Surface-smoothed metal member and method for manufacturing the same

Abstract

Provided are a surface-smoothened metal member and a method for easily and effectively manufacturing the same, said surface-smoothened metal member having been smoothened to such an extent that in a surface of a large metal member formed from titanium or a titanium alloy, a flat surface portion has a maximum height roughness (Rz) of 1.1 µm or less and a portion with a curvature radius of 0.05 to 2.5 mm has a maximum height roughness (Rz) of less than 2 µm. This method for manufacturing the surface-smoothened metal member is characterized in that an anodic oxide film is formed on a surface of a substrate formed from titanium or a titanium alloy by applying an anodization treatment to the substrate, and the surface of the substrate is smoothened by removing the anodic oxide film.

Description

Technical Field

[0001] The present invention relates to a metal member made of titanium or a titanium alloy that requires surface smoothing and a method for manufacturing the same.

Background Art

[0002] In addition to being lightweight, titanium and titanium alloys have excellent corrosion resistance and high specific strength, and are utilized in various applications such as structural members of aircraft and bicycles, engine parts, optical members, electronic parts, and ornaments.

[0003] Here, particularly in the case of optical members and ornaments, the surface state of the member is often regarded as important, and methods for smoothing the surface of a member made of titanium or a titanium alloy have been studied.

[0004] For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2008-223139), in a method of electrolytic polishing and / or electrochemically deburring the surface of a titanium or titanium-containing alloy, the electrolytic solution used contains methanesulfonic acid and one or more alkanediphosphonic acids, and the one or more alkanediphosphonic acids may be selectively substituted with hydroxy groups and / or amino groups. A method of electrolytic polishing and / or electrochemical deburring is disclosed.

[0005] In the method of electrolytic polishing and / or electrochemical deburring described in the above Patent Document 1, the electrolytic solution used is not flammable, not particularly corrosive, and easy to handle, and in normal operations, it does not pose a high risk to people working in an electrolytic polishing factory or people working around the factory, or a high risk to the environment. In particular, the electrolytic solution described here is said not to generate toxic gases or vapors.

[0006] Furthermore, Patent Document 2 (Japanese Patent Application Publication No. 2004-43850) discloses an etching method for titanium or a titanium alloy characterized by treating with an aqueous solution containing (a) 5 to 30 wts of hydrogen peroxide, (b) 1 to 20 wts of fluoride, (c) 1 to 10 wt% of at least one selected from sulfuric acid, nitric acid, and phosphoric acid, and (d) 0.001 to 0.1 wt% of a fluorine-based surfactant, wherein the weight ratio of [(a) hydrogen peroxide concentration] / [(b) fluorine concentration of fluoride] is 1.5 to 3.0.

[0007] The etching method for titanium or titanium alloys described in Patent Document 2 states that by etching with an aqueous solution to which hydrogen peroxide, fluoride, inorganic acid, and fluorine-based surfactant are added, surface scale removal and smoothing of titanium or titanium alloys can be achieved simultaneously. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2008-223139 [Patent Document 2] Japanese Patent Publication No. 2004-43850 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, although the electrolytic polishing and / or electrochemical deburring method described in Patent Document 1 above provides a good working environment, it does not improve the smoothness compared to the prior art, as it states that "it can achieve surface smoothing or deburring to the same extent as the method described in the prior art, even if it is not superior."

[0010] Furthermore, although the etching method for titanium or titanium alloys described in Patent Document 2 above can simultaneously achieve surface scale removal and smoothing, the surface roughness obtained by smoothing is only about 0.4 μm, and it cannot be used when higher smoothness is required.

[0011] Furthermore, the methods described in Patent Documents 1 and 2 above only yield a good smooth surface in a relatively narrow area, making it difficult to efficiently reduce foreign matter and achieve a mirror-like finish over the entire surface of a large metal member. In addition, it is extremely difficult to smooth the inner surfaces of metal members that have corners with extremely small radii of curvature, or that have openings or through holes.

[0012] In view of the problems of the prior art described above, the present invention aims to provide a surface-smoothed metal member, in which the surface of a large metal member made of titanium or a titanium alloy is smoothed to the extent that the maximum height roughness (Rz) of the flat portion is 1.1 μm or less and the maximum height roughness (Rz) of the portion with a radius of curvature of 0.05 to 2.5 mm is less than 2 μm, and a simple and efficient method for manufacturing the same.

[0013] Furthermore, the present invention also aims to provide a surface-smoothed metal member, even a large metal member or a titanium or titanium alloy metal member having openings or through holes, in which the maximum height roughness (Rz) of the inner wall of the through holes or openings is smoothed to less than 2 μm, and a simple and efficient method for manufacturing the same. [Means for solving the problem]

[0014] In order to achieve the above objective, the inventors of the present invention have diligently researched methods for smoothing the surface of metal components made of titanium or titanium alloys. As a result, they have found that removing an anodic oxide film formed under appropriate conditions is extremely effective, and have arrived at the present invention.

[0015] In other words, the present invention is A metal component made of titanium or a titanium alloy, The maximum length of the metal member is 50 to 1000 mm, the maximum height roughness (Rz) of the flat portion on the surface of the metal member is 1.1 μm or less, the maximum height roughness (Rz) of a portion on the surface of the metal member having a curvature radius of 0.05 to 2.5 mm is less than 2 μm, and a surface-smoothed metal member characterized by the above is also provided.

[0016] It is preferable that the maximum length of the metal member is 50 to 1000 mm, and more preferably 100 to 500 mm. It is difficult to smooth the entire surface of a large metal member by a conventionally known method. However, in the surface-smoothed metal member of the present invention, even for a metal member having a maximum length of 50 mm or more, the maximum height roughness (Rz) of the flat portion on the surface is 1.1 μm or less, and the maximum height roughness (Rz) of a portion having a curvature radius of 0.05 to 2.5 mm is less than 2 μm. Further, by setting the maximum length of the metal member to 1000 mm or less, the maximum height roughness (Rz) in a portion having a curvature radius of 0.05 to 2.5 mm can also be surely made less than 2 μm.

[0017] In the surface-smoothed metal member of the present invention, it is preferable that through holes and / or apertures exist in the metal member, and the maximum height roughness (Rz) of the inner wall of the through holes and / or the apertures is also less than 2 μm. In a conventional surface-smoothed metal member, the region where a good smooth surface is formed is limited. In particular, it is extremely difficult to smooth the inner wall of through holes and apertures. However, in the surface-smoothed metal member of the present invention, all surfaces are sufficiently smoothed.

[0018] Further, the present invention is a metal member made of titanium or a titanium alloy, the maximum length of the metal member is 50 to 1000 mm, the arithmetic mean roughness (Ra) of a portion on the surface of the metal member having a curvature radius of 0.05 to 2.5 mm is less than 0.4 μm, and a surface-smoothed metal member characterized by the above is also provided.

[0019] The maximum length of the metal member is preferably 50 to 1000 mm, more preferably 100 to 500 mm. Although it is difficult to smooth the entire surface of a large metal member by a conventionally known method, in the surface-smoothed metal member of the present invention, even for a metal member with a maximum length of 50 mm or more, the arithmetic mean roughness (Ra) of a portion having a curvature radius of 0.05 to 2.5 mm on the member surface is less than 0.4 μm. Further, by setting the maximum length of the metal member to 1000 mm or less, the arithmetic mean roughness (Ra) of a portion having a curvature radius of 0.05 to 2.5 mm can be surely made less than 0.4 μm.

[0020] In the surface-smoothed metal member of the present invention, it is preferable that through holes and / or apertures are present in the metal member, and the arithmetic mean roughness (Ra) of the inner walls of the through holes and / or the apertures is also less than 0.4 μm. In a conventional surface-smoothed metal member, the region where a good smooth surface is formed is limited. In particular, it is extremely difficult to smooth the inner walls of through holes and apertures. However, in the surface-smoothed metal member of the present invention, all surfaces are sufficiently smoothed.

[0021] In the surface-smoothed metal member of the present invention, it is preferable that the equivalent circle diameter of the through holes and / or the apertures is 0.1 to 5 mm. A more preferable equivalent circle diameter is 0.2 to 2 mm, and the most preferable equivalent circle diameter is 0.5 to 1 mm. In the surface-smoothed metal member of the present invention, even when fine through holes and / or apertures with an equivalent circle diameter of the apertures of 5 mm or less are formed, the arithmetic mean roughness (Ra) and the maximum height roughness (Rz) of the inner surface can be sufficiently reduced. Further, if the equivalent circle diameter of the through holes and / or the apertures is 0.1 mm or more, the variation in the arithmetic mean roughness (Ra) and the maximum height roughness (Rz) of the inner wall can be reduced.

[0022] Furthermore, in the surface-smoothed metal member of the present invention, it is preferable that the depth of the through-hole and / or opening is 1 to 50 mm. A more preferable depth for the opening is 1 to 10 mm, and the most preferable depth for the opening is 2 to 8 mm. In the surface-smoothed metal member of the present invention, even when deep through-holes and / or openings with a depth of 1 mm or more are formed, the arithmetic mean roughness (Ra) and maximum height roughness (Rz) of the inner surface can be sufficiently reduced. Also, if the depth of the through-hole and / or opening is 50 mm or less, the variation in the arithmetic mean roughness (Ra) and maximum height roughness (Rz) of the inner wall can be reduced.

[0023] Furthermore, in the surface-smoothing metal member of the present invention, it is preferable that the metal member is a frame. By making the metal member a frame, it can be suitably used, for example, as a pellicle frame.

[0024] Furthermore, the present invention is A substrate made of titanium or a titanium alloy is subjected to anodizing treatment to form an anodic oxide film on the surface of the substrate. The surface of the substrate is smoothed by removing the aforementioned anodic oxide film. We also provide a method for manufacturing a surface-smoothed metal member characterized by the above.

[0025] In the method for manufacturing a surface-smoothed metal member of the present invention, the formation of an anodic oxide film consumes the protrusions on the substrate surface (metal member surface), thereby promoting smoothing, and the detachment of the anodic oxide film yields a smoothed surface. In addition, foreign matter adhering to the substrate surface is removed by the detachment of the anodic oxide film, resulting in a clean surface. Furthermore, the anodic oxide film can be formed on large substrates, enabling the smoothing of the surface of large metal members.

[0026] Furthermore, in the method for manufacturing a surface-smoothed metal member of the present invention, it is preferable that the thickness of the anodic oxide film be 2 to 10 μm. More preferably, by making the thickness of the anodic oxide film 4 to 6 μm, the protrusions on the surface of the substrate are efficiently consumed, and the anodic oxide film can be naturally removed without any special process.

[0027] Furthermore, in the manufacturing method for the surface-smoothed metal member of the present invention, it is preferable to set the applied voltage in the anodic oxidation treatment to 20 to 100 V. The anodic oxidation treatment conditions are not particularly limited as long as they do not impair the effects of the present invention, and various conventionally known treatment conditions can be used, but more preferably, by setting the applied voltage to 40 to 50 V, the protrusions on the surface of the substrate are efficiently consumed, and the anodic oxidation film can be naturally removed without performing any special steps.

[0028] Furthermore, in the method for manufacturing a surface-smoothed metal member of the present invention, it is preferable to repeat the formation and detachment of the anodic oxide film until an arithmetic mean roughness (Ra) of less than 0.4 μm and / or a maximum height roughness (Rz) of less than 2 μm is obtained on the surface of the substrate.

[0029] Since the formation and detachment of the anodic oxide film leads to smoothing of the substrate surface, repeating this process can reliably obtain an arithmetic mean roughness (Ra) of less than 0.4 μm and / or a maximum height roughness (Rz) of less than 2 μm on the substrate surface. [Effects of the Invention]

[0030] According to the present invention, it is possible to provide a surface-smoothed metal member, and a simple and efficient method for manufacturing the same, in which the surface of a large metal member made of titanium or titanium alloy is smoothed to such an extent that the maximum height roughness (Rz) of the flat portion is 1.1 μm or less and the maximum height roughness (Rz) of the portion with a radius of curvature of 0.05 to 2.5 mm is less than 2 μm. Furthermore, according to the present invention, even for large metal members or metal members made of titanium or titanium alloy having openings or through holes, it is possible to provide a surface-smoothed metal member, and a simple and efficient method for manufacturing the same, in which the maximum height roughness (Rz) of the inner walls of through holes and openings is also smoothed to such an extent that it is less than 2 μm. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic diagram of a pellicle frame, which is one embodiment of the surface-smoothing metal member of the present invention. [Figure 2] This is a cross-sectional view taken along line B-B' in Figure 1. [Figure 3] This is a schematic diagram of the surface smoothing process in the present invention. [Figure 4] These are SEM images of the substrate surface for the pellicle frame before anodizing, the surface with the anodized coating, and the surface of the substrate for the pellicle frame after the anodized coating has been removed. [Figure 5] This is an SEM image of the cross-section of the detached anodic oxide film and the substrate for the pellicle frame. [Figure 6] These are SEM images of the substrate surface for the pellicle frame, the surface of the anodized film, and the cross-section of the anodized film after anodizing treatment at various voltages. [Figure 7] These are SEM images of the side surface of the through-hole before anodizing and after the removal of the anodized coating. [Figure 8] This is a schematic diagram showing the measurement curves for maximum height roughness (Rz) and arithmetic mean roughness (Ra). [Figure 9] These are microscope images of the surface of a pure titanium square bar before and after anodizing treatment. [Figure 10] These are microscope images of the inner surface of a through-hole before and after anodizing treatment. [Figure 11] These are SEM images of the inner surface of a through-hole before and after anodizing. [Modes for carrying out the invention]

[0032] The following describes typical embodiments of the surface-smoothed metal member and its manufacturing method according to the present invention, using a pellicle frame as a representative example of a surface-smoothed metal member, with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, some or all of the components in the embodiments can be combined as appropriate. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions may be omitted. Also, since the drawings are for conceptual explanation of the present invention, the dimensions of each component shown and their ratios may differ from those of the actual components.

[0033] 1. Surface-smoothed metal members Figure 1 shows a schematic diagram of a pellicle frame, which is one embodiment of the surface-smoothed metal member of the present invention. The pellicle frame 1 is made of titanium or a titanium alloy, and all of its surfaces are smoothed.

[0034] The maximum length of the pellicle frame 1 is 50 to 1000 mm. Here, the maximum length of the pellicle frame 1 is the length of the diagonal shown as A in Figure 1. The maximum length is preferably 100 to 500 mm, and more preferably 150 to 300 mm. Although it is difficult to smooth the entire surface of a large metal member using conventionally known methods, in the case of the pellicle frame 1, even when the maximum length is 50 mm or more, the maximum height roughness (Rz) of the flat surface portion is 1.1 μm or less, and the maximum height roughness (Rz) of the portion with a radius of curvature of 0.05 to 2.5 mm is less than 2 μm. Furthermore, by setting the maximum length of the pellicle frame 1 to 1000 mm or less, the maximum height roughness (Rz) of the portion with a radius of curvature of 0.05 to 2.5 mm can be reliably kept below 2 μm.

[0035] Furthermore, in pellicle frame 1, even when the maximum length exceeds 50 mm, the arithmetic mean roughness (Ra) of the portion with a radius of curvature of 0.05 to 2.5 mm is less than 0.4 μm. Also, by limiting the maximum length to 1000 mm or less, it is possible to reliably ensure that the arithmetic mean roughness (Ra) of the portion with a radius of curvature of 0.05 to 2.5 mm is less than 0.4 μm.

[0036] The pellicle frame 1 has through holes and / or openings, and it is preferable that the maximum height roughness (Rz) of the inner wall of the through holes and / or openings is less than 2 μm and the arithmetic mean roughness (Ra) is less than 0.4 μm. Figure 1 shows the case where through holes 2 are present, and Figure 2 shows a cross-sectional view of Figure 1 along line B-B'. The inner surface of the through holes 2, indicated by the dotted line, is also sufficiently smoothed, with a maximum height roughness (Rz) of less than 2 μm and an arithmetic mean roughness (Ra) of less than 0.4 μm.

[0037] The equivalent circular diameter (R in Figure 2) of the opening portion of the through-hole 2 is preferably 0.1 to 5 mm. A more preferable equivalent circular diameter is 0.2 to 2 mm, and the most preferable equivalent circular diameter is 0.5 to 1 mm. In the pellicle frame 1, even when fine through-holes 2 with an equivalent circular diameter of 5 mm or less are formed, the maximum height roughness (Rz) and arithmetic mean roughness (Ra) of the inner surface can be sufficiently reduced. Furthermore, if the equivalent circular diameter of the through-hole 2 is 0.1 mm or more, the variation in the maximum height roughness (Rz) and arithmetic mean roughness (Ra) of the inner wall can be reduced.

[0038] Furthermore, the depth of the through-hole 2 (D in Figure 2) is preferably 1 to 50 mm. A more preferable depth for the through-hole 2 is 1 to 10 mm, and the most preferable depth for the through-hole 2 is 2 to 8 mm. In the pellicle frame 1, even when deep through-holes with a depth of 1 mm or more are formed, the maximum height roughness (Rz) and arithmetic mean roughness (Ra) of the inner surface can be sufficiently reduced. Also, if the depth of the through-hole 2 is 50 mm or less, the variation in the maximum height roughness (Rz) and arithmetic mean roughness (Ra) of the inner wall can be reduced.

[0039] The shape of the pellicle frame 1 is not particularly limited as long as it does not impair the effects of the present invention, and can be various conventionally known shapes depending on the shape of the exposure master plate. Generally, the planar shape of the pellicle frame 1 is ring-shaped, rectangular, or square, and has a size and shape that covers the circuit pattern portion provided on the exposure master plate.

[0040] The height (thickness) of the pellicle frame 1 is preferably 0.5 to 10 mm, more preferably 1 to 7 mm, and most preferably 1.0 to 3.0 mm. By setting the height (thickness) of the pellicle frame 1 to these values, deformation of the pellicle frame 1 can be suppressed, and good handling performance can be ensured.

[0041] The cross-sectional shape of the pellicle frame 1 is not particularly limited as long as it does not impair the effects of the present invention, and can be various conventionally known shapes, but it is preferable that it be a quadrilateral with parallel upper and lower sides. The upper side of the pellicle frame 1 needs to have a width for stretching the pellicle film, and the lower side needs to have a width for providing an adhesive layer for bonding and adhering it to the exposure plate. For this reason, it is preferable that the widths of the upper and lower sides of the pellicle frame 1 be about 1 to 3 mm.

[0042] Since the pellicle frame 1 is made of titanium or titanium alloy, it has higher strength and Young's modulus compared to conventionally used aluminum alloy pellicle frames. In addition, titanium and titanium alloys have a relatively light specific gravity of about 4.5, which helps to suppress weight increase of the pellicle frame 1.

[0043] Furthermore, since the pellicle frame 1 is made of titanium or a titanium alloy, it has a lower coefficient of thermal expansion compared to aluminum, effectively suppressing distortion during heating. Also, because titanium or titanium alloy is a metallic material, it has superior toughness compared to ceramics or cemented carbide, making it easy to handle. In addition, its good machinability allows for reduced manufacturing costs, and it enables high dimensional accuracy in the pellicle frame 1.

[0044] Furthermore, when the surface-smoothed metal member of the present invention is a type of optical member, the coefficient of linear expansion of the optical member is 6 × 10⁻⁶. -6 ~11×10 -6 It is preferable that the coefficient of linear expansion is 6 × 10⁻⁶. -6 By setting the temperature to K or higher, the coefficients of thermal expansion of the optical component and the material made of ceramic or silicon become similar. This reduces distortion and cracking caused by the difference in deformation due to thermal expansion when the temperature rises between the optical component and the material made of ceramic or silicon. An example of a combination that achieves this effect is when the optical component is a lens holder and the material made of ceramic or silicon is a lens for a camera, etc. Also, setting the coefficient of linear expansion to 11 × 10⁻¹⁰ -6 By keeping the temperature below K, strain during heating can be reduced. A more preferable coefficient of linear expansion is 7 × 10⁻⁶. -6 ~10×10 -6 The most preferred coefficient of thermal expansion is 8 × 10 / K, and the most preferred coefficient of thermal expansion is 8 × 10 -6 ~9×10 -6 The coefficient of linear expansion is / K. In this specification, the coefficient of linear expansion represents the value in the temperature range of 0 to 100°C. These coefficients of linear expansion can be achieved, for example, by making the optical components from titanium or a titanium alloy.

[0045] The titanium alloy used in the pellicle frame 1 is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known titanium alloys can be used. Examples of titanium alloys include Ti-6Al-4V alloy, Ti-6Al-6V-2Sn alloy, Ti-6Al-2Sn-4Zr-6Mo alloy, Ti-10V-2Fe-3Al alloy, Ti-7Al-4Mo alloy, Ti-5Al-2.5Sn alloy, Ti-6Al-5Zr-0.5Mo-0.2Si alloy, Ti-5.5Al-3.5Sn-3Zr-0.3Mo-1Nb-0.3Si alloy, T i-8Al-1Mo-1V alloy, Ti-6Al-2Sn-4Zr-2Mo alloy, Ti-5Al-2Sn-2Zr-4Mo-4Cr alloy, Ti-11.5Mo-6Zr-4.5Sn alloy, Examples include Ti-15V-3Cr-3Al-3Sn alloy, Ti-15Mo-5Zr-3Al alloy, Ti-15Mo-5Zr alloy, and Ti-13V-11Cr-3Al alloy.

[0046] When workability and corrosion resistance are important, it is preferable to use pure titanium. From the viewpoint of achieving both high strength and good workability, it is preferable to use an α+β type alloy. Furthermore, from the viewpoint of material cost and availability, it is even more preferable to use a Ti-6Al-4V alloy.

[0047] In the embodiments described above, the pellicle frame 1 was used as an example of a surface-smoothed metal member, but the surface-smoothed metal member is not limited to this. For example, it can be various optical members, such as pellicle frames, lens holders, barrels, shades, and reflectors.

[0048] 2. Method for manufacturing surface-smoothed metal members When manufacturing a pellicle frame 1 with a smoothed surface using the manufacturing method for surface-smoothed metal members of the present invention, the frame made of titanium or a titanium alloy is subjected to anodizing treatment to form an anodic oxide film on the surface of the frame, and the surface of the frame is smoothed by removing the anodic oxide film.

[0049] Figure 3 shows a schematic diagram of the surface smoothing process. The surface of the frame is smoothed by the removal of protrusions through the formation of an anodized film, and a smooth surface is obtained when the anodized film is removed. In addition, foreign matter adhering to the surface of the frame is removed by the removal of the anodized film, so a clean surface can be obtained.

[0050] Conventional surface smoothing methods make it extremely difficult to uniformly and easily smooth the surface of large components. However, by using anodizing, it is possible to smooth the entire surface of a large pellicle frame 1 with a maximum length of 50 to 1000 mm.

[0051] Furthermore, the thickness of the anodic oxide film formed on the surface of the frame is preferably 2 to 10 μm. More preferably, by setting the thickness of the anodic oxide film to 4 to 6 μm, the protrusions on the surface of the frame are efficiently consumed, and the anodic oxide film can be naturally removed without any special process. If any anodic oxide film remains, it may be removed by applying ultrasonic vibration, reverse electrolysis, or the like.

[0052] Furthermore, the applied voltage during the anodizing process is preferably 20 to 100V. The anodizing conditions are not particularly limited as long as they do not impair the effects of the present invention, and various conventionally known processing conditions can be used. However, by applying a voltage of 40 to 50V, the protrusions on the surface of the frame are efficiently consumed, and the anodized film can be naturally removed without any special steps.

[0053] Furthermore, if the maximum height roughness (Rz) of the frame surface exceeds 2 μm after a single anodic oxide film formation and detachment, it is preferable to repeat the formation and detachment of the anodic oxide film until this value is less than 2 μm. Since the frame surface becomes smoother with each formation and detachment of the anodic oxide film, repeating this process ensures that the maximum height roughness (Rz) on the substrate surface is reliably reduced to less than 2 μm.

[0054] Furthermore, if the arithmetic mean roughness (Ra) of the frame surface is 0.4 μm or more after a single anodic oxide film formation and detachment, it is preferable to repeat the formation and detachment of the anodic oxide film until the value becomes less than 0.4 μm. Since the frame surface becomes smoother with the formation and detachment of the anodic oxide film, repeating this process ensures that the arithmetic mean roughness (Ra) of the substrate surface is reliably reduced to less than 0.4 μm.

[0055] Although typical embodiments of the present invention have been described above, the present invention is not limited to these, and various design modifications are possible, all of which fall within the technical scope of the present invention. [Examples]

[0056] <Example 1> A frame made of pure titanium, with a long side of 160 mm and a short side of 130 mm, was cut out to create a base material for the pellicle frame. The thickness and width of this base material for the pellicle frame were the same, 1 mm and 4 mm, respectively.

[0057] The obtained pellicle frame substrate was subjected to anodizing treatment to form an anodic oxide film over the entire surface. The anodizing conditions were as follows: an aqueous solution containing 5 g / L of ammonium fluoride and 134 g / L of ammonium sulfate was used as the anodizing bath, and the treatment was carried out for 15 minutes at a bath temperature of 55°C and a voltage of 30-80V.

[0058] Figure 4 shows scanning electron microscope (SEM) images of the pellicle frame substrate surface before anodizing, the anodized film surface, and the pellicle frame substrate surface after the anodized film has detached, when the voltage is set to 45V. Figure 5 shows SEM images of the detached anodized film and the cross-section of the pellicle frame substrate in the detached region. Here, most of the anodized film detached spontaneously during the anodizing process.

[0059] The surface of the substrate for the pellicle frame is remarkably smoothed by the removal of the anodic oxide coating, resulting in a perfectly smooth surface completely free of foreign matter. Furthermore, cross-sectional photographs confirm that the surface irregularities of the substrate are less than 0.4 μm. This smooth surface was formed across the entire surface of the substrate for the pellicle frame.

[0060] Figure 6 shows SEM images of the surface of the pellicle frame substrate, the surface of the anodized film, and the cross-section of the anodized film for pellicle frame substrates that have been anodized at various voltages. The thickness of the anodized film and the degree of delamination were also evaluated and the results obtained are shown. Note that no spontaneous delamination of the anodized film was observed at a voltage of 30V.

[0061] Figure 6 shows that there is a suitable voltage range for the spontaneous detachment of the anodic oxide film, and that detachment can be promoted by applying a voltage of 40-50V. Furthermore, the thickness of the anodic oxide film also affects the spontaneous detachment phenomenon, and detachment can be promoted by setting the thickness of the anodic oxide film to 4-6 μm.

[0062] <Example 2> Except for providing cylindrical through-holes with a diameter of 800 μm in the thickness direction of the substrate for the pellicle frame, the same procedure as in Example 1 was followed, and an anodizing treatment was performed at a voltage of 45 V for 10 minutes.

[0063] Figure 7 shows SEM images of the side surface of the through-hole before anodizing and after the removal of the anodized coating. Compared to before anodizing, it can be seen that the surface after the removal of the anodized coating is significantly smoother.

[0064] <Example 3> A square bar made of pure titanium measuring 40mm x 4mm x 1mm was cut out, and a through hole with a diameter of 0.8mm was made on the 40mm x 1mm side, penetrating to the back. Next, the surface of the square bar was physically polished to remove burrs, and then chemically polished using chemical polishing solution (TCP-08) at 30°C for 10 seconds. Then, in the same manner as in Example 1, anodizing treatment was performed at a voltage of 45V for 10 minutes.

[0065] The maximum height roughness (Rz) and arithmetic mean roughness (Ra) were measured on a 40 mm × 1 mm surface and on the inner surface of through holes before anodizing (after chemical polishing) and after anodizing (after removal of the anodic oxide film). A white light interference microscope was used for the measurements. Figure 8 schematically shows the measurement lines on the 40 mm × 1 mm surface. The length of the measurement lines in the vertical direction is 322 μm, and the length of the measurement lines in the horizontal direction is 244 μm. The measurement line on the inner surface of the through holes was set to 322 μm in the axial direction. Measurements were performed in 3 regions for each of 9 fields of view, and the average of a total of 27 measurements was calculated. The obtained results are shown in Table 1.

[0066] [Table 1]

[0067] The maximum height roughness (Rz) and arithmetic mean roughness (Ra) both decreased due to the removal of the anodic oxide film. The maximum height roughness (Rz) of the flat surface areas was 1.1 μm or less in all cases, and the maximum height roughness (Rz) of the inner surface of the through holes was less than 2 μm. Furthermore, after the anodic oxidation treatment, the arithmetic mean roughness (Ra) was less than 0.4 μm in all measurement areas.

[0068] The surface condition before anodizing (after chemical polishing) and after anodizing (after removal of the anodic oxide film) was observed using a scanning electron microscope (SEM) and a microscope. Figure 9 shows a microscope image of a 40 mm × 1 mm surface, Figure 10 shows a microscope image of the inner surface of a through hole, and Figure 11 shows a SEM image of the inner surface of a through hole. In all of the observed images, it can be seen that the surface has been smoothed by the removal of the anodic oxide film. [Explanation of Symbols]

[0069] 1. Pellicle frame, 2...Through hole.

Claims

1. A metal component made of titanium or a titanium alloy, The maximum length of the aforementioned metal member is 50 to 1000 mm. The maximum height roughness (Rz) of the flat surface portion of the metal member is 1.1 μm or less. The maximum height roughness (Rz) of the portion of the surface of the metal member with a radius of curvature of 0.05 to 2.5 mm is less than 2 μm. The metal member has through holes and / or openings, The maximum height roughness (Rz) of the inner wall of the through hole and / or opening is also less than 2 μm. A metal component characterized by a smoothed surface.

2. A metal component made of titanium or a titanium alloy, The maximum length of the aforementioned metal member is 50 to 1000 mm. The arithmetic mean roughness (Ra) of the portion of the surface of the metal member with a radius of curvature of 0.05 to 2.5 mm is less than 0.4 μm. The metal member has through holes and / or openings, The arithmetic mean roughness (Ra) of the inner wall of the through hole and / or opening is also less than 0.4 μm. A metal component characterized by a smoothed surface.

3. The equivalent circular diameter of the through hole and / or the opening is 0.1 to 5 mm. A surface-smoothed metal member according to claim 1 or 2, characterized by the above.

4. The depth of the through hole and / or the opening is 1 to 50 mm. A surface-smoothed metal member according to claim 1 or 2, characterized by the above.

Images