Tantalum-tungsten alloy products and preparation methods therefor

Abstract

Tantalum-tungsten alloy product and preparation method thereof. The preparation method for the tantalum-tungsten alloy product comprises the steps of (1) providing spherical tantalum-tungsten alloy powder (4), wherein the spherical tantalum-tungsten alloy powder (4) has a particle size lower limit of 15 μm to 25 μm and an upper particle size limit of 50 μm to 60 μm, the time for 50 g of the powder (4) to pass through a standard funnel is 5 seconds to 10 seconds, the sphericity of the powder (4) is 0.8 or more, the hollow particle ratio of the powder (4) is 5% or less, and the apparent density is 9 to 11 g / cm 3 (2) processing and shaping the spherical tantalum-tungsten alloy powder (4) by using a 3D printing process to obtain a printed blank; (3) performing post-printing treatment on the printed blank; and (4) performing vacuum heat treatment on the product from the previous step, wherein the temperature of the vacuum heat treatment is 1350°C to 1750°C, and the time is 30 to 90 minutes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority from Chinese Patent Application No. 202210885960.5, filed on July 26, 2022, the disclosure of which is incorporated herein by reference in its entirety. [Technical Field]

[0002] The present application relates to the technical field of material processing, in particular to a tantalum-tungsten alloy product and a preparation method therefor, and more particularly to a preparation process of a tantalum-tungsten alloy product by 3D printing. [Background technology]

[0003] Due to its excellent high-temperature performance and corrosion resistance, tantalum-tungsten alloys have great potential for application in the aerospace and military industries. However, due to their high hardness and high melting point, they are very difficult to process using traditional processing methods, resulting in low material utilization, long processing times, and difficulty in fabricating complex components. Therefore, researching the preparation of tantalum-tungsten alloy materials using additive manufacturing technology to promote the development of third-generation and subsequent generations of aerospace engines is of great and profound significance to China's national defense construction. Furthermore, given the current lack of additive manufacturing technology for tantalum-tungsten alloys at home and abroad, researching and manufacturing tantalum-tungsten alloy products with small, complex structures will fill a gap in related technology both at home and abroad.

[0004] There are two conventional preparation processes for preparing tantalum-tungsten alloy products: One is the subtractive manufacturing method for ingots, which involves the following steps: ingot casting → forging → rolling → cutting → machining → polishing → welding, riveting → assembly → product. The other is a powder metallurgy processing method, which involves mixing tantalum and tungsten powders in a certain ratio, followed by sintering and compacting the powders.

[0005] There remains a need in the art for better processes for preparing tantalum tungsten alloy products. Summary of the Invention

[0006] The inventors have found that due to the high melting point and high hardness characteristics of tantalum-tungsten alloys, traditional forging processes, powder metallurgy, etc., have complicated preparation procedures, are expensive, and cannot be used to prepare complex components, limiting the wide application of this alloy in fields such as aerospace and corrosion resistance.

[0007] In this application, by adjusting multiple parameters in the 3D printing procedure, a suitable 3D printing process for tantalum-tungsten alloy materials is developed, so that tantalum-tungsten alloy products can be prepared by the 3D printing process, thereby solving the problems existing in the preparation of tantalum-tungsten alloy products by traditional processes, reducing processing costs, and shortening product research periods.

[0008] The present application aims to overcome the shortcomings of conventional processes, such as the great difficulties involved in processing and the difficulty of processing complex components, and to develop a suitable 3D printing process for tantalum-tungsten alloy materials by a selective laser melting process using spherical tantalum-tungsten powder as raw material, so that tantalum-tungsten alloy products can be manufactured by the 3D printing process, thereby solving the existing problems in preparing tantalum-tungsten alloy products by conventional processes, reducing processing costs, shortening product research periods, and producing complex tantalum-tungsten products that meet the performance requirements of high temperature resistance and corrosion resistance in the military and aerospace fields.

[0009] In a first aspect, the present application provides a preparation method for a tantalum-tungsten alloy product, comprising the steps of: (1) providing a spherical tantalum-tungsten alloy powder, wherein the spherical tantalum-tungsten alloy powder is the lower limit of the particle size is 15 μm to 25 μm (for example, 18 μm to 22 μm, for example, 20 μm); the upper limit of the particle size is 50 μm to 60 μm (for example, 53 μm to 58 μm, for example, 55 μm); The time it takes for 50 g of this powder to pass through a standard funnel is 5 to 10 seconds (e.g., 6 to 8 seconds), The sphericity of the powder is ≧0.8 (e.g., ≧0.9), The hollow particle ratio of the powder is ≦5% (e.g., ≦3%); Apparent density: 9g / cm 3 ~11g / cm 3 (For example, 9.5g / cm 3 ~10g / cm 3 ) (2) processing and shaping the spherical tantalum-tungsten alloy powder by using a 3D printing process to obtain a printed blank; (3) performing post-printing processing on the printed blanks; (4) A process of vacuum heat treatment of the product from the previous process; Here, the vacuum heat treatment is carried out at a temperature of 1350°C to 1750°C (for example, 1450°C to 1550°C, for example, 1550°C to 1650°C) for 30 to 90 minutes (for example, 40 to 60 minutes, for example, 60 to 80 minutes).

[0010] In some embodiments, the tantalum-tungsten alloy has a titanium content of 85% to 95% (e.g., 90%) by weight and a tungsten content of 5% to 15% (e.g., 10%) by weight.

[0011] In some embodiments, the post-printing treatment comprises one or more operations selected from the group consisting of machining, surface treatment, and cleaning.

[0012] In some embodiments, in a 3D printing process, the printed component comprises a profile portion, a fill portion, an upskin portion, a downskin portion, and a support portion.

[0013] In some embodiments, the printing parameters of the outline portion include one or more parameters selected from the group consisting of: 190W~210W contour laser power, Contour speed of 550mm / s~650mm / s, Contour STD segmentation threshold of 0.01.

[0014] In some embodiments, the printing parameters of the fill portion include one or more parameters selected from the group consisting of: 1 to 3 filling scans, Filling rotation angle of 45°~67°, 300W~330W filling laser power, Filling speed: 550 (mm / s) to 650 (mm / s) Filling distance of 0.1mm~0.14mm, Strip width from 3mm to 10mm, Strip filling distance of 0.1mm~0.15mm, Strip overlap of 0.08mm~0.16mm, Strip offset from 6.10mm to 6.18mm.

[0015] In some embodiments, the printing parameters of the upskin portion include one or more parameters selected from the group consisting of: Upskin filling times: 2 to 3 times, Upskin laser output of 200W~300W, Upskin speed of 450mm / s~550mm / s, Upskin filling distance of 0.01mm~0.12mm.

[0016] In some embodiments, the printing parameters of the down skin portion include one or more parameters selected from the group consisting of: 2 to 3 times down skin filling, Down skin laser output of 200W~300W, Downskin speed of 450mm / s~550mm / s, Down skin filling distance of 0.01mm~0.12mm.

[0017] In some embodiments, the printing parameters of the support portion include one or more parameters selected from the group consisting of: 1 to 2 scans of the support Support scanning laser power of 200W~280W, Support scanning speed of 650mm / s~750mm / s.

[0018] In a second aspect, the present application provides a tantalum-tungsten alloy product prepared by any one of the methods described above.

[0019] In some embodiments, the tantalum-tungsten alloy product has one or more of the following characteristics: a tensile strength of 650 MPa to 850 MPa, for example, 700 MPa to 800 MPa, for example, 750 MPa; a yield strength of 550 MPa to 750 MPa, for example, 600 MPa to 700 MPa, for example, 650 MPa; 25% to 45%, for example, 30% to 40%, for example, 35% elongation; 16g / cm 3 ~17g / cm 3 , e.g., 16.4 g / cm 3 ~16.9g / cm 3 density.

[0020] In some embodiments, 3D printing technology is a technology for fabricating three-dimensional solid models by layering materials such as powders, wire stock, and liquids according to a path planned by establishing a three-dimensional digital model and using slicer software. As a supplement to traditional fabrication, 3D printing technology is characterized by the absence of die-cutting, high material utilization, and the ability to fabricate complex structural components that have rarely been processed in traditional fabrication. Therefore, it has been widely applied in various fields, such as aerospace, industrial manufacturing, and medical education. Among these, representative processes of powder bed fusion technology include selective laser sintering (SLS), selective laser melting (SLM), and electron beam melting (EBM), and a representative process of directed energy deposition technology is laser engineered net shaping (LENS). Selective laser melting (SLM) is also a powder bed fusion technology and is a metal 3D printing technology developed based on SLS. Its forming principle is very similar to that of SLS, but it differs in that SLM has a high laser temperature that can completely melt all the metal powder.

[0021] SLM should be classified as SLS. SLS technology was born in 1986. The first SLS molding machine was successfully developed in 1988 and subsequently commercialized by DTM in the United States, with the commercial SLS manufacturing equipment, the Sinterstation 2000 molding machine, introduced in 1992. SLS technology has been widely used in various fields for over 20 years, and companies researching selective laser sintering equipment and processes include DTM, 3D Systems, and EOS of Germany.

[0022] The molding principle of the selective laser sintering process is shown in Figure 3. In the selective laser sintering (SLS) processing procedure, a layer of powder 4 is first spread on the top surface of the molded workpiece 3 by a press roller 6. A numerical control system 1 controls a laser 2 to emit a laser beam 5 to scan and irradiate the powder layer according to the cross-sectional contour of the layer, raising the temperature of the powder 4 to its melting point and thereby sintering the powder 4 to bond it to the underlying molded workpiece 3. After one cross-section of the layer is sintered, the worktable is lowered by one layer thickness, and at this time, the press roller 6 uniformly spreads another layer of powder 4 on the table to begin sintering the cross-section of the new layer. In this way, these operations are repeated until the workpiece is completely molded.

[0023] [Beneficial effects of the present application] (1) This application provides a new process for processing tantalum-tungsten alloy products, which is a 3D printing process, to overcome the shortcomings of the conventional process, such as the great processing difficulties and the difficulty of processing complex components. It develops a suitable 3D printing process for tantalum-tungsten alloy materials by a selective laser melting process using spherical tantalum-tungsten powder as raw material, so that tantalum-tungsten alloy products can be prepared by the 3D printing process, thereby solving the existing problems in preparing tantalum-tungsten alloy products by conventional processes, reducing processing costs, shortening product research periods, and producing complex tantalum-tungsten products that meet the performance requirements of high temperature resistance and corrosion resistance in the military and aerospace fields. (2) The present application achieves 3D printed products with excellent mechanical performance by optimizing the physical and chemical properties of raw material powders, optimizing 3D printing parameters, and performing specific vacuum heat treatment processes. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a 200-times enlarged photograph of the spherical tantalum-tungsten alloy powder of Example 1. [Figure 2] FIG. 2 shows a photograph of a tantalum-tungsten alloy product according to some embodiments. [Figure 3] FIG. 3 is a schematic diagram illustrating the forming principle of a selective laser sintering (SLS) process in some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0025] PARTICULAR MODES FOR CARRYING OUT THE INVENTION Next, specific embodiments of the present application will be described in detail. While the present application will be described in combination with these specific embodiments, it should be understood that they are not intended to limit the present application to these specific embodiments. On the contrary, these embodiments are intended to cover alternatives, modifications, and equivalent embodiments that may be included within the spirit and scope of the present application as defined by the appended claims. In the following description, several specific details are set forth in order to provide a thorough understanding of the present application. The present application may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail in order to avoid unnecessarily obscuring the present application.

[0026] The singular forms "a," "an," and "the," when used in conjunction with the words "comprising," "method comprising," or similar expressions, in this specification and the appended claims include plural references unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0027] Unless otherwise exemplified, the test conditions used in the examples of this application are routine test conditions in the art. Unless otherwise exemplified, all reagents used in the examples of this application are commercially available.

[0028] The process of the present application is generally described as follows: Preparation of printing materials → Modeling → 3D printing → Post-processing

[0029] The main processes using tantalum-tungsten alloy as the main raw material are as follows:

[0030] 1. Preparation of Printing Materials The raw material selected was a low-oxygen spherical tantalum-tungsten powder with a particle size distribution of 15 microns to 55 microns, high sphericity, and good fluidity, which was formed by subjecting a tantalum-tungsten alloy obtained by electron beam melting to a plasma spheroidizing treatment.

[0031] 2. Modeling 2.1 The model was established by using modeling software (e.g., Solidworks). 2.2 In some embodiments, the model was processed using 3-Matic to reduce weight or create a porous structure. Because the tantalum-tungsten alloy itself has a high density, in certain weight requirements, some solid parts of the part can be converted into a porous structure, thereby effectively reducing the weight of the part. At the same time, the model was converted into STL mode and processed based on triangular facets to reduce the cycle between reverse engineering and traditional CAD. 2.3 Magic software was used to repair the model, process the details of the model, and analyze the feasibility of printing the model and whether the support should be designed. If necessary, the support was designed according to the characteristics of the material to ensure that the printing would not be impossible and warping would not occur due to partial suspension in the printing process.

[0032] 3. Printing 3.1 Based on the designed model and support, Buildstar software was used to typeset, set the material pack, adjust the workpiece parameters, and then perform the slicing process, i.e., observe the printing procedure of the model under theoretical conditions, and predict the printing time and required powder loading, thereby ensuring the smooth printing of the part. 3.2 By controlling parameters such as laser spot size, laser power, scanning speed, scanning path, and powder layer thickness, tensile specimens, metallographic specimens, density specimens, and other specimens were printed under different parameters to detect performance parameters. From the sample detection results, optimal printing parameters can be obtained, thereby effectively controlling internal metallurgical defects in the printed parts and ensuring that their mechanical and high-temperature performance meets the required standards.

[0033] 4.Post-print processing The printed part was separated from the substrate by wire cutting, and then the support and other materials on the printed part were removed with a tool, the area where the support had been removed was finished with a file, and the entire part was treated with a sandblasting machine.

[0034] 5. Vacuum heat treatment The product from the previous process is kept at a vacuum level of 7 x 10 -3 The heat treatment was carried out using a vacuum furnace at 1000 kPa, and the heat treatment was set to have a temperature of 1350°C to 1750°C and a time of 30 minutes to 90 minutes.

[0035] A specific test scheme using tantalum-tungsten alloy as an example is shown below:

[0036] [Example 1] 1. Preparation of Printing Materials The raw material powder was a spherical tantalum-tungsten alloy powder with a particle size distribution of 22.74 μm to 50.95 μm, high sphericity, and low oxygen content, which was formed by subjecting a tantalum-tungsten alloy (Ta=90 wt % and W=10 wt %) obtained by electron beam melting to a plasma spheroidizing treatment. The powder had a high fluidity and a high particle size distribution of 22.74 μm to 50.95 μm.

[0037] [Table 1]

[0038] The physical properties of the raw powder are shown in the table below.

[0039] [Table 2]

[0040] *For the detection criteria of particle size distribution, refer to GB / T19077-2016 "Particle Size Analysis - Laser Diffraction Method". *For the detection criteria for flowability, refer to GB / T1482 "Metallic Powders - Determination of Flow Time by Means of a Calibrated Funnel (Hall flowmeter)." *For the detection standard of sphericity, refer to YS / T1297-2019 "Measuring Method for Sphericity Ratio of Titanium and Titanium Alloy Powders." *See metallographic methods for the criteria for hollow particle detection, which was observed by mounting and polishing the sample. *For the detection standard of apparent density, refer to GB / T1479.1-2011 "Metallic Powders - Determination of Apparent Density - Part 1: Funnel method".

[0041] A scanning electron microscope photograph of the raw material powder is shown in Figure 1. As shown in the figure, the raw material powder had high sphericity.

[0042] 2. Modeling To study the suitable printing parameters of the tantalum-tungsten alloy powder, a model for the tensile test specimen was established in the modeling software, and the size specifications of the tensile test specimen were in accordance with the standard GB / T6397-1986 "Metallic Materials - Test Pieces for Tensile Testing".

[0043] 3. Setting the Tantalum-Tungsten Alloy Printing Parameters The printing parameters for the tantalum tungsten alloy were set with reference to the table below.

[0044] Important 3D printing parameters include: Contour parameters: the power of the laser scanning the surface area of ​​the component and the Contour STD number, where when the Contour STD number is 1, the scan distance is 0, and when the Contour STD number is greater than 1, the scan distance is valid. The distance parameter is set in the proportional parameter. The Contour STD laser power is the laser power. Multiple lasers with different Contour STD laser powers and contour scan speeds can be arranged, and the number of arranged lasers depends on the value of the Contour STD number. Contour STD Split Threshold: A critical value for distinguishing between up-skin and down-skin during laser scanning. This value was only valid when the corresponding parameter of Contour STD Split On / Off was 1. When the overhang value of a region was greater than the Contour STD Split Threshold, the contour of this region would be determined as the contour of down-skin. The Contour STD Split Threshold depended on both the layer thickness and the overhang parameter, and its value was an absolute value. Up-skin and down-skin parameters: according to the position where the component is placed, there will be two surfaces parallel to the forming substrate of the component, one of which will not be scanned further after one laser scan is the up-skin, and the other of which will be scanned further after one laser scan is the down-skin, which can be scanned repeatedly to meet the forming requirements of the component. Support: A structure was set for the down skin of the component to assist in the scanning and forming of the down skin and ensure successful printing of the component, where the structure can be classified into linear structures, dot-like structures, solid structures, conical structures, net-like structures, contour structures, tree-like structures, and many other structures. Fill scan count: The number of laser scans of the non-contoured area of ​​the component, where the directions of two adjacent scans were perpendicular to each other. Fill Speed: The speed at which the laser scans this area. Fill distance: The distance between two adjacent laser lines in the same scan cross section. Fill rotation angle: The included angle formed between two scan directions, where one layer is scanned with a laser in one scan direction, and then the next layer is scanned in another scan direction obtained by rotating the previous scan direction by a certain angle. Strip Width: The width of the distance formed by the combination of lasers during laser scanning. Strip Fill Distance: The distance between lasers at a fixed strip width. Strip overlap: The overlap width distance formed by two adjacent strips. Strip Offset: The offset distance of the strips between adjacent layers.

[0045] Samples 1 and 3 were printed according to the parameters in Table 3.1. Samples 2 and 4 were printed according to the parameters in Table 3.2.

[0046] [Table 3-1]

[0047] [Table 3-2]

[0048] 4.Post-print processing The printed part was separated from the substrate by wire cutting, and then the support and other materials on the printed part were removed with a tool, the area where the support had been removed was finished with a file, and the entire part was treated with a sandblasting machine.

[0049] 5. Vacuum heat treatment The tensile test specimen products prepared in the previous step were numbered 1 to 4. Products No. 1 and No. 2 were not subjected to vacuum heat treatment. Products Nos. 3 and 4 were subjected to vacuum heat treatment. The parameters of the vacuum heat treatment were as follows: for the product of the previous process, vacuum level ≦7×10 -3 The heat treatment was carried out using a vacuum furnace at 1000 Pa, and the heat treatment temperature was set to 1450°C and maintained at this temperature for 90 minutes.

[0050] 6. Performance testing of tantalum-tungsten alloy printing products Using the printing method described above, tensile test specimens numbered 1 to 4 and density and hardness test specimens numbered 5 to 10 were prepared. The tensile test specimens were subjected to mechanical performance testing in accordance with GB / T228-2002 "Metallic Materials - Tensile Testing at Ambient Temperature," density testing in accordance with GB / T3850-2015 "Impermeable Sintered Metal Materials and Hardmetals - Determination of Density," and hardness testing in accordance with GB / T230.1-2009 "Metallic Materials - Rockwell Hardness Test." The results are shown in Tables 4 and 5 below.

[0051] [Table 4]

[0052] As can be seen by analyzing Table 4, the samples that underwent vacuum heat treatment exhibited improved tensile strength, yield strength and elongation.

[0053] [Example 2] Density blocks of 10 × 10 × 10 mm were printed using different printing process parameters and then subjected to vacuum heat treatment using the following vacuum heat treatment parameters: vacuum level ≤ 7 × 10 for the product of the previous process; -3 The heat treatment was carried out using a vacuum furnace at 1000 Pa, and the heat treatment temperature was set to 1450°C and maintained at this temperature for 90 minutes.

[0054] [Table 5]

[0055] As can be seen by analyzing Table 5, after the 10x10x10 mm density blocks printed with different process parameters were heat treated, they had different density values, where the sample block printed with a laser power of 330 W and a scan speed of 600 mm / s had the highest density.

[0056] [Example 3] Referring to the above process parameters, various types of manufactured products were further printed, the photographs of which are shown in FIG.

[0057] As can be seen from the above description and the demonstration in the examples, the present application uses spherical tantalum-tungsten alloy powder with specific physicochemical parameters to prepare tantalum-tungsten alloy printed samples with improved mechanical performance.

[0058] Finally, the above examples are intended to illustrate that they are only used to illustrate the technical solutions of the present application, and are not used to limit the present invention; while the present application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications to the specific embodiments of the present application and equivalent substitutions for part of the technical features may still be made without departing from the spirit of the present application, and each of them should fall within the scope of the technical solutions described in the claims of the present application.

Claims

1. 1. A preparation method for a tantalum-tungsten alloy product, comprising: (1) providing a spherical tantalum-tungsten alloy powder, wherein the spherical tantalum-tungsten alloy powder comprises: The lower limit of the particle size is 15 μm to 25 μm, the upper limit of the particle size is 50 μm to 60 μm, The time required for 50 g of the powder to pass through a standard funnel is 5 to 10 seconds; The sphericity of the powder is ≧0.8, The hollow particle ratio of the powder is ≦5%; Apparent density: 9 g / cm ３ ~11g / cm ３ characterized in that (2) processing and shaping the spherical tantalum-tungsten alloy powder by using a 3D printing process to obtain a printed blank; (3) performing post-printing processing on the printed blank; (4) performing a vacuum heat treatment on the product from the previous step; The vacuum heat treatment is carried out at a temperature of 1350°C to 1750°C for 30 to 90 minutes.

2. 2. The method of claim 1, wherein the tantalum-tungsten alloy has a titanium content of 85% to 95% by weight and a tungsten content of 5% to 15% by weight.

3. The method of claim 1 , wherein the post-printing treatment comprises one or more operations selected from the group consisting of machining, surface treatment, and cleaning.

4. 10. The method of claim 1, wherein in the 3D printing process, the printed component comprises a contour portion, a fill portion, an upskin portion, a downskin portion, and a support portion.

5. The print parameters for the contour portion are: 190W-210W contour laser power, Contour speed of 550 mm / s to 650 mm / s, Contour STD segmentation threshold (absolute value) between 0.01 and 0.03 5. The method of claim 4, comprising one or more parameters selected from the group consisting of:

6. The printing parameters of the filling portion are: Filling scan count: 1 to 3 Filling rotation angle of 45° to 67°, 300W-330W filled laser power, Filling speed of 550 (mm / s) to 650 (mm / s), Filling distance of 0.1mm to 0.14mm, Strip width of 3mm to 10mm, Strip filling distance of 0.1 mm to 0.15 mm; Strip overlap of 0.08 mm to 0.16 mm, Strip offset of 6.10mm to 6.18mm 5. The method of claim 4, comprising one or more parameters selected from the group consisting of:

7. The printing parameters of the upskin portion are: Upskin filling times: 2 to 3 times, Upskin laser output of 200W to 300W, Upskin speed of 450 mm / s to 550 mm / s; Upskin filling distance of 0.01mm to 0.12mm 5. The method of claim 4, comprising one or more parameters selected from the group consisting of:

8. The printing parameters of the down skin portion are: Two to three times down skin filling, Down skin laser output of 200W to 300W, Downskin speed of 450mm / s to 550mm / s, Down skin filling distance of 0.01mm to 0.12mm 5. The method of claim 4, comprising one or more parameters selected from the group consisting of:

9. The printing parameters of the support portion are: 1 to 2 scans of the support 200W-280W substrate scanning laser power; Substrate scanning speed of 650 mm / s to 750 mm / s 5. The method of claim 4, comprising one or more parameters selected from the group consisting of:

10. A tantalum-tungsten alloy product prepared by the method of any one of claims 1 to 9.

11. Tensile strength of 650 MPa to 850 MPa; Yield strength of 550 MPa to 750 MPa, 25% to 45% growth rate, 16.4 g / cm ３ ~16.9g / cm ３ density of 11. The tantalum-tungsten alloy product of claim 10, wherein the tantalum-tungsten alloy product has one or more of the following characteristics:

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