JPH0341536B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an aluminum alloy for copy drums, and more particularly to a rolled annealed aluminum alloy plate suitable for forming copy drums by DI processing. (Prior art) Copy drums are used as drums in dry copying machines, facsimile machines, etc. In recent years, there have been remarkable advances in photoreceptors for copying machines, and at the same time, the performance of the copy drum base has improved in roundness and straightness. Requirements for dimensional accuracy, surface quality, etc., are also becoming stricter. Aluminum alloys with excellent workability have conventionally been used as the copy drum material, and have been manufactured by cutting pipes by extrusion, drawing, etc. However, this type of processing has the drawbacks of low productivity and poor performance. Therefore, in recent years, 1070, 1050, 1100, etc.
Pure aluminum is used. (Problem to be Solved by the Invention) Recently, however, attempts have been made to further reduce the drum side wall thickness in order to reduce costs. It was found that the system had drawbacks such as low strength, insufficient rigidity, and difficulty achieving dimensional accuracy. Therefore, alloying elements were added.
There have been proposals to apply aluminum alloys such as 3004 (Al-Mn system) (for example,
(See No. 40411). However, especially when machining the rotating shaft part (hereinafter referred to as "boss") on the bottom of the drum, the 3004 alloy that has been proposed has high strength and is too hard to work. There is a problem in that it is difficult to form the boss-processed part. The present invention has been made to solve the problems of the prior art described above, and by performing DI processing on a rolled plate with good productivity, it has excellent shape and surface quality, and furthermore, the boss part can be formed. The object of the present invention is to provide an aluminum alloy rolled plate for manufacturing a thin-walled, high-strength copy drum. (Means for Solving the Problems) In order to achieve the above object, the present inventor conducted intensive research in view of the above-mentioned problems, and as a result of repeated consideration, developed an aluminum alloy plate that does not cause problems even when thinned. was developed. That is, in the present invention, Fe: 0.2 to 1.0%, Mn:
Contains 0.30-0.7% and Mg: 0.20-0.7%, and
An aluminum alloy that satisfies the relationship of Fe + (Mn x 1.07) + (Mg x 0.27) ≦ 1.3%, and the remainder is substantially Al, and the size of the intermetallic compound seen from the rolled plate surface is 25 μm or less, The area occupancy rate of intermetallic compounds with a particle size of 5 to 25 μm is 0.1 to 2%,
Furthermore, the average width of crystal grains seen from the surface of the rolled plate is 70 μm.
The gist of the present invention is an aluminum alloy rolled annealed plate for copy drums formed by DI processing, which is characterized by the following characteristics. The present invention will be explained in more detail below. The reasons for limiting the chemical components in the present invention are as follows. Fe forms an intermetallic compound of (Fe/Mn)Al ₆ together with Mn, and is an element necessary to prevent seizure of the die during ironing.
It has the effect of promoting 45° selvage and reducing the anisotropy of soft materials that tend to generate 0-90° selvage. It is also effective in refining crystal grains and preventing flow marks. However, if the Fe content is less than 0.2%, this effect will be small, and if it is more than 1.0%, it will be easier to form giant compounds, which will reduce moldability and impair the electrical properties of the copy drum. The image quality will deteriorate. Therefore, the amount of Fe is set in the range of 0.2 to 1.0%. Mg is an essential element for reducing thickness and weight by increasing strength. However, if it is less than 0.2%, the effect will be small, and if it is added in excess of 0.7%, moldability such as ironing and stretching will be reduced, and scoring will occur more easily. In particular, work hardening increases, making it difficult to form the boss portion. Therefore, the amount of Mg is 0.2-0.7%
The range shall be . Mn is an important element that provides strength together with Mg, and also coexists with Fe to form MnAl ₆ , (Fe・Mn)
It forms intermetallic compounds such as Al ₆ and has the effect of preventing scoring. Furthermore, when Mn is contained at the same time as Mn, it has the effect of stabilizing the texture during recrystallization after heat treatment and stabilizing the deep drawing edges.
However, such effects cannot be expected when the Mn content is less than 0.3%, and when the Mn content increases, both the amount and size of crystallized substances increase, and when the Mn content exceeds 0.7%, the ironing workability is reduced. , the machinability of the boss portion is reduced and at the same time the electrical characteristics of the copy drum are impaired. Therefore, Mn should be in the range of 0.3 to 0.7%. However, it is important that the amounts of Fe, Mn, and Mg satisfy a specific relationship within the above range, and Fe + (Mn x 1.07) + (Mg x 0.27) ≦ 1.3%.
It is necessary to satisfy the following relationship. The reason is as follows. In other words, intermetallic compounds are broadly divided into crystallized substances and precipitates. Crystallized substances are generated during solidification during casting, and precipitates are those that become supersaturated during casting and are formed in the solid during subsequent heat treatment. and
The size of the precipitate is usually 1 μm or less, and because of its small size, it poses no particular problem as a stress concentration source or electrical properties. Further classification of crystallized substances can be divided into primary crystal compounds, which are formed in the liquid just before solidification, and eutectic compounds, which are formed during solidification.
In particular, primary crystal compounds tend to grow into giant compounds, and in industrial casting, molten metal may stagnate.
In practice, the passing time of the formation temperature has a large influence on growth, but as long as the above formula is satisfied, the generation of giant compounds can be prevented, improving moldability and electrical properties as a copy drum. It is possible to improve this. Therefore, Fe+
The amount of (Mn x 1.07) + (Mg x 0.27) shall be 1.3% or less. Note that the above aluminum alloy may contain impurities, but the amount of impurities is allowed within a limit that does not impair the effects of the present invention. For example, containing Si in an amount of Si≦0.3% is effective in improving strength and drawability. Cu
Also, it is permissible to contain Cu≦0.3wt%, which is effective in improving strength and does not impair corrosion resistance. The addition of Ti and B is effective in refining the casting structure and improving formability, and if Ti < 0.2% and B < 0.1%, there will be no formation of giant intermetallic compounds, and it is acceptable like Si and Cu. be done. Next, the reason for limiting the metal structure in the present invention will be explained. Copy drums are required not only to have dimensional accuracy in appearance and surface flatness, but also to have a fine and uniform microstructure on the drum surface. In other words, the presence of intermetallic compounds with a size exceeding 25 μm as seen from the surface of the rolled plate, or the presence of intermetallic compounds with a particle size of 5 to 5 μm.
Even for intermetallic compounds in the 25 μm range, the area ratio is 2.
In materials with a non-uniform structure, where more than 20% of intermetallic compounds are present, the electrical properties differ between areas with more and less intermetallic compounds, which can cause uneven shading in images. be. In addition, if the area ratio is less than 0.1%, ironing workability will decrease. Therefore, it is necessary that the intermetallic compounds having a particle size of 25 μm or less be uniformly distributed and that the area ratio of the intermetallic compounds having a particle size of 5 to 25 μm be 0.1 to 2%. Furthermore, in order to suppress the occurrence of rough skin and wrinkles due to DI processing, it is necessary that the average width of crystal grains as viewed from the surface of the rolled plate is 70 μm or less. Note that the metallographic structure differs not only depending on the chemical composition but also on manufacturing conditions such as cooling speed during casting, soaking conditions, hot rolling conditions, and rolling reduction rate (hot rolling + cold rolling). In order to achieve the purpose, it is necessary to deliberately stipulate it strictly. Furthermore, the rolled annealed aluminum alloy plate of the present invention is a finish annealed material that is annealed after cold rolling, and the annealing conditions are industrially batch annealing (slow heating slow cooling annealing) at 40°C/ At a heating and cooling rate of about hr
Heat annealing at about 370 to 380°C is preferred. Next, examples of the present invention will be shown. (Example) An aluminum alloy plate having a thickness of 2.5 mm was manufactured by applying the manufacturing method under the conditions shown in Table 2 to an aluminum alloy having the chemical composition shown in Table 1.
The observation results of the metal structure were as shown in Table 3. The obtained aluminum alloy plate is 60mm in diameter and length
A copy drum was manufactured by DI processing to 350 mm, and its characteristics were investigated. The results are shown in Table 4. Regarding the image quality, after DI molding, washing, and so-called OPC processing, it was installed in a dry type copying machine, copies were made, and the uniformity of the image quality was visually evaluated. As shown in Table 2, the materials of the present invention in which intermetallic compounds are finely and uniformly distributed and have small crystal grain sizes also have good DI formability and boss part formability, as shown in Table 4. The shape and surface quality after DI molding are also good. In addition, good formability means that the gap between the charging device/developing device of a dry copying machine and the copy drum is constant over the entire surface of the photosensitive layer, which increases the uniformity of the surface potential and amount of developer, resulting in a uniform This makes it possible to obtain high image quality. Thus, it can be seen that the material of the present invention is superior in all product properties as a high-strength, thin-walled material compared to the currently used 1100 material as well as the 3004 material.

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[Table] (Effects of the Invention) As detailed above, according to the present invention, it is possible to provide a thin-walled high-strength material for use in a copy drum that has excellent shapeability and surface quality and can be molded into a boss portion. is possible.

Claims (1)

[Claims] 1% by weight (the same applies hereinafter), Fe: 0.2-1.0%,
An aluminum alloy that contains Mn: 0.30 to 0.7%, Mg: 0.20 to 0.7%, and satisfies the relationship of Fe + (Mn x 1.07) + (Mg x 0.27) ≦ 1.3%, and the remainder is substantially Al. The size of the intermetallic compound viewed from the surface of the rolled plate is 25 μm or less, and the particle size is 5 to 25 μm.
The area occupation rate of the intermetallic compound of m is 0.1 to 2%, and the average width of the crystal grains as seen from the surface of the rolled plate is
An aluminum alloy rolled annealed plate for copy drums formed by DI processing characterized by a thickness of 70 μm or less.