Method for detecting formability of tungsten powder

Abstract

The invention discloses a tungsten powder forming performance detection method which comprises the following steps: applying pressure to tungsten powder for pressing to obtain a pressed blank, reading the pressure fed back by the pressed blank in the pressing process, and judging the forming performance of the tungsten powder according to a pressure feedback value P. The forming performance comprises the density D1 of the pressed blank and the density D2 of a sintered tungsten alloy, the judgment standard comprises: when P is greater than or equal to 140 MPa and less than or equal to 200 MPa; and judging that D1 is more than or equal to 15.0 g / cm < 3 > and less than or equal to 16.0 g / cm < 3 >, and / or D2 is more than or equal to 18.0 g / cm < 3 > and less than or According to the detection method, accurate quantitative detection of the forming performance of the tungsten powder can be completed in the powder stage, detection data are stable and reliable, and a reference basis can be provided for tungsten powder production and subsequent alloy production.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology, specifically relating to a method for testing the forming performance of tungsten powder. Background Technology

[0002] Among metals, tungsten has the highest melting point, resulting in excellent high-temperature strength, creep resistance, thermal conductivity, electrical conductivity, and electron emission properties, as well as a high specific gravity. Tungsten and its alloys are widely used in the electronics and electric light source industries, and are also used in aerospace, casting, and weaponry industries to manufacture rocket nozzles, die-casting molds, armor-piercing projectile cores, contacts, heating elements, and heat shields. They have found widespread application in cutting-edge scientific fields, defense industries, and civilian industries. Tungsten alloys have stringent performance requirements. For example, in the preparation of tungsten wires, the alloys must possess high strength and high toughness to ensure unbroken wires during drawing, thus extending the lifespan of the tungsten wires. High-density tungsten alloys require high density, high strength, and no defects. Therefore, the powder dispersibility and formability of the raw tungsten powder must meet extremely high requirements, making the formability of tungsten powder a key indicator for evaluating its quality. Existing methods for testing the formability of tungsten powder mainly involve preparing small batches of tungsten alloy from the powder and evaluating the density of the pressed tungsten alloy and the density of the sintered tungsten alloy during the preparation process to assess the material properties of the tungsten powder. This method has a long evaluation process, a long cycle, and requires a large amount of raw materials. Summary of the Invention

[0003] The purpose of this invention is to provide a method for testing the molding performance of tungsten powder, so as to solve at least one aspect of the problems and defects mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A method for testing the forming performance of tungsten powder includes applying pressure to tungsten powder to form a compact, reading the pressure feedback from the compact during the pressing process, and judging the forming performance of the tungsten powder by the pressure feedback value P. The forming performance includes the compact density D1 and the density D2 of the sintered tungsten alloy. The judgment criteria include: When 140MPa≤P≤200MPa is satisfied; Determine 15.0 g / cm³ 3 ≤D1≤16.0g / cm 3 And / or 18.0 g / cm 3 ≤D2≤19.0g / cm 3 .

[0005] This invention evaluates the forming performance of tungsten powder by detecting the feedback pressure during tungsten powder compaction. The pressure value is stable and reliable, the detection method is simple, and the detection speed is fast. When pressure is applied during tungsten powder compaction, different batches of tungsten powder will provide different pressure values. Measurements of the compact density and the density of the sintered tungsten alloy reveal a good correlation between density and pressure: the larger the pressure feedback value P, the lower the tungsten powder compact density D1 and the sintered tungsten alloy density D2. When 140MPa≤P≤200MPa is satisfied, the tungsten powder compact density D1 will meet the requirement of 15.0 g / cm³. 3 ≤D1≤16.0g / cm 3 Furthermore, the density D2 of the sintered tungsten alloy also satisfies 18.0 g / cm³. 3 ≤D2≤19.0g / cm 3 .

[0006] As a further embodiment of the present invention: the judgment criteria include: when 140MPa≤P≤160MPa, a value of 15.5g / cm is determined. 3 ≤D1≤16.0g / cm 3 , and / or 18.5 g / cm 3 ≤D2≤19.0g / cm 3 When the alloy density reaches 18.5 g / cm³ 3 At the above levels, the forming properties of tungsten powder can usually meet the density requirements for tungsten alloy production.

[0007] As a further embodiment of the present invention, the tungsten alloy is a pure tungsten alloy.

[0008] As a further aspect of the present invention, the sintering temperature of the tungsten alloy is 2000~2300℃, preferably 2300℃.

[0009] As a further aspect of the present invention, the sintering time of the tungsten alloy is 4 to 6 hours, preferably 6 hours.

[0010] As a further embodiment of the present invention: the Fsss particle size of the tungsten powder is 1~5μm, preferably 1.0~4.4μm.

[0011] As a further embodiment of the present invention: the mass ratio of tungsten powder to solvent in the pressed blank is 100g:0.5~2.5ml.

[0012] As a further embodiment of the present invention, the solvent includes at least one of ethanol and acetone, preferably ethanol.

[0013] As a further embodiment of the present invention, the weight of the tungsten powder compact is 10~15g.

[0014] As a further embodiment of the present invention, the dimensions of the tungsten powder compact are: length = 19.5~20.5mm, width = 5.0~5.5mm, and height = 6.0~7.0mm.

[0015] As a further embodiment of the present invention, the dimensions of the tungsten powder compact are: 20mm in length × 5.25mm in width × 6.5mm in height.

[0016] As a further embodiment of the present invention, the pressing process is carried out on a press.

[0017] As a further embodiment of the present invention: the pressure feedback value is the average pressure feedback value of 3 to 7 compacts prepared from the same batch of tungsten powder under the same applied pressure, preferably the average pressure feedback value of 5 compacts.

[0018] As a further embodiment of the present invention, the detection method includes the following steps: S1. Mix tungsten powder and solvent evenly to obtain a mixture; S2. Apply pressure to the mixture to obtain a compact, read the pressure feedback from the compact during the pressing process, and determine the forming performance of the tungsten powder through the pressure feedback value P. The forming performance includes the compact density D1 and the density D2 of the sintered tungsten alloy. The judgment criteria include: When 140MPa≤P≤200MPa is satisfied; Determine 15.0 g / cm³ 3 ≤D1≤16.0g / cm 3 And / or 18.0 g / cm 3 ≤D2≤19.0g / cm 3 .

[0019] As a further embodiment of the present invention, the detection method includes the following steps: S1. Weigh 200g of tungsten powder with a particle size of 1.0~5.0μm, add 1~5ml of ethanol and mix well to obtain a mixture; S2. The mixture is pressed under pressure to form a compact. The compact weighs 10-15g and has dimensions of length 19.5-20.5mm, width 5.0-5.5mm, and height 6.0-7.0mm. The pressure feedback from the compact during the pressing process is read. 3-7 compacts from the same batch of tungsten powder are pressed consecutively, and the average value is taken. The forming performance of the tungsten powder is judged by the pressure feedback value P. The forming performance includes the compact density D1 and the density D2 of the sintered tungsten alloy. The judgment criteria include: When 140MPa≤P≤200MPa is satisfied; Determine 15.0 g / cm³ 3 ≤D1≤16.0g / cm 3And / or 18.0 g / cm 3 ≤D2≤19.0g / cm 3 .

[0020] The present invention has at least the following technical effects: (1) The molding performance of tungsten powder is quantitatively tested in the powder stage. The test data is stable and reliable, which can provide a reference for the subsequent processing of tungsten powder and the production of alloys. (2) The detection speed is fast. After the standard is established, the detection time for a sample is within 30 minutes. It can be used as a routine detection item for tungsten powder to evaluate the quality of each batch of tungsten powder. (3) The process is short and the testing cost is low. Only a conventional press is needed for testing. Each batch of products only requires a sample of less than 200g, and the material and labor input costs are low. Attached Figure Description

[0021] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is the linear fitting result of the pressure feedback value and the compact density in the embodiments of the present invention; Figure 2 This is the linear fitting result between the pressure feedback value and the density of the sintered tungsten alloy in the embodiments of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, and not all embodiments.

[0024] Therefore, the following detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0026] Example 1 A method for testing the molding performance of tungsten powder includes the following steps: S1. Weigh 200g of tungsten powder with an Fsss particle size of 1.08 μm and measure 2.5ml of anhydrous ethanol; S2. Mix the above tungsten powder and anhydrous ethanol evenly, weigh 13g of the mixture of tungsten powder and anhydrous ethanol, press it on a press with a pressing pressure of 600Mpa, and the size of the pressed blank is 20×5.25×6.5mm (length×width×height). Read the pressure value fed back by the pressed blank during the pressing process (i.e. the value when the instrument is stable). Press 5 samples under the same conditions, take the average value of the 5 samples, and record the pressure feedback value P. S3. The density of the pressed billet is tested to obtain the density D1 of the billet. The billet is then sintered into a tungsten alloy. The tungsten alloy is a pure tungsten alloy. The sintering temperature is 2300℃ and the sintering time is 6h. The density D2 of the sintered tungsten alloy is then measured.

[0027] Example 2 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder is adjusted to 1.62 μm; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0028] Example 3 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder was adjusted to 2.26 μm, and the amount of anhydrous ethanol added was adjusted to 2.0 ml. In step S2, the mass of the tungsten powder and ethanol mixture is adjusted to 14g; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0029] Example 4 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder was adjusted to 3.12 μm, and the amount of anhydrous ethanol added was adjusted to 1.5 ml. In step S2, the mass of the tungsten powder and ethanol mixture is adjusted to 14.5g; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0030] Example 5 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder was adjusted to 4.17 μm, and the amount of anhydrous ethanol added was adjusted to 1.5 ml. In step S2, the mass of the tungsten powder and ethanol mixture is adjusted to 15g; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0031] Example 6 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder was adjusted to 2.57 μm, and the amount of anhydrous ethanol added was adjusted to 2.0 ml. The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0032] Example 7 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder was adjusted to 3.09 μm, and the amount of anhydrous ethanol added was adjusted to 1.5 ml. The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0033] Example 8 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder was adjusted to 4.35 μm, and the amount of anhydrous ethanol added was adjusted to 1.5 ml. In step S2, the mass of the tungsten powder and ethanol mixture is adjusted to 14g; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0034] Example 9 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder is adjusted to 1.97 μm; In step S2, the mass of the tungsten powder and ethanol mixture is adjusted to 13.5g; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0035] Example 10 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder is adjusted to 1.12 μm; In step S2, the mass of the tungsten powder and ethanol mixture is adjusted to 13.5g; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0036] Comparative Example 1 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder was adjusted to 4.51 μm, and the amount of anhydrous ethanol added was adjusted to 2.0 ml. The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0037] Comparative Example 2 The difference from Example 1 is as follows: In step S1, the Fsss particle size of the tungsten powder is adjusted to 1.12 μm; In step S2, the mass of the tungsten powder and ethanol mixture is adjusted to 14g; The remaining conditions and parameters are the same as in Example 1. The pressure feedback value P, the compact density D1, and the density D2 of the sintered tungsten alloy are recorded.

[0038] The test results of the pressure feedback value P during pressing of tungsten powder compacts in Examples 1-10 and Comparative Examples 1-2, as well as the density D1 of the tungsten powder compacts and the density D2 of the sintered tungsten alloy, are shown in Table 1.

[0039] Table 1. Detection results of Examples 1-10 and Comparative Examples 1-2

[0040] The results showed that in Examples 1-10, the pressure value P fed back during the pressing of the tungsten powder compact satisfied 140 MPa ≤ P ≤ 200 MPa, and the measured density D1 of the tungsten powder compact all satisfied 15.0 g / cm³. 3 ≤D1≤16.0g / cm 3 Furthermore, the density D2 of the sintered tungsten alloy all meets the requirement of 18.0 g / cm³. 3 ≤D2≤19.0g / cm 3 In Comparative Examples 1 and 2, the pressure feedback value P did not satisfy 140 MPa ≤ P ≤ 200 MPa, and the density of the tungsten powder compact and the density of the sintered tungsten alloy were also outside the corresponding ranges, indicating that the detection method provided by the present invention can be used to evaluate the forming performance of tungsten powder.

[0041] The pressure feedback values, compact density, and sintered tungsten alloy density data obtained in Examples 1-10 were linearly fitted, and the results are as follows: Figure 1 , Figure 2 As shown. The results indicate that, in this invention, the pressure value fed back during tungsten powder compaction is linearly related to the compaction density, R 2 =0.9253; it also shows a linear relationship with the density of the sintered tungsten alloy, R 2= 0.9604.

[0042] Any numerical value mentioned in this invention, if there is only a two-unit interval between any minimum and any maximum value, includes all values ​​that increase by one unit each time from the minimum to the maximum value. For example, if the amount of a component, or the value of a process variable such as temperature, pressure, or time, is stated as 60 to 90, in this specification it means specifically listing values ​​such as 61 to 89, 62 to 88, ..., 61 to 71, and 80 to 81. For non-integer values, it may be appropriate to consider a unit of 0.1, 0.01, 0.001, or 0.0001. These are merely some specifically specified examples. In this application, in a similar manner, all possible combinations of numerical values ​​between the listed minimum and maximum values ​​are considered to have been disclosed.

[0043] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for testing the molding performance of tungsten powder, characterized in that, The process includes applying pressure to tungsten powder to obtain a compact, reading the pressure feedback from the compact during the pressing process, and judging the formability of the tungsten powder based on the pressure feedback value P. The formability includes the compact density D1 and the density D2 of the sintered tungsten alloy. The judgment criteria include: When 140MPa≤P≤200MPa is satisfied; Determine 15.0 g / cm³ 3 ≤D1≤16.0g / cm 3 And / or 18.0 g / cm 3 ≤D2≤19.0g / cm 3 .

2. The detection method according to claim 1, characterized in that, The tungsten alloy is a pure tungsten alloy.

3. The detection method according to claim 1, characterized in that, The sintering temperature of the tungsten alloy is 2000~2300℃.

4. The detection method according to claim 1, characterized in that, The sintering time of the tungsten alloy is 4-6 hours.

5. The detection method according to claim 1, characterized in that, The Fsss particle size of the tungsten powder is 1~5μm.

6. The detection method according to claim 1, characterized in that, The mass ratio of tungsten powder to solvent in the pressed blank is 100g:0.5~2.5ml.

7. The detection method according to claim 5, characterized in that, The solvent is ethanol.

8. The detection method according to claim 1, characterized in that, The weight of the pressed blank is 10~15g.

9. The detection method according to claim 1, characterized in that, The dimensions of the pressed blank are: length = 19.5~20.5mm, width = 5.0~5.5mm, height = 6.0~7.0mm.

10. The detection method according to claim 1, characterized in that, The pressure feedback value is the average pressure feedback value of 3 to 7 compacts prepared from the same batch of tungsten powder under the same applied pressure.

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