Metal member and product
A Ru-Re-Mo/W alloy with a hexagonal close-packed structure addresses the stability and temperature control issues of existing metal resistance heating elements, offering excellent heat resistance, mechanical properties, and cost-effectiveness for various industrial applications.
Patent Information
- Application Number
- JP2023208246
- 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, particularly those made of tantalum, suffer from changes in electrical resistivity and mechanical strength due to recrystallization during energization heating, leading to instability and potential disconnection. Additionally, tantalum's temperature-dependent electrical resistivity makes it difficult to control temperature accurately.
A metal member composed of Ru, Re, and either Mo or W, with a total content of 60 at% or more, featuring a primary crystal part with a hexagonal close-packed structure. This alloy can include additional elements like Ir, Rh, Pt, Pd, and Os, and is manufactured using methods like μ-PD to enhance crystallinity and mechanical properties.
The resulting metal member is inexpensive, exhibits excellent heat resistance, corrosion resistance, and mechanical properties, making it suitable for applications such as heating devices and film-forming equipment. It maintains stability and durability, even when used as a wire, with improved resistance to deformation and disconnection.
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 set to 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, the inside of the furnace is heated by energizing the resistance heating element, and the evaporation raw material in the container is melted. 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 resistance heating elements, 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 a 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 current sources and electric wires. Note that tantalum, tungsten, and molybdenum used for resistance heating elements 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 have been problems such as changes in the current and voltage application conditions for raising the temperature to a predetermined temperature, and a decrease in mechanical strength causing deformation of the resistance heating element, leading to unexpected contact with peripheral members or disconnection. Also, during use, there has often been a problem that the formation of a nodular structure deteriorates the electrical and mechanical properties and leads to disconnection.
[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 or 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 or current is low.
[0009] Recently, in response to these problems, as alternative materials for tantalum, improvement of the electrical characteristics of metal members using noble metals such as ruthenium (Ru) 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 and the like. For this reason, there is a long-awaited need for an inexpensive metal member having 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 and mechanical properties.
Means for Solving the Problems
[0011] The metal member according to the present invention is a metal member containing Ru, Re, and any one element of Mo and W, wherein the total content of Ru, Re, and the element is 60 at% or more with respect to the entire metal member, and has a primary crystal part having a hexagonal close-packed structure.
[0012] 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.
[0013] In one configuration example of the above metal member, the content of the element is in the range of 0.1 at% to 50 at% with respect to the entire metal member.
[0014] 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.
[0015] In one configuration example of the above metal member, the content of the additive element is 0.001 at% to 15 at% with respect to the entire metal member.
[0016] In one configuration example of the above metal member, the metal member is a wire.
[0017] The product according to the present invention is a product including the above metal member.
[0018] 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.
[0019] In one configuration example of the above product, the product is a reaction device, a reaction vessel, or a component thereof.
[0020] In one configuration example of the above product, the product includes a wire made of the above metal member.
[0021] In one configuration example of the above product, the product is a heater.
[0022] In one configuration example of the above product, the product is a heating device, a film forming device, or a crystal growth device.
Effects of the Invention
[0023] As described above, according to the present invention, it contains Ru, Re, and either one of Mo and W, and the total content of Ru, Re, and the element is 60 at% or more with respect to the entire metal member. Furthermore, since it has a primary crystal part with a hexagonal close-packed structure, a metal member that is inexpensive and has excellent heat resistance and mechanical properties can be provided.
Brief Description of the Drawings
[0024]
Figure 1A
Figure 1B
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
DETAILED DESCRIPTION OF THE INVENTION
[0025] Hereinafter, a metal member according to an embodiment of the present invention will be described. This metal member is a metal member containing Ru, Re, and any one of the elements Mo and W, and the total content of Ru, Re, and the element is 60 at% or more with respect to the entire metal member. Further, this metal member has a primary crystal part with a hexagonal close-packed structure. This metal member is a so-called alloy.
[0026] For example, in the metal member according to the embodiment, the composition ratio of Ru and Re can be 1 or more in terms of atomic ratio. By setting this composition ratio, it is preferable because the resistance of the metal member to loading and the like can be further improved. Further, the content of either one of the elements Mo and W can be in the range of 0.1 at% to 50 at% with respect to the entire metal member. By setting the content of the above elements within this range, it is preferable because the adhesion and stability of the metal member as an alloy can be further improved.
[0027] In addition, the metal member according to the embodiment can further include 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 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.
[0028] Note that the "metal member" does not mean only a metal member composed only of an element (metal material) containing Ru, Re, and either one of the elements Mo and W, but means a member containing at least each of the above-described elements, and other elements can be included. Further, 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. Note that the metal member according to the present invention can include unavoidable impurities.
[0029] 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.
[0030] In a suitable 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 grown 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 table 109 inside a processing chamber 108. Note that FIG. 1B shows an enlargement of the area within the dotted circle in FIG. 1A.
[0031] The metal member thus manufactured 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.
[0032] 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.).
[0033] Hereinafter, it will be described in more detail using examples.
[0034] [Example 1] Ru, Mo, W, Re raw materials with a purity of 99.9% or more were used to obtain Ru 0.6-x Mo 0.15 W 0.25 Re x(x = 0.01, 0.1, 0.15) alloy button ingots were prepared by arc melting method, and φ0.8 mm wires were grown by Dewetting μ-PD method to obtain samples of the metal members of the present invention. The prepared samples were cut, and heat treatment was carried out at a temperature condition of 2273 K for 3 hours in a high-purity Ar atmosphere. For the heat-treated samples, composition analysis and crystal orientation analysis were performed by wavelength-dispersive fluorescence X-ray spectroscopy (WDX) and electron backscatter diffraction (EBSD) method. As a result, all wires had good crystallinity of Ru 0.6-x Mo 0.15 W 0.25 Re x It was confirmed that they were (x = 0.01, 0.1, 0.15) alloy wires.
[0035] In Fig. 2, a photograph of the grown Ru 0.59 Mo 0.15 W 0.25 Re 0.01 wire is shown. (a) in Fig. 2 shows the whole of the wire grown to a length of 14.2 m wound in a ring and bundled, and (b) in Fig. 2 shows a partial enlargement. 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 wire was a very high-quality single-crystal alloy wire as shown in the photograph of Fig. 3. Note that 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%.
[0036] 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) used as samples of the metal members of the present invention, wires of 1 m or more were obtained, and bending processing was easily possible at room temperature. Also, by thermodynamic calculation, the solidus temperature increased according to the Re substitution amount, and Ru 0.45 Mo 0.15 W 0.25 Re0.15 The solidus temperature was estimated to be about 2493K. Also, in the above configuration, the primary crystal part has a hexagonal close-packed (HCP) structure, and it was also possible to confirm microporosity with an equivalent circle diameter of 20 μm or less, which is formed in a plurality of rows derived from the primary crystal part of the HCP structure. Therefore, the metal member according to the present invention can include microporosity with an equivalent circle diameter of 20 μm or less, which is formed in a plurality of rows in the longitudinal direction and is derived from the primary crystal part of the HCP structure.
[0037] [Example 2] By following the same procedure as in Example 1 described above, Ru, Mo, W, and Re raw materials with a purity of 99.9% or more were used to produce Ru 0.6-x Mo 0.15 W 0.25 Re x (x = 0, 0.01, 0.1, 0.15) alloy button ingots were produced, and wire rods with a diameter of φ0.8 mm were grown to obtain sample wire rods. The results of evaluating each of the produced sample wire rods are shown in FIGS. 4 to 7. FIG. 4 shows the results of the micro-indentation test, and FIG. 5 shows the results of the indentation elastic modulus test. From the micro-indentation test in FIG. 4 and the results of the indentation elastic modulus test in FIG. 5, in the Ru 0.6-x Mo 0.15 W 0.25 Re x alloy, the mechanical properties were particularly good when the Re content was between 1 atomic % and 15 atomic %.
[0038] FIG. 6 shows the evaluation results of the electrical resistivity. From the evaluation results of the electrical resistivity such as FIG. 6, in the Ru 0.6-x Mo 0.15 W 0.25 Re x alloy, the properties were excellent when the Re content exceeded 0 atomic % and was less than 23 atomic %, and it was found that the properties were even more excellent when the Re content was between 0.3 atomic % and 15 atomic %. FIG. 7 shows the test evaluation results of elongation. From the test evaluation results of elongation such as FIG. 7, in the Ru 0.6-x Mo 0.15 W 0.25 Re x alloy, it was found that the elongation was more excellent when the Re content was between 4 atomic % and 14 atomic %.
[0039] As described above, according to the present invention, it contains Ru, Re, and one element selected from Mo and W, and the total content of Ru, Re, and the element is 60 at% or more with respect to the whole of the metal member. Further, since it has a primary crystal part with a hexagonal close-packed structure, it becomes possible to provide a metal member that is inexpensive and excellent in heat resistance and mechanical properties.
[0040] 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.
Explanation of Reference Numerals
[0041] 101... High-frequency induction coil, 102... Crucible, 103... Molten metal, 104... Growing crystal, 105... Solidified metal (wire rod), 106... Nozzle, 107... Bottom, 108... Processing chamber, 109... Crucible stand.
Claims
1. A metal member containing Ru, Re, and one element selected from Mo and W, wherein the total content of Ru, Re, and the element is 60 at% or more with respect to the whole of the metal member, and the metal member has a primary crystal part with a hexagonal close-packed structure.
2. The metal member according to Claim 1, wherein the composition ratio of Ru and Re is 1 or more in terms of atomic ratio.
3. The metal member according to Claim 2, wherein the content of the element is in the range of 0.1 at% to 50 at% with respect to the whole of the metal member.
4. 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.
5. The metal member according to Claim 4, wherein the content of the additive element is 0.001 at% to 15 at% with respect to the whole of the metal member.
6. The metal member according to Claim 1, which is a wire.
7. A product containing the metal member, wherein the metal member is the metal member according to Claim 1.
8. The product according to Claim 7, which is a component of a heating device, a film forming device, or a crystal growth device.
9. The product according to Claim 7, which is a reaction device, a reaction vessel, or a component thereof.
10. A product containing a wire made of the metal member, wherein the metal member is the metal member according to Claim 1.
11. The product according to Claim 10, which is a heater.
12. The product according to claim 7 or 10, which is a heating device, a film forming device, or a crystal growth device.