JPH0328343A - Aluminum alloy for photosensitive drum of copying machine - Google Patents

Abstract

PURPOSE:To prevent the surface exposure of crystallized products and to secure the electrical smoothness on the surface of an Al matrix by specifying the contents of Mg, Cu, Fe and Si and regulating the maximum grain size of the crystallized products in an Al alloy. CONSTITUTION:The compsn. of the alloy is formed from, by weight, 0.6 to 1.5% Mg, 0.02 to 0.5% Cu, <=0.1% Fe, <=0.1% Si and the balance Al with inevitable impurities, and the maximum grain size of crystallized products is regulatd to <=15mum. Or, the compsn. is regulated to contain the above Mg, Cu and Fe and contg. one or more kinds among 0.15 to 0.4% Si, 0.05 to 0.2% Cr and 0.05 to 0.2% Mn. The alloy has excellent workability and machinability, furthermore makes good the quality of a photosensitive body, is free from the generation of micro black spots and is therefore suitable as the material for a photosensitive drum of a copying machine.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aluminum alloy suitable as a material for a photosensitive drum of a copying machine, which particularly requires surface smoothness.

[Conventional technology]

Conventionally, materials used for photoconductors of copying machines include a JIS 3003 tube mirror-cut and coated with an organic semiconductor layer, or a selenium film deposited on the cut surface.

[Problems to be Solved by the Invention] However, when various image tests were conducted on the photosensitive drum of a copying machine using such materials, it was found that minute black spots were generated under certain conditions, which became a problem. ．． The cause of these minute sunspots is presumed to be noise caused by electrical charges on the surface of the photoreceptor layer discharging for some reason. Further investigating the cause of the noise reveals that photoreceptor drums are generally made of JIS3003 tubes with a surface roughness of Rm, as outlined above.
It is used after mirror finishing with ax of 0.1 to 0.8μ, but this processed surface contains Affi-Fe-Mn, A, which is unique to 3003 alloy.
Although l-Fe-Si crystallized substances are dispersed, electron microscopic observation shows that most of these crystallized substances are covered with a thin layer of α-phase aluminum due to the burnishing effect during mirror finishing. ．． However, upon closer observation, in areas where the crystallized material is coarse or agglomerated, the friction between the cutting tool and the crystallized material causes cracks in the thin layer of α phase, causing the crystallized material to form. What is exposed is recognized.

In order to maintain the quality of images on photosensitive drums, electrical smoothness as well as mechanical smoothness of the aluminum base surface is required.

However, as mentioned above, when the crystallized material is exposed, there is a difference in electrode potential between the α-phase aluminum and the crystallized material, which causes noise. Conventionally, in order to prevent noise, for example, the thickness of the undercoat of the organic semiconductor layer has been controlled, or a special surface treatment has been applied to the mirror-finished surface of the aluminum material. There was a problem in that the processing cost of the photoreceptor drum increased because it required strict condition control and complicated process control. [Means for Solving the Problems] In view of the above circumstances, the present invention has developed a material for a photosensitive drum of a copying machine that does not generate noise as a result of intensive research. 6-1.5wt%, C
u0. 0 2 ~ 0. 5wt%, Fe0. lw
t% or less, Si 0.1wt% or less, the balance consisting of aluminum and unavoidable impurities, and the maximum particle size of crystallized products is 15μ or less, The second invention is Mg0.
6-1.5wt%, Cu0.0 2-0.5wt%, F
e0.1@t% or less, and S i 0. 1 5～0
．． 4wt%, Cr 0. 0 5 ~ 0. 2wt%
, M n 0. 0 5 ~ 0. 1 out of 2wt%
This is an aluminum alloy for use in photosensitive drums of copying machines, characterized in that it contains at least one species, the remainder being aluminium, and unavoidable impurities, and the maximum particle size of the crystallized product is 151 or less. [Operation] The present invention was created as a result of pursuing the electrical smoothness of the surface of the aluminum base material, and limits the constituent elements of crystallized substances to eliminate the problem of coarse crystallized substances and agglomeration of crystallized substances. The basic idea is to prevent surface exposure of crystallized substances. In both the first and second inventions, the maximum particle size of the crystallized material is 15
This is the reason why we limited it to less than μ. Regarding the alloy composition of the present invention and the reason for limiting its range, the reason why Mg was selected as the basic additive element for both the first and second inventions is that this element has a large solid solubility limit with aluminum and forms harmful coarse crystals. This is because it does not generate debris, increases the strength of the base, and provides stable surface roughness during mirror cutting. The amount added is 0.6~1.5w
t% (hereinafter simply abbreviated as %) is limited to 0. This is because if it is less than 6%, a sufficient strength improvement effect is not observed, and if it exceeds 1.5%, extrusion and cold workability deteriorate. Cu also has a large solid solubility limit with respect to aluminum, and is added because it can increase the strength of the base without producing harmful coarse crystallized substances, and the amount of Cu added is 0.02 to 0.0.
The reason why it is limited to 5% is that if it is less than 0.02%, the effect will not appear, and if it exceeds 0.5%, harmful crystallized substances may be generated.Fe is a constituent element of harmful crystallized substances. Therefore, it was limited to 0.1% or less. Si is an element that increases the strength of the base by forming a fine compound with Mg, but in the first invention, Si is added to 0. The reason why the content was limited to 1% or less was to keep the particle size of the crystallized product smaller, but in the second invention, it was set to 0.15 to 0.4%. This is used when it is desired to increase the strength of the base and improve machinability even if it slightly increases the particle size of the product. If it is less than 0.15%, the effect of improving strength and machinability is not achieved. The reason for this limitation is that if it exceeds 0.4%, it will adversely affect the smoothness of the surface. Mn and Cr are elements that have the effect of improving cutting workability by curling cutting chips, but the amount added is 0.0
The reason why it is limited to 5 to 0.2% is that if it is less than 0.05%, the effect will not appear, and if it exceeds 0.2%, harmful crystallized substances will be produced.

Although not essential, Ti is known as an additive for refining the internal structure during casting, and there is no problem with adding a small amount of Ti. [Example] The alloys of the present invention, comparative alloys, and conventional alloys having the compositions shown in Table 1 were cast into a diameter of 9 inches and homogenized at 550°C to form billets for extrusion. After heating these to 480°C, they were extruded into a boathole tube with an outer diameter of 301 mm and a wall thickness of 1 fl mm to obtain a test material. The evaluation items were the particle size of the crystallized product, workability, cutting ability, and photoreceptor quality, and a comprehensive evaluation was made based on these characteristics. (1) The particle size of the crystallized product was determined by image analysis of SEM observation photographs. (2) Processability was judged by whether or not porthole extrusion was possible. (3) Machinability was evaluated by the curl diameter of chips during cutting with a diamond tool. (4) Photoreceptor quality was evaluated by the presence or absence of minute black spots in an image test. The above results are shown in Table 1.

In addition, No. 9 in the table listed as a conventional alloy is JIs105.
0, NolO is JIS3003, Noll is JIS60
This corresponds to 63 alloy. As is clear from Table 1, alloys Nos. 1 to 5 of the present invention all have crystallized particles with a particle size of 15 μm or less, have excellent workability and cutting properties, and have good photoreceptor quality, with no occurrence of minute sunspots. It can be seen that this material is extremely excellent as a photoreceptor drum material. On the other hand, comparative alloy N in which the added elements exceed the limited range
All of o6 to o8 had particle diameters exceeding 15 irgA and had some defects in characteristics, and the overall evaluation was low.

Furthermore, all of the conventional alloys Nos. 9 to 1l had poor photoreceptor quality and the occurrence of minute black spots.

〔Effect of the invention〕

Claims (2)

[Claims] (1) Mg0.6-1.5wt%, Cu0.02-0.
5 wt%, Fe 0.1 wt% or less, Si 0.1 wt% or less, the remainder consisting of aluminum and unavoidable impurities, and having a maximum particle diameter of crystallized material of 15 μm or less. Aluminum alloy. (2) Mg0.6-1.5wt%, Cu0.02-0.
5wt%, Fe0.1wt% or less, and Si0.15
~0.4wt%, Cr0.05~0.2wt%, Mn0
．． Aluminum for photosensitive drums of copying machines, characterized in that the aluminum contains one or more of 05 to 0.2 wt%, the remainder is aluminum and unavoidable impurities, and the maximum particle size of the crystallized product is 15 μm or less. alloy.