JPH069980A - Aluminum plate for forming and lubricant used in forming aluminum - Google Patents

Abstract

PURPOSE:To obtain the title plate excellent in formability without the occurrence of defects, such as galling of a press and cracks, and excellent in the case of degreasing after forming without causing nonuniformity in coating by providing a specified solid lubricant film on an aluminum base plate. CONSTITUTION:The plate consists of an aluminum base plate and a mixture of a water-soluble high molecular resin (e.g. PVA) with at least 20wt.% emulsion of at least one lubricant selected from among a wax, an oil, a fat, a fatty acid, an ester, an alcohol and a metallic soap (e.g. a wax). The mixture is applied to the surface of the aluminum base plate and dried to thereby provide a solid lubricant film of a coating weight of 0.2-2.0g/m<2> thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum sheet material suitable as a material for producing automobile parts and the like formed by a pressing process and an aluminum forming lubricant used for producing the aluminum sheet material, and particularly, at the time of pressing. The present invention relates to an aluminum plate material for molding and a lubricant for aluminum molding, which are excellent in moldability and excellent in degreasing property after molding, and can obtain a good coated surface.

[0002]

2. Description of the Related Art Recently, the use of aluminum sheet materials is gradually increasing in order to reduce the weight of automobiles. However, since aluminum sheets are inferior in formability to steel sheets, yield loss due to cracking during forming and There are major problems such as the limitation of shape in design.

Further, since a conventional press line for a steel plate is also used for forming an aluminum plate, the lubricating oil or the like used in this press line is not always suitable for aluminum, and the press line is not suitable. It is disadvantageous in processing.

For this reason, it has been attempted to apply a solid lubricant to the surface of an aluminum plate in advance to improve press formability.

The types of solid lubricants can be broadly classified by composition and diluent as follows. That is, the composition includes a polymer resin type and a wax or fat type. Diluents include organic solvents and water. Each of these types has its own advantages and is used depending on the application. Resin systems generally have poor moldability, but they have excellent degreasing properties after molding. On the other hand, the wax or oil-based composition has excellent moldability, but the degreasing property after molding is poor. Further, when the diluent is an organic solvent type, it tends to be easily dried, but there is a sanitary problem, and in that respect, a water-soluble (emulsifier) is preferable.

[0006]

However, these conventional lubricants have a drawback that the formability of the aluminum plate is not sufficient. That is, it is impossible to sufficiently prevent the generation of defective products during the molding of the aluminum plate. For this reason, cracking, galling, and the like occur during molding, and restrictions on the shape of automobile parts have not been resolved.

Further, the conventional lubricant has a drawback that the degreasing property after molding is poor. For this reason, the lubricant cannot be completely removed in the degreasing step after press molding, resulting in unevenness during coating.

The present invention has been made in view of the above problems, and has improved press formability, can prevent press defects such as cracking and galling, has less restrictions on the formable shape, and is excellent in degreasing property. Another object of the present invention is to provide an aluminum plate material for forming and a lubricant for forming aluminum.

[0009]

The aluminum plate for molding according to the present invention is selected from the group consisting of an aluminum base plate, a water-soluble polymer resin, wax, fats and oils, fatty acids, esters, alcohols and metal soaps. It is composed of a mixture of 20% by weight or more of an emulsion of at least one lubricant, and is applied to the surface of the aluminum base plate and then dried to 0.2 to 2.0 g / m ²
And a solid lubricant film attached in an amount of.

The aluminum molding lubricant according to the present invention is applied to the surface of an aluminum plate, dried and solidified to obtain 0.2 to 2.0 g of the surface of the aluminum plate.
In the aluminum molding lubricant used as a coating film in an amount of / m ² , water-soluble polymer resin, wax, oil and fat,
It is characterized by comprising a mixture of 20% by weight or more of an emulsion of at least one lubricant selected from the group consisting of fatty acids, esters, alcohols and metal soaps.

[0011]

In the present invention, as the solid lubricant, a mixture of a water-soluble polymer resin and an emulsion of the following lubricant is used. Wax with excellent moldability, fatty acids (oleic acid, stearic acid, etc.), metallic soap (stearic acid C
a, Zn stearate, etc.), ester (butyl stearate, etc.), alcohol, etc. emulsified in water using a surfactant can be applied and dried to improve moldability. The lubricant has a large adsorption force with respect to the metal and may not be removed in the degreasing step after molding.

By mixing a water-soluble polymer lubricating resin such as polyvinyl alcohol, cellulose or the like with the above emulsion and applying it, a resin and the above lubricant which are uniformly dispersed are coated at the time of drying. During degreasing (generally alkali), the resin preferentially dissolves, destroys the film, and is completely removed.

The mixing ratio is controlled within the range of 20-80%. Although related to the types of the resin and the lubricant, both the water-soluble polymer resin and the lubricant emulsion contain 20% or more. That is, in both cases, the characteristics of both can be utilized by mixing within the range of 20 to 80%. If the content of each component is less than 20%, the above-mentioned effects cannot be obtained.

The coating amount is 0.2-2 g / m ² . When the amount of the coating film is less than 0.2 g / m ² , peeling of the coating film occurs during press working, which may cause galling during molding.
If it exceeds ² g / m ² , it is advantageous in moldability, but even if the proportion of the water-soluble resin is increased, the coating film may remain during degreasing.

As described above, the aluminum sheet material having the lubricant film formed thereon is press-formed in a steel sheet line as in the manufacturing process of automobile parts, and even if a rust preventive lubricating oil for a steel sheet is used, it cracks during forming. In addition, there is no occurrence of galling and the like, and good molding processing is possible.

[0016]

EXAMPLES Aluminum plates coated with various lubricants shown in Table 1 below were dried (50 ° C. × min) and adhered, and the formability and degreasing property were evaluated by the following tests. However, in Table 1, PVA means polyvinyl alcohol. The film thickness was adjusted with a bar coder.

The aluminum test material is an Al-4.5% by weight Mg alloy plate having a thickness of 1.0 mm, which has been subjected to JIS T4 tempering.

The formability was evaluated by a square tube drawing test. In this test, after applying a rust-preventive lubricant that is generally used for steel plate press forming on a solid lubricant, a drawing test is performed under the following conditions, and the formability is determined by the squeeze depth until cracking occurs. Was evaluated. The results are shown in Table 1 below. The obtained result is an average value of n = 3.

Test piece shape: thickness 1.0 mm, width 100 m
m, length 100 mm Conditions wrinkle holding force 39200N Punch 40 mm square (Corner R10) (Punch rp4.5 mm, die rd 3.0 mm) Punch speed 20 mm / min After applying the rust preventive lubricating oil used, a degreasing test was carried out under the following conditions, and the water wettability was evaluated by the area ratio of water wetness. That is, the degreasing liquid is a commercially available alkaline degreasing liquid (PH11).
It was immersed in a material heated to 40 ° C. for 2 minutes and then washed with water for 2 minutes. The results are shown in Table 1 below. This is also the average value of n = 3.

[0020]

[Table 1]

[0021]

The following effects can be obtained by applying the solid lubricant of the present invention to a forming aluminum plate.

The formability of the aluminum plate can be improved, and defects such as galling and cracking of the press can be prevented. Therefore, it becomes possible to mold a shape that could not be conventionally molded, and the aluminum plate material can be applied to an automobile part having a complicated shape, and the applicable range is expanded.

The excellent degreasing property improves the quality of the coated surface of the product.

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Claims (2)

[Claims] 1. An aluminum base plate and a water-soluble polymer resin, and at least one selected from the group consisting of waxes, fats and oils, fatty acids, esters, alcohols and metal soaps.
It is composed of a mixture of 20% by weight or more of an emulsion of one kind of lubricant, and is applied in an amount of 0.2 to 2.0 g / m ² by applying it to the surface of the aluminum base plate and then drying it. An aluminum plate material for molding which has a solid lubricant film. ^2. A lubricant for forming aluminum, which is applied to the surface of an aluminum plate, dried and solidified to form a coating film on the surface of the aluminum plate in an amount of 0.2 to 2.0 g / m ² , and 20% by weight or more of a mixture of a water-soluble polymer resin and an emulsion of at least one lubricant selected from the group consisting of waxes, oils and fats, fatty acids, esters, alcohols and metal soaps. Lubricant for aluminum molding.