JPS6089541A - Aluminum alloy material for reflection mirror and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an Al alloy material for a reflection mirror having a large grain size and contg. no coarse crystallized product by subjecting an Al-Mg alloy ingot having a specified composition to homogenization, hot working and reheating under specified conditions. CONSTITUTION:An Al alloy consisting of 3-6% Mg, <=0.15% Cr, <=0.4% Mn, <=0.05% Ti, <=0.1% Fe, <=0.05% Si, <=0.1% Cu, <=0.2% Zn and the balance Al is cast into an ingot. This Al alloy ingot is homogenized at 400-500 deg.C for >=1hr, hot worked by extrusion or other method at 300-450 deg.C, and heated at 500-550 deg.C for >=1hr. By this treatment, the average grain size is increased to >=500mum, and the average diameter of crystallized products is regulated to <=10mum. An Al alloy material for a reflection mirror hardly scattering laser light in case of a rotating polygon mirror is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a J-fulminium alloy Uipal used for manufacturing metal reflecting mirrors such as rotating polygon mirrors for laser beam printers, and a method for manufacturing the same.

If this type of aluminum alloy ingot contains large crystallized substances, a rotating polygon mirror for a laser beam printer made from this material may not be able to print well because the laser beam is scattered. In addition, the mirror surface of the above-mentioned rotating polygon mirror is often formed by machining with a high-precision diamond turning machine, or when the mirror surface is formed by diamond turning, plastic deformation on the surface of the steel during turning Depending on the orientation of the crystal grains, that is, the turning depth differs for each grain with the grain boundary as the boundary.
There is a risk that the laser beam may be scattered by the rotating polygon mirror, which has a roughened surface.

In order to prevent this surface roughening, it is necessary to coarsen the crystal grains of the aluminum alloy material for manufacturing the rotating polygon mirror and reduce the number of grain boundaries.

This invention was made in view of the above circumstances, and has coarse crystal grains and does not contain large crystallized substances, and as a result, it is possible to reduce the degree of laser scattering in the resulting rotating polygon mirror. The purpose of the present invention is to provide an aluminum alloy material for reflective mirrors that can be used.

In this specification, "chi" indicates weight ffi%.

One aluminum alloy material for a reflecting mirror of the present invention contains as essential components Mg 3 to 6, Cr 0.15% or less, and MTl 0.4% or less, and impurities Fe 1 % or less, Si 0. 05% or less,
Contains 0.1% or less of Cu, 0.2 qb or less of Zn, and 0.05% or less of Ti, with the balance consisting of aluminum, and has an average crystal grain size of 500 μ or more and an average crystallized material size of 10 μ or less. It is characterized by
Another method for producing an aluminum alloy material for a reflecting mirror according to the present invention includes 3 to 6% Mg and Cr as essential components.
0.15% or less and Mn Q, 4% or less, as impurities Fe011 or less, Si 0.05% or less, Cu 0.1% or less, ZnO, 2% or less.
An aluminum alloy ingot containing 0.05% or less of i and the remainder being aluminum is homogenized at 400 to 500°C for 1 hour or more, then hot worked at 300 to 450°C, and then heated to 500 to 550°C. By heating for 1 hour or more, the average crystal grain size is 500 P or more and the average crystallized material size is 101 L or less.

In the above, the reflecting mirror may be a rotating polygon mirror of a laser φ beam printer, but is not limited thereto.

In the above, the reasons for limiting each component of the aluminum alloy material are as follows.

Mg: Since the rotating polygon mirror of a laser beam printer is rotated at high speed, it must have high mechanical strength. Mg has the property of increasing the mechanical strength of the aluminum base metal, but if the content is less than 3%, the above effect will not be obtained, and if it exceeds 6%, the crystallized substances will become large. The content should be chosen within the range of 3-6%.

Cr: Since Cr has the property of enlarging the crystal grains of the aluminum alloy, or its content occurs, the content should be 0.15%.

Mn: Like Cr, does Mn have the property of enlarging the crystal grains of the aluminum alloy mentioned above?If its content exceeds 0.4%, AJ? Since -Mn-based crystallized products are formed, the content should be 0.4 or less.

Fe:, Fe content is 0. 'AA if over 1%'
-Fe The content should be less than 0.1 because the crystallized material becomes large.

Si: If the Si content exceeds 0.05%, MgZ
Since Si crystallized products are formed, the content should be kept below 0.05 inch.

Cu: If the iH content of Cu exceeds 0.1%, the corrosion resistance of the aluminum alloy described above will deteriorate, so the content should be
, ], should be lowered by 1%.

Zn: If the Zn content exceeds 0.2%, the corrosion resistance of the aluminum alloy will deteriorate, so the content should be set at 0.2%.
It should be moved to Section 2 or below.

Ti: If the Ti content exceeds 0.05%, the crystal grains of the aluminum alloy will be refined, so the content should be 0.05%.
Since the above-mentioned Cr and Mn are essential components, the content should not be 0% or less. on the other hand,
Fe.

Since Si, Cu, Zn, and Ti are impurities, the content may be 0%. Also, Fe,
Are there unavoidable impurities in addition to Si, Cu, Zn and Ti?
May be included.

In the above, the average crystallized material diameter for each aluminum alloy phase is 1
If the average crystal grain size is 0μ or less and 500μ or more, the degree of laser scattering on the mirror surface of a rotating polygon mirror for a laser beam printer obtained from this material by diamond turning will be reduced.

At the same time, a method for producing an aluminum alloy material for a reflecting mirror will be explained in detail.

M is an essential component for raw material aluminum alloy ingots.
g 3 to 6, Cr O, 15 or less, and Mn 0
．． 4% or less, as well as impurities Fe011% or less, Si0.05% or less, cuo, 1% or less, Z
The reason why an aluminum alloy containing 0.2% or less of n, 0.05% or less of TiO, and the balance consisting of aluminum was used is because the crystal grains of this aluminum alloy are large and the number of crystallized substances is small.

Further, in the above, if homogenization treatment is performed at 400 to 500°C for 1 hour or more, the diameter of the crystallized product becomes smaller. On the other hand, if the treatment temperature is less than 400°C and the treatment time is less than 1 hour, the above effect cannot be obtained, and if the treatment temperature exceeds 500°C, the crystallized substances will become larger. Therefore, the processing temperature was set to 4
The temperature should be selected within the range of 00 to 500°C, and the treatment time should be at least 1 hour. The processing time is preferably about 10 hours or less in consideration of workability.

In the above, if hot working is performed at 300 to 450'C, crystal grains can be coarsened during heating in a subsequent step.

On the other hand, if the processing temperature is less than 300°C, the processability deteriorates, and if it exceeds 450°C, the above effect cannot be achieved.

Previously, hot working was carried out within a humidity range of 300 to 450°C. Preferably, the processing method is an extrusion method. This is because if the extrusion method is used, only the crystal grains in the open area become coarse. For example, in the case of manufacturing a rotating polygon mirror for a laser beam printer, only the crystal grains on the L1d plane, where the mirror surface is to be formed, need to be enlarged to the 11th size.

In the above, when heated at 500 to 550°C for 1 hour or more after hot working, the crystal grains become coarse.

On the other hand, if the heating temperature is less than 500°C and the heating time is less than 1 hour, the above effects cannot be obtained, and if the heating temperature exceeds 550°C, the melting temperature starts to deteriorate. Once, the heating temperature was
The temperature should be selected within the range of 500 to 550'C, and the heating time should be at least 1 hour.

The processing time is preferably about 10 hours or less in consideration of workability.

Next, examples of the present invention will be shown together with comparative examples.

A fillet with a 1σ diameter of 250 mm was obtained by the continuous U18 method from an aluminum alloy with J-=IM JM"l shown in Table 1. Then, it was subjected to homogenization treatment and hot extrusion under six types of conditions shown in Table 2. , heating was performed to obtain a round bar with a 1σ diameter of 80 mm.Then, the average crystallized substance diameter and average grain size of this round bar were measured, and a rotating polygon mirror was formed from each round bar by diamond turning. The degree of scattering was investigated by applying a Ha-Ne laser to the mirror surface.The results are shown in Table 3.

As is clear from the results shown in Table 2 and Table 3, the mirror surface of the rotating polygon mirror made from the aluminum alloy material according to the present invention has the following properties:
Compared to the mirror surfaces of rotating polygon mirrors made from other aluminum alloys, the degree of laser scattering is reduced.

2 Patent Applicant: Showa Aluminum Co., Ltd. L″L 222l-2; Procedural Amendment 1 Old Seal No. 5831 November 211 Patent application filed on October 21, 1983 (3) 1, V
l l'l's manual labor →=→Kariun 4 Niuni= Year 2 2nd name of invention Aluminum alloy material for reflective mirror A;-1 and 3
, and TIE f-J-718 its manufacturing method.
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Applicant, 1st Attorney, 591st Administrative Order) 1a;” Showa, Month 1-16
? The number of inventions that increase from this point II iu (
? ili iE > 1. Name of the invention Aluminum alloy material for reflective mirrors and method for manufacturing the same 2. Claims (1) Mg 3-6%, cro, 15% or less, Mn014
% or less, Ti 0.05% or less, Fe 0°1% or less, Si
O, 05% or less, Cub, 1% or less and Zn0.2%
An aluminum alloy forest material for anti-I8 mirrors containing the following, the balance being aluminum, and having an average crystal grain size of 500μ or more°C and an average crystallized material diameter of 10μ or less.

(2) Mg3-6%, Oro, 15% or less, MnO, 4
% or less, Ti0.05% or less, FeO.

After homogenizing an aluminum alloy ingot consisting of 1% or less, s: o, o 5% or less, Cub, 1% or less, and Zn 0.2% or less, and the balance being aluminum at 400 to 500 ° C. for 1 hour or more. , by hot working at 300-450'0, and then heating at 500-550''C for 1 hour or more to make the average crystal grain size 5゜Oμ or more and the average crystallized material size 10μ or less. A manufacturing method for aluminum alloys for reflective mirrors, characterized by:

3. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum alloy material 1 and a % F method thereof for manufacturing a gold B reflective mirror such as a rotating polygon mirror for a laser beam link.

If this kind of aluminum alloy material contains large crystallized substances, there is a problem that a rotating polygon mirror for a Rayleigh beam printer made from this material cannot print well because the laser is scattered. In addition, the mirror surface of the above-mentioned rotating polygon mirror is often formed by machining with a high-precision diamond turning machine, but when forming a mirror surface by diamond turning, plastic deformation on the surface during turning occurs. Therefore, depending on the orientation of the crystal grains, that is, the turning depth differs for each crystal grain with the grain boundary as a boundary, and the surface becomes rough, and there is a risk that the ray 1f will be scattered by the resulting rotating polygon mirror.

In order to prevent this surface roughening, it is necessary to coarsen the crystal grains of the aluminum alloy material for manufacturing the rotating polygon mirror and reduce the number of grain boundaries.

This invention was made in view of the above-mentioned circumstances, and has coarse crystal grains and does not contain large crystallized substances, and as a result, the scattering of the laser beam on the 1:1 rotating polygon mirror is reduced. It is an object of the present invention to provide an aluminum alloy material for a reflecting mirror that can reduce the degree of damage.

In this ellipse, ``%J'' indicates weight %.

One aluminum alloy material for a reflective mirror of this invention is M
g3~6%, Cr0.1'5% or less, Mn0.4% or less, Tto, 05% or less, EO, 1% or more F, SiO,0
5% or less, Cub.

It is characterized by containing 1% or less of J3 and 0.2% or less of Zn, the balance being aluminum, and having an average crystal grain size of 500μ or more and an average crystallized substance size of 10μ or less, and the present invention. Another method for producing an aluminum alloy material for a reflective mirror includes Mo 3 to 6%, Cr0
515% or less, Mn 0.4% or less, -riO, 0.5% or more, Fe 0.1% or less, SiO, 0.5% or less, Cu0
．． 1% or more and 0.2% or less of Zn, and the balance is aluminum.
After homogenization treatment at 0°C for more than 1 hour and LC, 300-4
By performing hot working at 50°C and then heating at 500 to 550°C for 1 hour or more, the average grain size is reduced to 500°C.
It is characterized by having a diameter of μ or more and an average crystallized substance diameter of 10 μ or less.

In d3 above, the reflecting mirror may be a rotating polygon mirror of a laser beam printer, but is not limited to this.

In the above, the reasons for limiting each component of the aluminum alloy IJr31 are as follows.

Mg: Since the rotating polygon mirror of a laser beam printer is rotated at high speed, it must have high mechanical strength. MQ has the property of increasing the mechanical strength of aluminum alloys, but if the content is less than 3%, the above effect will not be achieved, and if it exceeds 6%, the product will become larger. , its content should be selected within the range of 3-6%.

Cr: Cr has the property of enlarging the crystal grains of the aluminum alloy, but if the m content exceeds 0.15%, A/-Cr-based crystallized substances are generated, so the m content is 0.15%.
Should be:

Mn: Like Cr, Mn has the property of enlarging the crystal grains of the aluminum alloy, but when its content is 0
．． If it exceeds 4%, △l- to 1n-based crystallized products will occur, so
The content m should be less than 0°4%.

- "i: Tt has the property of preventing casting vj when casting an aluminum alloy ingot, but if its content exceeds 0.05%, the crystal grains of the aluminum alloy will be refined. , the content should be less than 0.05%.

Fe: If the e content exceeds 0.1%, the Δρ-Fe-based product becomes large, so the content should be kept below 0.1%.

3i: If the content of 3i exceeds 0.05%, +V1g□
Since 3i crystallization occurs, the content should be below 0.05%.

If the content of CU:CLI exceeds 0.1%, the corrosion resistance of the aluminum alloy described above will deteriorate, so the content m is 0.1%.
The following is Nizuhiki.

Zn: If the Zn content m exceeds 0.2%, the corrosion resistance of the aluminum alloy will deteriorate, so the content should be 0.2% or less.

In the above, since Cr, Mn, and 1-1 have the properties described in 2, it may be preferable to actively include them depending on the river.

In addition, the alloy components other than Ml soot, namely Cr, Mn, and T
The content of i, Fe, Si, Cud:i and Zn may be 0% each.

In the above, the average grain size of the aluminum alloy material is 5
00μ or more and the average crystallized particle diameter is 10μ or less,
The degree of laser scattering is reduced in the mirror surface of a rotating polygon mirror for a laser beam printer obtained by diamond turning from this material.

Next, a method for producing an aluminum alloy material for a reflecting mirror will be explained in detail.

As raw material aluminum alloy Uj BIT, Mg3-
6%, Cr0115% or less, Mn0.4% or less, Ti0
．． The reason why we used an aluminum alloy containing 0.05% or less, Fed, 1% or less, Si 0.05% or less, Cub, 1% or less, and 7N0.2% or less, with the balance being aluminum is because the mechanical strength of this aluminum alloy is high. This is because the crystal grains are large and there are few products available.

Moreover, in the above, if the homogenization treatment is performed at 400 to 5.00°C for 1 hour or more, the diameter of the crystallized product becomes smaller. However, if the processing temperature is less than 4.00℃ and the processing time is 1 hour, the above effect will not be obtained.
If the temperature exceeds 0°C, the crystallized substances will become larger. Therefore, the treatment temperature should be selected within the range of 400 to 500°C, and the treatment time should be set to 1 inch or more. The processing time is preferably about 10 hours or less in consideration of workability.

In this case, the crystal grains can be coarsened during heating in a subsequent process, such as by hot working at 300 to 450°C. However, if the processing temperature is less than 300°C, the processability deteriorates, and if it exceeds 4.50°C, the above effects cannot be obtained. Therefore, hot working should be carried out within the temperature range of 300-450°C. As the processing method, it is preferable to use an extrusion processing method. This is because, according to the extrusion method, only the crystal grains on the peripheral surface become coarse. For example, when making a rotating polygon mirror for a laser beam printer, it is sufficient that the crystal grains on the peripheral surface where the mirror surface is to be formed are coarse.

In the above, when heated at 500 to 550° C. for 1 hour or more after hot working, the crystal grains become coarse.

However, if the heating temperature is less than 500°C and the heating time is less than 1 hour, the above effect cannot be obtained, and if the heating temperature exceeds 550°C, dissolution begins. Therefore, the heating temperature should be set to 500~
It is advisable to select a temperature within the range of 550°C and to set the heating time to 1 hour or more.

Processing time (J) is preferably about 10 hours or more considering workability.

Next, one fillet with a diameter of 250 mm was cast by a continuous casting method from four types of aluminum alloys shown in Table 1, which shows examples of the present invention together with comparative examples. Then, homogenization treatment, hot extrusion and heating were performed in this order under the six conditions shown in Table 2 to obtain a round bar with a diameter of 8 Qmm. After that, the average product diameter and average crystal grain size of the round bars were measured, and a rotating polygon mirror was formed by turning a diamond (diamond) from each round bar, and a 1 to 1e-Ne laser was applied to the mirror surface to measure the degree of scattering. The results are shown in Table 3.

Table in1 [ (hereinafter referred to as "Kinpaku") Table 2 Table 3 As is clear from the above results, the mirror surface "C" of the rotating polygon mirror made from the aluminum alloy material according to the present invention is different from that of the mirror surface "C" made from other aluminum alloy materials. The degree of laser scattering is lower than that of a rotating polygon mirror.

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Claims (2)

[Claims] (1) Essential components: Mg 3-6%, Cr 0.15% or less, and R'In 0.4% or less, and impurities FeQ, 1% or less, Si 0.05% or less, C.
uO 91 or less, Zn 0.2 or less, and TiQ
, Q5 or lower, the balance consists of aluminum, the average crystal grain size is 500μ or more, and the average crystallized substance size is 107L or less. (2) Mg 3-6%, □r□, 15% as essential components
and Mn 0.4% or less, as impurities F'c O, 1'% or less, SiO, 05% or less, Cu 0.1% or less, Zn 0.2% or less, and Ti.
After homogenizing an aluminum alloy ingot containing 0.05% or less and the balance being aluminum at 400 to 500°C for 1 hour or more, hot working at 300 to 450°C, and then 500 to 550°C. A method for producing an aluminum alloy material for a reflective mirror, characterized in that the average crystal grain size is 500 μm or more and the average crystallized material size is 10 μm or less by heating for 1 hour or more.