Metal member and product
The metal member, featuring a combination of metals like ruthenium and micro-porosities, addresses the instability and performance limitations of existing resistance heating elements by providing enhanced heat resistance, corrosion resistance, and mechanical properties.
Patent Information
- Application Number
- JP2023208252
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-12-11
- Publication Date
- 2025-06-23
AI Technical Summary
Existing metal resistance heating elements undergo recrystallization during energization, leading to changes in electrical resistivity and mechanical strength, which results in instability and potential disconnection, and they have limitations in heat resistance and corrosion resistance.
A metal member composed of two or more metals, including a noble metal like ruthenium (Ru) and micro-porosities with a true circle equivalent diameter of 20 μm or less formed in a dot pattern, which enhances heat resistance, corrosion resistance, and mechanical properties.
The proposed metal member achieves excellent heat resistance, corrosion resistance, and mechanical properties, making it suitable for use in resistance heating elements while being cost-effective and maintaining stability over time.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to metal members and products.
Background Art
[0002] In a resistance heating furnace, a direct current or an alternating current is applied to a resistance heating element disposed in the furnace to generate heat in the resistance heating element and heat the inside of the furnace. Generally, carbon-based materials such as carbon and SiC, ceramic materials such as zirconia and lanthanum chloride, and metal-based materials such as tungsten and tantalum are used for the resistance heating element. The material that can be used for the resistance heating element is mainly selected according to the atmosphere required for heating and the target temperature to be reached.
[0003] For example, an evaporation cell used for film formation in the production of an organic electroluminescence device is a type of resistance heating furnace, and generally the inside of the furnace is used at a high vacuum (about ~10 5 Pa). In vacuum evaporation using this type of evaporation cell, a crucible-shaped container filled with an evaporation raw material is placed in a region surrounded by a resistance heating element, and the inside of the furnace is heated by energizing the resistance heating element to melt the evaporation raw material in the container. Atoms or molecules desorbed from the surface of the melted evaporation raw material are given directivity by the evaporation cell and adhere to a substrate disposed above the evaporation cell, thereby proceeding with film formation.
[0004] In film formation as described above, since it is required that desorption of substances other than the evaporation raw material inside the evaporation cell is small, the resistance heating element that can be used for the evaporation cell is limited to substances with low volatility in a high temperature and high vacuum.
[0005] Conventionally, as the resistance heating element, refractory metals such as tungsten, molybdenum, and tantalum, which are exclusively of high melting point and low vapor pressure, have been used. In particular, tantalum, unlike tungsten and molybdenum, has high ductility and is thus widely used because it can be easily processed into the desired resistance heating element shape even at room temperature. Also, tantalum has a higher electrical resistivity compared to tungsten and molybdenum, so heating can be achieved with a lower current to heat a resistance heating element of the same volume. Therefore, it has the advantage of enabling miniaturization and reduction in diameter of the current source and electric wires. Note that tantalum, tungsten, and molybdenum used for the resistance heating element are all used in the state of pure metal or an alloy containing a small amount of additives.
Prior Art Documents
Non-Patent Documents
[0006]
Non-Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0007] However, existing metal resistance heating elements are polycrystalline because they are formed through machining such as forging and wire drawing. Recrystallization occurs during energization heating, resulting in changes over time in electrical resistivity and mechanical strength. As a result, there are problems such as changes in the applied current and voltage conditions for raising the temperature to a predetermined temperature, and a decrease in mechanical strength causing the resistance heating element to deform, leading to unexpected contact with surrounding members or disconnection. Also, during use, often a nodular structure is formed, deteriorating the electrical and mechanical properties and leading to disconnection, which is a problem.
[0008] Also, as described above, tantalum has a higher electrical resistivity compared to tungsten and molybdenum, but has a low electrical resistivity with respect to the required characteristics. Furthermore, there is a problem that the temperature dependence of the electrical resistivity of tantalum is larger than that of tungsten and molybdenum. Generally, the electrical resistivity of a metal increases with an increase in temperature, but in the case of tantalum, a slight temperature change leads to a change in the electrical resistivity compared to tungsten and molybdenum, and the controllability of temperature by controlling voltage and current is low.
[0009] Recently, in response to these problems, the improvement of the electrical characteristics of metal members using noble metals such as ruthenium (Ru) as alternative materials for tantalum has been studied (Non-Patent Document 1). However, these metal members also have problems such as high cost, and are not always satisfactory in terms of mechanical properties, etc. For this reason, there is a long-awaited need for an inexpensive metal member with excellent heat resistance, corrosion resistance, and mechanical properties.
[0010] The present invention has been made to solve the above problems, and an object thereof is to provide an inexpensive metal member having excellent heat resistance, corrosion resistance, and mechanical properties.
Means for Solving the Problems
[0011] The metal member according to the present invention is a metal member containing two or more metals other than noble metals and a noble metal, and includes micro-porosities having a true circle equivalent diameter of 20 μm or less formed in a dot pattern.
[0012] In one configuration example of the above metal member, it contains at least one noble metal selected from the group consisting of Ru, Ir, Rh, Pt, Pd, and Os.
[0013] In one configuration example of the above metal member, it contains Ru as the noble metal.
[0014] In one configuration example of the above metal member, it contains Ru as the noble metal and further contains Re.
[0015] In one configuration example of the above metal member, the composition ratio of Ru and Re is 1 or more in terms of atomic ratio.
[0016] In one configuration example of the above metal member, it further contains at least one additive element selected from the group consisting of Ir, Rh, Pt, Pd, and Os, and the content of the additive element is 0.001 at% to 15 at% with respect to the entire metal member.
[0017] In one configuration example of the above metal member, it contains Ru, Re, and at least one element of Mo and W.
[0018] In one configuration example of the above metal member, the total content of Ru, Re, and the above element is 60 at% or more with respect to the entire metal member.
[0019] The product according to the present invention is a product containing the above metal member.
[0020] In one configuration example of the above product, the product is a component of a heating device, a film forming device, or a crystal growth device.
[0021] In one configuration example of the above product, the product is a reaction device, a reaction vessel, or a component thereof.
Effects of the Invention
[0022] As described above, according to the present invention, there is provided a metal member containing two or more metals other than precious metals and a precious metal, and including microporosities having a true circle equivalent diameter of 20 μm or less formed in a dot array, so that a metal member that is inexpensive and has excellent heat resistance, corrosion resistance, and mechanical properties can be provided.
Brief Description of the Drawings
[0023]
Figure 1A
Figure 1B
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DETAILED DESCRIPTION OF THE INVENTION
[0024] Hereinafter, a metal member according to an embodiment of the present invention will be described. This metal member is a metal member containing two or more metals other than precious metals and a precious metal, and includes microporosity having a true circle equivalent diameter of 20 μm or less formed in a plurality of dot arrays. This metal member is a so-called alloy containing two or more metals other than precious metals and a precious metal. The metal member according to the embodiment is inexpensive and excellent in heat resistance, corrosion resistance, and mechanical properties, and can be used as a resistance heating element.
[0025] The microporosities contained in the metal member can be formed in a row of 10 or more. Further, the microporosities contained in the metal member can be formed in a row over 0.1 mm or more (preferably 1 mm or more, more preferably 10 mm or more). Further, the metal member can contain microporosities having an equivalent circle diameter of 10 μm or less, or microporosities having an equivalent circle diameter of 5 μm or less. According to the metal member according to the embodiment including such microporosities, for example, mechanical properties and the like become better.
[0026] For example, the metal member according to the embodiment can contain at least one noble metal selected from the group consisting of Ru, Ir, Rh, Pt, Pd, and Os, and can contain Ru as the noble metal. According to this metal member, heat resistance and corrosion resistance can be further improved. Further, the metal member can contain Ru as the noble metal and further contain Re. By adopting this configuration, the metal member can be made inexpensive and have excellent heat resistance, corrosion resistance, and mechanical properties. Further, the composition ratio of Ru and Re in the metal member can be 1 or more in terms of atomic ratio. By adopting this composition ratio, it is preferable because the resistance of the metal member to load and the like can be further improved.
[0027] Further, the metal member according to the embodiment can contain Ru, Re, and at least one element of Mo and W. The total content of Ru, Re, and the above element in the metal member is 60 at% or more with respect to the whole of the metal member, and further, it can have a primary crystal part with a hexagonal close-packed structure. By adopting this configuration, the metal member can be made inexpensive and have more balanced and excellent heat resistance and mechanical properties.
[0028] Further, the metal member according to the embodiment can contain at least one element of Mo and W. By setting the content of the above element within the range of 0.1 at% to 50 at%, this metal member can preferably improve the adhesion and stability as an alloy and the like.
[0029] In addition, the metal member according to the embodiment can further contain at least one additive element selected from the group consisting of Ir, Rh, Pt, Pd, and Os. The content of this additive element can be set to 0.001 at% to 15 at% with respect to the entire metal member. By including the additive element with the content within this range, the heat resistance and corrosion resistance of the metal member can be further improved.
[0030] Note that the "metal member" does not mean only a metal member composed only of an element (metal material) containing Ru, Re, and at least one of Mo and W elements, but means a member containing at least the above-described elements, and other elements can be included. In addition, the shape of this metal member is not particularly limited, and for example, it also includes a metal member to which components or members made of materials such as ceramics, other metals, and plastics are joined. The metal member according to the present invention can contain unavoidable impurities.
[0031] Since the metal member according to the embodiment is inexpensive and excellent in heat resistance, corrosion resistance, and mechanical properties, it can be made into a wire. In the present invention, the metal member can be easily manufactured by the μ-PD method.
[0032] In a preferred μ-PD method, as shown in FIGS. 1A and 1B, a molten metal 103 as a raw material is accommodated in a crucible 102 that can be heated by a high-frequency induction coil 101, and a metal (wire) 105 solidified through a growth crystal 104 is pulled down while passing through a nozzle 106 to perform crystal growth. The nozzle 106 is provided at the bottom 107 of the crucible 102. The crucible 102 is supported and fixed on a crucible stand 109 inside a processing chamber 108. Note that FIG. 1B shows an enlarged view of the inside of the dotted circle in FIG. 1A.
[0033] The metal member manufactured in this way not only has excellent crystallinity, but also has better mechanical properties such as elongation and strength. Even when used as a wire, higher durability can be achieved, and furthermore, it can exhibit more excellent mechanical properties, heat resistance, etc.
[0034] The metal member according to the embodiment can be applied to various products according to a conventional method. For example, it can be suitably used as a heating device, a film forming device, a crystal growth device, or parts thereof. Also, the metal member according to the embodiment can be suitably used as a reaction device, a reaction vessel, or parts thereof. The heating device, the film forming device, the crystal growth device, the reaction device, or the reaction vessel can be known devices such as a heater device, a CVD device, a PLD device, a vapor phase crystal growth device, a liquid phase crystal growth device, etc. Also, the parts can be known parts of the device (for example, parts for an evaporation cell, a heater wire, a brazing material, etc.).
[0035] Hereinafter, it will be described in more detail using examples.
[0036] [Example 1] Using Ru, Mo, W, Re raw materials with a purity of 99.9% or more, Ru 0.6-x Mo 0.15 W 0.25 Re x (x = 0.01, 0.1, 0.15) alloy button ingots were produced by an arc melting method, and φ0.8 mm wires were grown by the Dewetting μ-PD method to obtain samples of the metal member of the present invention. The produced samples were cut, and heat treatment was carried out at a temperature condition of 2273K for 3 hours in a high-purity Ar atmosphere. When composition analysis and crystal orientation analysis were performed on the heat-treated samples by wavelength dispersive fluorescent X-ray spectroscopy (WDX) and electron backscatter diffraction (EBSD) methods, it was confirmed that all the wires were Ru 0.6-x Mo 0.15 W 0.25 Re x (x = 0.01, 0.1, 0.15) alloy wires.
[0037] Figure 2 shows the grown Ru 0.59 Mo 0.15 W 0.25 Re 0.01 photograph of the wire. (a) in Figure 2 shows the whole of the wire grown to a length of 14.2 m wound in a ring and bundled, and (b) in Figure 2 shows a partially enlarged view. The wire diameter of this wire was 0.80 ± 0.01 mm, and the surface was smooth. Also, Ru 0.59 Mo 0.15 W 0.25 Re 0.01 the wire was a very high-quality single-crystal alloy wire as shown in the photograph of Figure 3. Incidentally, the grown Ru 0.59 Mo 0.15 W 0.25 Re 0.01 wire showed a maximum tensile strength of about 658 MPa and a good elongation at break of about 89%.
[0038] For any of the Ru 0.6-x Mo 0.15 W 0.25 Re x (x = 0.01, 0.1, 0.15) alloy wires (Re-substituted alloy wires), wires of 1 m or more were obtained and could be easily bent at room temperature. Also, by thermodynamic calculation, the solidus temperature increased according to the Re substitution amount, and the solidus temperature of Ru 0.45 Mo 0.15 W 0.25 Re 0.15 was estimated to be about 2493 K. Also, in the above configuration, the primary crystal part has a hexagonal close-packed (HCP) structure, and it was also possible to confirm micro-porosities with an equivalent true circle diameter of 20 μm or less formed in a row-like manner derived from the primary crystal part of the HCP structure (Figure 4). As shown in Figure 4, in the direction of the arrow line, a plurality of micro-porosities are formed in a row-like manner. Therefore, the metal member according to the present invention can include micro-porosities with an equivalent true circle diameter of 20 μm or less formed in a row-like manner in the longitudinal direction, derived from the primary crystal part of the HCP structure.
[0039] [Example 2] By the same procedure as in Example 1 described above, using Ru, Mo, W, Re raw materials with a purity of 99.9% or more, Ru0.6-x Mo 0.15 W 0.25 Re x (x = 0, 0.01, 0.1, 0.15) alloy button ingots were produced, and φ0.8 mm wire rods were grown to obtain sample wire rods. The results of evaluating each of the produced sample wire rods are shown in FIGS. 5 to 8. FIG. 5 shows the results of the micro-indentation test, and FIG. 6 shows the results of the indentation elastic modulus test. From the micro-indentation test in FIG. 5 and the results of the indentation elastic modulus test in FIG. 6, Ru 0.6-x Mo 0.15 W 0.25 Re x the mechanical properties were particularly good when the Re content in the alloy was between 1 atomic % and 15 atomic %.
[0040] FIG. 7 shows the evaluation results of the electrical resistivity. From the evaluation results of the electrical resistivity such as FIG. 7, Ru 0.6-x Mo 0.15 W 0.25 Re x it was found that when the Re content in the alloy exceeded 0 atomic % and was less than 23 atomic %, the properties were excellent, and when it was between 0.3 atomic % and 15 atomic %, the properties were even more excellent. FIG. 8 shows the test evaluation results of elongation. From the test evaluation results of elongation such as FIG. 8, Ru 0.6-x Mo 0.15 W 0.25 Re x it was found that the elongation was more excellent when the Re content in the alloy was between 4 atomic % and 14 atomic %.
[0041] As described above, according to the present invention, there is provided a metal member including two or more metals other than precious metals and a precious metal, and including micro-porosities having a true circle equivalent diameter of 20 μm or less formed in a dot array, so that an inexpensive metal member excellent in heat resistance, corrosion resistance, and mechanical properties can be provided.
[0042] It should be noted that the present invention is not limited to the embodiments described above, and it is obvious that many modifications and combinations can be implemented by those having ordinary knowledge in the art within the technical idea of the present invention.
Description of Symbols
[0043] 101…High-frequency induction coil, 102…Crucible, 103…Molten metal, 104…Grown crystal, 105…Solidified metal (wire rod), 106…Nozzle, 107…Bottom, 108…Processing chamber, 109…Crucible stand.
Claims
1. A metal member containing two or more metals other than precious metals and a precious metal, the metal member containing microporosity having a true circle equivalent diameter of 20 μm or less formed in a dot pattern.
2. In the metal member according to Claim 1, A metal member containing at least one precious metal selected from the group consisting of Ru, Ir, Rh, Pt, Pd, and Os.
3. In the metal member according to Claim 1, A metal member containing Ru as the precious metal.
4. In the metal member according to Claim 1, A metal member containing Ru as the precious metal and further containing Re.
5. In the metal member according to Claim 4, A metal member in which the composition ratio of Ru and Re is 1 or more in terms of atomic ratio.
6. In the metal member according to Claim 1, Further containing at least one additive element selected from the group consisting of Ir, Rh, Pt, Pd, and Os, A metal member in which the content of the additive element is 0.001 at% to 15 at% with respect to the entire metal member.
7. In the metal member according to Claim 1, A metal member containing Ru, Re, and at least one of the elements Mo and W.
8. In the metal member according to Claim 7, A metal member in which the total content of Ru, Re, and the element is 60 at% or more with respect to the entire metal member.
9. A product containing a metal member, wherein the metal member is the metal member according to Claim 1.
10. The product according to claim 9, which is a component of a heating device, a film forming device, or a crystal growth device.
11. The product according to claim 9, which is a reaction device, a reaction vessel, or a component thereof.