Method for manufacturing metal film and metal coating member

Abstract

To provide a method for manufacturing a metal film that can readily and inexpensively acquire a metal film having a desired composition, and to provide a metal coating member that can be acquired by the method of manufacturing.SOLUTION: A method for forming a metal film by pressing a metal material to a surface of a substrate while rotating the metal material and coating the softened metal material at the surface of the substrate includes a step of rolling a metal foil into a rod shape to make the metal foil become a metal material, where the step preferably includes laminating metal foils having different compositions to make the metal film become an alloy film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for producing a metal film by forming a metal film on a substrate surface, and a metal-coated member obtained by the method. [Background technology]

[0002] Various methods have been proposed for forming metal films on the surfaces of various substrates. In recent years, attention has been focused on the fact that the stir zones obtained by friction stir welding and friction stir processes exhibit good mechanical properties, and techniques have been developed for forming metal build-up layers in the solid phase by utilizing the friction stir phenomenon.

[0003] For example, Patent Document 1 (JP 2009-161793 A) discloses a friction stir coating method in which a rod-shaped body having a surface layer made of a material having a lower high-temperature deformation resistance than the inner periphery of a hole having a circular cross-sectional shape and bounded by an inner periphery of a cylindrical inner surface and / or a tapered surface having a diameter which varies in the axial direction is pressed into the hole in the axial direction while rotating the substrate and the rod-shaped body relative to each other, and the surface layer of the rod-shaped body is softened and fluidized by heat generated by friction, thereby coating at least the surface layer onto the inner periphery of the hole.

[0004] In the friction stir coating method described in Patent Document 1, the inner circumferential surface of the hole and the outer circumferential surface of the rod-shaped body undergo relative sliding friction, so that the surface layer of the rod-shaped body softens and plastically flows due to heat generated by friction. The surface layer of the rod-shaped body softens and flows, adhering to the friction surface, and at least the surface layer is coated onto the inner circumferential surface of the hole due to solid-phase diffusion accompanying the heat generation phenomenon. At this time, since the surface layer of the rod-shaped body is made of a material with lower high-temperature deformation resistance than the inner circumferential part of the hole, mixing of the components of the base material and the components of the rod-shaped body due to plastic flow is avoided, and the coating is performed in a good bonding state.

[0005] Furthermore, Patent Document 2 (JP Patent Publication No. 2009-28756) discloses a surface build-up method for building up a build-up material on the surface of a metal base material used for reactor internal structures, characterized in that a build-up material having high hardness and high corrosion resistance is built up on the surface of the metal base material by friction stirring.

[0006] The surface build-up method described in the above Patent Document 2 is said to provide a surface build-up method for build-up-coating a high-hardness, high-corrosion-resistant build-up material on a metal substrate, with improved bondability and suppressed formation of a weld heat-affected zone and a dilution region. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2009-161793 A [Patent Document 2] JP 2009-28756 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the friction stir coating method disclosed in Patent Document 1 requires the production of a rod-shaped body having a surface layer made of a material that has a lower high-temperature deformation resistance than the inner circumference of the hole and an outer diameter that is larger than the inner diameter of the hole, which not only results in poor productivity but also high process costs.

[0009] In addition, the surface build-up method disclosed in the above Patent Document 2 involves softening a high-hardness, high-corrosion-resistant build-up material by heat input caused by friction stirring to coat it on the substrate surface, which results in a large process load and requires the use of a dedicated machine with high rigidity to carry out the process.

[0010] Furthermore, in the friction stir coating method disclosed in Patent Document 1 and the surface build-up method disclosed in Patent Document 2, it is necessary to obtain a coating material having the same composition as the desired coating and build-up layer in advance, which not only increases the process cost but also limits the types of metal films that can be obtained.

[0011] In view of the problems in the conventional techniques as described above, an object of the present invention is to provide a simple and inexpensive method for producing a metal film, which can provide a metal film having a desired composition, and a metal-coated member obtained by said method. [Means for solving the problem]

[0012] In order to achieve the above-mentioned object, the inventors conducted extensive research into methods for producing metal films using the friction stir phenomenon, and discovered that rolling metal foil into a rod shape to use as a coating material is extremely effective, leading to the invention.

[0013] That is, the present invention provides: A method for forming a metal film by pressing a rotating metal material against a surface of a substrate and coating the surface of the substrate with the softened metal material, comprising the steps of: Rolling the metal foil into a rod shape to obtain the metal material; The present invention provides a method for producing a metal film, comprising the steps of:

[0014] In the method for manufacturing a metal film of the present invention, a coating material (a rod-shaped body equivalent to a tool in friction stir welding and friction stir processing) can be obtained simply and inexpensively by rolling a metal foil into a rod shape to form a metal material.

[0015] In addition, metal material made of rolled metal foil has a moderate amount of voids (gaps between the metal foil) and has a lower overall thermal conductivity compared to dense metal materials. Therefore, frictional heat generated by friction between the surface of the substrate and the metal material is easily stored at the ends of the metal material, allowing the temperature of these ends to be easily raised, and the metal material can be efficiently coated on the surface of the substrate.

[0016] In addition, the base area of ​​a rolled metal foil that actually contacts the substrate is smaller than that of a dense rod having the same outer diameter. As a result, even if the pressing load is small, the pressure applied to the metal material is high, and the end of the metal body can be efficiently heated. In the method for producing a metal film of the present invention, there is no need to use an expensive and large dedicated friction stir machine with high rigidity and pressing force, and a general-purpose drill press, milling machine, etc. can be used to produce a metal film.

[0017] In addition, in the method for producing a metal film of the present invention, it is preferable to laminate the metal foils having different compositions, roll them into a rod shape to obtain the metal material, and make the metal film into an alloy film. By appropriately combining metal foils having different compositions, a metal material having a desired composition of the metal film can be easily obtained. In addition, the metal foils are heated and mixed with each other by a strong friction stirring effect, so that an alloy film can be produced. At this time, since a large strain is introduced into the metal foil, the diffusion of each element is promoted, and alloying can be achieved very effectively. Furthermore, a fine and uniform metal structure can be obtained by dynamic recrystallization and an increase in precipitation sites due to the introduction of strain. In addition, since it is a low-temperature and short-time process in the solid phase, it is also possible to suppress, for example, the coarsening of precipitates that contribute to high hardness and high strength of the metal film.

[0018] In the method for producing a metal film of the present invention, it is preferable to form the metal film in the atmosphere. In the method for producing a metal film of the present invention, the metal material is not melted, and the process is a low-temperature, short-time process in the solid phase, so there is almost no need to consider the influence of oxidation, etc. As a result, atmospheric control using an inert gas such as argon is not essential, and the metal film can be produced simply and inexpensively.

[0019] Furthermore, in the method for producing a metal film of the present invention, it is preferable to use two or more of the metal foils selected from Zr foil, Al foil, Ni foil, and Cu foil. By using these metal foils with relatively low melting points, it is possible to easily form a metal film by friction stirring, and to obtain an alloy film with excellent properties. For example, by using all of Zr foil, Al foil, Ni foil, and Cu foil, it is possible to obtain a hard alloy film with an average hardness of 30 GPa or more. Furthermore, by using Ni foil and Cu foil, it is possible to obtain an alloy film with a magnetization of 10% or less compared to a metal material having the same composition.

[0020] The present invention also provides a method for producing a semiconductor device comprising the steps of: A metal film is provided on the surface of the substrate, the metal film is an alloy film containing Zr, Al, Ni, and Cu, The average hardness of the alloy film is 30 GPa or more; The present invention provides a metal-coated member comprising:

[0021] The metal-coated member of the present invention is obtained by the method for producing a metal film of the present invention, and is a member in which an alloy film is formed on the surface of a substrate. It may be used as a metal-coated member, or the metal film may be separated from the substrate and used as the alloy film alone. Here, the material, shape, and size of the substrate are not particularly limited as long as they do not impair the effects of the present invention, and various conventionally known metal substrates, ceramic substrates, etc. may be used.

[0022] The alloy film in the metal-coated member of the present invention is formed by a process involving severe deformation, and has a crystallinity that is significantly different from that of alloy films formed by physical vapor deposition, arc discharge, laser cladding, etc., and has low crystallinity, including non-uniform distortion and small crystallite sizes.

[0023] In addition, since the alloy film contains Zr, Al, Ni, and Cu, Zr-(Ni,Cu)-Al alloy (metallic glass) and fine alumina are dispersed, resulting in a high average hardness of 30 GPa or more. The average hardness of the alloy film is preferably 35 GPa or more, and more preferably 40 GPa or more.

[0024] Furthermore, the present invention provides A metal film is provided on the surface of the substrate, the metal film is an alloy film made of Ni and Cu, The magnetization of the alloy film is 10% or less compared to a metal material having the same composition; Also provided is a metal-coated member, comprising:

[0025] When the metal film is an alloy film made of Ni and Cu, it can be a Ni·Cu alloy film of 67Ni·33Cu (mass %), etc. Here, the Ni·Cu alloy film of the metal-coated member of the present invention has low crystallinity and is therefore unlikely to become magnetic, and can be used, for example, as a replacement for electroless Ni plating.

[0026] Electroless Ni plating is formed for the purpose of suppressing the diffusion of a base material such as copper or a plating material in an underlying layer to an upper layer, but since the Ni plating film is crystalline, it is easily magnetized, which may result in adverse effects on the product quality of precision instruments, etc. In contrast, in the metal-coated member of the present invention, the magnetization of the alloy film is 10% or less compared to a metal material having the same composition, so it is less likely to become magnetized and can be suitably used as a substitute for a Ni plating film. Effect of the Invention

[0027] According to the present invention, it is possible to provide a simple and inexpensive method for producing a metal film by which a metal film having a desired composition can be obtained, and a metal-coated member obtained by the method. [Brief description of the drawings]

[0028] [Figure 1] 1 is a schematic diagram of a method for producing a metal film according to the present invention. [Diagram 2] 1 is a schematic diagram of a method for producing a metal material used in the present invention. FIG. [Diagram 3] 1 is a schematic cross-sectional view of a metal-coated member according to one embodiment of the present invention. [Figure 4] 1 is a photograph showing the appearance of an end portion of a metal material used in Example 1. [Diagram 5] 3 is a photograph showing the state of friction stirring in Example 1. [Figure 6] 1 is a photograph of the surface of the metal film obtained in Example 1. [Figure 7] 1 is an X-ray diffraction profile of the metal film obtained in Example 1. [Figure 8] 2 shows a secondary electron image and an element mapping image of the metal film obtained in Example 1. [Figure 9] 1 shows an EDS spectrum of the metal film obtained in Example 1. [Figure 10] 1 is a photograph of the surface of a metal film obtained in Example 2. [Figure 11] 1 is an X-ray diffraction profile of the metal film obtained in Example 2. [Figure 12] 1 is an X-ray diffraction profile of the metal film obtained in Example 3. [Figure 13] 1 shows the magnetization curve behavior of the metal film obtained in Example 3. [Figure 14] 1 shows the magnetization curve behavior of the metal film obtained in Example 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Representative embodiments of the method for producing a metal film and the metal-coated member of the present invention will be described in detail below with reference to the drawings, but the present invention is not limited to these. In the following description, the same or corresponding parts are given the same reference numerals, and duplicated descriptions may be omitted. In addition, since the drawings are intended to conceptually explain the present invention, the dimensions of each component shown and their ratios may differ from the actual ones.

[0030] (1) Method of manufacturing metal film The method for producing a metal film of the present invention is a method for obtaining a metal film by depositing a rod-shaped metal material on the surface of a substrate using the friction stirring phenomenon. Figure 1 shows a schematic diagram of the method for producing a metal film of the present invention. Here, Figure 1 shows a case where the metal material is moved only vertically to form a disk-shaped metal film.

[0031] The metal material 2, which is the raw material of the metal film, is rotated and brought into contact with the surface of the substrate 4, and the frictional heat between the metal material 2 and the substrate 4 causes the temperature of the end of the metal material 2 and the surface of the substrate 4 to rise. After the end of the metal material 2 has risen sufficiently in temperature and started to plastically flow, the metal material 2 is pulled up to form a disk-shaped metal film 6. After the end of the metal material 2 has risen sufficiently in temperature and started to plastically flow, the metal material 2 is moved laterally in any direction to obtain a linear metal film 6. Furthermore, by combining these metal films 6, a metal film 6 having any two-dimensional or three-dimensional shape and size can be obtained.

[0032] When a metallic substrate 4 is used, the metal film 6 and substrate 4 can be firmly bonded. The metallurgical bonding between the metal film 6 and substrate 4 can achieve a higher bonding strength than a metal film formed by plating, vapor deposition, or the like, and can suppress peeling of the metal film 6 from the substrate 4. On the other hand, when a ceramic substrate 4 is used, the metal film 6 can be peeled off from the substrate 4 as necessary, and the metal film 6 can also be used alone.

[0033] FIG. 2 is a schematic diagram showing a method for producing a metal material used in the method for producing a metal film of the present invention. The most important feature of the method for producing a metal film of the present invention is that a metal foil 8 is formed into a rod-like shape to form a metal material 2. As long as the metal foil 8 can be formed into a rod-like shape that can be used as the metal material 2, the method for rolling the metal foil 8 is not particularly limited, and for example, the rolled metal foil 8 may be appropriately folded. In addition, the thickness and size of the metal foil 8 are not particularly limited as long as they do not impair the effects of the present invention, and various conventionally known metal foils can be used. From the viewpoint of ease of forming into a rod shape and availability on the market, for example, the thickness of the metal foil can be 1 to 100 μm. In addition, the number of metal foils 8 to be laminated is not particularly limited, and may be appropriately set according to the diameter of the metal material 2 to be finally obtained, the desired density, strength, and the like.

[0034] The metal material 2 formed by rolling up the metal foil 8 has a moderate amount of voids (gaps between the metal foil 8) and has low overall thermal conductivity, so that frictional heat generated by friction between the surface of the base material 4 and the metal material 2 is easily stored in the ends of the metal material 2, making it easy to raise the temperature of those ends and allowing the metal material 2 to efficiently cover the surface of the base material 4. The gaps between the metal foils 8 can be controlled by the number and thickness of the metal foils 8, the diameter of the metal material 2, etc.

[0035] In addition, the metal material 2 formed by rolling the metal foil 8 has a smaller bottom area that actually contacts the substrate 4 compared to a dense rod-shaped body having the same outer diameter. As a result, even if the pressing force is small, the pressure applied to the metal material 2 is high, and the temperature of the end portion of the metal material 2 can be efficiently raised.

[0036] In the method for producing a metal film of the present invention, it is preferable to laminate metal foils 8 having different compositions to make the metal film 6 an alloy film. By appropriately combining metal foils 8 having different compositions, a metal material 2 having a desired composition of the metal film 6 can be easily obtained. In addition, the metal foils 8 are heated and mixed with each other by a strong friction stirring effect, so that an alloy film can be produced. At this time, since a large strain is introduced into the metal foil 8, the diffusion of each element is promoted, and alloying can be achieved very effectively. Furthermore, a fine and uniform metal structure can be obtained by dynamic recrystallization and an increase in precipitation sites due to the introduction of strain. In addition, since it is a low-temperature and short-time process in the solid phase, it is also possible to suppress, for example, the coarsening of precipitates that contribute to high hardness and high strength of the metal film 6.

[0037] Furthermore, by using the metal material 2 in which the metal foil 8 is rolled, the temperature of the end of the metal material 2 can be efficiently raised, so the process load is reduced, and there is no need to use an expensive, large dedicated friction stir machine having high rigidity and pressure, and the metal film 6 can be manufactured using a general-purpose drill press, milling machine, etc. In addition, by using the metal foil 8 with a low melting point, the pressure required for friction stirring can be further reduced, and the metal film 6 can be manufactured using a small drill press, milling machine, etc.

[0038] More specifically, it is preferable to use two or more kinds of metal foils 8 selected from Zr foil, Al foil, Ni foil, and Cu foil. By using these metal foils with relatively low melting points, it is possible to easily form the metal film 6 by friction stirring, and also to obtain an alloy film with excellent properties. For example, by using all of Zr foil, Al foil, Ni foil, and Cu foil, it is possible to obtain a hard alloy film with an average hardness of 30 GPa or more. Furthermore, by using Ni foil and Cu foil, it is possible to obtain an alloy film with a magnetization of 10% or less compared to a metal material having the same composition.

[0039] In addition, the method for producing a metal film of the present invention utilizes plastic flow caused by friction stirring, and is a process that does not involve a liquid phase, so it is possible to alloy metals with significantly different melting points, which was difficult to do with conventional technology. For example, Ti-based high-entropy alloys such as Ti-Zr-Hf-Nb-Ta-Mo alloys are considered promising as biomaterials, but since they are produced using an arc melting furnace, it is difficult to mix them with Mg, which is expected to reduce the weight of biomaterials. In contrast, by using the method for producing a metal film of the present invention, it is possible to obtain high-entropy alloys of any composition.

[0040] Examples of high-entropy alloys that can be suitably obtained using the metal film manufacturing method of the present invention include high-entropy cast iron alloys (Fe-Co-Cr-Mn-Ni-C), high-entropy brass alloys (Cu-Zn-Mn-Ni-Sn), eutectic high-entropy alloys (Al-Co-Cr-Fe-Ni), and alloys based on these with added elements.

[0041] The atmosphere during friction stirring is not particularly limited as long as it does not impair the effects of the present invention, but it is preferable to form the metal film 6 in air. Since friction stirring does not melt the metal material and is a low-temperature, short-time process in the solid phase, there is almost no need to consider the effects of oxidation, etc. As a result, atmospheric control using an inert gas such as argon is not essential, and the metal film 6 can be manufactured simply and inexpensively. On the other hand, for example, by forming the metal film 6 in air, fine oxide particles can be dispersed in the metal film 6, thereby increasing the hardness.

[0042] The friction stir welding conditions such as the rotation speed, applied load and moving speed of the metal material 2 may be appropriately adjusted according to the material, film thickness, diameter and void state of the metal foil 8 constituting the metal material 2, and the structure, shape and film thickness of the desired metal film 6, but the conditions of the conventionally known friction stir welding and friction stir processes can be referred to. Here, in the method for producing a metal film of the present invention, the friction stir welding conditions can be relatively low temperature and low load. For example, the process temperature can be reduced by reducing the rotation speed, reducing the applied load and increasing the moving speed. More specifically, for example, the rotation speed can be 1000 to 2000 rpm, the applied load can be 0.5 to 2.0 kN, and the moving speed can be 1 to 10 mm / sec.

[0043] (2) Metal-coated components The metal-coated member of the present invention has a metal film 6 formed on any surface of a substrate 4. Fig. 3 shows a schematic cross-sectional view of a metal-coated member according to one embodiment of the present invention. The metal film 6 is directly bonded to the substrate 4, and in particular, when the substrate 4 is made of a metal material, the metal film 6 and the substrate 4 are firmly bonded to each other.

[0044] The material of the substrate 4 is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known metal materials and ceramic materials can be used. In addition, the shape and size of the substrate 4 are also not particularly limited as long as it does not impair the effects of the present invention, and the substrate 4 can have any shape and size.

[0045] The metal film 6 does not need to be formed over the entire surface of the substrate 4, but may be formed in any desired region of the substrate 4. The thickness of the metal film 6 may be adjusted appropriately depending on the purpose. For example, when a thin film is required, the thickness may be set to about 1 to 100 μm, and when a thick film is required, the metal film 6 may be laminated to obtain any desired thickness.

[0046] One of the characteristics of the metal film 6 is that it contains non-uniform distortion and small crystallite size, resulting in low crystallinity. This characteristic can be confirmed, for example, by a broadened X-ray diffraction pattern or by direct observation with a transmission electron microscope.

[0047] In one embodiment of the metal-coated member 10 of the present invention, the metal film 6 is an alloy film containing Zr, Al, Ni, and Cu. Zr-(Ni,Cu)-Al alloy (metallic glass) and fine alumina are dispersed in the metal film 6, and the metal film 6 has a high average hardness of 30 GPa or more. The average hardness of the alloy film is preferably 35 GPa or more, and more preferably 40 GPa or more. The method of measuring the hardness is not particularly limited as long as it does not impair the effects of the present invention, and various conventionally known methods can be used. For example, a cross-sectional sample including the metal film 6 may be prepared and measured using a nanoindenter.

[0048] When the metal film 6 has high hardness, the metal-coated member 10 can be suitably used in applications that require excellent wear resistance and durability, such as cutting tools, dies, and sliding members.

[0049] In another embodiment of the metal-coated member of the present invention, the metal film 6 is an alloy film made of Ni and Cu, such as a Ni·Cu alloy film of 67Ni·33Cu (mass%). The Ni·Cu alloy film of the metal-coated member of the present invention is difficult to become magnetic due to its low crystallinity, and the magnetization of the alloy film is 10% or less compared to a metal material having the same composition, and can be used, for example, as a replacement for electroless Ni plating. The magnetization of the alloy film compared to a metal material having the same composition is preferably 8% or less, more preferably 6% or less, and most preferably 4% or less.

[0050] Here, since the crystallinity of the metal film 6 tends to decrease due to a decrease in temperature during film formation (during friction stirring) and an increase in strain rate, the magnetism of the metal film 6 can be controlled by the manufacturing conditions.

[0051] When the magnetization of the metal film 6 is suppressed, the metal coating member 10 can be suitably used, for example, as power device-related parts (semiconductor electrodes, lead frames, aluminum heat sinks, etc.) that require reduced magnetization.

[0052] In the metal-coated member 10, the metal film 6 formed on the surface of the substrate 4 is not limited to one type, and metal films 6 having different compositions and / or microstructures may be formed in different regions. Also, for example, metal films 6 having different compositions and / or microstructures may be laminated.

[0053] Representative embodiments of the present invention have been described above, but the present invention is not limited to these, and various design modifications are possible, all of which are included in the technical scope of the present invention. EXAMPLES

[0054] Example 1 A 50mm x 50mm sheet of Zr foil (purity 99.2%, thickness 0.05mm), Al foil (purity 99%, thickness 0.006mm), Ni foil (purity 99%, thickness 0.005mm) and Cu foil (purity 99.9%, thickness 0.008mm) were stacked and rolled into a rod with a diameter of about 6mm to prepare the metal material to be used in friction stirring. Figure 4 shows a photograph of the appearance of the end of the metal material. It can be seen that the metal foils are stacked and an appropriate gap is formed.

[0055] An alumina (Al2O3) substrate was used as the base material. The relative density of the alumina substrate was 99.5%, the purity was 99.5%, and the arithmetic mean roughness (Ra) of the surface was 0.347μm. As shown in Fig. 5, a rod-shaped metal material was attached to the rotating part of a general-purpose drilling machine (HiKOKI B23S), and while rotating at 1590rpm, the end of the metal material was pressed against the surface of the alumina substrate with a maximum of 1.5kN and held for 60 seconds to form a metal film (a circular metal film was formed without moving the metal material sideways). In addition, no shielding gas was used, and the treatment was carried out in the air.

[0056] The tip of the metal material was heated quickly, and the metal film was formed very smoothly without any vibration of the drill press. A photograph of the surface of the obtained metal film is shown in Figure 6. From Figure 6, it can be seen that a circular metal film with metallic luster was formed. Next, the crystallinity of the metal film was evaluated using an X-ray diffraction device (RIGAKU Smart Lab). Figure 7 shows the X-ray diffraction profile obtained by measuring the metal film surface. The observation of a broad peak originating from the metal film indicates that the crystallinity of the metal film is low. The sharp peak of Al2O3 originates from the alumina substrate, but a broad peak of oxides is also observed due to the treatment in air. This peak indicates that extremely fine oxides are dispersed.

[0057] Next, SEM-EDS analysis of the metal film surface was performed. The obtained secondary electron image and mapping image of each element are shown in Figure 8, and the EDS spectrum is shown in Figure 9. A Hitachi High-Tech TM3030Plus was used for the analysis. Figure 8 shows that Zr, Al, Ni, Cu and O are uniformly present without uneven distribution, and that the metal film is a metal alloy film. In addition, cross-sectional observation of the metal film showed that the film thickness was 4 μm.

[0058] Next, the hardness of the metal film was measured using a nanoindenter (ENT-1100a, Elionix). Measurements were taken at nine different points on the metal film surface, and the average hardness was 42 GPa (standard error 3 GPa), confirming that a metal film with extremely high hardness had been formed.

[0059] Example 2 A metal film was obtained in the same manner as in Example 1, except that only a 50 mm x 50 mm Zr foil (purity 99.2%, thickness 0.05 mm) was used, which was rolled into a rod shape with a diameter of about 6 mm to be used as the metal material for friction stirring. A surface photograph of the obtained metal film is shown in Figure 10. Even when one type of metal foil was used, a metal film was obtained, and it can be seen that by using the method for producing a metal film of the present invention, a metal film can be obtained simply and efficiently, regardless of whether the metal film is a metal alloy film or a pure metal film.

[0060] The X-ray diffraction profile obtained in the same manner as in Example 1 is shown in Figure 11. In addition to the sharp peaks derived from the alumina substrate, broad peaks derived from the metal film are observed, and it is understood that even if the metal film is not a metal alloy film, a metal film with poor crystallinity is formed. In addition, similar to Example 1, broad peaks derived from oxides are also observed.

[0061] When the hardness of the metal film was measured in the same manner as in Example 1, the average hardness at nine points was 12 GPa (standard error 1 GPa), which was lower than the hardness of the metal alloy film obtained in Example 1.

[0062] Example 3 A metal film was obtained in the same manner as in Example 1, except that a 50 mm × 50 mm Ni foil (purity 99%, thickness 0.02 mm) and a Cu foil (purity 99.9%, thickness 0.01 mm) were rolled into a rod shape with a diameter of approximately 6 mm so that the overall composition was 67Ni·33Cu (mass %), and the rod was used as the metal material for friction stirring.

[0063] 12 shows an X-ray diffraction profile obtained in the same manner as in Example 1. In addition to the sharp peaks derived from the alumina substrate, broad peaks derived from the metal film were observed, indicating that a metal alloy film was formed and that the metal alloy film had poor crystallinity.

[0064] Next, the magnetic properties of the obtained metal film were evaluated using a vibrating sample magnetometer (Riken Denshi BHV-50). The obtained magnetization curve behavior is shown in Figure 13. It can be seen from Figure 13 that the maximum magnetization was about 200 Gauss. Normally, the magnetization of Ni is about 6000 Gauss, and the 200 Gauss of the obtained metal film is a significantly lower value. This is thought to be due to the metal film containing non-uniform distortion and small crystallite size, resulting in poor crystallinity.

[0065] Example 4 A metal film was obtained in the same manner as in Example 1, except that only a 50 mm x 100 mm Ni foil (purity 99%, thickness 0.02 mm) was used and rolled into a rod shape with a diameter of approximately 6 mm to be used as the metal material for friction stirring.

[0066] The magnetization curve behavior of the metal film obtained in the same manner as in Example 3 is shown in Figure 14. It can be seen from Figure 14 that the maximum magnetization is about 600 Gauss. Normally, the magnetization of Ni is about 6000 Gauss, and the 600 Gauss of the obtained metal film is a significantly lower value. This is thought to be due to the metal film containing non-uniform distortion and small crystallite size, resulting in poor crystallinity.

[0067] From the above results, it was confirmed that the formation of metal films using friction stirring can be achieved very simply and efficiently by rolling metal foil into a rod-like shape to prepare a metal material. It was also found that various metal alloy films can be obtained by appropriately combining metal foils with different compositions to prepare a metal material. In addition, it was found that the obtained metal films exhibit unique physical properties such as high hardness and low magnetization compared to conventional metal films with the same composition. [Explanation of symbols]

[0068] 2...metal material, 4...Base material, 6 Metal film, 8. Metal foil, 10 Metal coated member.

Claims

1. A method for forming a metal film by pressing a rotating metal material against a surface of a substrate and coating the surface of the substrate with the softened metal material, comprising the steps of: Rolling the metal foil into a rod shape to obtain the metal material; A method for producing a metal film, comprising the steps of:

2. The metal foils having different compositions are laminated and rolled into a rod shape to obtain the metal material; The metal film is an alloy film; The method for producing a metal film according to claim 1 ,

3. forming the metal film in air; The method for producing a metal film according to claim 1 or 2, characterized in that

4. Using two or more metal foils selected from Zr foil, Al foil, Ni foil and Cu foil; The method for producing a metal film according to claim 1 or 2, characterized in that

5. A metal film is provided on the surface of the substrate, the metal film is an alloy film containing Zr, Al, Ni, and Cu, The average hardness of the alloy film is 30 GPa or more; A metal-coated member comprising:

6. A metal film is provided on the surface of the substrate, the metal film is an alloy film made of Ni and Cu, The magnetization of the alloy film is 10% or less compared to a metal material having the same composition; A metal-coated member comprising:

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