A manufacturing method that significantly improves the uniformity of tungsten-rhenium alloy

Abstract

The present invention relates to a manufacturing method that significantly improves the uniformity of a tungsten-rhenium alloy. The method comprises selecting blue tungsten with a purity of no less than 4N and ammonium perrhenate with a purity of no less than 4N; dissolving the ammonium perrhenate in deionized water and then adding the blue tungsten; placing the ammonium perrhenate and blue tungsten mixture in a mixing reactor equipped with heating, stirring, and ultrasonic vibration, and concentrating the mixture to dryness at 105°C under stirring and ultrasonic vibration conditions; grinding the concentrated and dried product into a powder, mixing it uniformly in a mixer, reducing it in a hydrogen reduction furnace, and calcining it in situ; crushing and sieving the calcined alloy particles, and then mixing them uniformly to obtain a tungsten-rhenium alloy powder with good composition uniformity, moderate particle size, and ease of subsequent manufacturing; and finally, analyzing the uniformity of the alloy powder using a large grid sampling system to determine the uniformity of the impurities. This method has the advantages of high alloy composition uniformity, moderate powder particle size for easy subsequent processing, low equipment investment, and ease of operation.

Description

Technical Field

[0001] The invention belongs to the field of powder metallurgy preparation, and in particular relates to a manufacturing method for significantly improving the uniformity of tungsten-rhenium alloy components. Background Art

[0002] Tungsten-rhenium alloys, due to their exceptional properties under harsh high-temperature conditions, are widely used in cutting-edge fields such as aviation, aerospace, atomic energy, ultra-high-temperature alloys, and other high-temperature, high-tech industries. In addition to its high-temperature resistance, the addition of rhenium significantly enhances tungsten metal's high-temperature strength, high-temperature ductility, high-temperature ductile-brittle transition, and resistivity. Depending on the rhenium content, these properties exhibit a variety of unique properties. However, these properties often exhibit significant instability due to the uneven composition of the alloy. This is particularly true in high-precision industries, where alloy parts require precise and consistent performance. Tungsten-rhenium alloys with inconsistent compositional uniformity often fail to meet user requirements. Three current industrial approaches are available: the solid-solid mixing method, which involves mixing tungsten powder with rhenium powder or reducing tungsten powder with ammonium perrhenate. This method offers accurate compositional accuracy and simple operation, but its uniformity is limited and cannot meet the requirements of high-precision industries. The second method is the two-liquid mixing reduction method. This method achieves good uniformity, but the total composition fluctuates significantly, and the powder is too fine, making it difficult to sinter. A third method, solid-liquid mixed reduction, involves mixing tungsten powder with an ammonium perrhenate solution. This method appears promising, but in practice, it's ineffective. The ammonium perrhenate film formed on the tungsten powder's surface easily flakes off during reduction. Because the powder formed by the film is too fine, homogenization becomes even more difficult after flakes. In short, homogenizing the composition of tungsten-rhenium alloys has always been an industry challenge. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a manufacturing method that can significantly improve the uniformity of tungsten-rhenium alloy. Through unique raw material settings and creative process routes, tungsten-rhenium alloy powder with higher uniformity can be produced relatively economically.

[0004] The technical solution adopted by the present invention is: a manufacturing method for significantly improving the uniformity of tungsten-rhenium alloy, comprising the following steps:

[0005] 1) According to the mass percentage of tungsten and rhenium required by the tungsten-rhenium alloy grade, take ammonium perrhenate and blue tungsten; heat the ammonium perrhenate at 100°C and dissolve it in deionized water, then add blue tungsten;

[0006] 2) placing the mixture obtained in step 1) into a mixing reactor with stirring and ultrasonic vibration, heating to 105° C., and concentrating the mixture to dryness under stirring and ultrasonic vibration;

[0007] 3) Grinding the concentrated and dried product into powder, mixing it evenly, and reducing it in a hydrogen reduction furnace to obtain a crude tungsten-rhenium alloy reduced powder;

[0008] 4) The crude tungsten-rhenium alloy reduction powder obtained in step 3) is directly calcined in situ, the calcined particles are crushed and then sieved, and mixed evenly to obtain a tungsten-rhenium alloy with good uniformity.

[0009] Furthermore, the above-mentioned manufacturing method for significantly improving the uniformity of tungsten-rhenium alloys uses a large grid method to sample and analyze the uniformity of impurities to determine the uniformity of the prepared tungsten-rhenium alloy.

[0010] Furthermore, in the above-mentioned manufacturing method for significantly improving the uniformity of tungsten-rhenium alloy, the ammonium perrhenate is selected to have a purity greater than 4N.

[0011] Furthermore, in the above-mentioned manufacturing method for significantly improving the uniformity of tungsten-rhenium alloy, the blue tungsten is selected to have a purity greater than 4N.

[0012] Furthermore, in the above-mentioned method for significantly improving the uniformity of tungsten-rhenium alloy, in step 3), the conditions for reduction in the hydrogen reduction furnace are: first reduction: 350-500°C, hydrogen flow rate 2-5M 3 / h, reduction time 2h; second reduction: 650-950℃, hydrogen flow rate 2-4M 3 / h, reduction time 2h.

[0013] Furthermore, in the above-mentioned manufacturing method for significantly improving the uniformity of tungsten-rhenium alloy, in step 4), the direct in-situ calcination is to calcine the crude tungsten-rhenium alloy reduction powder directly in a hydrogen furnace at 1250°C-1350°C for 3 hours without crushing or mixing.

[0014] The beneficial effects of the present invention are:

[0015] 1. The present invention adopts a solid-liquid mixing method of blue tungsten and ammonium perrhenate, which can avoid the problem of difficulty in uniformity in the solid-solid method and the excessive fineness of the reduced powder in the liquid-liquid method, which is not conducive to subsequent processing. At the same time, the characteristics of blue tungsten cavities with multiple gaps are utilized to facilitate the penetration and doping of rhenium elements, which decomposes again during reduction, and can obtain better uniformity.

[0016] 2. In the present invention, ultrasonic vibration is added during the doping process of blue tungsten and ammonium perrhenate, which can maximize the penetration effect and uniformity of the doping elements.

[0017] 3. In the present invention, the crude tungsten-rhenium alloy reduced powder obtained after reduction in a hydrogen reduction furnace cannot be stirred and mixed, but is directly calcined at high temperature. This can avoid component segregation, increase powder particle size, and facilitate subsequent processing.

[0018] 4. The present invention has the advantages of low investment, simple operation and easy detection.

[0019] 5. Whether the alloy composition of the present invention is uniform or not is not determined by testing the main content itself, but by dividing a large grid into multiple points for sampling and testing the uniformity of the impurity components to determine whether the main elements are uniform or not. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of large grid multi-point sampling. DETAILED DESCRIPTION

[0021] Example 1 A manufacturing method for significantly improving the uniformity of tungsten-rhenium alloy

[0022] This embodiment is described using a tungsten-rhenium alloy grade W97%Re3% as an example. The technical solution of the present invention is not limited to this specific tungsten-rhenium alloy grade and is applicable to any grade of tungsten-rhenium alloy.

[0023] (1) The manufacturing method is as follows:

[0024] 1) Based on the W97%Re3% tungsten alloy, which contains 97% tungsten and 3% rhenium, prepare 4N pure ammonium perrhenate and 4N pure blue tungsten. Heat the ammonium perrhenate at 100°C and dissolve it in deionized water. Once the ammonium perrhenate is completely dissolved, add the blue tungsten.

[0025] 2) The mixture obtained in step 1) is placed in a mixing reactor with stirring and ultrasonic vibration, the temperature is raised to 105° C., and the mixture is concentrated to dryness under stirring and ultrasonic vibration.

[0026] 3) Grind the concentrated and dried product into powder, mix well, and then reduce it in a hydrogen reduction furnace. First reduction: 500℃, hydrogen flow rate 5M 3 / h, reduction time 2h; second reduction: 950℃, hydrogen flow rate 4M 3 / h, reduction time 2h, to obtain crude tungsten-rhenium alloy reduced powder;

[0027] 4) The crude tungsten-rhenium alloy reduction powder obtained in step 3) is directly calcined in situ without crushing or mixing, that is, directly calcined in a hydrogen furnace at 1350° C. for 3 h.

[0028] 5) The tungsten-rhenium alloy particles obtained in step 4) are crushed, sieved, and mixed to obtain a tungsten-rhenium alloy powder product.

[0029] (2) Testing

[0030] Sampling was performed in a large grid manner to analyze the uniformity of impurities in order to determine the uniformity of the prepared tungsten-rhenium alloy.

[0031] 1. Sampling device:

[0032] like Figure 1As shown, the large grid sampling plate is a square flat plate, on which 16 square lines of 50 mm × 50 mm are drawn at equal distances to form a large grid.

[0033] 2. Sampling:

[0034] The prepared tungsten-rhenium alloy powder was spread out on a large grid sampling plate, and 4-6 points of the finished product were randomly scattered at the cross points as samples. The impurity element content in the samples at each point was determined by ICP-MS, and then the uniformity deviation (%) and average deviation rate (W) of the same element in each sample were calculated.

[0035]

[0036] Where C1: the measured value of the same element in a single point sample

[0037] C2: The average value of the same element in all sample points

[0038] Average deviation rate (W): refers to the average value of all negative numbers and the average value of all positive numbers in the uniformity deviation calculated for the same element.

[0039] 3. Judgment criteria:

[0040] A (excellent): -5% < W < 5%

[0041] B (qualified): -10%<W≤-5% and 5%≤W<10%

[0042] C (unqualified): W≤-10% or W≥10%

[0043] Single point deviation: Among all the tested samples, if the uniformity deviation of any element is ≤-25% or ≥25%, the batch of samples can be judged as unqualified.

[0044] 4. In this embodiment, Figure 1 As shown in the figure, the prepared tungsten-rhenium alloy powder was spread on a large grid sampling plate, and the finished products at four points A, B, C and D were randomly sampled at the cross points. The content of K, Na, Ca, Fe, Mo and Si in the sample at each point was determined by ICP-MS, and the uniformity deviation and average deviation rate of each single element in each sample were calculated. The results are shown in Table 1.

[0045] Table 1 Unit: ppm

[0046]

[0047] As can be seen from Table 1, the tungsten-rhenium alloy prepared by the method of the present invention has a qualified uniformity.

[0048] Example 2 Comparative Example

[0049] (1) Manufacturing method

[0050] 1) Based on the W97%Re3% tungsten alloy, which contains 97% tungsten and 3% rhenium, prepare 4N pure ammonium perrhenate and 4N pure blue tungsten. Heat the ammonium perrhenate at 100°C and dissolve it in deionized water. Once the ammonium perrhenate is completely dissolved, add the blue tungsten.

[0051] 2) The mixture obtained in step 1) is placed in a mixing reactor with stirring, the temperature is raised to 105° C., and the mixture is concentrated to dryness under stirring.

[0052] 3) Grind the concentrated and dried product into powder, mix well, and then reduce it in a hydrogen reduction furnace. First reduction: 500℃, hydrogen flow rate 2M 3 / h, reduction time 2h; second reduction: 950℃, hydrogen flow rate 2M 3 / h, reduction time 2h, to obtain crude tungsten-rhenium alloy reduced powder.

[0053] 4) The crude tungsten-rhenium alloy reduction powder obtained in step 3) is directly calcined in situ without crushing or mixing, that is, directly calcined in a hydrogen furnace at 1350° C. for 3 h.

[0054] 5) The tungsten-rhenium alloy particles obtained in step 4) are crushed, sieved, and mixed to obtain a tungsten-rhenium alloy powder product.

[0055] (2) Testing

[0056] The method is the same as Example 1. The results are shown in Table 2.

[0057] Table 2 Unit: ppm

[0058]

[0059] As can be seen from Table 2, the tungsten-rhenium alloy prepared in the comparative example was judged to be unqualified in terms of uniformity.

Claims

1. A method for significantly improving the uniformity of a tungsten-rhenium alloy, characterized in that: The steps include: 1) Take ammonium perrhenate and blue tungsten according to the mass percentage of tungsten and rhenium required by the tungsten-rhenium alloy grade; heat the ammonium perrhenate at 100°C and dissolve it in deionized water, then add blue tungsten; 2) placing the mixture obtained in step 1) into a mixing reactor with stirring and ultrasonic vibration, heating to 105° C., and concentrating the mixture to dryness under stirring and ultrasonic vibration; 3) Grind the concentrated and dried product into powder, mix it evenly, and then reduce it in a hydrogen reduction furnace to obtain a crude tungsten-rhenium alloy reduced powder; 4) The crude tungsten-rhenium alloy reduction powder obtained in step 3) is directly calcined in a hydrogen furnace at 1250° C.-1350° C. for 3 hours without crushing or mixing. The calcined particles are crushed, sieved, and mixed to obtain a tungsten-rhenium alloy with good uniformity. Sampling was performed in a large grid manner to analyze the uniformity of impurities in order to determine the uniformity of the prepared tungsten-rhenium alloy.

2. A method for significantly improving the uniformity of a tungsten-rhenium alloy according to claim 1, characterized in that: The ammonium perrhenate is selected to have a purity greater than 4N.

3. A method for significantly improving the uniformity of a tungsten-rhenium alloy according to claim 1, characterized in that: The blue tungsten is selected to have a purity greater than 4N.

4. A method for significantly improving the uniformity of a tungsten-rhenium alloy as claimed in claim 1, 2 or 3, characterized in that: In step 3), the conditions for the reduction in the hydrogen reduction furnace are: first reduction: 350-500°C, hydrogen flow rate 2-5M 3 / h, reduction time 2h; Second reduction: 650-950℃, hydrogen flow rate 2-4M 3 / h, reduction time 2h.

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