A manufacturing method for an elongated tungsten alloy tube

Abstract

The present invention discloses a manufacturing method for an elongated tungsten alloy tube, belonging to the technical field of manufacturing tungsten alloy powder billet tubes, which includes the following steps: preparing the raw materials for the tungsten alloy powder billet tube, where the raw materials for the tungsten alloy powder billet tube are tungsten alloy mixed powder or tungsten alloy granulated powder; filling the raw materials for the tungsten alloy powder billet tube into a mold; placing the mold into a dry bag isostatic pressing device, and then pressing the mold radially without pressing the mold axially; after the pressing is completed, demolding is carried out, and after demolding, a tungsten alloy powder billet tube with an outer diameter of 33 - 230 mm, an inner diameter of 5 - 30 mm, and a length of 620 - 660 mm is obtained; the tungsten alloy powder billet tube is sintered to obtain a finished tungsten alloy tube. Through this manufacturing method, a tungsten alloy tube with a length greater than 300 mm can be manufactured. By prefabricating tungsten alloy powder billet tubes with the required outer diameter, inner diameter, and length, it is used to prepare an elongated tungsten alloy tube at low cost, reducing the preparation difficulty and processing cost of the elongated tungsten alloy tube.

Description

Technical Field

[0001] The present invention relates to the technical field of manufacturing tungsten alloy powder billet tubes, and particularly relates to a method for manufacturing slender tungsten alloy tubes. Background Art

[0002] There are two traditional preparation methods for tungsten alloy tubes with a length not greater than 300 mm: one is to drill a hole in the center of a tungsten alloy solid rod, which has high processing costs and low efficiency; the other is to prefabricate a tungsten alloy powder billet tube with a steel core and form it in cold isostatic pressing. Due to radial and axial pressures, the prepared tungsten alloy powder billet tube bends and cannot meet customer requirements. When customers need tungsten alloy tubes with a length greater than 300 mm or even more than 500 mm, neither drilling nor cold isostatic pressing to prefabricate tungsten alloy powder billet tubes can manufacture slender tungsten alloy tubes. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for manufacturing slender tungsten alloy tubes.

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

[0005] A method for manufacturing a slender tungsten alloy tube includes the following steps:

[0006] S1: Prepare the raw material of the tungsten alloy powder billet tube, and the raw material of the tungsten alloy powder billet tube is tungsten alloy mixed powder or tungsten alloy granulated powder;

[0007] S2: Fill the raw material of the tungsten alloy powder billet tube into a mold;

[0008] S3: Place the mold into a dry bag isostatic pressing device, and then press the mold radially without pressing the mold axially;

[0009] S4: After the pressing is completed, perform demolding work. After demolding, a tungsten alloy powder billet tube with an outer diameter of 33 - 230 mm, an inner diameter of 5 - 30 mm, and a length of 620 - 660 mm is obtained;

[0010] S5: Sinter the tungsten alloy powder billet tube to obtain a finished tungsten alloy tube.

[0011] Further, the mold includes a lower positioning plug, an upper positioning plug, a core rod, a die sleeve, a moving tube, and a filler. A plurality of through forming channels are provided in the die sleeve. The lower positioning plug is hermetically and fixedly arranged at the lower end of the forming channel. The upper positioning plug is hermetically and fixedly arranged at the upper end of the forming channel. The core rod is coaxially arranged in the die sleeve and is connected to the lower positioning plug and the upper positioning plug at both ends respectively. The filler is coaxially and detachably sleeved on the core rod, and the outer wall thereof cooperates with the inner wall of the forming channel. The moving tube is sleeved on the core rod, and the lower end thereof is fixedly connected to the filler. A plurality of through filler slots are provided on the filler.

[0012] Further, the straightness of the core rod is ≤ 0.03 / 100, the surface roughness of the core rod is ≤ Ra0.8, and the inner wall roughness of the die sleeve is ≤ Ra1.6.

[0013] Further, the thicknesses of both the lower positioning plug and the upper positioning plug are 30 - 50 mm.

[0014] Further, the outer diameter d of the core rod = d0 / (0.83 - 0.86). When the raw material of the tungsten alloy powder blank tube is the tungsten alloy mixed powder, the inner diameter of the forming channel is D = (D0 + 5) / (0.68 - 0.70); when the raw material of the tungsten alloy powder blank tube is the tungsten alloy granulated powder, the inner diameter of the forming channel is D = (D0 + 5) / (0.54 - 0.56), where d0 is the inner diameter of the finished tungsten alloy tube, and D0 is the outer diameter of the finished tungsten alloy tube.

[0015] Further, a sleeve is arranged in the forming channel. Both ends of the sleeve are hermetically fitted with the lower positioning plug and the upper positioning plug respectively. The raw material of the tungsten alloy powder blank tube is filled between the inner wall of the sleeve and the core rod.

[0016] Further, six of the filler slots are evenly arranged on the filler.

[0017] Further, the operation method of the mold includes the following steps

[0018] S2.1: Hermetically and fixedly arrange the lower positioning plug in the lower end of the forming channel;

[0019] S2.2: Insert the core rod into the central part of the lower positioning plug;

[0020] S2.3: Sleeve the combination of the moving tube and the filler on the core rod, and make the filler located in the upper middle part of the die sleeve;

[0021] S2.4: Add the tungsten alloy powder blank tube raw material from the upper end of the forming channel. The tungsten alloy powder blank tube raw material enters the forming channel through the filler through - slot. During the process of adding the tungsten alloy powder blank tube raw material, a compaction operation is carried out. When the tungsten alloy powder blank tube raw material approaches the filler, move the filler upward by a certain distance relative to the upper end of the die sleeve, and then add the tungsten alloy powder blank tube raw material and compact it again.

[0022] S2.5: When the filling height of the tungsten alloy powder blank tube raw material in the die sleeve reaches 620 - 660 mm, remove the filler.

[0023] S2.6: Seal and fix the upper positioning plug at the upper end of the forming channel, and the upper positioning plug presses on the upper surface of the tungsten alloy powder blank tube raw material.

[0024] Further, there is one forming channel arranged in the die sleeve, or three forming channels are evenly arranged in the die sleeve.

[0025] Further, when the tungsten alloy powder blank tube raw material is the tungsten alloy mixed powder, the pressure of the dry - bag isostatic pressing equipment is 160 - 200 MPa; when the tungsten alloy powder blank tube raw material is the tungsten alloy granulated powder, the pressure of the dry - bag isostatic pressing equipment is 60 - 150 MPa.

[0026] The beneficial effects of the present invention are:

[0027] 1) In this technology, tungsten alloy tubes with a length greater than 300 mm can be manufactured by this manufacturing method. By pre - manufacturing tungsten alloy powder blank tubes with the required outer diameter, inner diameter, and length, it is used to prepare slender tungsten alloy tubes at low cost, reducing the preparation difficulty and processing cost of slender tungsten alloy tubes.

[0028] 2) In this technology, the structure of the mold is simple and the operation is convenient.

[0029] 3) In this technology, through the combined use of the core rod, the moving tube, and the filler, the situation of uneven wall thickness of the manufactured tungsten alloy powder blank tube can be effectively avoided. Description of the Drawings

[0030] Figure 1 It is a top - view connection structure diagram with one forming channel arranged on the die sleeve;

[0031] Figure 2 For Figure 1 The A - A sectional connection structure diagram of

[0032] Figure 3 It is a cooperation structure diagram among the die sleeve, the moving tube, and the filler;

[0033] Figure 4 It is a top view connection structure diagram of the filler.

[0034] Figure 5 It is a top view connection structure diagram with three forming channels arranged on the die sleeve.

[0035] Figure 6 For Figure 5 B - B sectional connection structure diagram of

[0036] In the figure, 1 - lower positioning plug, 2 - upper positioning plug, 3 - core rod, 4 - die sleeve, 5 - moving tube, 6 - filler, 7 - filler through - slot, 8 - sleeve. Specific implementation manner

[0037] Next, in combination with the embodiments, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all 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.

[0038] Refer to Figures 1-6 , the present invention provides a technical solution:

[0039] A method for manufacturing an elongated tungsten alloy tube, comprising the following steps:

[0040] (1) Prepare the raw material of the tungsten alloy powder billet tube. The raw material of the tungsten alloy powder billet tube is tungsten alloy mixed powder or tungsten alloy granulated powder. Among them, there are two ways to add the raw material of the tungsten alloy powder billet tube into the mold. One is to directly add the tungsten alloy mixed powder into the mold; the other is to make the tungsten alloy mixed powder into tungsten alloy granulated powder and then add it into the mold in the form of tungsten alloy granulated powder. When directly adding the tungsten alloy mixed powder, it takes more time to shake and compact the tungsten alloy mixed powder in the mold, and at the same time, the dry - bag isostatic pressing equipment needs to provide a greater pressing force; if the tungsten alloy mixed powder is made into tungsten alloy granulated powder by adding a binder in the prior art, it is easier to shake when added to the mold, which can reduce the pressing force of the dry - bag isostatic pressing equipment, but the binder in the tungsten alloy powder billet tube needs to be removed during the subsequent sintering process.

[0041] (2) Fill the raw material of the tungsten alloy powder billet tube into the mold; the operation method of the mold includes the following steps.

[0042] (2.1) Seal and fix the lower positioning plug 1 at the lower end inside the forming channel.

[0043] (2.2) Insert the core rod 3 into the central part of the lower positioning plug 1. The lower positioning plug 1 is provided with a mounting hole, and the lower end of the core rod 3 is inserted into the mounting hole. The mounting hole cooperates with the core rod 3 and plays a role of limiting.

[0044] (2.3) The combination of the moving tube 5 and the filler 6 is sleeved on the core rod 3, and the filler 6 is placed in the middle and upper part of the mold sleeve 4. A through hole is coaxially arranged in the filler 6, and the end of the moving tube 5 is inserted into the through hole to fix the moving tube 5 and the filler 6 together. The lower end of the through hole is a tapered hole. The function of the tapered hole is to facilitate the sleeve of the filler 6 on the core rod 3. The inner wall of the moving tube 5 is coaxially arranged with the outer wall of the core rod 3 and contacts and fits together, thereby ensuring the coaxiality between the core rod 3 and the molding channel during the powder filling process.

[0045] (2.4) Add the raw material of tungsten alloy powder tube from the upper end of the forming channel. The raw material of tungsten alloy powder tube enters the forming channel through the filler slot 7. During the process of adding the raw material of tungsten alloy powder tube, perform a vibration operation. When the raw material of tungsten alloy powder tube is close to the filler 6, move the filler 6 to the upper end of the mold sleeve 4 for a distance, and then add the raw material of tungsten alloy powder tube and vibrate it. In this process, it is necessary to ensure that the raw material of tungsten alloy powder tube is added uniformly, and at the same time, ensure that the raw material of tungsten alloy powder tube in the forming channel is uniform and vibrated. It is also necessary to ensure the coaxiality between the forming channel and the core rod 3 after adding the raw material of tungsten alloy powder tube to prevent uneven wall thickness of the tungsten alloy powder tube after forming.

[0046] (2.5) When the filling height of the raw material of the tungsten alloy powder blank tube in the die sleeve 4 reaches 620~660mm, remove the filler 6. In this technology, the length of the die sleeve 4 is designed to be 720mm. If the height of the lower positioning plug 1 and the upper positioning plug 2 are both 30mm, then the filling height of the raw material of the tungsten alloy powder blank tube is 660mm; if the height of the lower positioning plug 1 and the upper positioning plug 2 are both 50mm, then the filling height of the raw material of the tungsten alloy powder blank tube is 620mm. The height of the lower positioning plug 1 and the upper positioning plug 2 is between 30 and 50mm, so the filling height of the raw material of the tungsten alloy powder blank tube in the forming channel in the die sleeve 4 is 620~660mm.

[0047] (2.6) The upper positioning plug 2 is sealed and fixed on the upper end of the forming channel, and the upper positioning plug 2 is pressed tightly on the upper surface of the raw material of the tungsten alloy powder blank tube. The upper positioning plug 2 is fixed to the upper end of the forming channel and sealed to prevent leakage during the pressing process.

[0048] (3) Place the mold into a dry bag isostatic pressing equipment, and then press the mold radially while not pressing axially. When the raw material of the tungsten alloy powder billet tube is tungsten alloy mixed powder, the pressure of the dry bag isostatic pressing equipment is 160 - 200 MPa; when the raw material of the tungsten alloy powder billet tube is tungsten alloy granulated powder, the pressure of the dry bag isostatic pressing equipment is 60 - 150 MPa. Among them, the dry bag isostatic pressing equipment is an existing technology. During operation, both ends of the die sleeve 4 are fixed inside the dry bag isostatic pressing equipment, so that both ends of the die sleeve 4 do not bear pressure, and only the radial direction of the die sleeve 4 bears pressure.

[0049] (4) After the pressing is completed, carry out the demolding work. After demolding, a tungsten alloy powder billet tube with an outer diameter of 33 - 230 mm, an inner diameter of 5 - 30 mm, and a length of 620 - 660 mm is obtained.

[0050] (5) Sinter the tungsten alloy powder billet tube to obtain a finished tungsten alloy tube. The finished tungsten alloy tube is cut into a specific length according to requirements to obtain the final tungsten alloy tube product.

[0051] The mold includes a lower positioning plug 1, an upper positioning plug 2, a core rod 3, a die sleeve 4, a moving tube 5, and a filler 6. There are several through-forming channels arranged inside the die sleeve 4. The lower positioning plug 1 is hermetically and fixedly arranged at the lower end of the forming channel, the upper positioning plug 2 is hermetically and fixedly arranged at the upper end of the forming channel. The core rod 3 is coaxially arranged inside the die sleeve 4 and is connected to the lower positioning plug 1 and the upper positioning plug 2 at both ends respectively. The filler 6 is coaxially and detachably sleeved on the core rod 3 and cooperates with the inner wall of the forming channel. The moving tube 5 is sleeved on the core rod 3 and its lower end is fixedly connected to the filler 6. There are several through-filler slots 7 arranged on the filler 6. Among them, the lower positioning plug 1, the upper positioning plug 2, and the die sleeve 4 are all made of polyurethane material, the core rod 3 is made of Cr12MoV, and the hardness of the core rod 3 is HRC50 - 55. The lower positioning plug 1 is used to seal the lower end of the forming channel, the upper positioning plug 2 is used to seal the upper end of the forming channel. A model cavity for manufacturing the tungsten alloy powder billet tube is formed between the lower positioning plug 1, the upper positioning plug 2, and the die sleeve 4. The moving tube 5 and the filler 6 are used when loading the raw material of the tungsten alloy powder billet tube. The moving tube 5 is used to drive the filler 6 to slide on the core rod 3. The filler 6 stabilizes the core rod 3 inside the forming channel, prevents the core rod 3 from bending during the powder filling process, and ensures the coaxiality of the core rod 3 and the forming channel. The filler slots 7 on the filler 6 facilitate the passage of the raw material of the tungsten alloy powder billet tube.

[0052] In some embodiments, the straightness of the core rod 3 is ≤ 0.03 / 100, the surface roughness of the core rod 3 is ≤ Ra0.8, and the inner wall roughness of the die sleeve 4 is ≤ Ra1.6. The thicknesses of the lower positioning plug 1 and the upper positioning plug 2 are both 30 - 50 mm. Among them, the outer diameter of the core rod 3 is 6 - 36 mm, the length is 710 - 712 mm, and the lower positioning plug 1 and the upper positioning plug 2 are both provided with mounting holes for mounting the core rod 3 and mating with the core rod 3. The length of the die sleeve 4 is 720 - 721 mm, the diameter of the forming channel on the die sleeve 4 is 42 - 242 mm, and the forming length of the tungsten alloy powder blank tube is 620 - 660 mm. Therefore, in order to obtain a tungsten alloy powder blank tube with better quality, there are roughness requirements for the inner walls of both the core rod 3 and the die sleeve 4.

[0053] In some embodiments, the outer diameter of the core rod 3 is d = d0 / (0.83 - 0.86). When the raw material of the tungsten alloy powder blank tube is tungsten alloy mixed powder, the inner diameter of the forming channel is D = (D0 + 5) / (0.68 - 0.70); when the raw material of the tungsten alloy powder blank tube is tungsten alloy granulated powder, the inner diameter of the forming channel is D = (D0 + 5) / (0.54 - 0.56), where d0 is the inner diameter of the finished tungsten alloy tube and D0 is the outer diameter of the finished tungsten alloy tube.

[0054] In some embodiments, a sleeve 8 is arranged in the forming channel. The two ends of the sleeve 8 are respectively in sealing fit with the lower positioning plug 1 and the upper positioning plug 2. The raw material of the tungsten alloy powder blank tube is filled between the inner wall of the sleeve 8 and the core rod 3. Among them, the sleeve 8 is made of polyurethane material. The sleeve 8 can be arranged between the lower positioning plug 1 and the upper positioning plug 2, or the lower positioning plug 1 and the upper positioning plug 2 can be arranged inside the two ends of the sleeve 8, so that tungsten alloy powder blank tubes with different diameters can be formed.

[0055] In some embodiments, six filling through slots 7 are evenly arranged on the filler 6. Among them, one filling through slot 7, two filling through slots 7, three filling through slots 7, four filling through slots 7, five filling through slots 7, six filling through slots 7, seven filling through slots 7 or eight filling through slots 7 can be arranged on the filler 6, and arranging six filling through slots 7 is the optimal choice. The raw material of the tungsten alloy powder blank tube is more evenly filled through the filling through slots 7.

[0056] In some embodiments, one forming channel is arranged in the die sleeve 4, or three forming channels are evenly arranged in the die sleeve 4. Among them, two forming channels, five forming channels and six forming channels can also be arranged in the die sleeve 4. The forming quality of the tungsten alloy powder blank tube is good with one forming channel and three forming channels.

[0057] Embodiment 1: The outer diameter of the slender tungsten alloy powder blank tube is 40 mm, the inner diameter is 6.8 mm, and the length is 620 mm; a die sleeve 4 with three forming channels is used. The outer diameter of the die sleeve 4 is 275 mm, the inner diameter of the forming channel is 62 mm, the diameter of the core rod 3 is 6.8 mm, the length of the die sleeve 4 is 720 mm, the length of the core rod 3 is 712 mm, the thicknesses of the lower positioning plug 1 and the upper positioning plug 2 are both 50 mm, the powder loading section length is 620 mm, the raw material of the tungsten alloy powder blank tube is tungsten alloy granulated powder, the pressing force of the dry bag isostatic pressing equipment is 100 MPa. After forming, the outer diameter of the tungsten alloy powder blank tube is 40 mm, the inner diameter is 6.8 mm, and the length is 620 mm. After sintering and cutting, three finished tungsten alloy tubes with an outer diameter of 34 mm, an inner diameter of 6 mm, and a length of 520 mm are obtained.

[0058] Embodiment 2: The outer diameter of the slender tungsten alloy powder blank tube is 50 mm, the inner diameter is 6.8 mm, and the length is 620 mm; a die sleeve 4 with three forming channels is used. The outer diameter of the die sleeve 4 is 275 mm, the inner diameter of the forming channel is 62 mm, the diameter of the core rod 3 is 6.8 mm, the length of the die sleeve 4 is 720 mm, the length of the core rod 3 is 712 mm, the thicknesses of the lower positioning plug 1 and the upper positioning plug 2 are both 50 mm, the powder loading section length is 620 mm, the raw material of the tungsten alloy powder blank tube is tungsten alloy mixed powder, the pressing force of the dry bag isostatic pressing equipment is 200 MPa. After forming, the outer diameter of the tungsten alloy powder blank tube is 50 mm, the inner diameter is 6.8 mm, and the length is 620 mm. After sintering and cutting, three finished tungsten alloy tubes with an outer diameter of 42 mm, an inner diameter of 6 mm, and a length of 520 mm are obtained.

[0059] Embodiment 3: The outer diameter of the slender tungsten alloy powder blank tube is 150 mm, the inner diameter is 24 mm, and the length is 620 mm; a die sleeve 4 with one forming channel is used. The outer diameter of the die sleeve 4 is 275 mm, the inner diameter of the forming channel is 230 mm, the diameter of the core rod 3 is 23.6 mm, the length of the die sleeve 4 is 720 mm, the length of the core rod 3 is 712 mm, the thicknesses of the lower positioning plug 1 and the upper positioning plug 2 are both 50 mm, the powder loading section length is 620 mm, the raw material of the tungsten alloy powder blank tube is tungsten alloy granulated powder, the pressing force of the dry bag isostatic pressing equipment is 100 MPa. After forming, the outer diameter of the tungsten alloy powder blank tube is 150 mm, the inner diameter is 23.6 mm, and the length is 620 mm. After sintering and cutting, one finished tungsten alloy tube with an outer diameter of 127 mm, an inner diameter of 20 mm, and a length of 520 mm is obtained.

[0060] Embodiment 4: The outer diameter of the slender tungsten alloy powder billet tube is 184 mm, the inner diameter is 24 mm, and the length is 620 mm; a die sleeve 4 with one forming channel is used, the outer diameter of the die sleeve 4 is 275 mm, the inner diameter of the forming channel is 230 mm, the diameter of the core rod 3 is 23.6 mm, the length of the die sleeve 4 is 720 mm, the length of the core rod 3 is 712 mm, the thicknesses of the lower positioning plug 1 and the upper positioning plug 2 are both 50 mm, the powder loading section length is 620 mm, the raw material of the tungsten alloy powder billet tube is tungsten alloy granulated powder, the pressing force of the dry bag isostatic pressing equipment is 100 MPa, the outer diameter of the formed tungsten alloy powder billet tube is 184 mm, the inner diameter is 23.6 mm, and the length is 620 mm. After sintering and cutting, a finished tungsten alloy tube with an outer diameter of 156 mm, an inner diameter of 20 mm, and a length of 520 mm is obtained.

[0061] The finished tungsten alloy tube is processed by drilling a solid rod:

[0062] Control Example 1: The finished tungsten alloy tube with an outer diameter of 34 mm, an inner diameter of 6 mm, and a length of 520 mm cannot be drilled through;

[0063] Control Example 2: The finished tungsten alloy tube with an outer diameter of 42 mm, an inner diameter of 6 mm, and a length of 520 mm cannot be drilled through;

[0064] Control Example 3: For the finished tungsten alloy tube with an outer diameter of 127 mm, an inner diameter of 20 mm, and a length of 520 mm, after turning the outer circle, drilling is carried out at both ends, and the connection part is misaligned. It takes 5 days, and the machining cost is 3,500 yuan per piece;

[0065] Control Example 4: For the finished tungsten alloy tube with an outer diameter of 156 mm, an inner diameter of 20 mm, and a length of 520 mm, after turning the outer circle, drilling is carried out at both ends, and the connection part is misaligned. It takes 5.5 days, and the machining cost is 4,000 yuan per piece.

[0066] The slender tungsten alloy powder billet tube with a prefabricated hole is directly manufactured by cold isostatic pressing:

[0067] Control Example 1: The outer diameter of the slender tungsten alloy powder billet tube is 40 mm, the inner diameter is 6.8 mm, and the length is 620 mm. Both the tungsten alloy powder billet tube and the core rod 3 are bent, the tungsten alloy powder billet tube fails to demold and breaks. Tungsten alloy tubes with a length of ≤ 200 mm can be made;

[0068] Control Example 2: The outer diameter of the slender tungsten alloy powder billet tube is 50 mm, the inner diameter is 6.8 mm, and the length is 620 mm. Both the tungsten alloy powder billet tube and the core rod 3 are bent, the tungsten alloy powder billet tube fails to demold and breaks. Tungsten alloy tubes with a length of ≤ 200 mm can be made;

[0069] Comparative Example 3: The outer diameter of the slender tungsten alloy powder blank tube is 150 mm, the inner diameter is 24 mm, and the length is 620 mm. Both the tungsten alloy powder blank tube and the core rod 3 are bent, and it is very difficult to demold the tungsten alloy powder blank tube. Tungsten alloy tubes with a length of ≤ 200 mm can be made;

[0070] Comparative Example 4: The outer diameter of the slender tungsten alloy powder blank tube is 184 mm, the inner diameter is 24 mm, and the length is 620 mm. Both the tungsten alloy powder blank tube and the core rod 3 are bent, and it is very difficult to demold the tungsten alloy powder blank tube. Tungsten alloy tubes with a length of ≤ 200 mm can be made.

[0071] The intact rate of the slender tungsten alloy powder blank tube prepared by the present invention is 100%, and the success rate of preparation is far better than that of the solid drilling and cold isostatic pressing prefabricated hole forming methods.

[0072] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "inner", "front part", "center", "both ends", etc. is based on the orientation or positional relationship shown in the drawings. It 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. Therefore, it should not be construed as a limitation to the present invention.

[0073] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "setting", "connection", "fixation", "hinged connection", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the internal communication of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, 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 situations.

[0074] The above description is only the preferred embodiment 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. Instead, it 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 the changes and alterations made by those skilled in the art that do not depart from the spirit and scope of the present invention should all be within the protection scope of the appended claims of the present invention.

Claims

1. A method for manufacturing an elongated tungsten alloy tube, characterized in that, It includes the following steps: S1: Prepare the raw material of the tungsten alloy powder billet tube, and the raw material of the tungsten alloy powder billet tube is tungsten alloy mixed powder or tungsten alloy granulated powder; S2: Fill the raw material of the tungsten alloy powder billet tube into the mold; S3: Place the mold into a dry bag isostatic pressing device, and then press the radial direction of the mold, without pressing the axial direction of the mold; S4: After the pressing is completed, carry out the demolding work. After demolding, a tungsten alloy powder billet tube with an outer diameter of 33 - 230 mm, an inner diameter of 5 - 30 mm, and a length of 620 - 660 mm is obtained; S5: Sinter the tungsten alloy powder billet tube to obtain a finished tungsten alloy tube; The mold includes a lower positioning plug (1), an upper positioning plug (2), a core rod (3), a die sleeve (4), a moving tube (5), and a filler (6). A number of through - forming channels are arranged in the die sleeve (4). The lower positioning plug (1) is hermetically and fixedly arranged at the lower end of the forming channel, the upper positioning plug (2) is hermetically and fixedly arranged at the upper end of the forming channel. The core rod (3) is coaxially arranged in the die sleeve (4) and is connected to the lower positioning plug (1) and the upper positioning plug (2) at both ends respectively. The filler (6) is coaxially and detachably sleeved on the core rod (3) and cooperates with the inner wall of the forming channel. The moving tube (5) is sleeved on the core rod (3) and the lower end is fixedly connected to the filler (6). A number of through - filler slots (7) are arranged on the filler (6).

2. The manufacturing method of an elongated tungsten alloy tube according to claim 1, characterized in that: The straightness of the core rod (3) is ≤0.03 / 100, the surface roughness of the core rod (3) is ≤Ra0.8, and the inner wall roughness of the die sleeve (4) is ≤Ra1.

6.

3. A method for manufacturing an elongated tungsten alloy tube according to claim 1 or 2, characterized in that: The thickness of both the lower positioning plug (1) and the upper positioning plug (2) is 30 - 50 mm.

4. A method for manufacturing an elongated tungsten alloy tube according to claim 1 or 2, characterized in that: The outer diameter of the core rod (3) is d = d0 / (0.83 - 0.86). When the raw material of the tungsten alloy powder billet tube is the tungsten alloy mixed powder, the inner diameter of the forming channel is D=(D0 + 5) / (0.68 - 0.70); when the raw material of the tungsten alloy powder billet tube is the tungsten alloy granulated powder, the inner diameter of the forming channel is D=(D0 + 5) / (0.54 - 0.56), where d0 is the inner diameter of the finished tungsten alloy tube and D0 is the outer diameter of the finished tungsten alloy tube.

5. A method for manufacturing an elongated tungsten alloy tube according to claim 1 or 2, characterized in that: A sleeve (8) is arranged in the forming channel. Both ends of the sleeve (8) are hermetically fitted with the lower positioning plug (1) and the upper positioning plug (2) respectively. The raw material of the tungsten alloy powder billet tube is filled between the inner wall of the sleeve (8) and the core rod (3).

6. A method for manufacturing an elongated tungsten alloy tube according to claim 1 or 2, characterized in that: Six of the filler slots (7) are evenly arranged on the filler (6).

7. A method for manufacturing an elongated tungsten alloy tube according to claim 1 or 2, characterized in that: The operation method of the mold includes the following steps, S2.1: Hermetically and fixedly arrange the lower positioning plug (1) inside the lower end of the forming channel; S2.2: Insert the core rod (3) into the central part of the lower positioning plug (1); S2.3: Sheath the combination of the movable tube (5) and the filler (6) onto the core rod (3), and position the filler (6) at the upper middle part of the die sleeve (4); S2.4: Add the tungsten alloy green tube raw material from the upper end of the forming channel. The tungsten alloy green tube raw material enters the forming channel through the filler through slots (7). During the process of adding the tungsten alloy green tube raw material, perform a compaction operation. When the tungsten alloy green tube raw material approaches the filler (6), move the filler (6) a certain distance upward along the die sleeve (4), then add the tungsten alloy green tube raw material again and compact it; S2.5: When the filling height of the tungsten alloy green tube raw material in the die sleeve (4) reaches 620 - 660 mm, remove the filler (6); S2.6: Sealingly fix the upper positioning plug (2) at the upper end of the forming channel, and press the upper positioning plug (2) against the upper surface of the tungsten alloy green tube raw material.

8. A method for manufacturing an elongated tungsten alloy tube according to claim 1 or 2, characterized in that: One forming channel is provided in the die sleeve (4), or three forming channels are evenly provided in the die sleeve (4).

9. A method for manufacturing an elongated tungsten alloy tube according to claim 1 or 2, characterized in that: When the tungsten alloy green tube raw material is the tungsten alloy mixed powder, the pressure of the dry bag isostatic pressing equipment is 160 - 200 MPa; when the tungsten alloy green tube raw material is the tungsten alloy granulated powder, the pressure of the dry bag isostatic pressing equipment is 60 - 150 MPa.

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