Surface-treated aluminum material, method for manufacturing the same, and component for semiconductor manufacturing equipment

Abstract

The present invention provides a surface-treated aluminum material that exhibits excellent corrosion resistance to corrosive gases and plasma, and can suppress the occurrence of cracks even when the temperature rises, as well as a method for manufacturing the same and a component for a plasma processing apparatus. [Solution] The surface-treated aluminum material 1 comprises a base material 2 made of aluminum or an aluminum alloy, and a protective film 3 formed on the base material. The protective film 3 comprises a first layer 31 made of aluminum oxide that covers the base material 2, and a second layer 32 containing hydrated aluminum oxide that covers the first layer 31. Cathode polarization measurement is performed on the base material 2 and the aluminum material 1 after heating at a temperature of 300°C for 1 hour using a predetermined measurement solution, and the current density at the center potential of the potential region showing the diffusion limit current of hydrogen ions in the base material 2 is measured, and the current density J of the base material 2 is measured. B Current density J of aluminum material 1 300 Ratio J 300 / J B 150 x 10 -4 The following applies:

Description

[Technical Field]

[0001] This invention relates to a surface-treated aluminum material, a method for manufacturing the same, and a component for semiconductor manufacturing equipment. [Background technology]

[0002] Aluminum materials, consisting of aluminum or aluminum alloys, are used in a wide variety of applications. These aluminum materials may have an anodic oxide coating applied to their surface to achieve various objectives, such as improved corrosion resistance, scratch resistance, and aesthetic appeal. Because the functions that can be imparted to aluminum materials by the anodic oxide coating are diverse, the application fields of aluminum materials with anodic oxide coatings are expanding rapidly.

[0003] For example, Patent Document 1 describes a component for a substrate processing apparatus that performs plasma processing on a substrate, characterized in that the component is connected to the anode of a DC power supply and has a coating formed on its surface by an anodic oxidation treatment in which it is immersed in a solution mainly composed of an organic acid, and the coating is subjected to a semi-sealing treatment using boiling water. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2008-81815 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, the component described in Patent Document 1 has a problem in that its durability against corrosive gases and plasma is low because the pores of the anodic oxide film are not completely sealed.

[0006] On the other hand, in the component described in Patent Document 1, a method of completely sealing the pores of the anodized coating can be considered to improve durability against corrosive gases and plasma. However, in this case, cracks are more likely to occur in the anodized coating when the temperature rises, and there is a risk of foreign matter consisting of small fragments of the anodized coating being generated. To suppress the generation of such foreign matter, it is desirable to further improve the heat resistance of aluminum material having an anodized coating on its surface.

[0007] This invention has been made in view of the above background, and aims to provide a surface-treated aluminum material that has excellent corrosion resistance to corrosive gases and plasma, and can suppress the occurrence of cracks even when the temperature rises, a method for manufacturing the same, and a component for semiconductor manufacturing equipment. [Means for solving the problem]

[0008] One aspect of the present invention comprises a base material made of aluminum or an aluminum alloy, and a protective skin formed on the base material. membrane and A surface-treated aluminum material having, The protective coating consists of an aluminum oxide and comprises a first layer covering the base material, It comprises a second layer containing aluminum hydrate oxide and covering the first layer, When the cathode polarization of the base material and the surface-treated aluminum material after heating at 300°C for 1 hour was measured using a measurement solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1, the current density of the base material was measured at the potential at the center of the potential region indicating the diffusion limit current of hydrogen ions in the base material. B Current density J of the surface-treated aluminum material 300 Ratio J 300 / J B 150 x 10 -4 The following is a surface-treated aluminum material.

[0009] Another aspect of the present invention is a member for a semiconductor manufacturing apparatus made of the surface-treated aluminum material of the above aspect.

[0010] Still another aspect of the present invention is a method for manufacturing the surface-treated aluminum material of the above aspect, wherein the first layer is formed on the base material by subjecting the base material to an anodic oxidation treatment in an electrolytic solution containing an organic acid, then, the base material and the first layer are heated at a temperature of 300°C or higher, and then, the second layer is formed on the first layer.

Advantages of the Invention

[0011] The surface-treated aluminum material (hereinafter referred to as "aluminum material") includes a first layer made of an aluminum oxide and a second layer containing a hydrated oxide of aluminum and covering the first layer, and has a protective film formed on the base material. Further, when the cathode polarization measurement of the surface-treated aluminum material and the base material after heating at a temperature of 300°C for 1 hour is performed, the ratio J B of the current density J 300 of the surface-treated aluminum material to the current density J 300 / J B of the base material is 150×10 -4 or less. The aluminum material having such characteristics is excellent in corrosion resistance against corrosive gases and plasmas, has excellent heat resistance, and can suppress the occurrence of cracks even when the temperature rises.

[0012] Since the member for the semiconductor manufacturing apparatus is made of the aluminum material, it is excellent in corrosion resistance against corrosive gases and plasmas, has excellent heat resistance, and can suppress the occurrence of cracks even when the temperature rises.

[0013] In the method for manufacturing the surface-treated aluminum material, a first layer is formed by anodic oxidation of the base material in an electrolyte containing an organic acid. Then, a second layer is formed after heating the first layer to a temperature within the specified range. The protective film thus formed has high heat resistance and can suppress the occurrence of cracks even when the temperature of the aluminum material rises.

[0014] As described above, according to the above embodiment, it is possible to provide a surface-treated aluminum material, a method for manufacturing the same, and a component for semiconductor manufacturing equipment that has excellent corrosion resistance to corrosive gases and plasma, and can suppress the occurrence of cracks even when the temperature rises. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a cross-sectional view of the surface-treated aluminum material in the embodiment. [Figure 2] Figure 2 is a cross-sectional view of the base material on which the first layer has been formed during the manufacturing process of the surface-treated aluminum material in the embodiment. [Figure 3] Figure 3 is an explanatory diagram showing the cathode polarization curve of the base material in the embodiment. [Figure 4] Figure 4 is an enlarged view of the stepped portion in the cathode polarization curve of the base material. [Modes for carrying out the invention]

[0016] (Surface-treated aluminum material) The base material of the aforementioned aluminum material is made of aluminum or an aluminum alloy. The shape of the base material is not particularly limited and can take various shapes depending on the application of the aluminum material. For example, the base material may be a wrought material such as a rolled plate or an extruded material, or it may be a cast material or a forged material. The base material may also be machined to form a desired shape. If the shape of the base material is a plate, the thickness of the base material is not particularly limited. More specifically, the base material may be a cold-rolled plate with a thickness of about 1 mm, or a hot-rolled plate with a thickness of about 50 mm.

[0017] Furthermore, the material of the base material can be appropriately selected from the group consisting of aluminum and aluminum alloys, depending on the application of the aluminum material. More specifically, for example, 1000 series aluminum can be used as the aluminum constituting the base material. For example, 2000 series aluminum alloy, 3000 series aluminum alloy, 4000 series aluminum alloy, 5000 series aluminum alloy, 6000 series aluminum alloy, 7000 series aluminum alloy, and 8000 series aluminum alloy can be used as the aluminum alloy constituting the base material. In addition, the base material may be a clad material in which two or more layers having different chemical compositions are laminated together.

[0018] A protective film is provided on the base material, comprising a first layer laminated on the base material and a second layer laminated on the first layer. The thickness of the protective film is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. In this case, the corrosion resistance of the aluminum material can be more reliably improved. From the viewpoint of improving corrosion resistance, there is no particular upper limit to the thickness of the protective film, but the manufacturing upper limit for the thickness of the protective film is, for example, 200 μm. From the viewpoint of further improving the productivity of the aluminum material, the thickness of the protective film is preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 60 μm or less.

[0019] In determining the preferred range of thickness for the protective film, the upper and lower limits of the protective film described above can be arbitrarily combined. The preferred range of thickness for the protective film may be, for example, 10 μm to 200 μm, 10 μm to 150 μm, 15 μm to 100 μm, 15 μm to 60 μm, or 20 μm to 60 μm.

[0020] The first layer is composed of aluminum oxide. The first layer may have pores. That is, the first layer may be a porous type anodic oxide film. Alternatively, the first layer may be a barrier type anodic oxide film that does not have pores. From the viewpoint of making it easier to increase the thickness of the anodic oxide film, it is preferable that the first layer has pores. Furthermore, it is preferable that the pores of the first layer are sealed by the second layer.

[0021] If the first layer has multiple pores, the average equivalent diameter of the pores is preferably 60 nm or more, more preferably 80 nm or more, and even more preferably 120 nm or more. In this case, the heat resistance of the protective film can be improved more reliably. The upper limit of the average equivalent diameter of the pores in the first layer may be, for example, 500 nm, 400 nm, or 300 nm.

[0022] From a similar perspective, the number of pores per unit area is 300 / μm. 2 Preferably, the following is true: 200 / μm 2 It is more preferable that the following conditions apply: 100 / μm 2 The following is even more preferable. Note that the lower limit of the number of pores per unit area in the first layer is, for example, 5 / μm. 2 It may also be 10 / μm 2 It may also be 20 / μm 2 That's fine.

[0023] The method for calculating the average equivalent diameter of pores and the number of pores per unit area is as follows. First, the aluminum material is embedded in resin and then polished to expose a cross-section that is approximately perpendicular to the thickness direction of the aluminum material. Then, a FIB processing machine is used to take a sample from the center of the protective film in the thickness direction. The surface of the protective film on the sample taken in this way is observed using an electron microscope, and a magnified photograph is obtained. Then, the equivalent diameter of each pore present in the field of view of the magnified photograph, that is, the diameter of a circle with an area equal to the cross-sectional area of ​​the pore, is calculated. The arithmetic mean of the equivalent diameters of the pores obtained in this way is taken as the average equivalent diameter of the pores. In addition, the number of pores present in the field of view of the magnified photograph is calculated based on the field of view area in 1 μm. 2 By converting this to a per-unit number, the number of pores per unit area can be calculated.

[0024] The first layer may be a dyed anodized layer, that is, a layer having an anodic oxide film with pores and a coloring agent sealed within the pores. In this case, the aesthetic appeal of the aluminum material can be further enhanced. The coloring agent used in the dyed anodized layer may be, for example, a dye. In this case, for example, the anodized film can be dyed by impregnating the pores of the anodized layer with a dye, and then forming a second layer to close the pores.

[0025] Furthermore, the coloring agent used in the dyed anodized layer may be a metal compound. In this case, for example, the anodized film can be dyed by depositing a metal compound in the pores of the anodized layer, and then forming a second layer to close the pores.

[0026] The second layer contains hydrated aluminum oxide. Because hydrated aluminum oxide has high chemical stability, it is less likely to deteriorate during use of the aluminum material. In addition, hydrated aluminum oxide also has excellent corrosion resistance.

[0027] Furthermore, the second layer is formed, for example, by hydrating the aluminum oxide contained in the first layer after the first layer has been formed by anodizing the base material. When aluminum oxide is hydrated, the hydrated oxide grows from the surface of the aluminum oxide, making it difficult for defects to form between the aluminum oxide and the hydrated oxide. Therefore, by forming a second layer containing aluminum hydrate on the first layer, the formation of defects at the interface between the first and second layers can be suppressed. As a result, by providing a second layer containing aluminum hydrate on the first layer, high corrosion resistance can be maintained over a long period of time.

[0028] More specifically, the second layer may consist of a hydrated aluminum oxide. Alternatively, the second layer may consist of a hydrated aluminum oxide and oxides and / or hydroxides of metal elements other than aluminum. Examples of metal elements included in the second layer include Ni (nickel), Cr (chromium), Zr (zirconium), Si (silicon), Ti (titanium), Au (gold), Ag (silver), Co (cobalt), Mo (molybdenum), Mn (manganese), Nb (niobium), Ta (tantalum), W (tungsten), Zn (zinc), Fe (iron), Ir (iridium), and Sc (scandium). In other words, the second layer may contain a hydrated aluminum oxide and oxides and / or hydroxides of one or more metal elements selected from the group consisting of Ni, Cr, Zr, Si, Ti, Au, Ag, Co, Mo, Mn, Nb, Ta, W, Zn, Fe, Ir, and Sc.

[0029] When a porosity test is performed according to the method specified in JIS H8683-2:2013, the mass loss per unit area of ​​the aluminum material is 0.3 g / dm². 2 The following is preferable: In such an aluminum material, the first layer is sufficiently covered by the second layer. Therefore, by keeping the mass loss in the porosity test within the specified range, the corrosion resistance of the aluminum material can be more easily improved.

[0030] The specific method for the porosity test is as follows: First, 35 mL of phosphoric acid and 20 g of chromic anhydride are dissolved in water to prepare 1 L of test solution. Next, a test piece containing the protective film is taken from the aluminum material, and the area of ​​the protective film on the test piece is measured. After removing any dirt from the surface of the test piece, its mass is measured. Then, the test piece is immersed in the test solution, which is maintained at a temperature of 38°C ± 1°C, for 15 minutes ± 5 seconds.

[0031] After the test specimen has been immersed in the test solution, it is washed with running water, and then with deionized water or distilled water. After the washed specimen is thoroughly dried, its mass is measured.

[0032] The area A (unit: dm²) of the protective coating on the test specimen obtained from the above is... 2 Using the mass m1 (unit: g) of the test specimen before immersion in the test solution and the mass m2 (unit: g) of the test specimen after immersion in the test solution, the mass loss per unit area δ is calculated based on the following formula (1). A (Unit: g / dm 2 It is possible to calculate ). δ A =(m1-m2) / A ···(1)

[0033] The aforementioned aluminum material was subjected to cathode polarization measurement of the base material and the surface-treated aluminum material after heating at 300°C for 1 hour using a measurement solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1. When the current density at the center potential of the potential region indicating the diffusion limit current of hydrogen ions in the base material was measured, the current density J of the base material was B Current density J of the surface-treated aluminum material 300 Ratio J 300 / J B 150 x 10 -4 It has the following characteristics: Current density J 300 Ratio J 300 / J BAluminum materials whose current density falls within the aforementioned specific range have the property of being less prone to cracking when the temperature rises. Therefore, equipped with the protective coating, the ratio of current density J 300 / J B Aluminum materials that fall within the aforementioned specific range exhibit excellent corrosion resistance and heat resistance.

[0034] From the viewpoint of further improving the heat resistance of the aluminum material, the current density J of the base material B Current density J of the surface-treated aluminum material 300 Ratio J 300 / J B is 130×10 -4 Preferably, it is 100 × 10 -4 More preferably, 80 × 10 -4 More preferably, the following: 50 × 10 -4 The following is particularly preferable: 20 × 10 -4 The following is most preferable. Furthermore, from the viewpoint of improving the heat resistance of the aluminum material, the ratio of current density J 300 / J B There is no lower limit, but the ratio of current densities J 300 / J B By definition, it will always be a value greater than 0.

[0035] Furthermore, when the cathode polarization of the base material and the surface-treated aluminum material after heating at 350°C for 1 hour was measured using a measurement solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1, the current density of the base material was measured at the potential at the center of the potential region indicating the diffusion limit current of hydrogen ions. B Current density J of the surface-treated aluminum material 350 Ratio J 350 / J B 110 x 10 -4 The following is preferable: 80 × 10 -4 More preferably, 50 × 10 -4 It is even more preferable that the following conditions apply: 20 × 10 -4The following is particularly preferable. In this case, the heat resistance of the aluminum material can be further enhanced, and the occurrence of cracks in the aluminum material can be suppressed even when used at higher temperatures.

[0036] From a similar viewpoint, the cathode polarization of the base material and the surface-treated aluminum material after heating at 400°C for 1 hour was measured using a measurement solution obtained by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1, and the current density at the center potential of the potential region showing the diffusion limit current of hydrogen ions in the base material was measured, and the current density J of the base material was measured. B Current density J of the surface-treated aluminum material 400 Ratio J 400 / J B 110 x 10 -4 The following is preferable: 80 × 10 -4 More preferably, 50 × 10 -4 It is even more preferable that the following conditions apply: 20 × 10 -4 The following is particularly preferable:

[0037] The aluminum material may have a coating film formed on the protective film. In this case, the aesthetic appeal of the aluminum material can be further enhanced. The coating film may be transparent or opaque. The coating film may also be colorless or colored. Furthermore, the coating film may be composed of inorganic materials such as silicon dioxide, or it may contain an organic resin. Examples of organic resins include acrylic resin, methacrylic resin, polyester resin, epoxy resin, polyurethane resin, polyolefin resin, and polysulfone resin.

[0038] As mentioned above, the aluminum material exhibits excellent corrosion resistance to corrosive gases and plasma, and can suppress the occurrence of cracks in the protective film even when the temperature rises. Therefore, the aluminum material is suitable for applications such as cover members provided around the fans of heating appliances and components for semiconductor manufacturing equipment. Examples of components for semiconductor manufacturing equipment include chambers in semiconductor manufacturing equipment such as film deposition equipment and etching equipment, and components placed inside the chambers. The aluminum material is particularly preferable for use as upper electrodes, lower electrodes, and shower plates in these semiconductor manufacturing devices.

[0039] (Manufacturing method for aluminum materials) The surface-treated aluminum material is, for example, The first layer is formed on the base material by subjecting the base material to anodizing treatment in an electrolyte containing an organic acid. Subsequently, the base material and the first layer are heated to a temperature of 300°C or higher. The material is then obtained by forming the second layer on the first layer. The method for manufacturing the aluminum material will be described in more detail below.

[0040] In producing the surface-treated aluminum material, first, a base material made of aluminum or an aluminum alloy is prepared. The method for manufacturing the base material is not particularly limited, and known methods can be used. For example, the base material may be produced by a method that appropriately combines casting, rolling, and heat treatment. For the casting method of the base material, either DC casting or continuous casting may be used. Furthermore, the base material may be formed into a desired shape by machining a cast material, forged material, or wrought material.

[0041] Furthermore, in the above manufacturing method, pretreatments such as degreasing, etching, desmatting, polishing, and grinding may be performed on the base material before anodizing, as necessary.

[0042] In the above manufacturing method, the first layer is formed on the base material by subjecting the base material prepared in this manner to an anodic oxidation treatment in an electrolyte containing an organic acid. In the anodic oxidation treatment, the first layer can be formed on the surface of the base material by DC electrolysis, that is, by passing a DC current between the base material and the counter electrode while the base material and the counter electrode are immersed in the electrolyte.

[0043] The electrolyte used in the anodizing process contains at least an organic acid. That is, the electrolyte contained in the electrolyte may consist of organic acids. Furthermore, the electrolyte contained in the electrolyte may contain both organic acids and inorganic acids. From the viewpoint of more easily forming a heat-resistant protective film, the electrolyte preferably contains one or more organic acids selected from the group consisting of oxalic acid, citric acid, malonic acid, etidronic acid, and formic acid, more preferably contains oxalic acid and / or citric acid, and even more preferably contains oxalic acid.

[0044] Examples of inorganic acids that can be included in the electrolyte include sulfuric acid, phosphoric acid, arsenic acid, selenic acid, phosphonic acid, chromic acid, and sulfamic acid. The electrolyte may contain one type of inorganic acid, or two or more types of inorganic acids.

[0045] The current density of the DC current in the anodizing process is, for example, 1 mA / cm². 2 More than 100mA / cm 2 The temperature can be set appropriately from the following range. Furthermore, the electrolyte temperature in the anodizing process can be set appropriately from, for example, a range of 0°C to 40°C.

[0046] The thickness of the first layer formed during the anodizing process is preferably 2 μm or more. By making the thickness of the first layer 2 μm or more, the thickness of the protective film obtained after sealing can be sufficiently increased, thereby further improving the corrosion resistance of the aluminum material.

[0047] In the above manufacturing method, after anodizing treatment, the base material and the first layer are heated to a temperature of 300°C or higher. By heating the first layer under the above specific conditions before forming the second layer on the first layer, it is believed that the internal stress of the first layer can be relieved. Furthermore, by forming the second layer after heating the first layer, the heat resistance of the protective film can be improved, and the occurrence of cracks in the protective film when heated can be suppressed.

[0048] From the viewpoint of further improving the heat resistance of the protective coating, the heating temperature of the first layer is preferably 330°C or higher, more preferably 350°C or higher, even more preferably 380°C or higher, and particularly preferably 400°C or higher. If the heating temperature of the first layer is less than 300°C, the relaxation of internal stress in the first layer tends to be insufficient. In this case, the heat resistance of the protective coating becomes insufficient, and there is a risk that cracks may easily occur in the protective coating when the temperature of the aluminum material rises.

[0049] On the other hand, if the heating temperature of the first layer is excessively high, the base material may melt during heating, or the first layer may not be able to keep up with the thermal expansion of the base material, potentially causing cracks to form in the first layer while it is being heated. To avoid these problems, the heating temperature of the first layer is preferably below the melting point of the base material, more preferably below 550°C, even more preferably below 500°C, and particularly preferably below 450°C.

[0050] In determining the preferred range for the heating temperature of the first layer, the upper and lower limits of the heating temperature of the first layer described above can be arbitrarily combined. For example, the preferred range for the heating temperature of the first layer may be 300°C or more and below the melting point of the base material, 300°C or more and below 550°C, 330°C or more and below 500°C, 350°C or more and below 500°C, 380°C or more and below 500°C, or 400°C or more and below 450°C.

[0051] Furthermore, when heating the first layer, heating may be terminated immediately after the temperature of the first layer reaches the desired temperature, or the temperature may be maintained for a certain period of time after reaching the desired temperature. From the viewpoint of sufficiently relieving the internal stress of the first layer and more reliably improving the heat resistance of the aluminum material, it is preferable that the heating time from the start to the end of heating of the first layer is 1 minute or more and less than 12 hours.

[0052] When forming a dyed anodized layer as the first layer, it is preferable to heat the first layer before coloring it. By coloring the first layer after heating it in this way, the second layer can be formed while maintaining the color tone of the first layer. As for the method of coloring the first layer, a method appropriate to the type of coloring agent can be appropriately adopted from known methods. For example, if the coloring agent is a dye, the dyed anodized layer can be formed by bringing the first layer into contact with the dye. Alternatively, if the coloring agent is a metal compound, the first layer can be colored by bringing a precursor of the metal compound into contact with the first layer and precipitating the metal compound.

[0053] In the above manufacturing method, after heating the first layer, a sealing agent is brought into contact with the first layer to form a second layer. As the sealing agent, for example, a substance that can react with aluminum oxide to form a hydrated oxide can be used, such as hot water or steam at a temperature of 80°C or higher, or an aqueous solution containing ions of one or more metal elements selected from the group consisting of Ni, Cr, Zr, Si, Ti, Au, Ag, Co, Mo, Mn, Nb, Ta, W, Zn, Fe, Ir, and Sc. When sealing is performed using hot water or steam, a second layer consisting of aluminum hydrated oxide can be formed on the first layer.

[0054] Furthermore, when an aqueous solution containing ions of the metal element is used as a sealing agent, a second layer containing hydrated aluminum oxide and oxides and / or hydroxides of the metal element can be formed on the first layer. The metal element may exist as a metal ion or as a complex ion in the aqueous solution. More specifically, aqueous solutions of metal salts containing the metal element, such as aqueous nickel acetate solution, aqueous cobalt acetate solution, aqueous nickel fluoride solution, aqueous chromate solution, and aqueous silicate solution, can be used as sealing agents.

[0055] From the viewpoint of more easily obtaining aluminum materials with excellent corrosion resistance and heat resistance, it is preferable that the sealant be hot water at a temperature of 80°C or higher. When using hot water as the sealant, it is even more preferable to form the second layer by contacting the first layer with hot water at 80°C or higher for 10 minutes or more but less than 120 minutes.

[0056] When obtaining the aluminum material with a coating, the coating is formed on the second layer after the second layer has been formed. The method for forming the coating is not particularly limited, and known methods can be appropriately selected and adopted.

[0057] For example, when forming a coating film, a method can be employed in which the coating agent is applied to the second layer and then heated. The method of applying the coating agent is not particularly limited, and the coating agent can be applied using known application devices such as bar coaters, roll coaters, and spray coaters. Furthermore, the thickness of the coating agent when applied can be appropriately set according to the desired thickness of the coating film.

[0058] In the above manufacturing method, it is preferable to apply the coating agent and then heat and bake the coating agent under conditions where the maximum temperature reached by the base material is 100°C or higher and below the heating temperature of the first layer. As mentioned above, the protective film formed by conventional methods has low heat resistance, which has the problem of being prone to cracking due to heating during baking.

[0059] In contrast, in the above manufacturing method, since the first layer is heated within the specified temperature range, crack formation in these layers can be suppressed even when the temperature of the protective film rises. Therefore, according to the above manufacturing method, the coating agent can be baked at a relatively high temperature without damaging the appearance of the aluminum material. Furthermore, by increasing the heating temperature during the baking of the coating agent, the durability of the coating film can be further enhanced. Moreover, by increasing the heating temperature during the baking of the coating agent, the heating time can be shortened, and the productivity of the aluminum material can be increased.

[0060] From the viewpoint of further improving the durability of the coating film, it is more preferable that the maximum temperature reached by the base material during baking be 120°C or higher, even more preferable that it be 140°C or higher, and particularly preferable that it be 160°C or higher.

[0061] On the other hand, from the viewpoint of suppressing the occurrence of cracks in the protective coating and avoiding deterioration of the coating film, the maximum temperature reached by the base material during baking is preferably 300°C or lower, more preferably 280°C or lower, and even more preferably 260°C or lower.

[0062] In determining the preferred range for the maximum temperature reached by the base material during baking, the upper and lower limits of the maximum temperature reached by the base material described above can be arbitrarily combined. For example, the preferred range for the maximum temperature reached by the base material during baking may be 100°C to 300°C, 120°C to 300°C, 140°C to 280°C, or 160°C to 260°C.

[0063] The reason why the aforementioned effects are obtained by setting the maximum temperature of the base material during baking to be below the heating temperature of the first layer is not entirely clear, but the following reasons are possible. Multiple strains exist in the first layer formed on the base material, and these strains are thought to be released when heated to a temperature corresponding to the state of each strain. Therefore, when the first layer is heated in the aluminum material manufacturing method, it is thought that the strains present in the first layer are released according to the heating temperature of the first layer, and the internal stress is relieved. Consequently, when the maximum temperature of the base material during baking is below the heating temperature of the first layer, it is thought that there are no strains to be released in the first layer. For the reasons above, it is thought that the occurrence of cracks associated with the release of strains in the first layer can be suppressed by setting the maximum temperature of the base material during baking to be below the heating temperature of the first layer.

[0064] During the baking process, heating may be terminated immediately after the base material reaches the desired maximum temperature, or the desired temperature may be maintained for a certain period of time after it has been reached.

[0065] As a coating agent, for example, an inorganic coating agent mainly composed of hydrolyzable silicon compounds such as alkoxysilanes, siloxanes, and silazanes can be used. By heating such a coating agent, a coating film mainly composed of silicon dioxide can be formed on the second layer.

[0066] Furthermore, organic coating agents primarily composed of resins such as acrylic resin, methacrylic resin, polyester resin, epoxy resin, polyurethane resin, polyolefin resin, and polysulfone resin can also be used as coating agents. The organic coating agents may contain additives such as silicone resin as needed. By heating such coating agents, a coating film containing organic resin can be formed on the second layer.

[0067] The coating agent preferably contains an organic resin. A coating agent containing an organic resin can form a highly durable coating film by applying the coating agent as a second layer and then baking it. However, protective films formed by conventional methods have problems with low heat resistance and are prone to cracking due to heating during baking.

[0068] In contrast, in the above manufacturing method, since the first layer is heated within the specified temperature range, crack formation can be suppressed even when the temperature of the protective film rises. Therefore, according to the above manufacturing method, even when using a coating agent containing an organic resin, which was previously difficult to bake at high temperatures, the coating agent can be baked at high temperatures without damaging the appearance of the aluminum material. Furthermore, by increasing the heating temperature during the baking of the coating agent, the durability of the coating film can be further enhanced. Moreover, by increasing the heating temperature during the baking of the coating agent, the heating time can be shortened, and the productivity of the aluminum material can be increased. [Examples]

[0069] (Example 1) Examples of the surface-treated aluminum material and its manufacturing method will be described with reference to Figures 1 to 4. As shown in Figure 1, the surface-treated aluminum material 1 of this example has a base material 2 made of aluminum or an aluminum alloy and a protective film 3 formed on the base material. The protective film 3 has a first layer 31 made of aluminum oxide that covers the base material 2 and a second layer 32 containing hydrated aluminum oxide that covers the first layer 31. Cathode polarization measurement of the base material 2 and the surface-treated aluminum material 1 after heating at 300°C for 1 hour was performed using a measurement solution obtained by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1, and the current density at the center potential of the potential region showing the hydrogen ion diffusion limit current of the base material 2 was measured, and the current density J of the base material 2 was measured. B Current density J of surface-treated aluminum material 1 300 Ratio J300 / J B 150 x 10 -4 The following applies:

[0070] In producing the aluminum material 1 in this example, first, the base material 2 is subjected to anodizing treatment to form a first layer 31 on the base material 2, as shown in Figure 2. Then, the base material 2 and the first layer 31 are heated to a temperature of 300°C or higher to relieve the internal stress of the first layer 31. Finally, the aluminum material 1 is obtained by forming a second layer 32 on the heated first layer 31.

[0071] Table 1 shows specific examples of aluminum material 1 (test materials A1 to A14). The method for preparing these test materials is as follows, for example.

[0072] [Test materials A1-A4] To prepare test materials A1 to A4, first, an aluminum plate with a thickness of 1 mm and a chemical composition represented by alloy number A5052 is prepared as base material 2. This base material 2 is subjected to a pretreatment for anodizing. Specifically, as a pretreatment, base material 2 is first subjected to alkaline etching by immersing it in a 5 mass% sodium hydroxide aqueous solution at a temperature of 55°C. After that, base material 2 is subjected to desmatt treatment by immersing it in 30 mass% nitric acid.

[0073] After pre-treating the base material 2 as described above, DC electrolysis is performed on the base material 2 as an anodizing treatment to form the first layer 31 on the surface of the base material 2. The electrolyte used in the anodizing treatment is an aqueous solution of oxalic acid with a concentration of 0.5 mol / L, and the temperature of the electrolyte is 10°C. The current density in the anodizing treatment is 10 mA / cm². 2 The processing time is set to 60 minutes. The first layer 31 formed in this way is a so-called porous anodized film, and as shown in Figure 2, it has a large number of pores 311. The thickness of the first layer 31 formed by anodic oxidation under the above conditions is approximately 15 μm, the average equivalent circle diameter of the pores 311 is 172 nm, and the number of pores per unit area is 49 / μm 2 That is the case.

[0074] After anodizing, the base material 2 is heated for 30 minutes in a heating furnace set to one of the following temperatures: 300°C, 350°C, 400°C, or 450°C, to relieve the internal stress of the first layer 31.

[0075] Subsequently, the base material 2 with the first layer 31 is immersed in hot water at 100°C for 60 minutes as a sealing agent to form a second layer 32 made of hydrated aluminum oxide on the first layer 31, and the pores 311 of the first layer 31 are sealed by the second layer 32. Through this process, test materials A1 to A4 shown in Table 1 can be obtained. Note that when sealing the pores 311 of the first layer 31 under these conditions, the mass loss per unit area of ​​the aluminum material 1 when performing a sealing degree test according to the method specified in JIS H8683-2:2013 is approximately 0.01 g / dm². 2 This is the result.

[0076] [Test materials A5-A8] The preparation method for test materials A5 to A8 is the same as that for test materials A1 to A4, except that an anodic oxidation treatment is performed using an aqueous solution of a mixed acid of 0.5 mol / L oxalic acid and 0.1 mol / L citric acid.

[0077] [Test materials A9-A12] The preparation method for test materials A9 to A12 is the same as that for test materials A1 to A4, except that an anodic oxidation treatment is performed using an aqueous solution of a mixed acid of 0.5 mol / L oxalic acid and 0.5 mol / L citric acid. The average equivalent circle diameter of the pores 311 formed by anodic oxidation treatment under these conditions is 158 nm, and the number of pores per unit area is 40 / μm 2 That is the case.

[0078] [Test material A13] The method for preparing test material A13 is the same as that for test material A2, except that an anodic oxidation treatment is performed using an aqueous solution of a mixed acid of 0.5 mol / L citric acid and 150 g / L sulfuric acid.

[0079] [Test material A14] The method for preparing test material A14 is the same as that for test material A2, except that an aqueous solution of a mixed acid of 0.5 mol / L oxalic acid and 150 g / L sulfuric acid is used, and an anodic oxidation treatment is performed at an electrolyte temperature of 20°C.

[0080] [Test material B1] Test material B1, shown in Table 1, is a test material for comparison with test materials A1 to A4. The method for preparing test material B1 is the same as that for test materials A1 to A4, except that the second layer is formed without heating after the first layer is formed.

[0081] [Test material B2] Test material B2, shown in Table 1, is a test material for comparison with test materials A5 to A8. The method for preparing test material B2 is the same as that for test materials A5 to A8, except that the second layer is formed without heating after the first layer is formed.

[0082] [Test material B3] Test material B3, shown in Table 1, is a test material for comparison with test materials A9 to A12. The method for preparing test material B3 is the same as that for test materials A9 to A12, except that the second layer is formed without heating after the first layer is formed.

[0083] [Test material C1] Test material C1, shown in Table 1, is a test material for comparison with test materials A1 to A12. The method for preparing test material C1 is the same as that for test materials A1 to A12, except that the anodizing treatment is performed using a 15% by mass sulfuric acid aqueous solution at a temperature of 5°C, and the heating temperature for the first stage is set to 400°C. The average equivalent circle diameter of the pores 311 formed by the anodizing treatment under these conditions is 40 nm, and the number of pores per unit area is 416 / μm 2 That is the case.

[0084] [Test material D1] Test material D1, shown in Table 1, is a test material used for comparison with test material A13. The method for preparing test material D1 is the same as that for test material A13, except that the second layer is formed without heating after the first layer is formed.

[0085] [Test material E1] Test material E1, shown in Table 1, is a test material for comparison with test material A14. The method for preparing test material E1 is the same as that for test material A14, except that the second layer is formed without heating after the first layer is formed.

[0086] Next, the method for measuring the cathode polarization of test materials A1-A14, B1-B3, C1, D1, and E1 will be explained.

[0087] [Cathode Polarization Measurement] The cathode polarization of the base material and the test material heated at 300°C for 1 hour was measured using the following method, and the current density J of the base material was determined based on these cathode polarization curves. B Current density J of surface-treated aluminum material 300 Ratio J 300 / J B The following calculation is performed: First, the test material is heated in an oven set to 300°C for 1 hour. After removing the test material from the oven and letting it cool to room temperature, an evaluation area is set on the protective film, and the parts of the test material surface other than the evaluation area are covered with silicone resin.

[0088] Next, a 5% by mass NaCl aqueous solution and a 99.7% acetic acid solution are prepared. The measurement solution is prepared by adding acetic acid to the NaCl aqueous solution so that the volume ratio of NaCl aqueous solution to acetic acid is NaCl aqueous solution:acetic acid = 1000:1. The test specimen, counter electrode, and reference electrode, which are electrically connected to the potentiostat, are immersed in this measurement solution and left to stand for 30 minutes to stabilize the potential of the measurement section. The measurement solution is not degassed. As a reference electrode, for example, an Ag / AgCl electrode can be used.

[0089] After the potential of the measurement section stabilizes, a voltage is applied between the test specimen and the counter electrode using a potentiostat, and the potential of the measurement section is swept at a sweep rate of 20 mV / min until the potential of the measurement section reaches -2000 mV relative to the reference electrode. By measuring the current density flowing through the measurement section at this time, the cathode polarization curve of the test material after heating is obtained. Similarly, the cathode polarization curve of the base material is obtained by performing the same measurement using the base material that has undergone pretreatment for anodizing using the method described above. The cathode polarization measurements of both the test material and the base material are performed in an atmospheric environment, with the temperature of the measurement solution maintained at 25°C. Furthermore, the cathode polarization measurements of both the test material and the base material are performed without stirring the measurement solution, with the measurement solution being substantially still.

[0090] Figure 3 shows an example of the cathode polarization curve of the base material. The vertical axis in Figure 3 represents the potential at the measurement point (unit: V), and the horizontal axis represents the current density (unit: μA / cm²). 2 ) Furthermore, the horizontal axis scale in Figure 3 is logarithmic. As shown in Figure 3, the cathode polarization curve of the base material has a stepped shape. In cathode polarization measurement, as the current approaches a state where it is rate-limited by the diffusion of hydrogen ions, the change in current becomes smaller in response to the change in potential at the measurement site. Therefore, in the cathode polarization curve, as shown in Figure 3, where the potential is represented on the vertical axis and the current density on the horizontal axis, the potential region indicating the diffusion limit current of hydrogen ions is included in the part of the cathode polarization curve where the slope of the curve is steep at the stepped section.

[0091] Figure 4 shows an enlarged view of the stepped portion of the cathode polarization curve in Figure 3. The method for determining the potential region that shows the diffusion limit current of hydrogen ions in the cathode polarization curve of the base material is as follows. First, as shown in Figure 4, a tangent line L is drawn at the stepped portion of the cathode polarization curve where the absolute value of the slope is largest. Then, the region R where this tangent line L and the cathode polarization curve overlap is defined as the potential region that shows the diffusion limit current of hydrogen ions. The current density J at the potential in the center of the region R determined in this way. B The current density J at the same potential as the center potential of the aforementioned potential region in the cathode polarization curve of the base material is calculated.300 is calculated.

[0092] The current density J calculated based on the cathode polarization curve of the test material after heating 300 can be used as an index of the contact area between the base material and the measurement solution in the test material after heating, and indicates that the larger the value of the current density, the wider the contact area between the base material and the measurement solution. Therefore, the current density J calculated using the base material B with respect to the current density J calculated using the test piece after heating 300 ratio J 300 / J B can be used as an index of the increase rate of the exposed area of the base material due to heating. More specifically, for example, when defects such as cracks are formed in the protective film in the test material after heating, the base material may be exposed by the cracks. Therefore, in this case, the current density ratio J 300 / J B becomes larger. The current density ratio J of test materials A1 to A14, test materials B1 to B3, test material D1, and test material E1 is shown in the "Current Density Ratio" column of Table 1 300 / J B .

[0093] The cathode polarization measurement of test material C1 is performed in the same manner as the cathode polarization measurement of test materials A1 to A12 and test materials B1 to B3, except that the test material is heated in an oven set at a temperature of 200 °C for 4 hours. The current density J of the base material when the cathode polarization measurement of test material C1 and the base material is performed after heating at a temperature of 200 °C for 4 hours is shown in the "Current Density Ratio" column of Table 1 B with respect to the current density J of test material C1 200 ratio J 200 / J B .

[0094]

Table 1

[0095] As shown in Table 1, the first layer of test specimens A1 to A14 is formed by an anodic oxidation treatment in an electrolytic solution containing an organic acid. Further, these test specimens are produced by forming the second layer after heating the first layer under the conditions within the specific range. Therefore, these test specimens have the current density ratio J 300 / J B and can suppress the generation of cracks in the protective film even when the temperature rises. Also, since the first layer of the protective film of these test specimens is covered by the second layer made of aluminum hydrated oxide, they are excellent in corrosion resistance against corrosive gases, plasma, etc.

[0096] On the other hand, when producing test specimens B1 to B3, test specimen D1, and test specimen E1, after forming the first layer on the base material, the second layer is formed without heating the first layer. Therefore, the current density ratio J 300 / J B of these test specimens becomes higher than the specific range, and cracks are likely to occur when the temperature rises.

[0097] Also, since the first layer of test specimen C1 is formed by an anodic oxidation treatment in an electrolytic solution containing an organic acid without containing an organic acid, cracks are likely to occur when heated. Therefore, the current density ratio J 200 / J B of test specimen C1 after being heated at a temperature of 200 °C becomes higher than 150×10 -4 . From such results, it is presumed that the current density ratio J 300 / J B of test specimen C1 after being heated at a temperature of 300 °C becomes higher than 150×10 -4 .

[0098] (Example 2) This example describes the results of cathode polarization measurements when test materials A1-A8, A10-A12, and B1-B3 in Example 1 were heated at a temperature of 350°C. In this example, cathode polarization measurements were performed in the same manner as in Example 1, except that each test material was heated at a temperature of 350°C for 1 hour. The current density J of the base material was measured when the cathode polarization of the surface-treated aluminum material and the base material was measured after heating at a temperature of 350°C for 1 hour. B Current density J of the surface-treated aluminum material 350 Ratio J 350 / J B Calculate the current density ratio J of each test material. 350 / J B This is shown in Table 2.

[0099] [Table 2]

[0100] As shown in Table 2, among test materials A1-A8 and A10-A12, the current density ratio J of test materials A2-A4, A6-A8, and A10-A12, where the heating temperature of the first layer is equal to or greater than the heating temperature used in the cathode polarization measurement, is as follows: 350 / J B The value of is the current density ratio J in Example 1. 300 / J B The value is approximately the same as [value]. Therefore, test materials A2-A4, A6-A8, and A10-A12 can suppress crack formation even when heated to 350°C.

[0101] In contrast, the current density ratio J of test material A1 and test material A5, where the heating temperature of the first layer is less than the heating temperature in the cathode polarization measurement, is... 350 / J B The value is the current density ratio J of test materials B1-B3 that have not been heated in the first layer. 350 / J BThe value is approximately the same as [value]. Therefore, it is difficult to suppress crack formation in test material A1 and test material A5 when heated to 350°C. Based on these results, it can be understood that increasing the heating temperature of the first layer during the manufacturing process of aluminum improves the heat resistance of the protective film, and that crack formation can be suppressed if the temperature of the aluminum material is below the heating temperature of the first layer.

[0102] (Example 3) This example describes the results of cathode polarization measurements when test material A4 and test material A12 in Example 1 are heated at a temperature of 400°C. In this example, cathode polarization measurements are performed in the same manner as in Example 1, except that each test material is heated at a temperature of 400°C for 1 hour. The current density J of the base material is measured when the cathode polarization of the surface-treated aluminum material and the base material is measured after heating at a temperature of 400°C for 1 hour. B Current density J of the surface-treated aluminum material 400 Ratio J 400 / J B The current density ratio J of test material A4 and test material A12 is calculated. 400 / J B This is shown in Table 3.

[0103] [Table 3]

[0104] As shown in Table 3, the first layer of test material A4 and test material A12 was heated to 450°C, which is higher than the heating temperature used in the cathode polarization measurement. Therefore, crack formation can be suppressed in these test materials even when heated to 400°C.

[0105] (Example 4) This example describes the results of cathode polarization measurements when test material A4 and test material A12 in Example 1 are heated at a temperature of 430°C. In this example, cathode polarization measurements are performed in the same manner as in Example 1, except that each test material is heated at a temperature of 430°C for 1 hour. The current density J of the base material is measured when the cathode polarization of the surface-treated aluminum material and the base material is measured after heating at a temperature of 430°C for 1 hour. B Current density J of the surface-treated aluminum material 430 Ratio J 430 / J B The current density ratio J of test material A4 and test material A12 is calculated. 430 / J B This is shown in Table 4.

[0106] [Table 4]

[0107] As shown in Table 4, the first layer of test material A4 and test material A12 was heated to 450°C, which is higher than the heating temperature used in the cathode polarization measurement. Therefore, crack formation can be suppressed even when these test materials are heated to 430°C.

[0108] Although the embodiments of the surface-treated aluminum material, its manufacturing method, and plasma processing apparatus component have been described above based on the examples, the specific embodiments of the surface-treated aluminum material, its manufacturing method, and plasma processing apparatus component according to the present invention are not limited to those of the examples, and the configuration can be appropriately modified without impairing the spirit of the present invention.

[0109] For example, the surface-treated aluminum material may take the following forms [1] to [8].

[0110] [1] A surface-treated aluminum material having a base material made of aluminum or an aluminum alloy, and a protective film formed on the base material, The protective coating consists of an aluminum oxide and comprises a first layer covering the base material, It comprises a second layer containing aluminum hydrate oxide and covering the first layer, When the cathode polarization of the base material and the surface-treated aluminum material after heating at 300°C for 1 hour was measured using a measurement solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1, the current density of the base material was measured at the potential at the center of the potential region indicating the diffusion limit current of hydrogen ions in the base material. B Current density J of the surface-treated aluminum material 300 Ratio J 300 / J B 150 x 10 -4 The following are surface-treated aluminum materials.

[0111] [2] Using a measurement solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1, the cathode polarization of the base material and the surface-treated aluminum material after heating at 400°C for 1 hour was measured, and the current density at the center potential of the potential region showing the diffusion limit current of hydrogen ions in the base material was measured, and the current density J of the base material was B Current density J of the surface-treated aluminum material 400 Ratio J 400 / J B 110 x 10 -4 The surface-treated aluminum material described in [1] is as follows: [3] When the degree of sealing test is performed according to the method specified in JIS H8683-2:2013, the mass loss per unit area is 0.3 g / dm 2 The surface-treated aluminum material described in [1] or [2] below. [4] The surface-treated aluminum material according to any one of [1] to [3], wherein the first layer has a plurality of pores, and the average circular diameter of the pores is 60 nm or more.

[0112] [5] The first layer has a plurality of pores, and the number of pores per unit area is 300 / μm 2The surface-treated aluminum material described in any one of the following [1] to [4]. [6] The surface-treated aluminum material according to any one of [1] to [5], wherein the second layer further comprises an oxide and / or hydroxide of one or more metal elements selected from the group consisting of Ni, Cr, Zr, Si, Ti, Au, Ag, Co, Mo, Mn, Nb, Ta, W, Zn, Fe, Ir, and Sc. [7] The surface-treated aluminum material according to any one of [1] to [6], wherein the preceding layer is a dyed anodized layer. [8] The surface-treated aluminum material according to any one of [1] to [7], wherein the surface-treated aluminum material has a coating film formed on the protective film.

[0113] Furthermore, the plasma processing apparatus component may take the form described in [9] below. A component for a plasma processing apparatus made of a surface-treated aluminum material as described in any one of [9], [1], to [8].

[0114] Furthermore, the method for manufacturing the surface-treated aluminum material may take the following forms

[10] to

[12] .

[0115] A method for manufacturing a surface-treated aluminum material as described in any one of

[10] , [1] to [8], The first layer is formed on the base material by subjecting the base material to anodizing treatment in an electrolyte containing an organic acid. Subsequently, the base material and the first layer are heated to a temperature of 300°C or higher. A method for manufacturing a surface-treated aluminum material, comprising subsequently forming the second layer on the first layer.

[0116]

[11] The method for producing a surface-treated aluminum material according to

[10] , wherein the electrolyte contains one or more organic acids selected from the group consisting of oxalic acid, citric acid, malonic acid, etidronic acid, and formic acid.

[12] A method for producing a surface-treated aluminum material according to

[10] or

[11] , wherein the electrolyte contains the organic acid and the inorganic acid. [Explanation of symbols]

[0117] 1. Surface-treated aluminum material 2 Base material 3. Protective coating 31 First layer 32 Second layer

Claims

1. A surface-treated aluminum material having a base material made of aluminum or an aluminum alloy, and a protective film formed on the base material, The protective coating consists of an aluminum oxide and comprises a first layer covering the base material, It comprises a second layer containing aluminum hydrate oxide and covering the first layer, When the cathode polarization of the base material and the surface-treated aluminum material after heating at 300°C for 1 hour was measured using a measurement solution prepared by mixing a 5% by mass NaCl solution and a 99.7% by mass acetic acid solution in a volume ratio of NaCl solution:acetic acid = 1000:1, the current density of the base material was measured at the potential at the center of the potential region indicating the diffusion limit current of hydrogen ions in the base material. B Current density J of the surface-treated aluminum material 300 Ratio J 300 / J B 150 x 10 -4 The following are surface-treated aluminum materials.

2. Using a measurement solution obtained by mixing a 5 mass% NaCl solution and acetic acid with a concentration of 99.7 mass% at a volume ratio of the NaCl solution: the acetic acid = 1000:1, the cathodic polarization measurement of the surface-treated aluminum material after heating the base material and the surface-treated aluminum material at a temperature of 400 °C for 1 hour was performed. When measuring the current density at the potential at the center of the potential region showing the diffusion-limiting current of hydrogen ions in the base material, the current density J of the base material B with respect to the current density J of the surface-treated aluminum material 400 of the ratio J 400 / J B is 110×10 -4 or less. The surface-treated aluminum material according to claim 1

3. When a porosity test is performed according to the method specified in JIS H8683-2:2013, the mass loss per unit area is 0.3 g / dm². 2 The surface-treated aluminum material according to claim 1, which is as follows:

4. The surface-treated aluminum material according to claim 1, wherein the first layer has a plurality of pores, and the average circular diameter of the pores is 60 nm or more.

5. The aforementioned layer has a plurality of pores, and the number of pores per unit area is 300 / μm 2 The surface-treated aluminum material according to claim 1, which is as follows:

6. The surface-treated aluminum material according to claim 1, wherein the second layer further comprises an oxide and / or hydroxide of one or more metal elements selected from the group consisting of Ni, Cr, Zr, Ti, Au, Ag, Co, Mo, Mn, Nb, Ta, W, Zn, Fe, Ir, and Sc.

7. The surface-treated aluminum material according to claim 1, wherein the first layer is a dyed anodized layer.

8. The surface-treated aluminum material according to claim 1, wherein the surface-treated aluminum material has a coating film formed on the protective film.

9. A component for a plasma processing apparatus, comprising a surface-treated aluminum material as described in any one of claims 1 to 8.

10. A method for manufacturing a surface-treated aluminum material according to any one of claims 1 to 8, The first layer is formed on the base material by subjecting the base material to anodizing treatment in an electrolyte containing an organic acid. Subsequently, the base material and the first layer are heated to a temperature of 300°C or higher. A method for manufacturing a surface-treated aluminum material, comprising subsequently forming the second layer on the first layer.

11. The method for producing a surface-treated aluminum material according to claim 10, wherein the electrolyte contains one or more organic acids selected from the group consisting of oxalic acid, citric acid, malonic acid, etidronic acid, and formic acid.

12. The method for producing a surface-treated aluminum material according to claim 10, wherein the electrolyte contains the organic acid and the inorganic acid.

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