JPH02250936A - Aluminum alloy material for photosensitive drum and its manufacture - Google Patents

Abstract

PURPOSE:To improve the mirror-like finishing properties in the aluminum alloy material and to reduce its manufacturing cost by incorporating specified amounts of Mg, Mn and Si into an Al alloy and according regulating the content of Fe as impurities and the number of crystallized materials having >=15mu maximum diameter to specified value or below. CONSTITUTION:The Al alloy contains, by weight, one or more kinds among 0.1 to 1.5% Mg, 0.1 to 1.2% Mn and 0.05 to 0.5% Si and the balance Al with inevitable impurities, in which the content of Fe as impurities can be regulated to <=0.5% and the number of crystallized materials having >=15mu maximum diameter to <=10 pieces/mm<2>. For manufacturing the Al alloy, the molten metal of the Al alloy contg. the above components is refined and the molten metal is continuously cast at >=10 deg.C/sec solidifying rate. In the above Al alloy, since the number of crystallized materials having >=15mu maximum diameter is regulated to <=10 pieces/mm<2>, tears at the time of mirror-like finishing are prevented, mirror-like finishing properties are made excellent and its manufacturing cost is reduced compared to the case of using a high purity Al ground metal.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an aluminum alloy material for photosensitive drums having excellent mirror finish properties and a method for manufacturing the same.

[Prior Art] Conventionally, photosensitive drums used in electrostatic copying machines and the like have been manufactured by the method described below.

First, in order to obtain a photosensitive drum base, a large ingot made of aluminum or aluminum alloy is hot extruded into a pipe, and then this pipe is drawn and formed into a predetermined diameter. Another method is to extrude aluminum or an aluminum alloy material into a rod-shaped material of a predetermined diameter, and then process this rod-shaped material by impact forging to form a pipe of a predetermined diameter.

Next, the peripheral surface of this pipe is finished into a mirror surface by cutting or ironing with natural diamond.

Next, the pipe whose circumferential surface has been mirror-finished in this manner is used as a base for a photosensitive drum, and a photosensitive layer is uniformly applied to the circumferential surface of this base. As a result, the photosensitive drum is completed.

Incidentally, in order to improve the resolution of an electrostatic copying machine, it is necessary that the thickness of the coating film of the photosensitive layer be uniform. To achieve this, it is necessary to uniformly finish the circumferential surface of the base with a mirror finish, and therefore, it is an important issue to suppress the occurrence of peeling that impedes the uniformity of the mirror finish on the circumferential surface of the base. There is.

Peeling is a phenomenon in which crystallized substances generated in the base material separate from the base surface and pores are formed on the base surface. If there is a lot of peeling, the substrate cannot be sufficiently cleaned, and the photosensitive layer cannot be uniformly applied to the peripheral surface of the substrate after cleaning.

By the way, in order to prevent peeling, it is necessary to make the crystallized substances fine. For this purpose, for example, it is possible to increase the solidification rate of the ingot and suppress the growth of crystallized substances. However, the hot extrusion process is essential to the conventional manufacturing method of bases, and due to the limitations of this process, the diameter of the ingot must be 200 mm or more for mass production. There is.

In this case, the cooling rate of the ingot is about 5°C/sec at most,
Refinement of the crystallized material cannot be achieved at this level of cooling rate.

For this reason, in conventional substrates for photoreceptor drums, the purity of the base metal must be kept high in order to reduce the crystallized substances and suppress the occurrence of peeling.

[Problems to be Solved by the Invention] However, when a high-purity aluminum base metal is used, there is a problem in that the manufacturing cost of the photoreceptor drum increases significantly.

In addition, the conventional method for manufacturing a photoreceptor base involves impact forging using an extruded material of aluminum or aluminum alloy as a raw material, which requires many manufacturing steps, further increasing the manufacturing cost of the photoreceptor drum.

The present invention has been made in view of such problems, and includes:
An object of the present invention is to provide an aluminum alloy material for a photoreceptor drum that has excellent mirror finish and can reduce the manufacturing cost of the photoreceptor drum, and a method for manufacturing the same.

[Means for Solving the Problems] The aluminum alloy material for photoreceptor drums according to the present invention has 0
．． 1 to 1.5% by weight M g N 0 , 1 to 1
．． 2% by weight Mn and 0.05-0.5% by weight Si
Contains at least one element selected from the group consisting of, the remainder being Al and unavoidable impurities, and regulating the content of impurity element Fe to 0.5% by weight or less,
It is characterized in that the number of crystallized substances with a maximum diameter of 15 μm or more is regulated to 10 pieces/mm 2 or less.

The method for producing an aluminum alloy material for a photoreceptor drum according to the present invention includes the steps of melting a molten aluminum alloy containing the components according to claim 1, and solidifying the molten metal at a cooling rate of 10° C./sec or more. It is characterized by a continuous casting process.

[Function] Next, the reason for adding each component of the aluminum alloy material according to the present invention and the reason for limiting the composition will be explained.

L Mg is a stone element that provides strength to A) alloys.

If the Mg content is less than 0.1% by weight, the effect of improving strength cannot be obtained. Furthermore, when the Mg content exceeds 1.5% by weight, the forgeability of the A7 alloy is inhibited.

Therefore, the Mg content is set to 0.1 to 1.5% by weight.

M''-Mn is also an element that imparts strength to the A1 alloy, similar to Mg. If the Mn content is less than 0.1% by weight, no effect of improving strength can be expected. On the other hand, the Mn content is 1.2
If the content exceeds % by weight, the corrosion resistance of the A7 alloy will deteriorate. Therefore, the Mn content is set to 0.1 to 1.2% by weight.

Like the two elements mentioned above, Si also has the effect of improving the strength of the A1 alloy. If the Si content is less than 0.055% by weight, this strength-improving effect cannot be obtained, while if the Si content exceeds 0.5% by weight, the corrosion resistance of the A1 alloy will be inhibited. Therefore, the Si content ranges from 0.05 to 0.
The amount shall be 5% by weight.

t Fe, which is an impurity element, combines with A to form a coarse product. In the conventional photosensitive drum manufacturing method described above, if the Fe content exceeds 0.1% by weight, coarse crystallized substances are produced, causing problems such as peeling. However, according to the method of the present invention, by controlling the Fe content to 0.5% by weight or less, the formation of bulky products can be suppressed. For this reason, the content of Fe is regulated to 0.5% by weight or less.

Next, the reason for limiting the metal structure of the aluminum alloy material according to the present invention will be explained.

As a result of intensive studies by the inventors of the present application on the relationship between the incidence of peeling of the substrate and the size of crystallized substances, it was found that almost all of the crystallized substances with a maximum diameter of 15 μm or more existing on the circumferential surface are It was discovered that the material detaches from the surface and causes peeling defects.

And the surface density of crystallized substances of 15 μm or more is 10/-
It has been found that if it exceeds 100%, cleaning defects tend to occur when cleaning the substrate.

For this reason, the density of crystallized substances with a maximum diameter of 15 μm or more was reduced to 10
No more than 2 pieces/mm2.

In addition, in the method of the present invention, after melting an aluminum alloy having the above-mentioned components and the above-mentioned composition, this molten metal is
Cast at a solidification rate of 0°C/sec or higher.

As a result, the dendrite arm spacing (DAS; De
ndrlte Arm Spacing) is approximately 15 μm, and the diameter of the crystallized material is also 15 μm or less, resulting in good forgeability.

[Example] Next, examples of the present invention will be described.

As an example, aluminum alloys shown in Table 1 below were melted by a conventional method, and rod-shaped materials having a diameter of fi5m+l were continuously cast. This rod-shaped material has a smaller diameter than the aluminum material that is continuously cast for conventional photoreceptor drums.
The solidification rate was extremely fast at 20°C/sec. This rod-shaped material was cut into a predetermined length and processed into a drum shape by impact forging. Thereafter, the circumferential surface of this drum was cut with natural diamond to give it a mirror finish. Then,
The peripheral surface of this drum was washed with an organic solvent and then dried.

Further, as a comparative example, an aluminum alloy whose components are shown in Table 1 was melted. As Comparative Examples 1 and 2, ingots with a diameter of 250III+ were obtained from this molten metal. Next, this ingot is hot extruded to a diameter of GOm.
It was molded into a bar-shaped material of 500 m in diameter and cut into a predetermined length. Then,
This rod-shaped material was processed into a drum shape by impact forging, and then a mirror finish was applied to the peripheral surface.

Moreover, the alloy of Comparative Example 3 is a JIS 3003 Af alloy. Similar to Examples 1 to 5, this alloy was prepared with a diameter of 8 mm.
It was continuously cast into a 5 mm bar, cut into a predetermined length, and then processed into a drum shape by impact forging, and its peripheral surface was mirror-finished.

Furthermore, in Comparative Example 4, M was added to an Al base metal with a purity of 93.9% by weight.
g was added in an amount of 1.5% by weight. This was hot extruded to form a drawn tube with a diameter of Go, 5+u+, and its peripheral surface was mirror-finished.

Furthermore, in Comparative Example 5, after obtaining an ingot with a diameter of 250 mm,
This ingot is hot extruded and drawn to a diameter of GO,
It is molded into a 5mm pipe, and its peripheral surface is mirror-finished.

The manufacturing methods and cooling rates after casting of Examples 1 to 5 and Comparative Examples 1 to 5 are also shown in Table 1.

Regarding these Examples 1 to 5 and Comparative Examples 1 to 5,
The surface condition, impact workability, cleanability and manufacturing cost were investigated. The results are summarized in Table 2 below.

However, the surface condition is such that the maximum diameter present per 1-
The number of crystallized substances of m or more was examined, and cases where the number was 10 or less and cases where it exceeded 110 were indicated by x.

Impact workability is measured using a simple method in which a material with a diameter of 35 mm as shown in Figure 1 (a) is forged into a pipe shape as shown in Figure 1 (b), and the critical wall thickness at which cracks occur in the pipe is measured. Evaluated by. The case where a crack occurs when the wall thickness is 231 is ×1. The case where cracking occurred when the wall thickness was 1 dragon and the case where cracking did not occur even when the wall thickness of 01 was reduced to 1+n were represented by ◎.

Furthermore, the cleanability was determined by a dew condensation test to determine the number of spots generated on the drum circumferential surface, and the case where no spots were generated was expressed as "X".

Furthermore, the manufacturing cost is expressed as a ratio to that of Comparative Example 4, a conventional photosensitive drum base using high-purity Al ingot.

As a comprehensive evaluation, those that are extremely suitable as a photoreceptor drum base are shown as Q, and those that have some defects are shown as X.

As is clear from this Table 2, Example 1 according to the present invention
All of Nos. 5 to 5 have good impact workability, no spots occur even in the dew condensation test, and are excellent in cleanability.

Furthermore, manufacturing costs are low.

On the other hand, in Comparative Examples 1 and 2, which were cast with a diameter of 250 mm and then extruded, the cooling rate after casting was slow, and as a result, many crystallized substances with a maximum diameter of 15 μm or more were generated. As a result,
Spots occurred during the condensation test. Furthermore, in Comparative Example 3, which had a high content of Fe, which is an impurity, many crystallized substances having a maximum diameter of 15 μm or more were generated, and spots were generated in the dew condensation test. Furthermore, in Comparative Example 4, although the cleaning performance was excellent,
Since high-purity Al metal is used, the manufacturing cost is extremely high. Furthermore, Comparative Example 5 in which Mg was added in excess was inferior in both cleaning performance and cost.

[Effects of the Invention] As explained above, according to the present invention, it is possible to obtain an aluminum alloy for photoreceptor drums having excellent mirror finish, workability, and washability at a low cost.
This significantly contributes to higher resolution and lower cost of electrostatic copying machines.

[Brief explanation of drawings]

FIG. 1(a) shows a test piece before impact forging used to evaluate impact workability, and FIG. 1(b) shows a test piece after forging. Loading■ (a)

Claims (2)

[Claims] (1) 0.1 to 1.5% by weight of Mg, 0.1 to 1.5% by weight;
Contains at least one element selected from the group consisting of 2% by weight of Mn and 0.05 to 0.5% by weight of Si, with the remainder being Al and unavoidable impurities, and the content of Fe as an impurity element. An aluminum alloy material for a photoreceptor drum, characterized in that the number of crystallized substances having a maximum diameter of 15 μm or more is regulated to 10 pieces/mm^2 or less, and the number of crystallized substances is regulated to 0.5% by weight or less. (2) A process comprising the steps of melting a molten aluminum alloy containing the components according to claim 1, and solidifying the molten metal at a cooling rate of 10° C./sec or more and continuously casting it. A method for manufacturing an aluminum alloy material for photoreceptor drums.