Efficient tungsten filament drawing process and electric drawing and gas annealing eleven-mold all-in-one machine

Abstract

The invention discloses an efficient tungsten filament drawing process and an electric drawing and gas annealing eleven-die all-in-one machine, and the efficient tungsten filament drawing process comprises the following steps: hot drawing: heating a tungsten lanthanum alloy with the wire diameter of 0.360-0.390 mm to 800-840 DEG C, and drawing the tungsten lanthanum alloy through a die at the area reduction rate of 16%-22% to obtain a tungsten filament with the wire diameter of 0.150-0.170 mm; annealing and stretching: annealing the tungsten filament subjected to hot stretching at the temperature of 1450-1500 DEG C, and then stretching the tungsten filament to 0.125-0.135 mm through a mold; the wires obtained in the annealing and stretching steps are subjected to electrolytic alkali washing to obtain white wires with the diameter ranging from 0.118 mm to 0.122 mm; electroplating: electroplating a nickel-zinc-copper alloy layer on the wire material subjected to alkali washing until the thickness is 0.124-0.126 mm; and cold drawing is conducted, specifically, the electroplated wire is subjected to multi-pass cold drawing at the room temperature through a mold with the area reduction rate of 12%-18%, the wire is drawn to the target wire diameter, and the target wire diameter is smaller than 28 micrometers. According to the method, the tungsten filament is subjected to structure reconstruction when the diameter of the tungsten filament is large, the machining rate of a follow-up cold drawing section is increased, and the strength of a final finished product can reach 6909 MPa and is far higher than that of a traditional process.

Description

Technical Field

[0001] This invention relates to the field of tungsten wire drawing technology, specifically to a high-efficiency tungsten wire drawing process and an integrated electro-drawing and pneumatic de-drawing die machine. Background Technology

[0002] Compared to hot drawing, cold drawing of tungsten wire has the following advantages: it completely eliminates recrystallization embrittlement, retains the fibrous fine-grained structure after work hardening, and has higher tensile strength and better toughness; hot drawing significantly increases the breakage rate when the wire diameter is below Φ0.06mm, while cold drawing can stably draw ultra-fine tungsten wires of Φ0.02mm or even finer; cold drawing, combined with diamond molds, can achieve a surface roughness of Ra below 0.1μm, and there is no risk of hydrogen embrittlement; the wire diameter tolerance of cold drawing can be stably maintained within ±1μm, with high precision; and there is no need to maintain a high-temperature furnace of 1000 degrees Celsius, which greatly reduces energy consumption.

[0003] In existing technologies, the hot-drawing process typically requires the use of large and medium ten-die machines in stages. For example, in the hot-drawing section, a 0.36mm tungsten wire is drawn to 0.18mm using a large ten-die machine; the 0.18mm wire is drawn to 0.065mm using a medium ten-die machine, and then the 0.065mm wire is cleaned to 0.060mm white wire; in the cold-drawing section, a 0.06mm wire is electroplated to 0.062mm, and the 0.062mm copper-plated wire is then drawn to various specifications of tungsten wire smaller than 28µm (this process is called Process A). However, Process A has the following drawbacks: 1. The efficiency of electrolytic alkaline washing and electroplating for fine wire segments (such as 0.065mm) is extremely low, resulting in excessively high production costs; 2. In the traditional hot-drawing process, high temperatures easily lead to grain coarsening, and if annealing is not properly controlled, it can result in insufficient strength of the finished product; 3. The equipment layout is scattered, the process is cumbersome, and it is difficult to achieve efficient continuous production. Therefore, how to improve the strength of tungsten wire while reducing costs through equipment integration and process innovation is an urgent problem to be solved in this field. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a high-efficiency tungsten wire drawing process and its matching electric drawing and pneumatic deflection eleven-die integrated machine, so as to solve the problems of low efficiency, high cost and limited strength of finished products in the prior art.

[0005] On the one hand, a high-efficiency tungsten wire drawing process is provided, comprising the following steps: hot drawing: heating a tungsten-lanthanum alloy with a wire diameter of 0.360-0.390 mm to a temperature of 800-840℃, and drawing it through a die with a reduction rate of 16%-22% to a tungsten wire with a wire diameter of 0.150-0.170 mm; annealing and stretching: annealing the hot-drawn tungsten wire at a temperature of 1450-1500℃, and then drawing it through a die to a diameter of 0.125-0.135 mm; electrolytic alkaline washing: electrolytically washing the wire obtained in the annealing and stretching steps to a white wire of 0.118-0.122 mm; electroplating: electroplating the alkaline-washed wire with a nickel-zinc-copper alloy layer to a diameter of 0.124-0.126 mm; cold drawing: performing multiple cold drawing passes through a die at room temperature with a reduction rate of 12%-18% to a target wire diameter, wherein the target wire diameter is less than 28 μm.

[0006] Preferably, the method includes the following steps: hot drawing: drawing a tungsten-lanthanum alloy with a wire diameter of 0.36 mm at 840°C with a reduction rate of 16%-22% to a tungsten wire with a wire diameter of 0.16 mm; annealing and stretching: annealing the hot-drawn tungsten wire at 1450°C, and then stretching it through a die to 0.13 mm; electrolytic alkaline washing: electrolytically washing the wire obtained in the annealing and stretching steps to a white wire of 0.12 mm; electroplating: electroplating the alkaline-washed wire with a nickel-zinc-copper alloy layer to 0.126 mm; cold drawing: performing multiple cold drawing operations at room temperature to draw the coated wire to 0.027 mm with a reduction rate of 15%.

[0007] Preferably, the tungsten-lanthanum alloy is a tungsten alloy busbar with a lanthanum oxide content of 0.60%-0.80%.

[0008] Preferably, in the hot drawing, annealing and stretching steps, the mold temperature is 400-450℃; in the cold drawing step, the mold is at room temperature.

[0009] On the other hand, an eleven-die integrated electric drawing and pneumatic annealing machine is also provided for processing and producing tungsten wire using any of the above-described high-efficiency drawing processes. The machine includes: a wire feeding mechanism for providing tungsten wire coils; a drawing mechanism including dies 1 to N set within the same die frame, and a roller assembly cooperating with the dies 1 to N for continuously drawing the tungsten wire through the 1st to Nth passes; an electric furnace set at the front end of the dies 1 to N for heating the tungsten wire through the 1st to Nth passes; an annealing drawing mechanism including a gas-heated grate and a die N+1 set within the die frame, the gas-heated grate being set at the front end of the die N+1 for heating and annealing the tungsten wire after the Nth pass and performing the N+1th pass drawing; and a wire take-up assembly for collecting the finished tungsten wire after the N+1th pass drawing; wherein the roller assembly is used for the Nth to N+1th passes of drawing, where N≥2.

[0010] Preferably, it also includes a shared graphite emulsion coating device, wherein the electric furnace and the gas-heated grate are arranged side by side, and the graphite emulsion coating device is located at the front end of the electric furnace and the gas-heated grate, for coating graphite emulsion before each tungsten wire drawing.

[0011] Preferably, the drawing mechanism further includes a large guide wheel and a small guide wheel; the wire threading paths for the first to Nth passes are as follows: the first pass of the large guide wheel, the graphite emulsion coating device, the electric furnace, the first mold, the small guide wheel and the first pass of the tower wheel assembly, the second pass of the large guide wheel, the graphite emulsion coating device... and so on until the Nth pass of the tower wheel assembly; the wire threading paths for the Nth to N+1th passes are as follows: the Nth pass of the tower wheel assembly, the N+1th pass of the large guide wheel, the graphite emulsion coating device, the gas-heated grate, the N+1th mold, the small guide wheel, the N+1th pass of the tower wheel assembly and the wire take-up assembly.

[0012] Preferably, the gas-heated grate has a main groove and a gas supply pipe connected to the main groove. The bottom of the main groove is provided with a plurality of gas holes evenly arranged along the layout direction of the main groove, and the plurality of gas holes are respectively connected to the gas supply pipe. The main groove is located on the stretching path of the N+1th pass.

[0013] Preferably, the device further includes an encoder assembly mounted between the pulley assembly and the take-up assembly for measuring the length of the tungsten wire.

[0014] Preferably, the take-up assembly includes an I-beam take-up machine and a guide rail. The bottom of the I-beam take-up machine is connected to the guide rail, and the I-beam take-up machine slides left and right on the guide rail to achieve uniform take-up.

[0015] Compared to existing technologies, the advantages of this invention are as follows: By integrating electric heating drawing with gas heating annealing drawing, continuous drawing with a large span from 0.36mm to 0.13mm is achieved on a single machine, thus eliminating the need for the ten-die machine process required in traditional processes, significantly reducing equipment investment and production costs. Secondly, the use of a gas-heated grate for high-temperature annealing at 1450-1500℃, combined with drawing using the 11th die, allows the tungsten wire to complete microstructure reconstruction at a larger wire diameter (0.13mm), improving the processing efficiency of the subsequent cold drawing stage. The final product strength can reach 6909MPa, far exceeding that of traditional processes. Thirdly, due to the increased starting wire diameter for cold drawing (starting from 0.12mm instead of the existing 0.065mm), the efficiency of electrolytic alkaline washing and electroplating is significantly improved, and the increased number of cold drawing passes further strengthens the fibrous fine-grained structure, reducing the photovoltaic wire breakage rate from 5.56% to 2.79%. Attached Figure Description

[0016] Figure 1This is a flowchart of a high-performance tungsten wire drawing process according to an embodiment of this application;

[0017] Figure 2 This is a schematic diagram of the structure of an eleven-die integrated electro-extraction and pneumatic retraction machine according to an embodiment of this application; Figure 3 This is a schematic diagram of a gas-heated grate structure according to an embodiment of this application.

[0018] In the figure, 10 is the wire feeding mechanism; 20 is the large guide wheel; 30 is the mold frame; 40 is the tower wheel assembly; 50 is the drive mechanism; 60 is the electric furnace; 70 is the electrical controller; 80 is the gas-heated grate; 81 is the main trough; 82 is the gas supply pipe; 83 is the gas vent; 90 is the wire take-up assembly; 91 is the I-beam reel take-up machine; 92 is the guide rail; 100 is the graphite emulsion coating device; small guide wheel (110); and 120 is the encoder assembly. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0021] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0022] This application provides a high-performance tungsten wire drawing process, including the following steps: Hot drawing: Tungsten-lanthanum alloy with a wire diameter of 0.360-0.390mm is heated to a temperature of 800-840℃ and drawn through a die with a reduction rate of 16%-22% to a tungsten wire with a wire diameter of 0.150-0.170mm; During hot drawing, the tungsten wire is in a plastic state, which rapidly reduces the wire diameter and improves efficiency.

[0023] Annealing and stretching: The hot-drawn tungsten wire is annealed at a temperature of 1450-1500℃, and then stretched through a die to 0.125-0.135mm; High-temperature annealing of tungsten wire eliminates the internal stress of the tungsten wire after hot drawing, allowing atoms to diffuse through heating and heat preservation, restoring the internal structure of the material from a "chaotic and tense" state to a "stable and relaxed" state, and finally preserving this state through slow cooling.

[0024] Electrolytic alkali washing: The filaments obtained from the annealing and stretching steps are electrolytically alkali washed until they become 0.118-0.122mm white filaments; During the heating process, oxides are generated on the surface of the tungsten wire. Electrolytic alkaline washing removes the oxides and stains from the surface, resulting in a smooth surface that facilitates the next step of electroplating, creating a "white wire".

[0025] Electroplating: Electroplating a nickel-zinc-copper alloy layer onto the alkaline-washed wire to a thickness of 0.124-0.126 mm; To enhance the tensile strength of the tungsten wire and prevent it from breaking.

[0026] Cold drawing: The electroplated wire is cold drawn multiple times at room temperature through a die with a reduction rate of 12%-18% to the target wire diameter, which is less than 28μm.

[0027] By refining the grains of tungsten wire through multiple cold drawing processes and maintaining a fibrous fine-grained structure, the strength of tungsten wire is enhanced and the surface roughness of tungsten wire is reduced.

[0028] Example 1 High-performance tungsten wire drawing process (Process B), reference Figure 1 This includes the following steps: (1) Hot drawing: Tungsten lanthanum alloy with a lanthanum oxide content of 0.60%-0.80% and a wire diameter of 0.36mm is drawn to a tungsten wire with a wire diameter of 0.16mm at a temperature of 840℃ with a 20% reduction in surface area. The die temperature is 400-450℃. (2) Annealing and stretching: The hot-drawn tungsten wire is annealed at 1450℃ and then stretched to 0.13mm through a die at a temperature of 400-450℃. (3) Electrolytic alkali washing: The filaments obtained from the annealing and stretching steps are electrolytically alkali washed until they are 0.12mm white; (4) Electroplating: Electroplating a nickel-zinc-copper alloy layer onto the alkaline-washed wire to a thickness of 0.126 mm; (5) Cold drawing: The coated wire is cold drawn multiple times at room temperature to a diameter of 0.027 mm with a 15% reduction in surface area. The mold temperature is room temperature. Graphite emulsion is applied before each molding process.

[0029] Ten coils of 0.36mm tungsten-lanthanum alloy were selected from both process A and process B for drawing to 27µm for comparison and cutting experiments. Data for process A, drawing from 0.36mm to 0.18mm. Data for process A, drawn from 0.18mm to 0.065mm. Process A involves washing the 0.065mm diameter material to 0.060mm, then copper plating to 0.062mm, and finally cold drawing to 0.027mm. Process B involves drawing from 0.36mm to 0.16mm, then annealing and drawing again to 0.13mm. Process B involves washing the 0.130mm diameter surface to 0.120mm, then copper plating to 0.126mm, and finally cold drawing to 0.027mm. Based on the data, the 0.36mm tungsten-lanthanum alloy wire of process B, drawn to 0.16mm using the electric drawing and pneumatic annealing eleven-die integrated machine of this invention at a temperature of 840°C, and then annealed and drawn to 0.130mm using a die at a temperature of 1450°C, has an average strength of 3232MPa. This is quite close to the average strength of 3228MPa of the 0.36mm tungsten-lanthanum alloy wire of process A, drawn to 0.18mm using a large ten-die machine at a temperature of 840°C. However, the wire diameter after drawing by process B is finer than that of process A. This indicates that although process B involves annealing, which slightly reduces the strength compared to other processes with the same wire diameter, the strength of process B increases rapidly from 0.130mm to 0.120mm, then copper-plated to 0.126mm, and finally cold-drawn to 0.027mm. The average strength is 6909MPa, which is much higher than the average strength of 6717MPa of process A when drawn to the final specification of 0.027mm. This is because process B starts with a larger wire diameter and more cold-drawing passes when drawing from 0.126mm to 0.027mm compared to process A when drawing from 0.062mm to 0.027mm. The multiple cold-drawing passes strengthen the hardened fibrous fine-grained structure, resulting in a faster and more significant increase in strength.

[0030] Comparison of wire breakage rates between silicon wafers cut from process A and process B after drawing to 0.027 mm diameter and undergoing sandblasting. The data in the table above shows that the tungsten wire produced by process B has a more uniform structure, higher strength, better reliability, and a significantly reduced wire breakage rate, demonstrating clear advantages.

[0031] Example 2 Verification of the lower limit of the hot-drawn temperature (800℃) According to the method of Example 1, the electric heating temperature of the main wire cyclic drawing in step (1) was adjusted to 800℃, while other parameters remained unchanged: the wire diameter after hot drawing was 0.16mm, the annealing temperature was adjusted to 1480℃ and drawn to 0.130mm, the alkali washing was to 0.120mm, the electroplating was to 0.126mm, and the cold drawing was to 0.027mm.

[0032] The strength of the 10 rolls of tungsten wire obtained was tested, and the average tensile strength was 6923 MPa, while the average wire breakage rate during silicon wafer cutting was 2.72%. The results show that the strength of the tungsten wire is enhanced at the lower limit of the hot-drawing temperature, and the wire breakage rate is less than 3%, which meets the cutting requirements.

[0033] Example 3: Verification of the lower limit of annealing temperature (1450℃) Following the method of Example 1, only the temperature of the gas-fired grate in step (2) of annealing and drawing was adjusted to 1450°C, while other parameters remained unchanged.

[0034] The average tensile strength of the 10 rolls of tungsten wire obtained was 6862 MPa, and the average wire breakage rate when cutting silicon wafers was 3.02%. The strength decreased slightly after the annealing temperature was lowered, but it was still significantly better than process A, with the wire breakage rate controlled at around 3%.

[0035] Example 4: Verification of the upper limit of annealing temperature (1500℃) Following the method of Example 1, only the temperature of the gas-fired grate in step (2) of annealing and drawing is adjusted to 1500℃, while other parameters remain unchanged.

[0036] The average tensile strength of the 10 rolls of tungsten wire obtained was 6898 MPa, and the average wire breakage rate when cutting silicon wafers was 2.85%. This indicates that appropriately increasing the annealing temperature helps to further refine the grains and improve the strength of the tungsten wire during the subsequent cold drawing process.

[0037] Example 5: Verification of the lower limit of cold-drawn surface reduction rate (12%) Following the method of Example 1, only the surface reduction rate of each pass in the cold drawing process of step (5) is adjusted to 12% (by increasing the number of passes to keep the total deformation constant), and the drawing is made to 0.027mm.

[0038] The average tensile strength of the 10 rolls of tungsten wire obtained was 6955 MPa, and the average wire breakage rate when cutting silicon wafers was 2.41%. Appropriately reducing the area reduction ratio can enhance work hardening.

[0039] Example 6: Verification of the upper limit of cold-drawn surface reduction rate (18%) Following the method of Example 1, only the surface reduction rate of each pass in the cold drawing process of step (5) is adjusted to 18%, and the drawing is reduced to 0.027mm.

[0040] The average tensile strength of the obtained 10 coils of tungsten wire is 6851 MPa, and the average wire breakage rate of the cut silicon wafers is 3.11%. After the area reduction rate is increased, the work hardening effect is slightly weaker, but the strength is still higher than that of Process A.

[0041] Example 7: Verification of different combinations of raw wire diameters According to the method of Example 1, change the raw wire diameter to 0.39 mm. In step (1), hot draw it to 0.17 mm, in step (2), anneal and draw it to 0.135 mm, alkali wash it to 0.122 mm, electroplate it to 0.126 mm, and cold draw it to 0.027 mm.

[0042] The average tensile strength of the obtained 10 coils of tungsten wire is 6919 MPa, and the average wire breakage rate of the cut silicon wafers is 2.75%. It shows that this process is also applicable to different initial wire diameters.

[0043] The above examples prove that within the limited parameter range, the process of the present invention can obtain high-performance tungsten wires with a tensile strength ≥ 6850 MPa and a wire breakage rate ≤ 3.11%, which is significantly better than the existing Process A.

[0044] On the other hand, the present invention also provides equipment配套 with the process production, an electric drawing and gas annealing eleven-mode integrated machine, including: A wire feeding mechanism 10, used to provide tungsten wire coils, specifically a damping wire feeding reel, which is convenient for the stretching and drawing of tungsten wire.

[0045] A drawing mechanism, including a large guide wheel 20, the first to tenth dies arranged in the same die holder 30, and a capstan assembly 40 cooperating with the first to tenth dies. The drawing mechanism is used for continuous drawing of tungsten wire in the first to tenth passes; among them, the capstan assembly 40 is also connected to a driving mechanism 50 through a belt or chain drive. The driving mechanism 50 provides power to drive the capstan assembly 40 to pull the tungsten wire; the die is used to limit the cross-sectional area through which the tungsten wire passes and draw and reduce the area of the tungsten wire. An electric furnace 60, arranged at the front end of the first to tenth dies for the tungsten wire to pass through, used to heat the tungsten wire in the first to tenth passes to the required temperature (such as 840 °C), and at the same time dry the graphite emulsion on the tungsten wire for subsequent drawing and area reduction; the electric furnace 60 is signal-connected to an electrical controller 70. The electrical controller 70 is a PLC (Programmable Logic Controller), and a PID (Proportional Integral Derivative) algorithm program is programmed on the PLC. The electrical controller 70 dynamically regulates the temperature in the electric furnace 60 to be maintained within the range of the set value ± 5 °C based on the PID algorithm.

[0046] The annealing and drawing mechanism includes a gas-heated grate 80 and an 11th die disposed within the die frame 30. The gas-heated grate 80 is disposed at the front end of the 11th die. The gas-heated grate 80 is used to heat and anneal the tungsten wire after the 10th drawing pass. The 11th die is used to perform the 11th drawing pass. Among them, reference Figure 3 The gas-heated grate 80 has a main groove 81 and two gas supply pipes 82 connected to the main groove. The bottom of the main groove 81 has multiple gas holes 83 evenly arranged along the groove's direction, each connected to a gas supply pipe 82. The main groove 81 is located on the (N+1)th pass of the stretching path. The gas-heated grate 80 is also connected to an electrical controller 70. The electrical controller 70 has a built-in PID algorithm program that dynamically calculates and outputs a control signal to an electric proportional valve based on the deviation between the set temperature and the measured temperature. The electric proportional valve then precisely adjusts the mixing ratio of natural gas and compressed air supplied to the gas-heated grate 80, thereby instantly adjusting the temperature and heat output of the combustion flame.

[0047] As can be seen from the above description, an electric furnace is used to heat the tungsten wire during the hot drawing process, while gas heating is used during the annealing process. This choice is mainly based on practical application. Electric furnaces have the advantages of higher temperature control precision and ease of implementation, but they can only provide temperatures below 1200℃, which is difficult to reach the annealing temperature of tungsten wires. Therefore, gas heating is used during the annealing process. However, under the control of the electrical controller 70, the temperature of the gas-heated grate 80 can still be controlled within the set value ±5℃.

[0048] The large guide wheel 20 has 11 passes, which are used to guide the tungsten wire from the wire feeding mechanism to the first pass and to guide the tungsten wire from the tower wheel assembly 40 to the next pass of the large guide wheel. After the tungsten wire is stretched by the die, it is pulled back to the large guide wheel and then stretched by the die in the next pass. This allows a single tungsten wire to be circulated and wound on the equipment, and to perform multi-pass processing of the tungsten wire in a continuous flow operation, thereby improving efficiency.

[0049] It also includes a wire take-up assembly 90 for collecting the finished tungsten wire after the 11th drawing pass; wherein, the pulley assembly is used for the drawing passes from the 1st to the 11th. In this embodiment, the large guide wheel, the die, and the pulley each have 11 passes. In other embodiments, 7-8 passes or more, up to 12-15 passes, can be set according to actual needs.

[0050] In a preferred embodiment of this application, a shared graphite emulsion coating device 100 is also included. The electric furnace 60 and the gas-heated grate 80 are arranged side by side. The graphite emulsion coating device 100 is located at the front end of the electric furnace and the gas-heated grate. The tungsten wire is dried by the heating of the electric furnace and the gas-heated grate, so that the graphite is evenly distributed on the tungsten wire. At the same time, it is also used to coat the tungsten wire with graphite emulsion before each time it passes through the mold, thereby enhancing the lubricity of the tungsten wire and reducing the probability of the tungsten wire breaking during the stretching process.

[0051] In this embodiment, the drawing mechanism further includes a small guide wheel 110, which is disposed between the die frame 30 and the tower wheel 40. The wire threading paths from the 1st to the 10th passes are as follows: wire feeding mechanism 10, the first pass of the large guide wheel 20, the graphite emulsion coating device 100, the electric furnace 60, the first die in the die frame 30, the small guide wheel 110 and the first pass of the tower wheel assembly 40, the second pass of the large guide wheel 20, the graphite emulsion coating device 100... and so on until the 10th pass of the tower wheel assembly. The wire threading paths from the 10th to the 11th passes are as follows: the 10th pass of the tower wheel assembly, the 11th pass of the large guide wheel, the graphite emulsion coating device, the gas-heated grate, the 11th die, the small guide wheel, the 11th pass of the tower wheel assembly, and the wire take-up assembly. It should be noted that the tungsten wire is no longer pulled back to the large guide wheel from the tower wheel assembly by passing through the electric furnace and gas-heated grate, but instead passes through the bottom of the electric furnace and gas-heated grate.

[0052] In a preferred embodiment of this application, an encoder assembly 120 is further included, which is installed between the roller assembly and the take-up assembly for measuring the length of the tungsten wire.

[0053] In a preferred embodiment of this application, the take-up assembly 90 includes a spool take-up machine 91 and a guide rail 92. The bottom of the spool take-up machine is movably connected to the guide rail, so that the spool take-up machine reciprocates on the guide rail 92, so that the wire is evenly distributed and wound around the spool take-up machine.

[0054] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A high-efficiency tungsten wire drawing process, characterized in that, Includes the following steps: Hot drawing: Tungsten-lanthanum alloy with a wire diameter of 0.360-0.390mm is heated to a temperature of 800-840℃ and drawn through a die with a reduction rate of 16%-22% to a tungsten wire with a wire diameter of 0.150-0.170mm; Annealing and stretching: The hot-drawn tungsten wire is annealed at a temperature of 1450-1500℃, and then stretched through a die to 0.125-0.135mm; Electrolytic alkali washing: The filaments obtained from the annealing and stretching steps are electrolytically alkali washed until they become 0.118-0.122mm white filaments; Electroplating: Electroplating a nickel-zinc-copper alloy layer onto the alkaline-washed wire to a thickness of 0.124-0.126 mm; Cold drawing: The electroplated wire is cold drawn multiple times at room temperature through a die with a reduction rate of 12%-18% to the target wire diameter, which is less than 28μm.

2. The high-efficiency tungsten wire drawing process as described in claim 1, characterized in that, Includes the following steps: Hot drawing: A tungsten-lanthanum alloy with a wire diameter of 0.36 mm is drawn to a tungsten wire with a wire diameter of 0.16 mm at a temperature of 840℃ with a 20% reduction in surface area; Annealing and stretching: The hot-drawn tungsten wire is annealed at 1450℃ and then stretched to 0.13mm through a die; Electrolytic alkali washing: The filaments obtained from the annealing and stretching steps are electrolytically alkali washed until they turn into 0.12mm white filaments; Electroplating: Electroplating a nickel-zinc-copper alloy layer onto the alkaline-washed wire to a thickness of 0.126 mm; Cold drawing: The coated wire is cold drawn multiple times at room temperature to a diameter of 0.027 mm with a 15% reduction in surface area; The tungsten wire is coated with graphite emulsion before each drawing process.

3. The high-efficiency tungsten wire drawing process as described in claim 2, characterized in that, The tungsten-lanthanum alloy is a tungsten alloy busbar with a lanthanum oxide content of 0.60%-0.80%.

4. The high-efficiency tungsten wire drawing process as described in claim 2, characterized in that, During the hot drawing, annealing, and stretching processes, the mold temperature is 400-450℃; during the cold drawing process, the mold temperature is room temperature.

5. An integrated electric drawing and pneumatic retraction die-cutting machine, characterized in that, The device is used to process and produce tungsten wire using the high-efficiency drawing process of any one of claims 1-4, comprising: a wire feeding mechanism (10) for providing tungsten wire coils; The drawing mechanism includes 1 to N dies arranged in the same die frame (30) and a pulley assembly (40) cooperating with the 1 to N dies for continuously drawing tungsten wire in 1 to N passes; An electric furnace (60) is installed at the front end of the first to Nth molds for heating the tungsten wires in the first to Nth passes; The annealing and drawing mechanism includes a gas-heated grate (80) and an N+1th mold disposed in the mold frame (30). The gas-heated grate (80) is disposed at the front end of the N+1th mold and is used to heat and anneal the tungsten wire after the Nth drawing pass and to perform the N+1th drawing pass. And a wire take-up assembly (90) for collecting the finished tungsten wire after the N+1th drawing pass; The pulley assembly (40) is used for the pulling of the Nth to N+1th passes, where N≥2.

6. The integrated electro-extraction and pneumatic retraction die-cutting machine according to claim 5, characterized in that, It also includes a shared graphite emulsion coating device (100), in which the electric furnace (60) and the gas-heated grate (80) are arranged side by side, and the graphite emulsion coating device (100) is located at the front end of the electric furnace (60) and the gas-heated grate (80) for coating graphite emulsion before each tungsten wire drawing.

7. The electro-extraction and pneumatic retraction eleven-mold integrated machine according to claim 6, characterized in that, The drawing mechanism further includes a large guide wheel (20) and a small guide wheel (110); the large guide wheel (20) has N+1 passes, used to draw the tungsten wire from the wire feeding mechanism (10) to the first pass, and to draw the tungsten wire from the tower wheel assembly (40) to the next pass of the large guide wheel (20); the wire threading paths of the first to Nth passes are as follows: wire feeding mechanism (10), the first pass of the large guide wheel (20), the graphite emulsion coating device (100), the electric furnace (60), the first mold, the small guide wheel (110), and The first pass of the tower wheel assembly (40), the second pass of the large guide wheel (20), the graphite emulsion coating device (100)... are cyclically pulled to the Nth pass of the tower wheel assembly (40); the wire threading path from the Nth to the N+1th pass is as follows: the Nth pass of the tower wheel assembly (40), the N+1th pass of the large guide wheel (20), the graphite emulsion coating device (100), the gas-heated grate (80), the N+1th mold, the small guide wheel (110), the N+1th pass of the tower wheel assembly (40), and the wire take-up assembly (90).

8. The integrated electro-extraction and pneumatic retraction die-cutting machine according to claim 7, characterized in that, The gas-heated grate (80) has a main groove (81) and a gas supply pipe (82) connected to the main groove (81). The bottom of the main groove (81) is provided with a plurality of gas holes (83) evenly arranged along the layout direction of the main groove (81). The plurality of gas holes (83) are respectively connected to the gas supply pipe (82). The main groove (81) is located on the stretching path of the N+1th pass.

9. The integrated electro-extraction and pneumatic retraction die-cutting machine according to claim 8, characterized in that, It also includes an encoder assembly (120) which is mounted between the pulley assembly (40) and the take-up assembly (90) for measuring the length of the tungsten wire.

10. The electro-extraction and pneumatic retraction eleven-mold integrated machine according to claim 9, characterized in that, The take-up assembly (90) includes a spool take-up machine (91) and a guide rail (92). The bottom of the spool take-up machine (91) is connected to the guide rail (92). The spool take-up machine (91) slides left and right on the guide rail (92) to achieve uniform take-up.

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