fe) be the effect of the potential difference of precipitate, make the easier and surperficial etching of corrosion more even, by using Ga, can reduce the use amount of Zn simultaneously, reduce total impurities.If content then lacks this effect less than 0.5ppm, surface dissolution increases when surpassing 40ppm; Based on same reason, preferred Ga content range is at 0.5-40ppm;

Mg：0.5ppm-40ppm

Identical with the effect of Ga element, can make surface etching more even.If content less than 0.5ppm, then lacks effect, surpass 40ppm, can cause dissolving; Based on same reason, preferred Mg content range is at 0.5-40ppm;

Mn：0.5ppm-12ppm

Identical with the effect of Ga element, can make surface etching more even.If content less than 0.5ppm, then lacks effect, surpass 12ppm, can cause dissolving; Based on same reason, preferred Mn content range is at 0.5-12ppm;

Ce：0.5ppm-12ppm

Identical with the effect of Ga element, can make surface etching more even.If content less than 0.5ppm, then lacks effect, surpass 12ppm, can cause dissolving; Based on same reason, preferred Mn content range is at 0.5-12ppm.

And use B, Ti, Zr and V in alloy, all to have the effect that improves pit corrosion density on a small quantity.If content surpasses 1ppm, then exist to produce mutual chemical combination, concentration of local produces the risk of pit; Therefore the content with these elements all is limited in below the 1ppm.

According to the component and the casting-rolling method of aluminum foil for low-voltage electrolytic capacitor anode material provided by the invention, not only operation is simple, and energy consumption is low, and lumber recovery has by a relatively large margin manufacturing cost and reduces above 85%.

Claims (3)

1. A kind of aluminum foil for low-voltage electrolytic capacitor anode, it is characterized in that, in chemical composition, Al purity 〉=99.99%, Cu:7-57ppm, Fe:5-55ppm, Si:5-55ppm, Zn:1-40ppm, Mg:0.5-40ppm, Ga:0.5-40ppm, Mn:0.5-12ppm, Ce:0.5-12ppm, B :≤1.5ppm, Ti :≤1.5ppm, Zr :≤1.5ppm, V :≤1.5ppm, and unavoidable impurities.

2. Aluminum foil for low-voltage electrolytic capacitor anode according to claim 1, it is characterized in that, in chemical composition, Al: Cu:26-33ppm, Fe:16-25ppm, Si:19-27ppm, Zn:2-8ppm, Mg:15-35ppm, Ga:1-20ppm, Mn:1-10ppm, Ce:1-10ppm, B :≤1.5ppm, Ti :≤1.5ppm, Zr :≤1.5ppm, V :≤1.5ppm 〉=99.99%,, and unavoidable impurities.

3. The production method of aluminum foil for low-voltage electrolytic capacitor anode according to claim 1 and 2 is characterized in that, by comprising the following steps:

1) aluminium alloy melting is prepared: with high-purity aluminium ingot fusing, add and adjust alloying element content, slagging-off, degasification, detect and control aluminium water elemental constituent, and in the control aluminium water air content below 0.12 milliliter/100 gram aluminium water;

2) aluminium alloy melting of preparing is filtered;

3) will be directly inputted in the casting and rolling machine through the aluminium alloy melting of filtering, and the coiled sheet of the thickness of casting one-tenth between the 8--9.5 millimeter, and be cooled to normal temperature;

4) the casting coiled sheet is cold-rolled to thickness between the 4.0--5.0 millimeter;

5) homogenizing annealing between 450--570 ℃ temperature retention time 18--26 hour, is cooled to normal temperature then;

6) the casting plate is cold-rolled to a predetermined thickness, this thickness is that further paper tinsel rolls the reduction ratio of reserving 18--30%; By controlled rolling speed, the aluminium sheet temperature is controlled at below 75 ℃;

7) continue paper tinsel and be rolled to predetermined aluminum foil thickness; Roll speed by the control paper tinsel, the aluminium sheet temperature is controlled at below 75 ℃.

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