Manufacturing device and manufacturing method for a small-diameter tungsten alloy rod with an aspect ratio greater than 30

Abstract

The present invention discloses a manufacturing device and a manufacturing method for a small-diameter tungsten alloy rod with a length-diameter ratio greater than 30, including a rubber sleeve. The rubber sleeve is composed of an inner conical section L1 and a straight cylinder section L2. A rubber end plate is hermetically arranged at the small-diameter end of the inner conical section L1. The large-diameter end of the inner conical section L1 is coaxially and hermetically connected to one end of the straight cylinder section L2. An outer plug is arranged inside the other end of the straight cylinder section L2. Tungsten alloy powder is filled between the inner plug and the bottom of the rubber sleeve. An outer conical section L3 is coaxially arranged outside the inner conical section L1. The small-diameter end of the outer conical section L3 is matched with the outer diameter of the rubber end plate. The included angle between the inner generatrices on two opposite sides ranges from 0.20 to 0.24°, and the included angle between the outer generatrices on two opposite sides ranges from 0.20 to 0.24°. By arranging the inner conical section and the outer conical section on the rubber sleeve and precisely controlling their taper angles, the diameter difference of the pressed tungsten alloy rod is controlled within 0.5 mm, effectively reducing the turning amount of the sintered rod blank and greatly saving costs.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing tungsten alloy rods, and particularly to a manufacturing device and method for small-diameter tungsten alloy rods with a length-diameter ratio greater than 30. Background Art

[0002] Tungsten alloy rods are widely used. Since the melting point of tungsten is very high, it cannot be melted and made into metal rods like metals such as aluminum and iron. The traditional processing method is to load tungsten alloy powder into a straight-cylinder rubber mold, and then cold isostatically press it. After forming, the powder blank rod needs to be sintered at high temperature to form a tungsten alloy blank rod. Finally, based on the tungsten alloy blank rod, it must be turned into a tungsten alloy rod with a uniform diameter. The breakage rate of the powder blank rods pressed by the traditional processing method is as high as over 70%. The broken tungsten alloy rods cannot meet the needs of users, and the diameter difference of the formed powder blank rods is between 2.5 - 5 mm. After turning the sintered tungsten alloy blank rods, tungsten alloy products with mechanical properties meeting the requirements are obtained. This manufacturing method has a high breakage rate, high material consumption, large diameter difference, and high turning cost of the tungsten alloy blank rods. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a manufacturing device and method for small-diameter tungsten alloy rods with a length-diameter ratio greater than 30.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A manufacturing device for small-diameter tungsten alloy rods with a length-diameter ratio greater than 30 includes a rubber sleeve, an inner plug, and an outer plug. The rubber sleeve is composed of an inner tapered section L1 and a straight-cylinder section L2. The small-diameter end of the inner tapered section L1 is hermetically provided with a rubber end plate. The large-diameter end of the inner tapered section L1 is coaxially and hermetically connected to one end of the straight-cylinder section L2. The outer plug is arranged inside the other end of the straight-cylinder section L2. The inner plug is slidably arranged inside the straight-cylinder section L2 and is arranged close to the inner tapered section L1 side. Tungsten alloy powder is filled between the inner plug and the rubber end plate. An outer tapered section L3 is coaxially arranged outside the inner tapered section L1, and the length of the outer tapered section L3 is less than the length of the inner tapered section L1. The small-diameter end of the outer tapered section L3 is matched with the outer diameter of the rubber end plate. The thickness of the rubber end plate is h. In the inner tapered section L1, the included angle between the inner generatrices on two opposite sides ranges from 0.20 to 0.24°. In the outer tapered section L3, the included angle between the outer generatrices on two opposite sides ranges from 0.20 to 0.24°.

[0006] Further, the rubber sleeve is arranged in a straight blind hole in the steel sleeve. The outer wall of the rubber sleeve is in clearance fit with the inner wall of the straight blind hole. A through first pressure equalizing hole is arranged on the side wall of the straight blind hole, and a through second pressure equalizing hole is arranged at the bottom of the straight blind hole. The length of the straight blind hole is L4, and there is a relational expression: L1 + h ≤ L4 < L1 + L2.

[0007] Further, a locking band is arranged on the outer wall of the rubber sleeve. The locking band cooperates with the outer plug and does not interfere with the steel sleeve.

[0008] Further, the steel sleeve is vertically arranged on the placement rack. The placement rack is arranged in a pressure vessel. The pressure vessel is filled with emulsion liquid. The pressure vessel is connected to a pressure device. A limiting ring cooperating with the placement rack is fixedly arranged at the opening of the steel sleeve. The temperature of the emulsion liquid is 16 - 25 °C.

[0009] Further, in the inner conical section L1, the included angle between the inner generatrices on two opposite sides ranges from 0.214°. In the outer conical section L3, the included angle between the outer generatrices on two opposite sides ranges from 0.214°.

[0010] Further, the hardness of the rubber sleeve and the rubber end plate is 50 - 55 HA.

[0011] Further, the inner diameter of the straight cylinder section L2 is D0, the wall thickness of the rubber sleeve is q, and the value of the wall thickness q is q = sD0, where the value range of the coefficient s is 0.04 - 0.75.

[0012] Further, when the inner diameter D0 of the straight cylinder section L2 is not greater than 40 mm, the value of the coefficient s is 0.075. When the inner diameter D0 of the straight cylinder section L2 is greater than 100 mm, the value of the coefficient s is 0.04.

[0013] Further, the clearance value range between the outer wall of the rubber sleeve and the inner wall of the straight blind hole is 0.8 - 1.2 mm.

[0014] A manufacturing method for a small - diameter tungsten alloy rod with a length - diameter ratio greater than 30 uses a manufacturing device for a small - diameter tungsten alloy rod with a length - diameter ratio greater than 30. The manufacturing method for the small - diameter tungsten alloy rod includes the following steps:

[0015] S1: Uniformly mix the tungsten alloy powder;

[0016] S2: Load the mixed tungsten alloy powder into the rubber sleeve;

[0017] S3: Press the tungsten alloy powder in the rubber sleeve into a small - diameter tungsten alloy rod;

[0018] S4: Remove the rubber sleeve from the small-diameter tungsten alloy rod.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1) In this technical solution, by providing an inner tapered section and an outer tapered section on the rubber sleeve and precisely controlling the taper angle thereof, the diameter difference of the pressed tungsten alloy rod is controlled within 0.5 mm, effectively reducing the turning amount of the sintered rod blank. The sintered rod blank does not need to be turned, greatly saving costs.

[0021] 2) In this technical solution, by this manufacturing method, the diameter difference of the tungsten alloy rod is within 0.5 mm, the blanking rate is less than 7%, and the intact rate of the rod blank after pressing is increased from 31% to 93%. The sintered tungsten alloy rod blank can be directly used for pressure processing, and the material consumption is reduced from 1.76 to 1.29.

[0022] 3) In this technical solution, by controlling the roughness of the inner wall of the rubber sleeve, the wall thickness of the rubber sleeve, the hardness of the rubber sleeve, and the temperature of the working environment (emulsion) of the rubber sleeve, when the isostatic pressure is relieved, the compressed rubber sleeve returns to its original state and generates an axial tensile force, thereby reducing the occurrence probability of the fracture of the powder blank rod, improving the intact rate of the formed powder blank rod, and enhancing the production efficiency of the powder blank rod pressing and forming. Description of the Drawings

[0023] Figure 1 is a structural diagram of the rubber sleeve;

[0024] Figure 2 is a connection structural diagram between the rubber sleeve, the inner plug, the outer plug and the steel sleeve;

[0025] Figure 3 is a connection structural schematic diagram between the rubber sleeve, the placement rack, the pressure vessel and the pressure equipment;

[0026] In the figure, 1 - rubber sleeve, 2 - inner plug, 3 - outer plug, 4 - rubber end plate, 5 - steel sleeve, 6 - straight blind hole, 7 - first pressure equalizing hole, 8 - second pressure equalizing hole, 9 - locking band, 10 - placement rack, 11 - pressure vessel, 12 - pressure equipment, 13 - limiting ring. Detailed Embodiments

[0027] The following will, in conjunction with the embodiments, clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0028] Refer to Figures 1 - 3 , the present invention provides a technical solution:

[0029] A manufacturing device for a small-diameter tungsten alloy rod with an aspect ratio greater than 30, comprising a rubber sleeve 1, an inner plug 2 and an outer plug 3. The rubber sleeve 1 consists of an inner conical section L1 and a straight cylindrical section L2. A rubber end plate 4 is hermetically arranged at the small-diameter end of the inner conical section L1. The large-diameter end of the inner conical section L1 is coaxially and hermetically connected to one end of the straight cylindrical section L2. An outer plug 3 is arranged inside the other end of the straight cylindrical section L2. The inner plug 2 is slidably arranged inside the straight cylindrical section L2 and is arranged close to the inner conical section L1 side. Tungsten alloy powder is filled between the inner plug 2 and the rubber end plate 4. An outer conical section L3 is coaxially arranged outside the inner conical section L1, and the length of the outer conical section L3 is less than the length of the inner conical section L1. The small-diameter end of the outer conical section L3 matches the outer diameter of the rubber end plate 4. The thickness of the rubber end plate 4 is h. In the inner conical section L1, the included angle between the inner generatrices on two opposite sides ranges from 0.20 to 0.24°. In the outer conical section L3, the included angle between the outer generatrices on two opposite sides ranges from 0.20 to 0.24°. Among them, in this technical solution, the aspect ratio greater than 30 means that the ratio of the length of the tungsten alloy rod to the diameter at its largest part is greater than 30. The function of the inner plug 2 is to prevent the filled tungsten alloy powder from flowing out and can also ensure that the end face of the pressed tungsten alloy rod is flat rather than having a pointed structure. The function of the outer plug 3 is to seal the opening of the rubber sleeve 1. Generally, the inner conical section L1 is completely filled with tungsten alloy powder. Due to the action of gravity, when the rubber sleeve 1 is erected, there is a density difference between the upper and lower sides of the tungsten alloy powder in the rubber sleeve 1, and the density of the tungsten alloy powder gradually increases from top to bottom. According to the density change, unit mass = unit volume * unit density. In order to ensure that each unit mass is equal or has a very small deviation, when the unit density increases, the unit volume is correspondingly reduced. Therefore, the inner conical section L1 and the outer conical section L3 are set.

[0030] In some embodiments, the rubber sleeve 1 is arranged in a straight blind hole 6 in a steel sleeve 5. The outer wall of the rubber sleeve 1 is in clearance fit with the inner wall of the straight blind hole 6. A through first pressure equalizing hole 7 is arranged on the side wall of the straight blind hole 6, and a through second pressure equalizing hole 8 is arranged at the bottom of the straight blind hole 6. The length of the straight blind hole 6 is L4, and there is a relational expression L1 + h ≤ L4 < L1 + L2. The clearance between the outer wall of the rubber sleeve 1 and the inner wall of the straight blind hole 6 ranges from 0.8 to 1.2 mm. Among them, arranging the straight blind hole 6 facilitates placing the rubber sleeve 1. The rubber sleeve 1 with the rubber end plate 4 is arranged at the bottom of the steel sleeve 5. Arranging the first pressure equalizing hole 7 and the second pressure equalizing hole 8 facilitates the emulsion to enter between the inner wall of the steel sleeve 5 and the outer wall of the rubber sleeve 1. A plurality of first pressure equalizing holes 7 are arranged on the side wall of the straight blind hole 6, and the outer wall of the rubber sleeve 1 is wrapped by the emulsion so that the outer wall of the rubber sleeve 1 is uniformly stressed. The function of the straight blind hole 6 is to ensure that the tungsten alloy rod formed inside the rubber sleeve 1 is straight, and the section filled with tungsten alloy powder inside the rubber sleeve 1 is entirely located inside the steel sleeve 5. The diameter of the first pressure equalizing hole 7 ranges from 7.5 to 8.5 mm, and the diameter of the second pressure equalizing hole 8 ranges from 4.5 to 5.5 mm.

[0031] In some embodiments, a locking band 9 is provided on the outer wall of the rubber sleeve 1. The locking band 9 cooperates with the outer plug 3 and does not interfere with the steel sleeve 5. Among them, the purpose of setting the locking band 9 is to fix the outer plug 3 and the rubber sleeve 1 together to prevent the outer plug 3 from separating from the rubber sleeve 1 during the processing.

[0032] In some embodiments, in the inner conical section L1, the included angle between the inner generatrices on two opposite sides ranges from 0.214°. In the outer conical section L3, the included angle between the outer generatrices on two opposite sides ranges from 0.214°. In this technical solution, when the included angles at both places are controlled at 0.214°, the maximum diameter of the small-diameter tungsten alloy powder blank rod measured along the length direction is 17.38 mm, and the minimum diameter is 16.92 mm. After sintering, the maximum diameter of the tungsten alloy blank is 14.75 mm, and the minimum diameter is 14.42 mm. No additional turning process is required, and direct pressure processing can be carried out to obtain product performance that meets user requirements.

[0033] In some embodiments, the steel sleeve 5 is vertically arranged on the placement rack 10. The placement rack 10 is arranged in the pressure vessel 11. The pressure vessel 11 is filled with emulsion. The pressure vessel 11 is connected to the pressure device 12. A limiting ring 13 that cooperates with the placement rack 10 is fixedly arranged at the opening of the steel sleeve 5. The temperature of the emulsion is 16 - 25°C. If the temperature of the emulsion is too low, the rubber sleeve 1 becomes hard, and the breakage rate of the small-diameter tungsten alloy rod during the forming process increases sharply, which is not conducive to the powder pressing of tungsten alloy. For example, when the temperature of the emulsion is lower than 10°C, the rubber mold becomes hard and its elasticity decreases, and the breakage rate increases sharply.

[0034] In some embodiments, the inner diameter of the straight cylindrical section L2 is D0, and the wall thickness of the rubber sleeve 1 is q. The value of the wall thickness q is q = sD0, where the value range of the coefficient s is 0.04 - 0.75. When the inner diameter D0 of the straight cylindrical section L2 is no more than 40 mm, the value of the coefficient s is 0.075. When the inner diameter D0 of the straight cylindrical section L2 is greater than 100 mm, the value of the coefficient s is 0.04. Among them, during actual use, when D0 is equal to 40 mm, the value of the coefficient s can also be selected from 0.05 - 0.06.

[0035] In some embodiments, the hardness of the rubber sleeve 1 and the rubber end plate 4 is 50 - 55 HA. The inner wall of the rubber sleeve 1 has a roughness Ra of less than 0.6. The breakage rate of the small-diameter tungsten alloy rod manufactured with the rubber sleeve 1 and the rubber end plate 4 at this hardness is the lowest, and demolding is also easy. If the rubber sleeve 1 and the rubber end plate 4 are too soft, in order for the rubber sleeve 1 to restore its elasticity, the small-diameter tungsten alloy rod fits against the inner wall of the rubber sleeve 1, resulting in difficult demolding. If the hardness of the rubber sleeve 1 and the rubber end plate 4 is a bit higher, demolding is easy, but the axial tension generated by restoring elasticity is too large, and the breakage rate of the small-diameter tungsten alloy rod increases.

[0036] A manufacturing method for small-diameter tungsten alloy rods with a length-diameter ratio greater than 30, using a manufacturing device for small-diameter tungsten alloy rods with a length-diameter ratio greater than 30. The manufacturing method for small-diameter tungsten alloy rods includes the following steps:

[0037] (1) Uniformly mix tungsten alloy powders. The processing of this technology starts from metal powders. Other metal powders need to be mixed into tungsten powders to enhance the performance of tungsten alloy rods. Therefore, tungsten powders and other metal powders need to be fully mixed.

[0038] (2) Load the mixed tungsten alloy powders into rubber sleeve 1. In this step, the tungsten alloy powders are loaded into rubber sleeve 1. After loading, inner plug 2 is placed into rubber sleeve 1, then outer plug 3 is covered on the opening of rubber sleeve 1, and outer plug 3 and rubber sleeve 1 are fixed together through locking belt 9. Finally, rubber sleeve 1 is placed into steel sleeve 5.

[0039] (3) Press the tungsten alloy powders in rubber sleeve 1 into small-diameter tungsten alloy rods. Steel sleeve 5 equipped with rubber sleeve 1 is placed on placement rack 10. Placement rack 10 is arranged inside pressure vessel 11. Then, emulsifying liquid with a temperature of 16 - 25 °C is injected into pressure vessel 11. After pressure vessel 11 is filled with emulsifying liquid, pressure vessel 11 is sealed. Then, pressure is applied to the emulsifying liquid through pressure device 12. The emulsifying liquid extrudes rubber sleeve 1 through the pressure equalizing holes on steel sleeve 5, causing the tungsten alloy powders in rubber sleeve 1 to become tungsten alloy rods under pressure.

[0040] (4) Remove rubber sleeve 1 from the small-diameter tungsten alloy rod. Remove the pressure on pressure device 12, open pressure vessel 11, take steel sleeve 5 off placement rack 10, remove steel sleeve 5, open locking belt 9 and remove outer plug 3, then take out inner plug 2 and take out the tungsten alloy rod.

[0041] Partial dimensional data of the device in this technical solution:

[0042] Name Representation letter Example data Length of the rubber sleeve L1 + L2 950 mm Inner diameter of the straight tube section D0 21.2 mm Length of the inner tapered section L1 640 mm Bottom inner diameter of the inner tapered section D4 19.2 mm Inner taper of the rubber sleeve 0.20-0.24° Outer diameter of the straight tube section D1 24.5 mm Outer taper of the rubber sleeve 0.20-0.24° Length of the outer tapered section L3 300 mm Bottom outer diameter of the outer tapered section D2 23.7 mm Thickness of the rubber end plate h 2.5 mm Length of the steel sleeve 850 mm Inner diameter of the steel sleeve 25.6 mm Outer diameter of the steel sleeve 28 mm

[0043] Comparison between using this device and using traditional methods to produce small-diameter tungsten alloy rods:

[0044] 1. Using this device to produce small-diameter tungsten alloy rods

[0045] In the rubber sleeve 1, the powder loading section has a length of 640 mm, a taper of 0.214°, a wall thickness of the rubber sleeve 1 of 1.5 mm, a surface roughness Ra of 0.5 on the inner wall of the rubber sleeve 1, a Shore hardness of the rubber mold of 53 HA, an emulsion temperature of 20 °C, and the finished small-diameter tungsten alloy rod has dimensions of Φ17.2 mm × 540 mm. The powder loading is 1.28 Kg per rod, and 635 tungsten alloy powder preform rods are loaded. The maximum diameter of the preform rod is 17.42 mm, and the minimum is 16.94 mm; the maximum length is 548 mm, and the minimum is 535 mm; the number of cut-off pieces is 43, and the integrity rate of the powder preform rod is 93.23%.

[0046] 2 The traditional method is used to produce small-diameter tungsten alloy rods

[0047] The traditional rubber sleeve 1 is straight cylindrical without any taper. The inner diameter of the straight cylindrical rubber sleeve 1 is 21 mm, the outer diameter is 26 mm, the length is 950 mm, the powder loading section length is 640 mm, the wall thickness is 2.5 mm, the surface roughness Ra of the inner wall of the rubber sleeve 1 is 3.2, the Shore hardness of the rubber sleeve 1 is 60 HA, and the emulsion temperature is 12 °C. The powder loading is 1.35 Kg per rod, and 45 tungsten alloy powder preform rods are loaded. The pressed powder preform rod has a large bottom and a small upper end. The maximum diameter is 19.2 mm, and the minimum is 16.75 mm, with a diameter difference of 2.45 mm; the maximum length is 552 mm, and the minimum is 528 mm; the number of cut-off pieces is 31, and the integrity rate of the powder preform rod is 31.1%.

[0048] Through comparison, the diameter of the powder preform rod and the cut-off rate of the pressing forming are respectively analyzed. The diameter difference of the tungsten alloy powder preform rod manufactured by this device is less than 0.5 mm, and the integrity rate of the powder preform rod is 93.3%. It is far superior to the tungsten alloy powder preform rod manufactured by the uncontrolled mold with a diameter difference of 2.45 mm and an integrity rate of only 31%. At the same time, due to the small diameter difference, the subsequent processed sintered semi-finished products do not need to be turned, saving 70 yuan per rod for machining costs, and the material consumption is reduced from 1.76 to 1.29, saving a large amount of raw materials.

[0049] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "bottom", "middle", "upper", "one side", "inner", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0050] In the present invention, unless otherwise clearly specified or limited, terms such as "installation", "setting", "connection", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. Unless otherwise clearly limited, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0051] The above are only the preferred embodiments of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications, and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And any changes and modifications made by those skilled in the art without departing from the spirit and scope of the present invention shall fall within the protection scope of the appended claims of the present invention.

Claims

1. An apparatus for manufacturing a small-diameter tungsten alloy rod with a length-to-diameter ratio greater than 30, characterized in that: It includes a rubber sleeve (1), an inner plug (2) and an outer plug (3). The rubber sleeve (1) is composed of an inner conical section L1 and a straight cylindrical section L2. The small-diameter end of the inner conical section L1 is hermetically provided with a rubber end plate (4). The large-diameter end of the inner conical section L1 is coaxially and hermetically connected to one end of the straight cylindrical section L2. The outer plug (3) is arranged inside the other end of the straight cylindrical section L2. The inner plug (2) is slidably arranged inside the straight cylindrical section L2 and is arranged close to the inner conical section L1 side. Tungsten alloy powder is filled between the inner plug (2) and the rubber end plate (4). An outer conical section L3 is coaxially arranged outside the inner conical section L1, and the length of the outer conical section L3 is less than the length of the inner conical section L1. The small-diameter end of the outer conical section L3 is matched with the outer diameter of the rubber end plate (4). The thickness of the rubber end plate (4) is h. In the inner conical section L1, the included angle between the inner generatrices on two opposite sides ranges from 0.20 to 0.24°. In the outer conical section L3, the included angle between the outer generatrices on two opposite sides ranges from 0.20 to 0.24°; The rubber sleeve (1) is arranged inside a straight blind hole (6) in a steel sleeve (5). The outer wall of the rubber sleeve (1) is in clearance fit with the inner wall of the straight blind hole (6). A through first pressure equalizing hole (7) is arranged on the side wall of the straight blind hole (6), and a through second pressure equalizing hole (8) is arranged at the bottom of the straight blind hole (6). The length of the straight blind hole (6) is L4, and it satisfies the relational expression L1 + h ≤ L4 < L1 + L2; The inner diameter of the straight cylindrical section L2 is D0, and the wall thickness of the rubber sleeve (1) is q. The value of the wall thickness q is q = sD0, where the value range of the coefficient s is 0.04 to 0.

75.

2. The manufacturing device for a small-diameter tungsten alloy rod with a length-diameter ratio greater than 30 according to claim 1, wherein: A locking band (9) is arranged on the outer wall of the rubber sleeve (1). The locking band (9) cooperates with the outer plug (3) and does not interfere with the steel sleeve (5).

3. The manufacturing device for a small-diameter tungsten alloy rod with a length-to-diameter ratio greater than 30 according to claim 1, characterized in that: The steel sleeve (5) is vertically arranged on a placement rack (10). The placement rack (10) is arranged inside a pressure vessel (11). The pressure vessel (11) is filled with emulsion. The pressure vessel (11) is connected to a pressure device (12). A limiting ring (13) that cooperates with the placement rack (10) is fixedly arranged at the opening of the steel sleeve (5). The temperature of the emulsion is 16 to 25°C.

4. The manufacturing device for a small-diameter tungsten alloy rod with a length-diameter ratio greater than 30 according to claim 1, characterized in that: In the inner conical section L1, the included angle between the inner generatrices on two opposite sides ranges from 0.214°. In the outer conical section L3, the included angle between the outer generatrices on two opposite sides ranges from 0.214°.

5. The manufacturing device for a small-diameter tungsten alloy rod with a length-diameter ratio greater than 30 according to claim 1, characterized in that: The hardness of the rubber sleeve (1) and the rubber end plate (4) is 50 to 55 HA.

6. The manufacturing device for a small-diameter tungsten alloy rod with a length-diameter ratio greater than 30 according to claim 1, characterized in that: When the inner diameter D0 of the straight cylindrical section L2 is not greater than 40 mm, the value of the coefficient s is 0.

075. When the inner diameter D0 of the straight cylindrical section L2 is greater than 100 mm, the value of the coefficient s is 0.

04.

7. The manufacturing device for a small-diameter tungsten alloy rod with a length-diameter ratio greater than 30 according to claim 1, wherein: The clearance value range between the outer wall of the rubber sleeve (1) and the inner wall of the straight blind hole (6) is 0.8 to 1.2 mm.

8. A manufacturing method of a small-diameter tungsten alloy rod with an aspect ratio greater than 30, using a manufacturing device for a small-diameter tungsten alloy rod with an aspect ratio greater than 30 as described in any one of claims 1-7, characterized in that: The manufacturing method of the small-diameter tungsten alloy rod includes the following steps: S1: Uniformly mix the tungsten alloy powder; S2: Load the mixed tungsten alloy powder into the rubber sleeve (1); S3: Press the tungsten alloy powder in the rubber sleeve (1) into a small-diameter tungsten alloy rod; S4: Remove the rubber sleeve (1) from the small-diameter tungsten alloy rod.

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