JP2021070865A - Aluminum metal material excellent in thermal resistance and method for producing the same - Google Patents

Abstract

To develop a material in which a black film surface is kept untarnished under high temperature environment in a processed product of an aluminum alloy.SOLUTION: This invention relates to a material comprising aluminum or its alloy and excellent in thermal resistance, the material having 2% or less of a content of manganese or silicon excellent in thermal resistance and having an anodic oxidation film in which the color difference (ΔE) between before and after heating, when a heat resistance test is executed at 300°C for two weeks, is 2.0 or less and the occurrence of cracks are not visually confirmed. This invention further relates to a method for producing such a material. The material has the anodic oxidation film having hardness, measured by a Vickers hardness test, of HV400 or more, and abrasion resistance, measured by a reciprocating flat surface abrasion test, of 120% or more in comparison with a reference test specimen. The material can be producing by forming the anodic oxidation film under an electrolytic coloring condition by using an electrolytic solution mainly comprising an organic acid.SELECTED DRAWING: Figure 1

Description

The present invention relates to an aluminum metal material having excellent heat resistance and a method for producing the same.

Aluminum materials are often used in various products as lightweight metal materials, but since they are easily corroded, they are usually surface-treated by alumite treatment (anodizing treatment), chemical conversion treatment, painting treatment, or the like.

Colored materials have been developed for dyeing in chemical conversion treatment and painting treatment, and electrolytic coloring in anodizing treatment. Black aluminum material, so-called black alumite, has been developed by electrolytic coloring in anodic oxidation, but electrolytic coloring requires two types of electrolytic solutions, which increases the number of processing steps and at the same time requires a wider treatment area. Since the hardness of the obtained anodized film is insufficient, the development of further improved materials is desired. Maintaining a black film surface in processed products of aluminum or its alloys is very important depending on the application, and materials that discolor even when exposed to a slight high temperature environment limit the usage environment. It is desired to develop a material having excellent heat resistance and no fading property.
On the other hand, a method of forming a good far-infrared radiator in which a black film is formed by an electrolytic coloring method in which an anodized film (anodized) of an aluminum alloy is subjected to a secondary electrolytic treatment has been proposed (Patent Document 1). The anodic oxide film obtained here is black and has fairly good heat resistance, but its surface hardness is insufficient, and it is necessary to improve wear resistance and scratch resistance.

Republished Patent (A1) WO 01/090447

The present invention improves the heat resistance of a conventionally used aluminum material, and changes the anodic oxide film to a brownish color at high temperature, which develops a blackish color without performing so-called electrolytic coloring accompanied by secondary electrolysis, which is troublesome to work. The purpose is to provide a material with minimal fading and a method for producing the same.

The present invention has a color difference (ΔE) of 2.0 or less before and after heating when a heat resistance test is carried out at 300 ° C. for 2 weeks, and has an anodized film in which cracks are not visually observed. A material made of aluminum or an alloy thereof having an excellent manganese or silicon content of 2% or less, and a method for producing the same.

The present invention also has a color difference (ΔE) of 2.0 or less before and after heating when a heat resistance test is carried out at 300 ° C. for 2 weeks, and the hardness is changed to the JIS-Z2244 (Vickers hardness test) method. Manganese or manganese with excellent heat resistance and surface hardness, having a hardness of HV400 or higher when measured with a load of 0.098 N (10 grf) and a holding time of 15 seconds, and having an anodized film in which cracks are not visually observed. A material made of aluminum or an alloy thereof having a silicon content of 2% or less, and a method for producing the same.

The present invention also has a color difference (ΔE) of 2.0 or less, particularly preferably 1.8 or less, when a heat resistance test is carried out at 300 ° C. for 2 weeks, and an HV of 400 or more in a Vickers hardness test. The hardness of the film is such that cracks are not visually observed, and the wear resistance of the anodic oxide film is a comparative test with the reference piece. Abrasion standard test piece (for hard film)), the test method is JIS-H8682-1 (reciprocating plane wear test), and the test condition is JIS-H8603 (hard anodic oxide film) hard film. Applicable, the ratio when the wear resistance of the wear resistance standard test piece is set to 100 is displayed as a percentage, and the film of the present invention has an anodized film having a wear resistance of 120% or more, and has heat resistance. A material made of aluminum or an alloy thereof having a manganese or silicon content of 2% or less, which is excellent in surface hardness and abrasion resistance, and a method for producing the same.

The present invention also has a color difference (ΔE) of 2.0 or less before and after heating when a heat resistance test is carried out at 300 ° C. for 2 weeks, has a hardness of HV400 or more in a Vickers hardness test, and cracks occur. Is not visible visually, and when the infrared emissivity is 100 ° C. and the emissivity of the black body is 100% (1.00), the total emissivity is within a wavelength of 3 to 6 μm. For heat resistance, surface hardness and thermal emissivity having an anodized film of 85% (0.85) or more in the infrared region and 80% (0.8) or more in the medium to far infrared region with a wavelength of 3 to 25 μm. A material made of aluminum or an alloy thereof having an excellent manganese or silicon content of 2% or less, and a method for producing the same.

The anodic oxide film in the material of the present invention is a film that reduces the fading of the black film particularly at a high temperature and reduces the surface cracks to the extent that it cannot be visually observed even when heat-treated at a high temperature of 300 ° C. The thickness is 6 to 50 μm, preferably 10 to 30 μm, particularly preferably 20 to 30 μm, when measured after calibration with a calibration standard plate (plastic film) using JIS-H8680-2 (eddy current measurement method). Is. Generally, the alumite film tends to change from brown to black when the film thickness is increased, and becomes black when the film thickness exceeds 80 μm, but when heated to 300 ° C., the entire surface becomes a mesh pattern due to cracks. The film of the present invention is thinner and blacker than the conventional film, has hardness, and has the characteristics that crack generation cannot be visually observed. Here, fading refers to a state in which the color gradually changes from brown to whitish brown due to heating.

The material of the present invention is mainly composed of an aluminum or an alloy thereof having a manganese or silicon content of 2% or less as a solution of an organic acid, to which an additive smaller than the amount of the organic acid used is added. In the electrolytic solution, the average current density of the positive current in one cycle is 0.1 to 10 A / dm ² , the average current of the negative current is 0.0 to 10 A / dm ² , and the liquid temperature is -10 to 60 ° C. Before and after heating when anodization treatment is performed using a direct current superimposed waveform, a pulse waveform, or a PR pulse waveform alone or in combination of two or more current or voltage waveforms, and a heat resistance test is performed at 300 ° C. for 2 weeks. A anodic oxide film having a color difference (ΔE) of 2.0 or less, a hardness of HV400 or more in the Vickers hardness test, and a dark brown to black color tone in which cracks are not visually observed is formed. Can be done. Further, it is also possible to produce an anodized film having a hardness of HV400 or more and at the same time having a wear resistance of 120% or more. Alternatively, regarding thermal radioactivity, it is possible to simultaneously achieve thermal radioactivity of 85% or more in the mid-infrared region having a wavelength of 3 to 6 μm and 80% or more in the mid-far infrared region having a wavelength of 3 to 25 μm.

As the organic acid used as the electrolytic solution, one or more of aliphatic or aromatic sulfonic acid, carboxylic acid or an anhydride or salt thereof was used, and as an additive, an inorganic acid system or an electrolytic solution was used. A solution using one or more organic acid-based compounds different from the organic acid and using water and / or a polyhydric alcohol as a solvent can be used as the electrolytic solution.

Here, the structure of the anodized film (anodized) and the coloring method will be described. This film is a honeycomb-shaped film with innumerable micropores. The part where the micropores exist is called the porous layer, and the boundary between the porous layer and the material is called the barrier layer. It is called an anodized film. There are three types of methods for coloring this anodic oxide film: the top surface, bottom, and wall of the hole, depending on the part to be colored. Generally, this is a dyeing method, an electrolytic coloring method (including secondary electrolytic coloring), and an electrolytic coloring method. , And the natural coloring method. The dyeing method is a method of immersing the film in a solution / dispersion of an organic or inorganic dye or pigment to allow the film to penetrate into the pores of the porous layer from the upper surface (outside), and the upper surface portion of the film is colored. The electrolytic coloring method is a method similar to the plating method in which metal is deposited on the bottom of the pores of the porous layer to develop color, and includes a coloring method by secondary electrolysis. Electrolytic color development and natural color development are methods in which the portion corresponding to the wall of the porous layer is colored as shown in FIG. 1 (color development diagram of the wall portion), and this is an electrolysis such as the composition of the electrolytic solution and the current or voltage used. There are a method of electrolyzing color development depending on the conditions and a method of spontaneous color development depending on the type of metal contained in the alloy material.

The material made of aluminum or an alloy thereof having a manganese or silicon content of 2% or less of the present invention forms a dark brown to black anodized film even in a film having a thickness of 6 to 50 μm, particularly 10 to 30 μm. However, this black film is not colored with dyes or pigments, and is not a natural color that is greatly affected by the alloy components in the materials used. It is formed by subjecting electrolytic coloring alone or both electrolytic coloring and electrolytic coloring, which are greatly affected by the above. Even if this film is heat-treated at 300 ° C. for 2 weeks, no visually observable cracks occur on the surface, and almost no discoloration is observed. On the other hand, when hard alumite is produced with a conventional sulfuric acid-based or sulfuric acid + mixed acid-based electrolytic solution, a black-based film can be formed by performing a film treatment so that the thickness of a pure aluminum-based material is 80 μm or more. However, cracks occur on the surface just by heating to about 100 ° C., and the color tone shifts to a slightly white color.

In addition, when dyeing black alumite is heated at 200 ° C, discoloration begins within a short time, and there are almost no dyeing black alumite products that can be used for a long time without discoloration in a usage environment exceeding 200 ° C. is there.

The reason why the temperature of 300 ° C. is used to detect the color difference ΔE indicating the index of fading in the present invention is as follows. The recrystallization temperature of aluminum is about 250 ° C, and at this temperature, coarse crystals that are the cause of work hardening (work strain generated when deformation processing such as rolling at room temperature) remain in the processed aluminum product are present. The crystal grains produced by softening at 250 ° C. or higher and recrystallizing become stable without internal strain. Practically, the work of softening at about 350 ° C. to reduce the internal stress, so-called annealing (annealing), is required. When processing aluminum, the case where it is performed below the recrystallization temperature is called cold processing, but in the case of this processing method, work hardening always occurs, so annealing is required, but when using the processed product, the recrystallization temperature is long. Since it is rare to use it as described above, if there is no abnormality in the color fading property in the heat resistance test at 300 ° C, which is the starting point of softening, it can be used without any problem in terms of practical fading. The test temperature selected from.

In the present invention, an electrolytic solution mainly composed of an organic acid is used, and the organic acid is an aliphatic or aromatic sulfonic acid and / or a carboxylic acid-based single or mixed system, specifically, oxalic acid and malonic acid. , Succinic acid, malic acid, maleic acid, citric acid, tartaric acid, pimelli acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, etc. Then, one kind or a combination of two or more kinds of these is used as an electrolytic solution at the time of anodization. The concentration of these liquids is preferably 0.1 to 4.5 mol / L. The electrolysis conditions are positive current average current density 0.1 to 10 A / dm ² , negative current average current density 0.0 to 10 A / dm ² , liquid temperature -10 to 60 ° C, and anodic oxidation treatment. The film thickness is manufactured to 6 to 50 μm.

The current density of DC electrolysis that is normally used is the value obtained by dividing the amount of electricity (A · second) by the electrolysis time (second) and the surface area (dm ² ) of the object to be processed, and is called DC constant current electrolysis (usually called DC electrolysis). In), the current density and the average current density are used as synonyms because the current does not change with time with respect to the object to be processed, and the unit is A / dm ² . However, in the case of a pulse or PR pulse waveform, a "positive current", "0 (time when no current flows)" or a "negative current" whose polarity is reversed flows depending on the time, so the average current density in the waveform is the current waveform. In one cycle (cycle), the positive current part and the negative current part are divided, and the respective electric amounts (A · second) divided by the electrolytic time and the surface area of the object to be processed are divided into the positive current average current density and the negative current. It is necessary to display it as the average current density. As an example, when an object to be processed with an electrolytic area of ² dm 2 is electrolyzed with a PR waveform, when one cycle of the waveform is 10 seconds and a positive current of 2 A is applied for 4 seconds and then a negative current is applied at 1 A for 6 seconds, the positive current is applied. and the average current, respectively density 0.4 a ^/ dm 2 of the negative current and 0.3 a / dm ^2. When only the positive current is used, the average current density of the negative current is 0.0 A / dm ² .

Those that can be added as an additive to an electrolytic solution containing an organic acid as a main component are one or more compounds of an inorganic acid type or an organic acid type. The organic acid-based compound is the above-mentioned aliphatic or aromatic sulfonic acid and / or carboxylic acid-based compound, but an additive different from the organic acid used in the electrolytic solution mainly composed of the organic acid is used as an additive. Use. In addition, alcohol compounds such as ethylene glycol, diethylene glycol, and glycerin can be used as a solvent, and the amount thereof is up to 60%, and these alcohol compounds can be used together with water as a part of the solvent. Examples of the inorganic acid-based compound include boric acid, silicic acid, hydrofluoric acid, sulfuric acid, phosphoric acid, nitrate or salts thereof, pyrophosphate, sulfamic acid or salts thereof, or fluoride salt, bicarbonate salt, permanganate. One kind or two or more kinds such as salt can be used. The amount of these additives used is less than the amount of the organic acid mainly used in the electrolytic solution, and the liquid concentration is preferably 0.001 to 0.9 mol / L.

The electrolytic conditions for forming a dark brown to black anodic oxide film by electrolytic coloring alone or by electrolytic coloring and electrolytic coloring are a combination of DC, pulse, and PR pulse current, and the average current density of positive current is 0.1 to 1. 10 A / dm ² , preferably 0.8 to 3.5 A / dm ² , average current density of negative current 0.0 to 10 A / dm ² , preferably 0.0 to 3.5 A / dm ² , liquid temperature- Electrolytic treatment is performed with an electrolytic solution containing mainly an organic acid at 10 to 60 ° C., preferably -5 to 30 ° C., and a small amount of an organic acid or an inorganic acid different from this organic acid is added as an additive, and the solution is immediately after the treatment. The time corresponding to 0.5 to 20% of the time required for film formation without being taken out from the inside is left in a state where the current is cut off, and then taken out, and the process proceeds to the next step such as washing with water. The thickness of the film to be formed is 6 to 50 μm, but preferably 10 to 30 μm from the viewpoints of workability, performance, cost and the like. If the energization cutoff immersion time after the completion of the electrolytic treatment is 20% or more of the time required for film formation, the film is dissolved from the surface and the hardness becomes soft, and the dissolved residue remains on the surface, making the film unsuitable. Further, if it is 0.5% or less, color unevenness is likely to occur in the color addition in the next step, which is not preferable.

As the current or voltage waveform of the anodic oxidation treatment used in the present invention, it is preferable to use a waveform of a DC waveform, an AC waveform, an AC / DC superimposition waveform, a pulse waveform, or a PR pulse waveform alone or in combination of two or more. Particularly preferable results can be obtained by using a pulse waveform or a PR pulse wave. In the electrolytic method, the current density ^{starts from a low voltage / current of about 1 A / dm 2} in the usual method, and the voltage or current increases with the passage of time. In the initial state, a method of flowing a high current density for a certain period of time and decreasing the current density with the passage of time is preferable.

In the present invention, it is possible to produce an anodic oxide film having excellent black fading property and excellent surface hardness only by electrolytic coloring, but in addition to this, electrolytic coloring can also be applied. In that case, the electrolytic conditions for electrolytic coloring are AC, DC, pulse, and PR pulse waveforms as current or voltage waveforms, either alone or in combination, with a voltage of 1 to 40 V, a time of 1 to 30 minutes, and a liquid temperature. Is performed at -10 to 40 ° C, preferably 10 to 25 V, 5 to 15 minutes, 16 to 30 ° C. If the power supply has polarity, set the (member to be processed) on the cathode side, and the anode side is a carbon plate electrode. Electrolysis is performed using the above, and washing with water before and after electrolytic coloring is sufficiently performed with deionized water or pure water. The electrolytic solution is a solution capable of dissolving the added metal, and typical examples thereof are a sulfuric acid compound and an oxalic acid compound, and a carboxylic acid-based organic acid, boric acid and the like are added as additives. As the metal compound that becomes a deposited metal by electrolytic coloring, gold, silver, copper, platinum, tin, cobalt, nickel, iron, tungsten, molybdenum, chromium, zinc, palladium, zirconium, vanadium, titanium, manganese and the like are used.

The color difference (ΔE) used as a measure of the low fading property in the present invention is a quantitative expression of a “color difference” that could only be evaluated by sensory analysis in the past. For example, even if they look the same to the human eye, the hue, saturation, and brightness of the reference color points are measured three-dimensionally using a colorimeter, and the sample color points are also measured in the same way. This is a method of expressing the distance between points as a color difference. In the present invention, when performing a heat resistance test, the color before heating is used as a reference point, the color after heating is measured with a spectrophotometer, and the distance between two three-dimensional points is indicated by ΔE. The spectrophotometer can automatically display the numerical value. In general, a color difference of about ΔE = 1 is a difference that makes a difference when two colors are placed side by side and compared, and a color difference of about ΔE = 2 to 3 is a difference that can be seen when two colors are separated and compared. Shown.

There is a method called the Hunter method as a measure of fading property, but this is an old standard and is not listed in the JIS standard. There is a Munsell (1905) method for expressing color, which is expressed in hue, lightness, and saturation. In the process of quantifying this, the International Commission on Illumination (CIE) established the XYZ color system in 1931 and the L * a * b * color space in 1976, and it was adopted in JISZ8781-4 in Japan as well. Furthermore, an L * C * h color space has been created, and today the XYZ color system is the basis of each color system as the CIE standard color system. The Hunter method was quantified in 1948 using a chromaticity diagram of the Lab color space, but was later improved to the L * a * b * color space and became a JIS standard. It is difficult to express the relationship between the hunter method based on the Lab color space and the color difference based on the L * a * b * color space with a specific function or formula, so it is the same to compare the measured values by the two methods. It is necessary to measure the sample in each color system to obtain color notation and color difference. The color difference (ΔE) of the present invention uses the L * a * b * color space method and the Hunter Lab color space method (hereinafter referred to as HLab) on the same surface of the sample using a spectrocolorimeter (CM-700d) manufactured by Konica Minolta. The color difference was calculated. In the comparison of the color difference of the measurement results here, ΔE (L * a * b *)> HΔE (HLab).

In the case of the conventional product, the anodized film of the present invention begins to fade to a brownish brown color when heated at a temperature exceeding 200 ° C., and at 300 ° C., the color difference ΔE exceeds 2.0 in about 1 hour. The ΔE of the product can be maintained at 2.0 or less even after a heat resistance test at the same temperature for 2 weeks. Further, in the case of an electrolytically colored film, there is a proposal of a film in which nickel or cobalt is deposited in the porous pores, and the fading property does not change for 100 hours (4 days) at 400 ° C., but a black anode No material having a ΔE of 2.0 or less has been found as shown in Comparative Example 3 by heat-treating the oxide film at 300 ° C. for as long as 2 weeks. Further, the surface hardness is about HV320, and further improvement is desired in practical use.

Further, the anodic oxide film of the present invention has excellent fading property and a hardness of HV400 or more in the Vickers hardness test. Further, it is a film having excellent wear resistance of 120% or more in the reciprocating plane wear test, and has this excellent feature at the same time in most cases. In addition, the above-mentioned thermal radioactivity can be achieved at the same time.

In the present invention, the additive may be used alone or in a mixed system as needed. In particular, when an organic acid compound and an inorganic acid compound are used in combination, liquid management becomes easy, which is preferable. The amount of these additives used is in the range of 0.001 to 0.9 mol / liter in the electrolytic solution, which is smaller than the organic acid used as the main component in the electrolytic solution. The anodizing treatment of a material made of aluminum or an alloy thereof having a manganese or silicon content of 2% or less in the electrolytic solution adjusted in this way is particularly preferably performed at a bath temperature of −10 to 60 ° C.

The aluminum-based material having excellent heat resistance of the present invention is also a material having a silicon and / or manganese content of 2% or less, and the total radiation when the infrared emissivity is measured at the measurement temperature of the substance to be measured at 100 ° C. Thermal emissivity with an anodized film having a rate of 85% (0.85) or more in the mid-infrared region with a wavelength of 3 to 6 μm and 80% (0.8) in the mid to far infrared region with a wavelength of 3 to 25 μm. It turned out to be excellent.

In the present invention, the aluminum metal material to be anodized can be widely applied to pure aluminum, but alloys such as wrought material containing 2% or more of silicon and / or manganese are difficult to obtain because they are special materials. In addition to being expensive, it is not suitable for use in the present invention because it has a drawback that the electrolysis work becomes difficult as the amount of such metal components increases.

Since the recrystallization temperature (around 250 ° C.) affects the high-temperature use of aluminum, it is usually used below this temperature. However, especially in the case of black alumite, it is sometimes used in the vicinity of this to the softening temperature of around 300 ° C. This requires a heat-resistant film that can withstand the recrystallization temperature to the initial stage of softening when used in internal combustion engines such as light weight and low cost, heat absorbers at high temperatures, etc. Since the properties are insufficient and there is no wear resistance, and the use is further limited, a film that clears these has been long-awaited. Since the material of the present invention has a heat resistance of 300 ° C. and a color difference of ΔE2.0 or less in the color notation in the L * a * b * color space before and after heat treatment for 2 weeks, and further has a hardness of HV400 or more. It is expected to be used as a material for use at high temperatures, as a material for thermal power generation, or as a material for a thermal cycle system.

Hereinafter, embodiments of the present invention will be specifically described.
In the examples, the Vickers hardness test was performed by a microscopic cross-sectional measurement method using a micro-hardness meter (HMV-G-XY-D) manufactured by Shimadzu Corporation at a load of 10 gf for 15 seconds to measure an average film. Indicates hardness. However, when the film thickness is 20 μm or less, it is measured with the same load and the same time using a noup type indenter. The film thickness indicates the average thickness measured by an eddy current film thickness meter (LH-373) manufactured by Kett Science Institute Headquarters. The color difference (ΔE) before and after heating is heat-treated at 300 ° C. for 2 weeks as a heat resistance test, measured with a spectrocolorimeter (CM-700d) manufactured by Konica Minolta, and the color difference before and after heating is L * a * b *. It was represented by the color difference (ΔE) in the color space method and the color difference (HΔE) in the Hunter Lab color space method. Abrasion resistance is the percentage (percentage) when the value obtained by performing a reference test piece under hard film test conditions with a reciprocating half-sided wear tester manufactured by Suga Test Instruments Co., Ltd. is set to 100. The thermal emissivity is when the temperature of the object to be measured is 100 ° C and the emissivity of the black body is 100% using a spectral emissivity measurement system (IRTracer-100) manufactured by Shimadzu Corporation as an infrared emissivity measuring device. The total emissivity of the mid-infrared wavelengths 3 to 6 and the total emissivity of the medium to far infrared region having a wavelength of 3 to 25 μm are measured and displayed in%.

Emulsion degreasing, 45 ° C x 5 minutes-5% nitric acid, room temperature x 3 minutes-with a test piece of 50 x 100 x t1.0 mm as a pretreatment with aluminum A1050 material (Si 0.25%, Mn 0.05% or less) Etching 20% sodium hydroxide, room temperature x 1 minute-de-smut, 10% sulfuric acid, room temperature x 3 minutes, the electrolyte is 0.7 mol / L of malonic acid, and 0.02 mol / L of oxalic acid + 0 sulfuric acid as an additive. It was assumed that 0.05 mol / L was added, the liquid temperature was 20 ° C., the power source was a DC waveform, the current density was 1.5 A / dm ² for 60 minutes, and the energization cutoff time was 2 minutes. The color tone of the film was a dark brownish black electrolyzed, and the average film thickness was 29 μm. The color difference (ΔE) in the L * a * b * color space before and after heating at 300 ° C. was 1.6, and the color difference HΔE by the Hunter process Lab (HLab) was 1.4. The average film hardness by the microscopic cross-section measurement method was HV480. The wear resistance was 142.9%. As for the infrared emissivity, when the emissivity of the blackbody is 100%, the total emissivity of the mid-infrared wavelength 3 to 6 μm is 91.3%, and the total emissivity of the medium to far infrared region of the wavelength 3 to 25 μm is 88.4. % Was obtained, and no cracks were observed.

Comparative Example 1

The material, pretreatment, and film were measured in the same manner as in Example 1. The electrolytic solution was 15% sulfuric acid, current density 1.0 to 1.1 A / dm ² , electrolytic voltage 14 V, bath temperature 20 ± 1 ° C, electrolysis. After the electrolysis is completed for 60 minutes, it is thoroughly washed with water, and as a dyeing process, the organic dye Alphast Black (manufactured by Orient Chemical Co., Ltd.) SW5804 is immersed at 20 g / L at 50 ° C. for 25 minutes. -100 (manufactured by Okuno Pharmaceutical Co., Ltd.) 7 g / L, 94 ° C., 15 minutes-washing with water 3 times-washing with pure water-drying, and a uniform black color was obtained. As a result of the measurement method of Example 1, the average film thickness was 20 μm, the average cross-sectional hardness of the Knoop type was HV290, and the heat resistance test was at 300 ° C. in one day, and the color difference in the L * a * b * color space before and after the heat treatment ( ΔE) was 31.0, and in HLab, the color difference (HΔE) was 26.6, and the test was discontinued. Abrasion resistance was discontinued due to substrate exposure, the total emissivity of the mid-infrared region (3 to 6 μm) was 64.8%, and the total emissivity of the mid to far infrared region (3 to 25 μm) was 83%. The cracks were generated in a mesh pattern on the entire surface. The black alumite production method of this comparative example conforms to the JIS standard (H8601-AA20), but the material intended by the present invention cannot be obtained by this production method.

Comparative Example 2

The material, pretreatment, and film were measured in the same manner as in Example 1, and the electrolyte and conditions were JIS-H8603: Abrasion resistance standard test piece of Annex I of hard anodized film of aluminum and aluminum alloy (for hard). ), The electrolytic solution has a free sulfuric acid concentration of 180 ± 1 g / L, a dissolved aluminum concentration of 3 g / L, a bath temperature of 0 to 1 ° C., a current density of 1.7 A / dm ² , a treatment time of 60 minutes, and after electrolysis is completed. The energization cutoff time was set to 2 minutes, and the dyeing step and the sealing step were carried out at room temperature. As a result, the color tone was brownish black, the average film thickness was 31 μm, the average cross-sectional hardness was HV408, the heat resistance test was 300 ° C.-4 days, the color difference (ΔE) was 7.3, and the HΔE was 6.1. So I stopped the test. Abrasion resistance is 102%, infrared emissivity is 60.3% in the mid-infrared region, 81% in the mid-to-far infrared region, and cracks are generated in a mesh pattern on the entire surface, which is the object of the present invention. No material was obtained.

The material, pretreatment, and film were measured in the same manner as in Example 1, the electrolyte composition was the same, a power supply with a PR pulse waveform was used as the electrolytic condition, and the positive (positive current) side current density was 2.5 A / dm. ^{2 -100ms,} the current density of the negative (negative current) side 0.5A ^/ dm 2 -40ms, average current density positive average current density is 1.79A / dm ^2, the negative side at this time is 0.14 a / It becomes dm ^2. The liquid temperature was 20 ± 1 ° C., the electrolysis time was 60 minutes, and the energization cutoff time after electrolysis was 5 minutes. As a result, the color tone of the film was dark brown black, the average film thickness was 33 μm, the cross-sectional average hardness was HV476, and heat resistance. Color difference (ΔE) before and after the test at 300 ° C for 2 weeks is 1.5, HΔE is 1.3, wear resistance is 131%, infrared emissivity is 89.3% in the mid-infrared region, medium to medium to In the far-infrared region, it was 91.4%, and no cracks were visually observed.

The material, pretreatment, and film were measured in the same manner as in Example 1, 2.5 mol / L of maleic acid was added as the electrolytic solution, 0.04 mol / L of sulfuric acid was added as an additive, and the electrolytic conditions were DC waveforms and current density. Was electrolyzed at 1.2 A / dm ^{2 at} a liquid temperature of 20 ° C. for 70 minutes. The energization cutoff time after electrolysis was 8 minutes. The color of the film is brownish black, the average thickness is 27 μm, the cross-sectional average hardness is HV460, the heat resistance test is 300 ° C x 2 weeks, the color difference ΔE is 1.9, HΔE is 1.6, and the wear resistance is 125. The total infrared emissivity was 88.6% in the mid-infrared region and 90.4% in the mid-to-far infrared region, and no cracks were visually observed.

The material, pretreatment, and film were measured in the same manner as in Example 1, and the electrolytic solution was 0.8 mol / L of sulfosalicylic acid plus 0.05 mol / L of sulfuric acid as an additive, and a pulse waveform was used as the electrolytic condition. performs electrolysis using a current density of 2.5A ^/ dm 2 -200ms, at rest 50 ms, the average current density of 2.0A / dm ^2, a liquid temperature 20 ° C., and electrolyte 50 minutes, three minutes energization interruption time As a result, the color tone of the film was dark grayish black, the film thickness was 30 μm, the hardness was HV470, the heat resistance test was 300 ° C. × the color difference (ΔE) before and after the test for 2 weeks was 1.8, and the HΔE was 1.5. The wear resistance was 130%, the infrared radiation rate was 89.1% in the mid-infrared region, and 91.8% in the mid-to-far infrared region, and no cracks were visually observed.

The material, pretreatment, and film were measured in the same manner as in Example 1, the electrolytic solution was 1.0 mol / L of tartrate acid plus 0.05 mol / L of sulfuric acid as an additive, and a pulse waveform was used as the electrolytic condition. The current electrolysis was performed at a current density of 2.5 A / dm ² , -200 ms, a pause of 50 ms, an average current density of 2.0 A / dm ² , and a liquid temperature of 20 ° C. for 50 minutes. As a result of setting the time to 3 minutes, the color tone of the film was dark grayish black, the average film thickness was 30 μm, and HV475. In the heat resistance test, the color difference (ΔE) before and after the test at 300 ° C for 2 weeks was 1.8, HΔE was 1.5, abrasion resistance was 138%, and the infrared emissivity was 89.1% in the mid-infrared region. In the mid to far infrared region, it was 91.8%, and no cracks were visually observed.

The material, pretreatment, and film were measured in the same manner as in Example 1, the electrolyte composition was the same, a pulsed power source was used as the electrolytic conditions, the liquid temperature was 18 ° C, and the current density was 3.5 A / dm ² . , Pulse waveform is performed at 200 ms and 100 ms average current density 2.3 A / dm ² for 15 minutes, then pulse waveform is 150 ms and 50 ms average current density 1.5 A / dm at 2.0 A / dm ^2. Treatment with dm ² for 15 minutes, further electrolysis with DC constant current electrolysis at a current density of 1.0 A / dm 2 for 20 minutes, and the energization cutoff time after electrolysis was set to 3 minutes. As a result, the total energization time was 50 minutes. The color tone is dark brownish black, the film thickness is 30 μm, the hardness is HV495, the color difference (ΔE) before and after the heat resistance test 300 ° C x 2 weeks is 1.7, HΔE is 1.4, and abrasion resistance. Was 146%, the infrared radiation rate was 88.3% in the mid-infrared region, and 90.7% in the mid-to-far infrared region, and no cracks were visually observed.

The material, pretreatment, and film were measured in the same manner as in Example 1, and the electrolytic solution was 1.0 mol / L of tartaric acid plus 0.05 mol / L of sulfuric acid as an additive, and the electrolytic conditions were the direct current method. At a liquid temperature of 20 ± 1 ° C., ^{electrolysis was performed at a current density of 1.5 A / dm 2} for 40 minutes, and the energization cutoff time was set to 3 minutes. When this sample was taken out and washed thoroughly with pure water, the color tone was brownish. Next, this sample was subjected to AC electrolysis as secondary electrolysis, and the liquid composition was a liquid of stannous sulfate 10 g / L, nickel sulfate hexahydrate 15 g / L, sulfuric acid 15 g / L, and tartrate acid 8 g / L, PH = 1. Secondary electrolysis was performed for 20 minutes at a bath temperature of 23 ° C. and an electrolysis voltage of 16 V, and boiling water was further sealed at 95 ° C. for 20 minutes as a sealing treatment. The color tone was brownish black due to electrolytic coloring by secondary electrolysis, the average film thickness was 18 μm, and the hardness was HV460 in the noup type. The color difference (ΔE) before and after the 300 ° C heat resistance test is 1.7, HΔE is 1.4, abrasion resistance is 124%, infrared emissivity is 87.3% in the mid-infrared region, and in the mid to far infrared region. At 89.3%, no cracks were visually observed.

The material, pretreatment, and film were measured in the same manner as in Example 1. The conditions for electrolysis were a liquid temperature of 20 ° C., a DC waveform was used as the power source, and electrolysis was performed at ^{a current density of 1.5 A / dm 2 for 40 minutes.} The energization cutoff time was set to 1.5 minutes, and when this sample was taken out and thoroughly washed with pure water, the color tone was brownish. Further, as secondary electrolysis, AC electrolysis is performed, and the liquid composition is a liquid of stannous sulfate 10 g / L, nickel sulfate hexahydrate 15 g / L, sulfuric acid 15 g / L, and tartrate acid 8 g / L, PH = 1, bath temperature 23. Secondary electrolysis was performed at ° C. and an electrolysis voltage of 16 V for 10 minutes, and boiling water was further sealed at 95 ° C. for 15 minutes as a sealing treatment. The color tone was brownish black due to electrolytic coloring by secondary electrolysis, the average film thickness was 13 μm, and the hardness was HV475 with a noup type. The color difference (ΔE) before and after the 300 ° C heat resistance test is 1.9, HΔE is 1.6, abrasion resistance is 136%, infrared emissivity is 86.8% in the mid-infrared region, and in the mid to far infrared region. At 87.1%, no cracks were visually observed.

Comparative Example 3

The material, pretreatment, and film were measured in the same manner as in Example 1, the electrolytic solution was 15% sulfuric acid, electrolysis was performed at a current density of 1.5 A / dm ² and a bath temperature of 15 ± 1 ° C. for 45 minutes, and electrolysis was completed. After that, it was thoroughly washed with water and used as secondary electrolysis by AC electrolysis. The liquid composition was 10 g / L of stannous sulfate, 15 g / L of nickel sulfate hexahydrate, 15 g / L of sulfuric acid, and 8 g / L of tartrate, PH = 1. The second electrolysis was performed at a bath temperature of 23 ° C. and an electrolysis voltage of 16 V for 20 minutes, and the hole was further sealed with boiling water at 95 to 98 ° C. for 20 minutes. The color tone was brownish black, the average film thickness was 20 μm, and the hardness was HV320 as a result of performing a noup method with a load of 10 gf for 15 seconds because the film was thin. In the heat resistance test, the color difference (ΔE) before and after the test at 300 ° C for 2 weeks was 2.2, the wear resistance was stopped due to the exposure of the substrate, the infrared emissivity was 78.0% in the mid-infrared region, and the mid to far infrared rays. In the region, it was 86.3%, and cracks were observed. It can be seen that it is difficult to reduce the color difference (ΔE) in the L * a * b * color space to 2.0 or less only by electrolytic coloring.

The material, pretreatment, and film were measured in the same manner as in Example 1. As for the electrolytic solution, 30% ethylene glycol was added as a solvent to the electrolytic solution of Example 1, the liquid temperature was 30 ° C., the power source was a DC waveform, and the current was used. Electrolysis was performed at a density of 2.0 A / dm ² for 40 minutes, the energization cutoff time was set to 0.5 minutes, and when this sample was taken out and thoroughly washed with pure water, the color tone was dark brown. Further, as a sealing treatment, boiling water was sealed at 95 ° C. for 15 minutes. The average film thickness was 24 μm, and the hardness was HV453 of the Noup type. The color difference (ΔE) before and after the 300 ° C heat resistance test is 1.9, HΔE is 1.6, abrasion resistance is 137%, infrared emissivity is 83.7% in the mid-infrared region, and in the mid to far infrared region. At 85.3%, no cracks were observed visually.

The material of the present invention has a heat resistance of 300 ° C. and a heat treatment of 2 weeks for a color difference of ΔE2.0 or less, and further has a hardness of HV400 or more. It is expected to be used as a material for thermal cycle systems.

Schematic cross-sectional view of the part corresponding to the wall of the porous pores of the anodic oxide film.

1. 1. Micropores 2. Wall 3. Material (aluminum) 4. Porous layer 5. Barrier layer

Claims (10)

Manganese with excellent heat resistance has a color difference (ΔE) of 2.0 or less before and after heating when a heat resistance test is carried out at 300 ° C. for 2 weeks, and has an anodized film in which cracks are not visually observed. A material made of aluminum or an alloy thereof having a silicon content of 2% or less. The color difference (ΔE) before and after heating when the heat resistance test was carried out at 300 ° C. for 2 weeks was 2.0 or less, the hardness was HV400 or more in the Vickers hardness test, and cracks were not visually observed. A material having an anodic oxide film and having an excellent heat resistance and surface hardness, and an aluminum having a content of manganese or silicon of 2% or less or an alloy thereof. The color difference (ΔE) before and after heating when the heat resistance test was carried out at 300 ° C. for 2 weeks was 2.0 or less, the hardness was HV400 or more in the Vickers hardness test, and no cracks were visually observed. Aluminum or aluminum having an anodized film having an abrasion resistance of 120% or more in a reciprocating plane wear test and having an excellent heat resistance, surface hardness, and abrasion resistance, and a manganese or silicon content of 2% or less. A material made of alloy. The color difference (ΔE) before and after heating when the heat resistance test was carried out at 300 ° C. for 2 weeks was 2.0 or less, and the Vickers hardness test showed a hardness of HV400 or more, and no cracks were visually observed. When the measured temperature of the substance to be measured is 100 ° C and the emissivity of the black body is 100% (1.00), the total emissivity is 85% (0) in the mid-infrared region with a wavelength of 3 to 6 μm. .85) or more, and contains manganese or silicon having an anodized film having an anodized film of 80% (0.8) or more in the medium to far infrared region having a wavelength of 3 to 25 μm and having excellent heat resistance, surface hardness and thermal emissivity A material consisting of aluminum or an alloy thereof in an amount of 2% or less. Claim 1 is characterized in that the color difference (ΔE) before and after heating when a heat resistance test is carried out at 300 ° C. for 2 weeks is 2.0 or less, and the film thickness of the anodized film is 6 to 50 μm. A material made of aluminum or an alloy thereof having a content of manganese or silicon having at least excellent heat resistance of any one of 4 to 4 of 2% or less. A claim characterized in that the color difference (ΔE) before and after heating when a heat resistance test is carried out at 300 ° C. for 2 weeks is 2.0 or less, and the anodized film has a dark brown to black color tone. A material made of aluminum or an alloy thereof having a content of manganese or silicon excellent in at least heat resistance of any one of 1 to 5 of 2% or less. A material composed of aluminum or an alloy thereof having a manganese or silicon content of 2% or less is anodized in an electrolytic solution containing an additive in water and / or an alcohol solution as an organic acid solvent, and at 300 ° C. The color difference (ΔE) before and after heating when the heat resistance test was carried out for 2 weeks was 2.0 or less, the hardness was HV400 or more in the Vickers hardness test, cracks were not visually observed, and the thickness was high. Manganese or silicon having excellent heat resistance and surface hardness, which is characterized by forming an anodized film having a dark brown to black color tone by electrolytic coloring alone or both electrolytic coloring and electrolytic coloring of 6 to 50 μm. A method for producing a material made of aluminum or an alloy thereof having a content of 2% or less. The organic acid used as the electrolytic solution is one or more of an aliphatic or aromatic sulfonic acid, a carboxylic acid or an anhydride thereof, or a salt thereof, and is used as an inorganic acid-based or electrolytic solution as an additive. The heat resistance of claim 7, which is one or more organic acid-based compounds different from the existing organic acid, and uses a solution using water and / or a polyhydric alcohol as a solvent as an electrolytic solution. A method for producing a material made of aluminum or an alloy thereof having a manganese or silicon content of 2% or less, which is excellent in surface hardness. A claim characterized in that the current or voltage waveform of the anodic oxidation treatment of aluminum or an alloy thereof is a waveform of a DC waveform, an AC waveform, an AC / DC superimposition waveform, a pulse waveform, or a PR pulse waveform alone or in combination of two or more. A method for producing a material made of aluminum or an alloy thereof having a manganese or silicon content of 2% or less, which is excellent in heat resistance and surface hardness of 7 or 8. As electrolytic conditions for forming an anodized film with a dark brown to black color tone by electrolytic coloring alone or by electrolytic coloring and electrolytic coloring, the average current density of positive current in one cycle is 0.1 to 10 A / dm ² , and negative current. Anodized in an electrolytic solution containing an organic acid solution as the main component and a smaller amount of additives than the main organic acid at an average current density of 0.0 to 10 A / dm ^{2 and a liquid temperature of -10 to 60 ° C.} Instead of taking it out of the solution immediately after the treatment, it is necessary to cut off the current for 0.5 to 20% of the time required for film formation, leave it in an immersed state, and then take it out to produce a film thickness of 6 to 50 μm. A method for producing a material made of aluminum or an alloy thereof having a manganese or silicon content of 2% or less, which is excellent in heat resistance and surface hardness according to any one of claims 7 to 9.

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