Metal member and product
The metal member alloy of Ru x Re y (Mo, W) z addresses the instability and temperature control issues of tantalum-based resistance heating elements by providing a cost-effective solution with superior heat resistance, corrosion resistance, and mechanical properties.
Patent Information
- Application Number
- JP2023208249
- 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 from 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 alloy composed of Ru x Re y (Mo, W) z, with specific atomic percentage ranges (0 < x ≤ 60, 0 < y ≤ -1.45x + 76.33, 40 ≤ z < 70, x + y + z ≤ 100), that exhibits excellent heat resistance, corrosion resistance, and mechanical properties, thereby addressing the limitations of tantalum-based elements.
The proposed metal member alloy demonstrates improved stability and mechanical properties, with enhanced heat resistance and corrosion resistance, allowing for more reliable and durable resistance heating elements with better temperature control.
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 cause the resistance heating element to generate heat 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 under a high vacuum (~10 5 Pa level). 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 progressing the film formation.
[0004] In the 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 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 deformation of the resistance heating element, leading to unexpected contact with peripheral members or disconnection. Also, during use, often, the formation of a nodular structure deteriorates the electrical and mechanical properties, leading to disconnection, which has been 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, 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, corrosion resistance, and mechanical properties.
Means for Solving the Problems
[0011] The metal member according to the present invention contains at least Ru x Re y (Mo, W) z (0 < x ≦ 60, 0 < y ≦ -1.45x + 76.33, 40 ≦ z < 70, x + y + z ≦ 100).
[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 total content of Ru, Re, Mo, and W is 60 at% or more with respect to the entire metal member, and further has a primary crystal part with a hexagonal close-packed structure.
[0014] In one configuration example of the above metal member, the contents of Mo and W are in the range of 0.1 at% to 50 at% with respect to the entire metal member.
[0015] 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.
[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, Ru x Re y (Mo, W) z (0 < x ≦ 60, 0 < y ≦ -1.45x + 76.33, 40 ≦ z < 70, x + y + z ≦ 100) is included at least, so that a metal member that is inexpensive and excellent in heat resistance, corrosion 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 contains at least Ru x Re y (Mo, W) z (0 < x ≦ 60, 0 < y ≦ -1.45x + 76.33, 40 ≦ z < 70, x + y + z ≦ 100). This metal member is a so-called alloy containing at least Ru, Re, Mo, and W.
[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. Setting the composition ratio in this way is preferable because it can further improve the resistance of the metal member to loading. Further, in the metal member according to the embodiment, the total content of Ru, Re, Mo, and W can be set to 60 at% or more with respect to the entire metal member, and furthermore, it can have a primary crystal part with a hexagonal close-packed structure. Setting the structure in this way is preferable because the metal member can be made inexpensive and have more balanced and excellent heat resistance and mechanical properties.
[0027] Also, in the metal member according to the embodiment, the content of Mo and W can be in the range of 0.1 at% to 50 at% with respect to the entire metal member. Setting the content of Mo and W in this range is preferable because it can further improve the adhesion and stability of the metal member as an alloy.
[0028] Further, 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 0.001 at% to 15 at% with respect to the entire metal member. By including the additive element with the content in this range, the heat resistance and corrosion resistance of the metal member can be further improved.
[0029] 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, but means a member containing at least the above-described elements and can contain other elements. 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 contain unavoidable impurities.
[0030] 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.
[0031] In a suitable μ-PD method, as shown in FIGS. 1A and 1B, 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 grow crystals. 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 enlarged view of the area within the dotted circle in FIG. 1A.
[0032] 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, more excellent mechanical properties, heat resistance, etc. can be exhibited.
[0033] 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, and a liquid phase crystal growth device. Also, the parts can be known parts of the device (for example, parts for an evaporation cell, a heater wire, a brazing material, etc.).
[0034] Hereinafter, it will be described in more detail using examples.
[0035] [Example 1] Ru, Mo, W, Re raw materials with a purity of 99.9% or more were used to make Ru 0.6-x Mo0.15 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 in a high-purity Ar atmosphere at a temperature condition of 2273 K for a treatment time of 3 hours. For the heat-treated samples, composition analysis and crystal orientation analysis were performed by wavelength-dispersive fluorescent 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.
[0036] Figure 2 shows a photograph of the grown Ru 0.59 Mo 0.15 W 0.25 Re 0.01 wires. (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 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 wires were very high-quality single-crystal alloy wires as shown in the photograph of Figure 3. Note that the grown Ru 0.59 Mo 0.15 W 0.25 Re 0.01 wires showed a maximum tensile strength of about 658 MPa and a good elongation at break of about 89%.
[0037] 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) prepared 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 0.45Mo 0.15 W 0.25 Re 0.15 The solidus temperature of [the alloy] was estimated to be approximately 2493K. Also, in the above configuration, the primary crystal part has a hexagonal close-packed (HCP) structure, and microporosity with an equivalent circular diameter of 20 μm or less, which is formed in a plurality of dot arrays derived from the primary crystal part of the HCP structure, could also be confirmed. Therefore, the metal member according to the present invention can include microporosity with an equivalent circular diameter of 20 μm or less, which is formed in a plurality of dot arrays in the longitudinal direction and is derived from the primary crystal part of the HCP structure.
[0038] [Example 2] By the same method 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 a micro-indentation test, and FIG. 5 shows the results of a push-in elastic modulus test. From the micro-indentation test in FIG. 4 and the results of the push-in elastic modulus test in FIG. 5, for 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 %.
[0039] FIG. 6 shows the evaluation results of the electrical resistivity. From the evaluation results of the electrical resistivity such as in FIG. 6, for the Ru 0.6-x Mo 0.15 W 0.25 Re x alloy, it was found that the properties were excellent when the Re content exceeded 0 atomic % and was less than 23 atomic %, and were even more excellent when it 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 in FIG. 7, for the Ru 0.6-x Mo 0.15 W 0.25 Re xIt was found that when the Re content in the alloy is in the range of 4 atomic % to 14 atomic %, the elongation becomes more excellent.
[0040] As described above, according to the present invention, Ru x Re y (Mo, W) z (0 < x ≤ 60, 0 < y ≤ -1.45x + 76.33, 40 ≤ z < 70, x + y + z ≤ 100) is included at least, so that an inexpensive metal member excellent in heat resistance, corrosion resistance, and mechanical properties can be provided.
[0041] Note 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 Signs
[0042] 101... High-frequency induction coil, 102... Crucible, 103... Molten metal, 104... Growing crystal, 105... Solidified metal (wire), 106... Nozzle, 107... Bottom, 108... Processing chamber, 109... Crucible stand.
Claims
1. Ru x Re y (Mo, W) z A metal member containing at least (0 < x ≤ 60, 0 < y ≤ -1.45x + 76.33, 40 ≤ z < 70, x + y + z ≤ 100).
2. In the metal member according to Claim 1, A metal member in which the composition ratio of Ru and Re is 1 or more in terms of atomic ratio.
3. In the metal member according to Claim 1, The total content of Ru, Re, Mo, and W is 60 at% or more with respect to the whole of the metal member, Further, A metal member having a primary crystal part with a hexagonal close-packed structure.
4. In the metal member according to Claim 1, The contents of Mo and W are in the range of 0.1 at% to 50 at% with respect to the whole of the metal member.
5. In the metal member according to Claim 1, A metal member further containing at least one additive element selected from the group consisting of Ir, Rh, Pt, Pd, and Os.
6. In the metal member according to Claim 5, The content of the additive element is 0.001 at% to 15 at% with respect to the whole of the metal member.
7. The metal member according to Claim 1, which is a wire.
8. A product containing a metal member, wherein the metal member is the metal member according to Claim 1.
9. The product according to Claim 8, which is a component of a heating device, a film forming device, or a crystal growth device.
10. The product according to Claim 8, which is a reaction device, a reaction vessel, or a component thereof.
11. A product including a wire made of a metal member, wherein the metal member is the metal member according to Claim 1.
12. The product according to Claim 11, which is a heater.
13. The product according to Claim 8 or 11, which is a heating device, a film forming device, or a crystal growth device.