WO2021193064A1

WO2021193064A1 - Aluminum alloy member and method for manufacturing same

Info

Publication number: WO2021193064A1
Application number: PCT/JP2021/009517
Authority: WO
Inventors: 飯塚　章; 直人古村; 耕一中野
Original assignee: 日本軽金属株式会社
Priority date: 2020-03-27
Filing date: 2021-03-10
Publication date: 2021-09-30
Also published as: EP4130315A1; CN115315544A; TW202140862A; US20230175159A1; KR20220158055A; JPWO2021193064A1; EP4130315A4

Abstract

The present invention provides: an aluminum alloy member which can be manufactured at a relatively low cost and has a light weight, and which can have high dimensional accuracy under a high-temperature environment and is less likely to undergo the color-fading of a blackened surface even under a high-temperature environment, and has excellent heat resistance; and a method for manufacturing the aluminum alloy member with high efficiency. The aluminum alloy member according to the present invention comprises: a substrate which comprises an extruded material of an aluminum powder alloy having an Si content of 20 to 40% by mass and has an anodic oxide coating film formed on the surface thereof; and an electrolytically colored layer which is formed by precipitating a metal or a metal salt on voids in the anodic oxide coating film.

Description

Aluminum alloy member and its manufacturing method

The present invention relates to an aluminum alloy member whose surface is required to be blackened or darkened, and a method for manufacturing the same.

In recent years, there has been an increase in demand for optical members and electronic circuit members for automobiles, and inspection devices for these members. Aluminum alloys, which are lightweight and easy to process, are widely used as these materials, but the temperature guarantee range of members for automobiles is wide, and the maximum temperature may be about 200 ° C. In addition, there is a demand for inspecting members for automobiles at the maximum temperature.

Here, the surface of the optical member, the electronic circuit member, and the aluminum alloy used for the inspection device of these members is blackened with an organic dye after anodizing treatment such as alumite sulfate treatment in order to suppress light reflection. It is common to be done.

However, in a high temperature environment for automobiles, the color of the aluminum alloy member blackened by the organic dye may be lost. In addition, where high dimensional accuracy is required for optical members, aluminum basically has a large coefficient of linear expansion, and in an in-vehicle environment where the durability temperature is high compared to the general environment, misalignment occurs due to thermal expansion. There is a concern that it may affect the operation and inspection.

On the other hand, for example, in Patent Document 1 (Japanese Unexamined Patent Publication No. 2010-237282), a support frame for a pellicle, which is formed of an aluminum material made of aluminum or an aluminum alloy, has an optical thin film body, and is used as a pellicle. A manufacturing method in which an anodized film is formed on the surface of an aluminum material by anodizing with an alkaline aqueous solution containing tartrate, dyed with an organic dye, and then sealed with steam. A method for manufacturing a support frame for a pellicle, which comprises the above, is disclosed.

In the method for producing a support frame for a pellicle described in Patent Document 1, the aluminum material is anodized with an alkaline aqueous solution containing tartaric acid without using sulfuric acid, which is the largest causative substance of haze, to provide corrosion resistance and It is said that it is possible to obtain a support frame for pellicle that has excellent durability and reduces the occurrence of haze as much as possible.

Further, in Patent Document 2 (Japanese Unexamined Patent Publication No. 2016-177120), the pellicle frame is formed in a frame shape, and is composed of a sintered body having a Young's modulus of 150 GPa or more and a Vickers hardness of 800 or more, and has a frame shape. The corner portion is secured to have a width equal to or larger than the width of the straight portion, and at least one of the corner portions is a pellicle frame wider than the width of the straight portion, and the pellicle frame is made of ceramics, cemented carbide or cermet. It is disclosed to do.

Since the pellicle frame described in Patent Document 2 uses a sintered body having a high Young's modulus and Vickers hardness, the pellicle frame is deformed by the film tension generated when the pellicle film is stretched on the pellicle frame. Can be suppressed. Moreover, since the width of at least one corner portion is wider than the width of the straight portion, the strength of the corner portion can be increased, and the deformation and damage of the pellicle frame can be further suppressed.

Japanese Unexamined Patent Publication No. 2010-237282 Japanese Unexamined Patent Publication No. 2016-177120

The support frame for a pellicle described in Patent Document 1 has excellent stability that does not form a reaction product (haze) such as ammonium sulfate even when energy is input from a high-power short-wavelength exposure light source. However, no consideration is given to color loss when the product is kept in a high temperature environment. Further, it has not been studied to suppress the misalignment caused by the large coefficient of linear expansion of the aluminum material.

Further, although the pellicle frame described in Patent Document 2 has high mechanical properties at room temperature, thermal expansion and blackening of the surface in a high temperature environment have not been studied. In addition, ceramics having poor workability, cemented carbide having a large specific gravity, and cermet are used, and it is difficult to widely use them as optical members.

In view of the above problems in the prior art, an object of the present invention is a lightweight aluminum alloy member that can be manufactured at a relatively low cost, has high dimensional accuracy in a high temperature environment, and is blackened even in a high temperature environment. It is an object of the present invention to provide an aluminum alloy member having excellent heat resistance and an efficient manufacturing method thereof, in which the surface of the aluminum alloy is not easily faded.

As a result of intensive studies on the composition of aluminum alloy members and the method of surface blackening in order to achieve the above object, the present inventors have obtained an extruded material of aluminum alloy powder having a specific composition having a low linear expansion coefficient. It has been found that it is effective to form an electrolytically colored layer in which a metal or a metal salt is precipitated in the pores of the anodized film, and the present invention has been reached.

That is, the present invention
It consists of an extruded aluminum powder alloy with a Si content of 20-40% by mass.
A base material with an anodized film on the surface and
Provided with an electrolytically colored layer in which a metal or a metal salt is precipitated in the pores of the anodized film.
Provided is an aluminum alloy member, which is characterized by the above.

Si has the effect of lowering the coefficient of linear expansion and improving Young's modulus and wear resistance by crystallizing as a Si phase in the Al matrix. In the aluminum alloy member of the present invention, a high Young's modulus, excellent wear resistance and a low coefficient of linear expansion are realized by setting the Si content to 20% by mass or more, and processing is performed by setting the Si content to 40% by mass or less. It suppresses the decrease in strength and toughness due to the decrease in properties and the coarsening of the Si phase. The more preferable Si content is 24 to 28% by mass.

Further, the surface of the aluminum alloy member of the present invention is blackened by an electrolytic colored layer in which a metal or a metal salt is precipitated in the pores of the anodized film, and the surface is blackened as compared with the case where the aluminum alloy member is blackened with an organic dye. Fading in a high temperature environment is suppressed extremely effectively. That is, in the aluminum alloy member of the present invention, both the reduction of the coefficient of linear expansion and the suppression of fading in a high temperature environment are realized.

Further, the aluminum alloy member of the present invention has a smaller specific gravity than the cemented carbide or cermet, and the optical member can be made lighter. In addition, it is easy to handle because it has excellent toughness as compared with ceramics and cemented carbide. Further, since it has good workability, it is possible to reduce the manufacturing cost and to impart high dimensional accuracy to the optical member.

In the aluminum alloy member of the present invention, the aluminum powder alloy contains Si: 20 to 40% by mass, Mg: 0.2 to 1.2% by mass, Cu: 2% by mass or less, Fe: 2% by mass or less, Cr. : It is preferably 0.4% by mass or less, and the balance is composed of Al and unavoidable impurities.

The aluminum alloy member is provided with excellent mechanical properties, corrosion resistance and heat resistance by strengthening precipitation by adding Mg and Cu, improving Young's modulus and corrosion resistance by adding Fe, and refining crystal grains by adding Cr. be able to.

Further, in the aluminum alloy member of the present invention, it is preferable that the metal and the metal salt contain at least one of Ni, Co, Cu, Sn, Mn, Fe, Pb, Ca, Zn and Mg. By including these elements, blackening of the surface can be efficiently and surely achieved.

Further, in the aluminum alloy member of the present invention, it is preferable that the coefficient of linear expansion is 10 × 10 ^-6 to 23 × 10 ^-6 / K. By setting the coefficient of linear expansion to 10 × 10 ^-6 / K or more, it is possible to suppress a decrease in workability and strength and toughness due to the addition of various elements more than necessary, as well as optical members and ceramics. The coefficient of linear expansion is close to that of a material made of silicon or the like. Further, by setting the value to 23 × 10 ^-6 / K or less, it is possible to suppress the displacement due to thermal expansion in a high temperature environment (for example, 200 ° C.). Here, the more preferable range of the coefficient of linear expansion is 13 × 10 ^-6 to 20 × 10 ^-6 / K, and the most preferable range of the coefficient of linear expansion is 15 × 10 ^-6 to 19 × 10 ^-6 / K. ..

In the aluminum alloy of the present invention, the difference between the L ^* value as before heat treatment L ^* value after the heat treatment of holding for 100 hours in an atmosphere of 200 ° C. is 3 or less, are preferred. If the difference between the L ^* value before heating L ^* value after heating is 3 or less, need hardly consider the fading in a high-temperature environment in which the optical member is used. Here, more preferably the difference between the L ^* value before heating L ^* value after heating is 2 or less, and most preferably 1 or less. ^{Further, by setting the L *} value of the aluminum alloy member to 60 or less, the light reflection of various optical components can be sufficiently suppressed. The L * value of the aluminum alloy member is more preferably 50 or less, and further preferably 45 or less.

Further, it is preferable that the aluminum alloy member of the present invention is an optical member or a member for an optical member inspection device. Since the aluminum alloy member of the present invention is an aluminum alloy member having high dimensional accuracy in a high temperature environment and having a blackened surface that is hard to fade even in a high temperature environment and has excellent heat resistance, it is an optical member or an optical member. It can be suitably used as a member for an inspection device. Here, as the optical member inspection device, an inspection light source device for a CCD / C-MOS image sensor can be exemplified.

In addition, the present invention
The first step of producing a base material by subjecting aluminum alloy powder having a Si content of 20 to 40% by mass to pressure molding, sintering and extrusion processing.
The second step of forming an anodized film on the surface of the base material and
The base material is electrolytically colored in an electrolytic solution containing a metal or a metal salt, and the metal or the metal salt is precipitated in the pores of the anodized film to form an electrolytically colored layer on the surface of the base material. Including the third step,
Also provided is a method for manufacturing an aluminum alloy member.

By extruding a sintered body of aluminum alloy powder, a homogeneous aluminum alloy can be obtained even if the Si content is 20 to 40% by mass. Further, by electrolytically coloring an aluminum alloy material having an anodized film in an electrolytic solution containing a metal or a metal salt, a metal or a metal salt is precipitated in the pores of the anodized film to achieve blackening. Can be done.

According to the present invention, it is a lightweight aluminum alloy member that can be manufactured at a relatively low cost, has high dimensional accuracy in a high temperature environment, and has excellent heat resistance because the blackened surface does not easily fade even in a high temperature environment. It is possible to provide an aluminum alloy member and an efficient manufacturing method thereof.

It is the schematic sectional drawing of the aluminum alloy member of an embodiment. It is a process drawing of the manufacturing method of the aluminum alloy member of embodiment.

Hereinafter, typical embodiments of the aluminum alloy member of the present invention and an efficient manufacturing method thereof will be described in detail with reference to the drawings, but the present invention is not limited to these. In addition, some or all of the components in the embodiment can be combined as appropriate. In the following description, the same or corresponding parts may be designated by the same reference numerals, and duplicate description may be omitted. Moreover, since the drawings are for conceptually explaining the present invention, the dimensions of each component represented and their ratios may differ from the actual ones.

1. 1. Aluminum alloy member FIG. 1 shows a schematic cross-sectional view of the aluminum alloy member of the present invention. The aluminum alloy member 1 has an anodic oxide film 4 formed on the surface of the aluminum alloy base material 2, and includes an electrolytic colored layer 6 in which a metal or a metal salt is deposited in the pores of the anodic oxide film 4.

The aluminum alloy base material 2 contains Si: 20 to 40% by mass, Mg: 0.2 to 1.2% by mass, Cu: more than 0 and 2% by mass or less, Fe: more than 0 and 2% by mass or less, Cr: more than 0 and 0. .4% by mass or less, and the balance is composed of extruded aluminum alloy powder sintered body composed of Al and unavoidable impurities. For example, 7000 series (Al-Zn-Mg series) aluminum alloy and 6000 series (Al). It has a low linear expansion coefficient and a high Young's ratio as compared with the −Mg—Si based) aluminum alloy and the 5000 series (Al—Mg based) aluminum alloy. The reasons for limiting each additive element will be described below.

(1) Si
In addition to contributing to the improvement of Young's modulus by crystallizing Si as the Si phase in the Al matrix phase, it has the effect of improving the wear resistance and lowering the coefficient of thermal expansion. In the aluminum alloy base material 2, a high Young's modulus, excellent abrasion resistance and a low coefficient of linear expansion are realized by setting the Si content to 20% by mass or more, and workability is achieved by setting the Si content to 40% by mass or less. The decrease in strength and toughness due to the decrease in Si phase and the coarsening of the Si phase are suppressed. The Si content is more preferably 22 to 35% by mass, further preferably 24 to 30% by mass, and particularly preferably 25 to 28% by mass.

(2) Mg
The Mg content is 0.2 to 1.2% by mass. By setting the Mg content in this range, it is possible to improve the strength by strengthening precipitation. (Precipitation strengthening with _{Mg 2} Si and Al _{2 Cu Mg).} The more preferable Mg content is 0.55 to 0.90% by mass.

(3) Cu
The Cu content is more than 0 and 2% by mass or less. By setting the Cu content in this range, it is possible to improve the strength by strengthening precipitation as in the case of Mg described above. (Precipitation strengthening with _{Mg 2} Si and Al _{2 Cu Mg).} It also contributes to improving Young's modulus and corrosion resistance. If it is more than 2% by mass, the anodizing film property is lowered. The more preferable Cu content is 0.11 to 0.30% by mass.

(4) Fe
The Fe content is more than 0 and 2% by mass or less. By setting the Fe content in this range, it contributes to the improvement of Young's modulus and the improvement of corrosion resistance. If it is more than 2% by mass, elongation, thermal conductivity, and extrusion decrease. The more preferable Fe content is 0.7% by mass or less.

(5) Cr
The Cr content is more than 0 and 0.4% by mass or less. By setting the Cr content in this range, the crystal is made finer and contributes to the improvement of toughness. The more preferable Cr content is 0.03 to 0.26% by mass.

(6) Al
In addition to the components (1) to (5), the rest is substantially composed of Al. In addition, unavoidable impurities may be contained as other components.

The aluminum alloy base material 2 preferably has a coefficient of linear expansion of 10 × 10 ^-6 to 23 × 10 ^-6 / K. By setting the coefficient of linear expansion to 10 × 10 ^-6 / K or more, it is possible to suppress a decrease in workability and strength and toughness due to the addition of various elements more than necessary, as well as optical members and ceramics. The coefficient of linear expansion is close to that of a material made of silicon or the like. Further, by setting the value to 23 × 10 ^-6 / K or less, it is possible to suppress the displacement due to thermal expansion in a high temperature environment (for example, 200 ° C.). Here, the more preferable range of the coefficient of linear expansion is 13 × 10 ^-6 to 20 × 10 ^-6 / K, and the most preferable range of the coefficient of linear expansion is 15 × 10 ^-6 to 19 × 10 ^-6 / K. ..

The film quality of the anodized film 4 is not particularly limited as long as the effects of the present invention are not impaired, and various conventionally known anodized films can be used. Anodizing treatment may be performed using a sulfuric acid bath, or the aluminum alloy base material 2 may be formed by anodizing treatment in an alkaline bath. For example, when anodizing is performed using a sulfuric acid bath, there is a risk that inorganic acids such as sulfuric acid and phosphoric acid may remain on the anodized film 4 on the surface of the aluminum alloy base material 2 due to this. There is. For example, when the aluminum alloy member 1 is a pellicle frame, the inorganic acid reacts with a basic substance such as ammonia present in the exposed atmosphere to generate a reaction product (haze) such as ammonium sulfate, and the reaction product (haze). ) Causes cloudiness in the pellicle and affects the pattern transfer image. On the other hand, by using an alkaline bath for the anodizing treatment, it is possible to prevent the residual inorganic acid forming the reaction product (haze) from remaining.

The film thickness of the anodized film 4 is not particularly limited as long as the effect of the present invention is not impaired, but it is preferably 1 to 15 μm. A homogeneous anodized film 4 can be formed by setting the film thickness to 1 μm or more, and a decrease in strength of the anodized film 4 can be suppressed by setting the film thickness to 15 μm or less.

With respect to the electrolytic colored layer 6, the metal or metal salt precipitated in the pores of the anodized film 4 contains at least one of Ni, Co, Cu, Sn, Mn, Fe, Pb, Ca, Zn and Mg. , Are preferred. By including these elements, blackening of the surface can be efficiently and surely achieved. In addition, fading in a high temperature environment can be reliably reduced as compared with the case of blackening with an organic dye. Among these elements, Ni, Co, Cu and Sn are more preferable, and Ni is even more preferable.

In the aluminum alloy member 1, the difference between the L ^* value before heating L ^* value after heating is 3 or less, are preferred. If the difference between the L ^* value before heating L ^* value after heating is 3 or less, need hardly consider the fading in a high-temperature environment in which the optical member is used. Here, more preferably the difference between the L ^* value before heating L ^* value after heating is 2 or less, and most preferably 1 or less. ^{Further, by setting the L *} value of the aluminum alloy member 1 to 60 or less, the light reflection of various optical components can be sufficiently suppressed. ^{The L *} value of the aluminum alloy member 1 is more preferably 50 or less, and further preferably 45 or less.

Further, it is preferable that the aluminum alloy member 1 is an optical member or a member for an optical member inspection device. Since the aluminum alloy member of the present invention is an aluminum alloy member having high dimensional accuracy in a high temperature environment and having a blackened surface that is hard to fade even in a high temperature environment and has excellent heat resistance, it is an optical member or an optical member. It can be suitably used as a member for an inspection device. Here, as the optical member inspection device, an inspection light source device for a CCD / C-MOS image sensor can be exemplified. Examples of the optical member include a pellicle frame, a lens holder, a barrel, a shade, a reflector, and the like.

2. Manufacturing Method of Aluminum Alloy Member As shown in FIG. 2, the manufacturing method of the aluminum alloy member of the present embodiment includes a first step (S01) of manufacturing a base material and a first step of forming an anodized film on the surface of the base material. It includes a second step (S02) and a third step (S03) of forming an electrolytically colored layer on the surface of the base material. Hereinafter, each process and the like including any process will be described in detail.

(1) Substrate manufacturing process (first process: S01)
The base material manufacturing step (S01) is a step for manufacturing the aluminum alloy base material 2 through pressure molding, sintering, and extrusion processing using an aluminum alloy powder having a Si content of 20 to 40% by mass as a raw material. .. The aluminum alloy powder contains Si: 20 to 40% by mass, Mg: 0.2 to 1.2% by mass, Cu: more than 0% by mass and less than 2% by mass, Fe: more than 0 and 2% by mass or less, Cr: more than 0 and 0.4% by mass. It is preferably mass% or less, and the balance is preferably composed of Al and unavoidable impurities.

The method of pressure molding on the aluminum alloy powder is not particularly limited as long as the effect of the present invention is not impaired, and various conventionally known methods can be used. For example, a press method, a CIP method, or the like can be used. .. The molding pressure for pressure molding may be appropriately set according to the composition, shape, particle size, etc. of the aluminum alloy powder.

Further, the conditions for sintering the pressure molded body are appropriately adjusted according to the composition, particle size and shape of the aluminum alloy powder, the density of the pressure molded body, etc., and a good extruded material is obtained by hot extrusion. The sintering conditions may be used so that a sintered body in a state where it can be obtained can be obtained. As the sintering conditions, for example, the pressure molded body is held in a vacuum furnace having a vacuum degree of 1 Torr or less and a furnace temperature controlled to 100 to 400 ° C. for 0.5 to 2 hours, and then the vacuum degree is 1 Torr. The temperature inside the furnace may be raised to 520 to 570 ° C. and held for 1 to 6 hours while keeping the temperature below (preferably 0.1 Torr or less).

It is preferable to use hot extrusion for extrusion of aluminum alloy powder sintered body. The hot extrusion method and conditions are not particularly limited as long as the effects of the present invention are not impaired, and conventionally known hot extrusion methods and conditions for aluminum alloy powder sintered bodies may be used, but the hot extrusion temperature. May be set to about 400 to 500 ° C.

Further, in the case of hot extrusion, a metal plate (for example, pure aluminum or a 5000 series aluminum alloy) may be placed in front of the sintered body which is an extrusion material in front of the mold. As a result, a thin film having a metal plate composition can be formed on the surface of the extruded material, which causes pitting corrosion and total corrosion over time at the interface between Si and Al, which may occur when the Al—Si material is on the outermost surface. It can be suppressed.

The hot-extruded molded product is forged or the like to give it a desired shape, if necessary. In this case, the molded product may be heat-treated prior to the forging or the like. For example, the forging property of the hot-extruded molded product can be improved by performing the heat treatment at 200 to 400 ° C. for about 0.5 to 2 hours.

(2) Anodizing film forming step (second step: S02)
The anodizing film forming step (S02) is a step for forming the anodizing film 4 on the surface of the aluminum alloy base material 2 obtained in the base material manufacturing step (S01). The conditions of the anodizing treatment are not particularly limited as long as the effects of the present invention are not impaired, and various conventionally known anodizing treatments can be used. As the bath, a sulfuric acid bath or any one or more inorganic alkaline components selected from the group consisting of sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, strontium hydroxide, and rubidium hydroxide may be used. An inorganic alkaline bath containing, or a salt of any one or more organic acids selected from the group consisting of tartaric acid, citric acid, oxalic acid, and salicylic acid, and sodium hydroxide, potassium hydroxide, lithium hydroxide, and water. An alkali mixed bath or the like containing any one or more inorganic alkali components selected from the group consisting of calcium oxide, strontium hydroxide, and rubidium hydroxide is preferably used.

(3) Electrolytic colored layer forming step (third step: S03)
The electrolytic colored layer forming step (S03) is a step for precipitating a metal or a metal salt in the pores of the anodic oxide film 4 formed in the anodic oxide film forming step (S02) to form the electrolytic colored layer 6. be.

The aluminum alloy base material 2 on which the anodic oxide film 4 is formed is immersed in an electrolytic treatment liquid containing a soluble metal salt, subjected to a color pretreatment for constant current electrolysis using the aluminum alloy base material 2 as an anode, and then the same electrolytic treatment liquid. Among them, the aluminum alloy base material 2 may be used as a cathode for electrolytic coloring treatment, or the coloring pretreatment may be omitted.

For the electrolytic coloring process, in addition to the direct current, a square wave having a positive component, a sine wave, a pulse wave, or an alternating current having a waveform combining these can be used. When performing the coloring pretreatment, it is preferable that the current density of the positive component is substantially equal to the current density at the time of the coloring pretreatment, and specifically, 1 / 0.6 to 1/0 of the cathode current density at the time of electrolytic coloring. It is preferable to set it in the range of 95 times. Further, when an alternating current having a negative component is supplied during the coloring pretreatment, the absolute value of the maximum current density of the negative component is preferably set in the range of 0.6 to 0.95 times the absolute value of the maximum current density of the positive component. maintain.

Further, for the purpose of expressing a uniform dark color tone, the potential difference in the electrolytic coloring treatment tank is kept at 4 V or less, and the absolute value of the current density at the time of electrolytic coloring is set to 0 of the current density at the time of pre-coloring treatment. It is preferable to maintain it at about 7 times.

When the current density of the cathode current flowing through the aluminum alloy base material 2 during electrolytic coloring is set to a value in the range of 0.6 to 0.95 times the anode current flowing through the aluminum alloy base material 2 during the pre-coloring treatment, the anode current flows. The current distribution is the same and uniform depending on whether the current flows or the cathode current flows. As a result, a uniform electrolytic coloring reaction occurs over the entire surface of the aluminum alloy base material 2, and a colored film having excellent color tone uniformity is formed. The coloring pretreatment is applied to the anodized aluminum alloy base material 2 using the same treatment liquid as the electrolytic coloring treatment liquid used in the subsequent coloring step. Since the same treatment liquid is used for the coloring pretreatment and the coloring treatment, the non-uniformity of the current distribution during the coloring treatment is corrected by the coloring pretreatment. On the other hand, when the coloring pretreatment and the coloring treatment are carried out in different tanks, that is, in different electrolytic cell conditions and bath conditions, the optimum current density ratio Rd for homogenizing the color tone differs between the tanks, so that the same electrolysis is performed. The uniformity of color tone is reduced as compared with the case of using a tank.

The electrolytic coloring treatment bath is not particularly restricted by the component type, concentration, etc., but usually a weakly acidic to neutral treatment bath is used. Metal salts include nitrates containing at least one of Ni, Co, Cu, Sn, Mn, Fe, Pb, Ca, Zn, and Mg, inorganic acid salts such as sulfates, phosphates, and chromate, and oxalic acid. There are organic acid salts such as salts, acetates and tartrates, which are added to the electrolytic coloring treatment bath alone or in combination. In the electrolytic coloring method, even if the same electrolytic treatment bath is used, different color tones are developed depending on the treatment conditions such as applied voltage, current, and time.

In the coloring pretreatment, electrolytic conditions such as voltage, current, temperature, and time are set in order to eliminate variations in the thickness of the barrier layer in these electrolytic coloring treatment liquids. The electrolytic conditions depend on the type of electrolytic coloring treatment liquid to be used, but are ^{appropriately selected within the range of a voltage of 20 to 70 V, a current of 10 to 50 A / m 2} , a temperature of 10 to 30 ° C., and a treatment time of 100 seconds or less. It is preferable to do so. In the electrolytic coloring treatment, a voltage of 20 to 70 V, a current of 10 to 50 A / m ^{2, and} a current of 10 to It is preferable to appropriately select the temperature within the range of 30 ° C. and the treatment time of 600 seconds or less.

The waveform of the current used for the coloring pretreatment and the electrolytic coloring treatment is not particularly restricted. For example, a direct current, a pulse wave, a square wave, a sine wave, a waveform similar to these, a waveform obtained by combining these, and the like can be used.

When a current having a positive component such as a rectangular wave current is used for the electrolytic coloring process, the positive component (anode current) during the electrolytic coloring process is used as the anode current during the pre-coloring process in order to make the current distribution of each part uniform. It is effective to make them substantially equal, or to set the anode current during the electrolytic coloring treatment to 1 / 0.6 to 1 / 0.95 of the cathode current during the electrolytic coloring pretreatment. In the aluminum alloy base material 2 subjected to the electrolytic coloring treatment in this manner, the electrolytic coloring reaction proceeds with a uniform current distribution over the entire surface, so that the electrolytic coloring layer 6 having excellent color tone uniformity is formed. The electrolytically colored aluminum alloy base material 2 can be sealed or the like according to a conventional method.

Hereinafter, the aluminum alloy member of the present invention and the method for producing the same will be further described in Examples, but the present invention is not limited to these Examples.

<< Example 1 >>
Aluminum alloy powder having a composition of Si: 27% by mass, Fe: 0.25% by mass, Cu: 0.25% by mass, Mg: 0.7% by mass, Cr: 0.15% by mass is 565 ° C. after CIP molding. It was sintered by holding it in a vacuum atmosphere for 4 hours, and formed into a columnar shape having ^{a bulk density of 2.3 g / cm 3 and an outer diameter of 250 mm.} The particle size of the aluminum alloy powder used as a raw material is 93%, which is less than 150 μm.

Next, the obtained sintered body was hot-extruded as a billet for hot extrusion. Specifically, the billet was heated at 450 ° C. and inserted into a container of a 10-inch extruder to obtain a plate-shaped extruder having a width of 100 mm and a thickness of 8 mm by extrusion molding. The obtained extruded material was cut to produce an aluminum alloy base material having a size of 50 × 50 × 10 mm.

The aluminum alloy base material was subjected to an anodic oxide film treatment under the conditions of ^{a current density of 15 mA / cm 2} and a treatment time of 1333 seconds using a sulfuric acid bath having a concentration of 180 g / l to form an anodic oxide film.

The aluminum alloy base material after forming the anodic oxide film is used as the anode, SUS304 pole is used as the counter electrode, and nickel sulfate hexahydrate: 140 g / l, boric acid: 40 g / l, and tartrate acid: 4 g / l as the electrolytic bath. Aluminum alloy group after pre-coloring treatment in which a DC current is passed under the conditions ^{of an anode current density of 2.5} mA / cm 2 and an energization time of 5 seconds in an electrolytic bath having a composition (pH 5, temperature 30 ° C.) Using the material as a cathode, a DC current with a pulsed voltage superimposed on the counter electrode (SUS304) is passed, frequency: 5 Hz, ta / tk ratio: 1/9, waveform: rectangular wave, cathode current density: 2.5 mA / cm. ^{2. The} electrolytic coloring layer was formed by performing the electrolytic coloring treatment under the conditions of the electrolytic time: 360 seconds, and the aluminum alloy member of Example 1 was obtained.

<< Comparative Example 1 >>
A 50 × 50 × 10 mm aluminum alloy base material was produced by cutting a JIS-A5052 aluminum alloy material. Using this aluminum alloy base material, the aluminum alloy of Comparative Example 1 is subjected to a dyeing treatment in which an organic dye (TAC411 manufactured by Okuno Pharmaceutical Co., Ltd.) is placed in an aqueous solution containing a concentration of 10 g / L and immersed at a temperature of 55 ° C. for 10 minutes. Obtained a member.

<< Comparative Example 2 >>
An aluminum alloy base material was produced in the same manner as in Example 1, and an anodized film was formed on the aluminum alloy base material in the same manner as in Example 1. The aluminum alloy base material after the formation of the anodized film was dyed in the same manner as in Comparative Example 1 to obtain the aluminum alloy member of Comparative Example 2.

<Evaluation of ^{L * value>}
Using a brightness measuring device (manufactured by Nippon Denshoku Kogyo Co., Ltd., NF777), the brightness index L * value of each aluminum alloy member obtained in Examples and Comparative Examples was measured. Next, the aluminum alloy member was heat-treated by holding it in an atmosphere of 200 ° C. for 100 hours, and the brightness index L * of the aluminum alloy member after the heat treatment was measured. Before heat treatment L ^* values, L ^* value after the heat treatment, and the difference in the L ^* value after the heat treatment and the L ^* value before the heat treatment shown in Table 1.

<Evaluation of coefficient of linear expansion>
The coefficient of linear expansion of each aluminum alloy member obtained in Examples and Comparative Examples was measured according to JIS Z2285: 2003. The obtained values are shown in Table 1.

1 ... Aluminum alloy member,
2 ... Aluminum alloy base material,
4 ... Anodized film,
6 ... Electrolytic coloring layer.

Claims

It consists of an extruded aluminum powder alloy with a Si content of 20-40% by mass.
A base material with an anodized film on the surface and
Provided with an electrolytically colored layer in which a metal or a metal salt is precipitated in the pores of the anodized film.
An aluminum alloy member characterized by.
The aluminum powder alloy contains Si: 20 to 40% by mass, Mg: 0.2 to 1.2% by mass, Cu: more than 0 and 2% by mass or less, Fe: more than 0 and 2% by mass or less, Cr: more than 0 and 0. 4% by mass or less, the balance consisting of Al and unavoidable impurities,
The aluminum alloy member according to claim 1.
The metal and the metal salt contain at least one of Ni, Co, Cu, Sn, Mn, Fe, Pb, Ca, Zn and Mg.
The aluminum alloy member according to claim 1 or 2.
The coefficient of linear expansion is 10 × 10 -6 to 23 × 10 -6 / K,
The aluminum alloy member according to any one of claims 1 to 3.
Difference in L * value after the heat treatment and L * value before the heat treatment of holding for 100 hours in an atmosphere of 200 ° C. is 3 or less,
The aluminum alloy member according to any one of claims 1 to 4.
Being an optical member or a member for an optical member inspection device,
The aluminum alloy member according to any one of claims 1 to 5.
The first step of producing a base material by subjecting aluminum alloy powder having a Si content of 20 to 40% by mass to pressure molding, sintering and extrusion processing.
The second step of forming an anodized film on the surface of the base material and
The base material is electrolytically colored in an electrolytic solution containing a metal or a metal salt, and the metal or the metal salt is precipitated in the pores of the anodized film to form an electrolytically colored layer on the surface of the base material. Including the third step,
A method for manufacturing an aluminum alloy member.