Fuel gas heating ten-die wire drawing machine and high-performance tungsten filament drawing process

Abstract

The invention relates to the technical field of tungsten filament drawing processing, and provides a fuel gas heating ten-die wire drawing machine and a high-performance tungsten filament drawing process. The fuel gas heating ten-mold wire drawing machine comprises a rack and an electric controller, wherein a magnetic damping pay-off reel, a guide wheel, a natural gas fire grate, a wire drawing mold frame, a cone pulley and a servo wire take-up reel are sequentially arranged on the rack along a wire machining path; the natural gas fire grate comprises ten heating units, an electric proportional valve is arranged on the rack, and the electric proportional valve is in signal connection with an electric controller; a temperature measuring sensor is arranged above the heating unit, the temperature measuring sensor is in signal connection with the electrical controller, and the temperature measuring sensor is used for monitoring the temperature of the wire rod in real time; the high-performance tungsten filament drawing process comprises the following steps: S1, rough drawing; s2, medium drawing; s3, fine drawing; the step S1 is implemented by adopting the fuel gas heating ten-die wire drawing machine; through collaborative innovation of equipment and a process, the effects of improving the strength of the tungsten filament, improving the performance of the tungsten filament and reducing the wire breakage rate are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of tungsten wire drawing processing, and particularly relates to a gas-heated ten-mode wire drawing machine and a high-performance tungsten wire drawing process. Background Art

[0002] As a photovoltaic cutting bus bar, tungsten wire shows significant advantages in the process of replacing traditional high-carbon steel wire, but there is still a certain wire breakage rate at the cutting end. In the traditional drawing process of tungsten wire, a 0.39 mm tungsten wire annealed non-annealed bus bar is selected. First, it undergoes flame annealing at a temperature of 1600°C - 1700°C; then it passes through an electrically heated ten-mode wire drawing machine, and the tungsten wire is roughly drawn to 0.16 mm tungsten wire at a temperature of 800 - 850°C; then it passes through an electrically heated ten-mode wire drawing machine again, and the tungsten wire is medium-drawn to 0.06 - 0.08 mm tungsten wire at a temperature of 400 - 500°C; finally, it passes through an electrically heated ten-mode wire drawing machine, and the tungsten wire is finely drawn to 0.016 - 0.028 mm tungsten wire at a temperature of 300 - 400°C. Currently, the cutting data of the 0.028 mm - 0.030 mm bus bar maintains a wire breakage rate of 6% - 10%.

[0003] Regarding the related technologies in the above process, during the process of drawing a 0.39 mm tungsten wire to 0.16 - 0.18 mm tungsten wire by an electrically heated ten-mode wire drawing machine, the electrically heated ten-mode wire drawing machine conducts contact heating on the surface of the tungsten wire. Due to the fineness of the tungsten wire, it is difficult for the tungsten wire to be heated evenly, and the refinement degree of the center point and surface structure of the tungsten wire is inconsistent, resulting in uneven refinement of the tungsten wire structure. In addition, in the traditional process, annealing is required to eliminate work hardening, and at the same time, it also makes the drawing strength of the same material lower, resulting in insufficient surface strength of the tungsten wire.

[0004] Therefore, the cutting bus bars obtained by drawing tungsten wire with traditional equipment and processes have problems such as uneven refinement of the structure, insufficient surface strength, and high wire breakage rate. Summary of the Invention

[0005] The purpose of the present invention is to provide a gas-heated ten-mode wire drawing machine and a high-performance tungsten wire drawing process to solve the problems of uneven refinement of the tungsten wire structure, insufficient surface strength, and high wire breakage rate.

[0006] In a first aspect, the present invention provides a gas-heated ten-mode wire drawing machine, which includes a frame and an electrical controller. Along the wire processing path on the frame, a magnetic damping wire pay-off reel, a guide pulley, a natural gas grate, a wire drawing die holder, a capstan, and a servo wire take-up reel are sequentially arranged; the natural gas grate includes 10 independently temperature-controlled heating units; an electro-pneumatic proportional valve is also arranged on the frame, and the electro-pneumatic proportional valve is used to adjust the mixing ratio of natural gas and compressed air in the heating unit, and the electro-pneumatic proportional valve is signal-connected to the electrical controller; a temperature sensor is further arranged above the heating unit, the temperature sensor is signal-connected to the electrical controller, the temperature sensor is used to monitor the wire temperature in real time and feedback it to the electrical controller, and the electrical controller dynamically controls the electro-pneumatic proportional valve based on the PID algorithm to keep the wire temperature in the heating unit within the range of the set value ±5°C.

[0007] As an optimization of a gas-heated ten-mode wire drawing machine, an anti-vibration and stability component is arranged between the magnetic damping wire pay-off reel and the guide pulley. The anti-vibration and stability component includes a support arm, a fixed pulley, and a floating pulley. The support arm is fixedly connected to the frame. The fixed pulley is detachably connected to one end of the support arm close to the guide pulley. A vertical guide rail is arranged on the support arm, and the floating pulley is slidably connected to the vertical guide rail. The wire is wound around the fixed pulley and the floating pulley in an "S" shape or a "Z" shape path.

[0008] As an optimization of a gas-heated ten-mode wire drawing machine, a graphite emulsion coating box is arranged between the guide pulley and the natural gas grate. Multiple through-type lubricating grooves are arranged in the graphite emulsion coating box, and the wire passes through the through-type lubricating grooves.

[0009] As an optimization of a gas-heated ten-mode wire drawing machine, an adjustable bracket is arranged on the frame. The adjustable bracket includes a fixing plate and a rotating frame. The temperature sensor is fixedly connected to the rotating frame. The side wall of the rotating frame is rotatably connected to the fixing plate. An arc-shaped limiting hole is arranged on the fixing plate, and the arc-shaped limiting hole is used to restrict the rotation angle of the rotating frame.

[0010] As an optimization of a gas-heated ten-mode wire drawing machine, a translation guide rail is arranged on the frame. The sliding direction of the translation guide rail is perpendicular to the wire processing path, and the translation guide rail is used to drive the servo wire take-up reel to slide reciprocally.

[0011] In a second aspect, the present invention provides a high-performance tungsten wire drawing process, which includes the following steps: S1. Rough drawing: draw the tungsten wire with a lanthanum oxide content of 0.60%-0.80%, a strength of 2300-2500MPa, and a wire diameter of 0.39mm without annealing at a temperature of 900-950℃ and a surface reduction rate of 16%-22% to a tungsten wire with a wire diameter of 0.16-0.18mm; S2, medium drawing: the rough drawn tungsten wire is drawn at 400-500℃ with a surface reduction rate of 16%-22% to a wire diameter of 0.06-0.08mm; S3, fine drawing: the tungsten wire after medium drawing is drawn at 300-400℃ with a surface reduction rate of 16%-22% to a target wire diameter of 0.028-0.030mm; Wherein, step S1 is implemented by using a gas-heated ten-die wire drawing machine as described in the first aspect.

[0012] As an optimization of a high-performance tungsten wire drawing process, the tungsten wire strength obtained in step S3 is ≥6500MPa, and the wire breakage rate is ≤2%.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The gas-heated ten-die wire drawing machine provided in the present application directly heats the wire through 10 independently temperature-controlled heating units, and forms a PID closed-loop control through an electrical controller, a temperature sensor, and an electrical proportional valve to achieve a heating temperature difference of ≤5°C across the entire cross-section of the wire, thereby solving the problem of coarse grains in the core caused by uneven temperature, promoting the refinement and uniformity of the tungsten wire structure, and significantly reducing the wire breakage rate of the tungsten wire.

[0014] (2) The high-performance tungsten wire drawing process provided in this application eliminates the traditional 1600℃-1700℃ annealing step and directly adopts a gas-heated ten-die wire drawing machine for rough drawing. It is the first 900-950℃ dynamic recrystallization rough drawing process, which avoids the grain coarsening defect caused by high-temperature annealing and makes the tungsten wire grains uniformly refined to 1.5μm, thereby making the tungsten wire strength higher than that of the tungsten wire produced by the traditional process. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 This is a schematic diagram of the overall structure of a gas-heated ten-die wire drawing machine according to an embodiment of the present application; Figure 2 This is a schematic diagram of the overall structure of the graphite emulsion coating box of the embodiment of the present application; Figure 3Schematic diagram of the exploded structure of the adjustable bracket in the embodiment of the present application; Figure 4 Flow chart of a high-performance tungsten wire drawing process in the embodiment of the present application.

[0017] In the figure: 1, frame; 2, electrical controller; 3, magnetic damping wire pay-off reel; 4, guide pulley; 5, natural gas grate; 51, heating unit; 52, electric proportional valve; 53, temperature measuring sensor; 54, adjustable bracket; 541, fixing plate; 542, rotating frame; 543, arc-shaped limiting hole; 6, wire drawing die holder; 7, capstan; 8, servo wire take-up reel; 9, anti-vibration and stability component; 91, support arm; 92, fixed pulley; 93, floating pulley; 94, vertical guide rail; 10, graphite emulsion coating box; 101, through lubrication groove; 102, water inlet pipe; 103, water outlet pipe; 11, translation guide rail. Specific embodiments

[0018] To make the technical solutions and advantages of the present invention clearer, the present invention and its beneficial effects will be further described in detail below in conjunction with specific embodiments and the accompanying drawings of the specification. However, the embodiments of the present invention are not limited thereto.

[0019] In the description of the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", "connection", "fixation" 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. 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.

[0020] The standard parts used in the present invention can all be purchased from the market. The special-shaped parts can be customized according to the description in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, and welding in the existing technology. The machines, parts, and equipment all adopt conventional models in the existing technology, and the circuit connection adopts the conventional connection method in the existing technology, which will not be elaborated here.

[0021] The following is a further detailed description of the present application in conjunction with the attached Figures 1-4 drawings.

[0022] Embodiment In the first aspect, the present application provides a gas-heated ten-die wire drawing machine, adopting the following technical solutions: Refer to Figure 1, The gas-heated ten-mode wire drawing machine includes a frame 1 and an electrical controller 2. The electrical controller 2 is installed on the tabletop of the frame 1. The electrical controller 2 is a PLC (Programmable Logic Controller), and a PID (Proportional Integral Derivative) algorithm program is programmed on the PLC. Along the wire processing path on the tabletop of the frame 1, a magnetic damping wire pay-off reel 3, a guide pulley 4, a natural gas grate 5, a wire drawing die holder 6, a capstan 7, and a servo wire take-up reel 8 are arranged and installed in sequence. Among them, the natural gas grate 5 includes 10 independently processed heating units 51. Each heating unit 51 is an independent working station. The flame is generated by mixing natural gas and compressed air to heat each heating unit 51 separately. The heating unit 51 heats the wire by thermal radiation. 10 wire drawing dies are correspondingly installed on the wire drawing die holder 6 to draw the heated wire and perform the drawing process. An electrical proportional valve 52 is installed at the bottom of the frame 1. The electrical proportional valve 52 is a two-channel magnetic flux valve. Natural gas and compressed air are respectively passed through the two channels. The electrical proportional valve 52 is signal-connected to the electrical controller 2. Through the instruction of the electrical controller 2, the mixing ratio of natural gas and compressed air is accurately adjusted to accurately control the combustion temperature of the heating unit 51. A separate temperature measuring sensor 53 is installed above each heating unit 51 to detect the temperature of the wire in the heating unit 51 in real time. In this embodiment, the temperature measuring sensor 53 is an infrared thermometer. The temperature measuring sensor 53 is signal-connected to the electrical controller 2 to feed back the temperature of the wire in the heating unit 51 to the electrical controller 2 in real time. The electrical controller 2 dynamically controls the electrical proportional valve 52 to adjust the mixing ratio of natural gas and compressed air in real time through the PID algorithm program according to the signal of the temperature measuring sensor 53, forming a closed-loop temperature control, thereby improving the uniformity of the wire heating temperature.

[0023] In a preferred embodiment of the present application, referring to Figure 1 , a anti-vibration and stability component 9 is fixedly installed between the magnetic damping wire pay-off reel 3 and the guide pulley 4. The anti-vibration and stability component 9 includes a support arm 91, a fixed pulley 92, and a floating pulley 93. One end of the support arm 91 is fixedly installed on the outer wall of the bearing seat of the magnetic damping wire pay-off reel 3 through bolts, and the other end of the support arm 91 extends towards the guide pulley 4. A plurality of first mounting holes are transversely formed in the support arm 91, and the fixed pulley 92 is inserted and installed in one of the first mounting holes, so that the fixed pulley 92 is detachably installed at one end of the support arm 91 close to the guide pulley 4. A vertical guide rail 94 is detachably and fixedly connected to the middle of the support arm 91, and the floating pulley 93 is slidably installed on the vertical guide rail 94, and the floating pulley 93 moves up and down in the vertical direction. The wire drawn from the magnetic damping wire pay-off reel 3 passes through the floating pulley 93 and the fixed pulley 92 in sequence, forming an "S" shape or a "Z" shape path between the floating pulley 93 and the fixed pulley 92 to reduce the up and down jitter of the wire.

[0024] In a preferred embodiment of the present application, with reference to Figure 1 and Figure 2 , a graphite milk coating box 10 is fixedly installed between the guide wheel 4 and the natural gas grate 5. An inlet water pipe 102 and an outlet water pipe 103 are connected to the outside of the graphite milk coating box 10. A plurality of through lubricating grooves 101 are integrally formed in the graphite milk coating box 10. Nozzles are provided at the bottoms of the through lubricating grooves 101, and the nozzles communicate with the inlet water pipe 102. The graphite milk lubricant is injected through the inlet water pipe 102, gushes upward through the nozzles, and fills the inside of the through lubricating grooves 101. The overflowing graphite milk lubricant in the through lubricating grooves 101 is discharged through the outlet water pipe 103, and after passing through an external circulation path, it is re-injected into the inlet water pipe 102, thereby forming a self-circulation of the lubricant in the graphite milk coating box 10. When the wire passes through the through lubricating grooves 101, the graphite milk lubricant in the through lubricating grooves 101 wraps and coats the wire, thereby improving the smoothness of the wire drawing process and being beneficial to improving the drawing efficiency.

[0025] In a preferred embodiment of the present application, with reference to Figure 3 . An adjustable bracket 54 is also fixedly installed on the frame 1. The adjustable bracket 54 includes a fixing plate 541 and a rotating frame 542. The bottom end of the fixing plate 541 is fixedly installed on the frame 1 by bolts. A circular hole and an arc-shaped limiting hole 543 are provided at the top end of the fixing plate 541. The rotating frame 542 includes an angle iron and a square plate. One end face of the angle iron is welded to the square plate. A plurality of temperature sensors 53 are fixedly installed on the main body of the angle iron. The positions of the plurality of temperature sensors 53 are successively corresponding to a plurality of heating units 51 on the natural gas grate 5. At least two studs are installed on the square plate. One of the studs passes through the circular hole of the fixing plate 541 to form a rotation center, and the other studs are inserted and slide or lock in the arc-shaped limiting hole 543, so as to realize the rotational installation of the rotating frame 542 on the fixing plate 541. The rotation angle of the rotating frame 542 is limited by the arc-shaped limiting hole 543, thereby adjusting the temperature measurement direction of the temperature sensors 53 and monitoring the temperature at different positions of the heating unit 51, which is beneficial to ensuring the stability of the temperature at each place on the processing path of the heating unit 51.

[0026] In a preferred embodiment of the present application, with reference to Figure 1 , a translation guide rail 11 is further installed on the table surface of the frame 1. The sliding direction of the translation guide rail 11 is perpendicular to the processing path of the wire. The bearing seat of the servo wire take-up reel 8 is fixedly installed on the slide of the translation guide rail 11. The servo wire take-up reel 8 reciprocates with the translation guide rail 11, so that the wire is evenly wound around the servo wire take-up reel 8 in a dispersed manner.

[0027] Implementation principle of this device: The innovative heat source form and closed-loop control system achieve high-precision and uniform control of the temperature during the tungsten wire drawing process. Specifically, the 10 independent temperature-controlled heating units 51 of the natural gas grate 5 use the mixed combustion of natural gas and compressed air to generate high-temperature flames, which mainly heat the wire in a non-contact manner through convection and thermal radiation. Compared with the traditional electric heating ten-mode wire drawing machine that conducts contact heating of the wire through conductive wheels or dies, it fundamentally solves the inherent non-uniformity problem of contact heating and realizes the uniformity of the wire's full cross-section temperature. At the same time, the temperature measurement sensor 53 located above each heating unit 51 monitors the actual temperature of the wire in real time and feeds the signal back to the electrical controller 2. The electrical controller 2 is built-in with a PID algorithm program, which dynamically calculates and outputs a control signal to the electro-hydraulic proportional valve 52 according to the deviation between the set temperature and the actual temperature. The electro-hydraulic proportional valve 52 accurately adjusts the mixing ratio of natural gas and compressed air introduced into the heating unit 51 accordingly, thereby instantly adjusting the temperature and heat output of the combustion flame. This closed-loop control system ensures that when the wire passes through each heating unit 51, its temperature can be stably maintained within a narrow range of the set value ±5°C, laying an equipment foundation for the uniform refinement of the tungsten wire structure and the improvement of strength in the subsequent wire drawing process.

[0028] In a second aspect, the present application also provides a high-performance tungsten wire drawing process. Referring to Figure 4, it includes the following steps: S1. Rough drawing: The tungsten wire mother bar with a lanthanum oxide content of 0.60% - 0.80%, a strength of 2300 - 2500 MPa, and a wire diameter of 0.39 mm is drawn without annealing at a temperature of 900 - 950°C with a reduction rate of 16% - 22% to a tungsten wire with a wire diameter of 0.16 - 0.18 mm; S2. Medium drawing: The tungsten wire after rough drawing is drawn at 400 - 500°C with a reduction rate of 16% - 22% to a tungsten wire with a wire diameter of 0.06 - 0.08 mm; S3. Fine drawing: The tungsten wire after medium drawing is drawn at 300 - 400°C with a reduction rate of 16% - 22% to a tungsten wire with a target wire diameter of 0.028 - 0.030 mm.

[0029] Further, step S1 is implemented using the gas heating ten-mode wire drawing machine as described above, with a temperature control accuracy of ±5°C.

[0030] Further, the tungsten wire obtained in step S3 has a strength ≥6500 MPa and a slicing breakage rate ≤2%.

[0031] Implementation principle of this process: The step of "high-temperature annealing at 1600 - 1700°C" in the traditional process is innovatively cancelled, and the "dynamic recrystallization rough drawing process at 900 - 950°C" is directly implemented in the rough drawing stage. During the plastic deformation process of metals, when the deformation temperature and strain rate meet specific conditions, deformation and recrystallization occur simultaneously. The recrystallization temperature of tungsten is approximately 800°C. The temperature range in step S1 of this process is higher than the recrystallization temperature of tungsten but much lower than the traditional annealing temperature. When drawing deformation is carried out at this temperature, the dislocation accumulation generated inside the tungsten wire due to deformation will trigger dynamic recrystallization - new grains nucleate and grow in real time during the deformation process, achieving ultra-finement and homogenization of the tungsten wire structure.

[0032] Compared with the traditional process, the improvement effects of this process are specifically manifested as follows: The grain size is refined from 2 - 3μm to 1.5μm, the radial uniformity is improved, and the tissue properties of the tungsten wire are enhanced; the strength of the finished tungsten wire is increased by about 200MPa, the wire breakage rate is reduced by 8 percentage points, and the mechanical properties of the tungsten wire are improved: The process steps and costs of annealing are saved, energy is saved by 40% and the production cycle is shortened, reducing the production cost.

[0033] Experimental example Select 20 shafts of tungsten wire non-annealed busbars with lanthanum oxide content of 0.60% - 0.80%, strength of 2300 - 2500MPa, and wire diameter of 0.39mm as wire materials. Take 10 shafts of tungsten wire non-annealed busbars each for two groups of experiments, namely Group A and Group B.

[0034] The experiment in Group A is the traditional tungsten wire drawing process, including the following steps: a. Annealing: The tungsten wire non-annealed busbars with lanthanum oxide content of 0.60% - 0.80%, strength of 2300 - 2500MPa, and wire diameter of 0.39mm are flame annealed at a temperature of 1600 - 1700°C to obtain tungsten wire busbars; b. Rough drawing: The annealed tungsten wire busbars are drawn to tungsten wires with a wire diameter of 0.16 - 0.18mm at a temperature of 800 - 850°C and a reduction ratio of 16% - 22% using an electrically heated large ten-die wire drawing machine; c. Medium drawing: The tungsten wires after rough drawing are drawn to tungsten wires with a wire diameter of 0.06 - 0.08mm at a temperature of 400 - 500°C and a reduction ratio of 16% - 22% using an electrically heated medium ten-die wire drawing machine; d. Fine drawing: The tungsten wires after medium drawing are drawn to tungsten wires with a wire diameter of 0.028 - 0.03mm at a temperature of 300 - 400°C and a reduction ratio of 16% - 22% using an electrically heated small ten-die wire drawing machine.

[0035] The experiment in Group B is the high-performance tungsten wire drawing process proposed in this application, including the following steps: S1. Rough drawing: The tungsten wire mother bar with a lanthanum oxide content of 0.60% - 0.80%, a strength of 2300 - 2500 MPa, and a wire diameter of 0.39 mm is drawn without annealing to a tungsten wire with a wire diameter of 0.16 - 0.18 mm at a temperature of 900 - 950 °C using a gas-heated ten-mode wire drawing machine with a reduction rate of 16% - 22%. S2. Medium drawing: The tungsten wire after rough drawing is drawn to a tungsten wire with a wire diameter of 0.06 - 0.08 mm at a temperature of 400 - 500 °C using an electrically heated medium ten-mode wire drawing machine with a reduction rate of 16% - 22%. S3. Fine drawing: The tungsten wire after medium drawing is drawn to a tungsten wire with a target wire diameter of 0.028 - 0.030 mm at a temperature of 300 - 400 °C using an electrically heated small ten-mode wire drawing machine with a reduction rate of 16% - 22%.

[0036] Experiment 1 In two groups of experiments A and B, the strength of the tungsten wire mother bar drawn to a tungsten wire with a diameter of 0.16 mm was detected, and the experimental data are shown in Table 1.

[0037] Table 1 Experiment 1 was to compare the strength of the tungsten wire after the rough drawing stage in groups A and B. From the data in Table 1, it can be concluded that compared with the traditional wire drawing process, the average strength of the tungsten wire after the rough drawing stage of the wire drawing process of the present application is 180 Mpa higher, and the tissue properties and mechanical properties of the tungsten wire are more excellent, which is beneficial for the subsequent wire drawing process.

[0038] Experiment 2 On the basis of Experiment 1, 100 meters were taken from each of these 20 shafts of 0.16 mm tungsten wire and electrolytically corroded with an etching solution to gradually reduce the diameter of the tungsten wire. When the diameters reached 0.15 mm, 0.13 mm, 0.11 mm, 0.08 mm, and 0.04 mm respectively, the corresponding strength was detected and recorded, and the experimental data are shown in Table 2.

[0039] Table 2 Experiment 2 was to detect the strength of each cross-section of the tungsten wire and analyze the strength difference between the core and the surface layer of the tungsten wire. From the data in Table 2, it can be seen that the strength of group A continued to decline as the wire diameter decreased, with a decline rate of 11.3%. In particular, the strength of the core dropped sharply, and the strength at the cross-section with a wire diameter of 0.04 mm was only 2963 MPa, indicating that the traditional process has surface refinement but coarse grains in the core, and the core becomes a weak area when drawn to a thin wire and is prone to fracture; while the strength of group B fluctuated less with the wire diameter, with a fluctuation range of only 0.3%, and the strength at the cross-section with a wire diameter of 0.04 mm still remained at 3352 MPa, indicating that the wire drawing process of the present application has more uniform strength from the inside to the outside of the tungsten wire, has uniform strength across the cross-section, and the overall strength is also higher, overall improving the tissue properties and mechanical properties of the tungsten wire.

[0040] Experiment III On the basis of Experiment I, the 20 axes of tungsten wires with a wire diameter of 0.16 mm were further drawn into tungsten wires with a wire diameter of 0.028 mm, and the strength of the tungsten wires was tested. The experimental data are shown in Table 3.

[0041] Table 3 Experiment III is to detect the strength of the tungsten wire finished products of the drawing process. It can be seen from Table 3 that the average strength of the tungsten wire finished products in Group A of the experiment is 6366 MPa, while the average strength of the tungsten wire finished products in Group B of the experiment is 6579 MPa. Group B is 213 MPa higher than Group A, and the strength of all the finished products in Group B is higher than 6500 Mpa. The drawing process of the present invention has stability during the processing, and the mechanical properties of the products are excellent.

[0042] Experiment IV On the basis of Experiment III, the 20 axes of finished tungsten wires with a wire diameter of 0.028 mm were tested for the wire breakage rate, and the experimental data are shown in Table 4.

[0043] Table 4 Experiment IV is a further analysis of the finished product wire breakage rate. It can be seen from the data in the above table that the wire breakage rate in Group A fluctuates greatly, and the difference between samples is significant. The wire breakage rate of 60% of the samples > 5%, and the highest reaches 12.5%, reflecting that the quality of the traditional process is unstable and is randomly affected by the non-uniformity of the structure (as shown in Table 2) and insufficient strength (as shown in Table 3). While the wire breakage rate in Group B is 0% for 8 groups of samples, and only 2 groups of samples are non-zero (6.67%, 4.35%), and it does not exceed 7%, reflecting that the drawing process provided by the present application has high reliability, and the advantages of structural uniformity and strength are transformed into a stable low wire breakage rate. Compared with the current industry wire breakage rate level (6% - 10%), the wire breakage rate in Group B is reduced by about 80%. The average wire breakage rate in Group B is 1.28%, meeting the requirement of the wire breakage rate ≤ 2% for photovoltaic cutting.

[0044] Through the collaborative innovation of a gas-heated ten-die wire drawing machine and a high-performance tungsten wire drawing process, this application systematically solves the problems of uneven microstructure refinement, insufficient surface strength, and high wire breakage rate existing in traditional tungsten wire drawing. The close combination of equipment and process creates basic conditions for dynamic recrystallization in the process with the high-precision temperature control provided by the gas-heated ten-die wire drawing machine. The process cancels the high-temperature annealing step and directly adopts a rough drawing process at 900-950 °C, which makes full use of the uniform heating characteristics of the equipment. Specifically, the 10 independent temperature-controlled heating units of the equipment achieve non-contact radiant heating of the wire through a PID closed-loop control system (including a temperature measurement sensor, an electric proportional valve, and an electric controller), ensuring the temperature uniformity of the entire cross-section and avoiding the problem of coarse grains in the core caused by the traditional electric heating contact method. In terms of the process, the first-ever dynamic recrystallization rough drawing step at 900-950 °C is directly implemented on the equipment. By utilizing the synchronous mechanism of deformation and recrystallization, the tungsten wire microstructure is promoted to be ultra-refined to 1.5 μm, significantly improving the strength and reducing the wire breakage rate. This correlation between equipment and process not only optimizes the tungsten wire microstructure and improves the radial uniformity but also brings significant macroscopic benefits: the strength of the finished tungsten wire ≥ 6500 MPa, the wire breakage rate for photovoltaic cutting ≤ 2%, while saving 40% of energy and shortening the production cycle. Experimental data show that compared with the traditional process, this application has achieved a breakthrough improvement in the strength uniformity and mechanical properties of the entire cross-section of the tungsten wire.

[0045] Based on the disclosure and teachings of the above specification, those skilled in the art to which the present invention pertains are also able to make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the above specific embodiments, and any obvious improvements, substitutions, or variations made by those skilled in the art based on the present invention fall within the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the present invention.

Claims

1. A gas-heated ten-mode wire drawing machine, characterized in that, It includes a frame (1) and an electric controller (2). Along the wire processing path on the frame (1), a magnetic damping wire pay-off reel (3), a guide pulley (4), a natural gas grate (5), a wire drawing die holder (6), a capstan (7) and a servo wire take-up reel (8) are sequentially arranged; the natural gas grate (5) includes 10 independently temperature-controlled heating units (51); an electric proportional valve (52) is further arranged on the frame (1), and the electric proportional valve (52) is used to adjust the mixing ratio of natural gas and compressed air in the heating unit (51), and the electric proportional valve (52) is signal-connected to the electric controller (2); a temperature measuring sensor (53) is further arranged above the heating unit (51), the temperature measuring sensor (53) is signal-connected to the electric controller (2), the temperature measuring sensor (53) is used to monitor the wire temperature in real time and feedback it to the electric controller (2), and the electric controller (2) dynamically regulates the electric proportional valve (52) based on the PID algorithm to keep the wire temperature in the heating unit (51) within the range of the set value ±5°C.

2. The gas-heated ten-mode wire drawing machine according to claim 1, characterized in that, An anti-vibration and stability component (9) is arranged between the magnetic damping wire pay-off reel (3) and the guide pulley (4). The anti-vibration and stability component (9) includes a support arm (91), a fixed pulley (92) and a floating pulley (93). The support arm (91) is fixedly connected to the frame (1), the fixed pulley (92) is detachably connected to one end of the support arm (91) close to the guide pulley (4), a vertical guide rail (94) is arranged on the support arm (91), the floating pulley (93) is slidably connected to the vertical guide rail (94), and the wire is wound around the fixed pulley (92) and the floating pulley (93) in an "S" shape or a "Z" shape path.

3. A gas-heated ten-mode wire drawing machine according to claim 1, characterized in that, A graphite emulsion coating box (10) is arranged between the guide pulley (4) and the natural gas grate (5). A plurality of through lubricating grooves (101) are arranged in the graphite emulsion coating box (10), and the wire passes through the through lubricating grooves (101).

4. A gas-heated ten-mode wire drawing machine according to claim 1, characterized in that, An adjustable bracket (54) is arranged on the frame (1). The adjustable bracket (54) includes a fixed plate (541) and a rotating frame (542). The temperature measuring sensor (53) is fixedly connected to the rotating frame (542), the side wall of the rotating frame (542) is rotatably connected to the fixed plate (541), and an arc-shaped limiting hole (543) is arranged on the fixed plate (541), and the arc-shaped limiting hole (543) is used to restrict the rotation angle of the rotating frame (542).

5. A gas-heated ten-mode wire drawing machine according to claim 1, characterized in that, A translation guide rail (11) is arranged on the frame (1). The sliding direction of the translation guide rail (11) is perpendicular to the wire processing path, and the translation guide rail (11) is used to drive the servo wire take-up reel (8) to slide back and forth.

6. A high-performance tungsten wire drawing process, characterized in that, It includes the following steps: S1. Rough drawing: The tungsten wire mother bar with a lanthanum oxide content of 0.60% - 0.80%, a strength of 2300 - 2500 MPa, and a wire diameter of 0.39 mm without annealing is drawn at a temperature of 900 - 950 °C with a reduction rate of 16% - 22% to a tungsten wire with a wire diameter of 0.16 - 0.18 mm; S2. Medium drawing: The tungsten wire after rough drawing is drawn at a temperature of 400 - 500 °C with a reduction rate of 16% - 22% to a tungsten wire with a wire diameter of 0.06 - 0.08 mm; S3. Fine drawing: The tungsten wire after medium drawing is drawn at a temperature of 300 - 400 °C with a reduction rate of 16% - 22% to a tungsten wire with a target wire diameter of 0.028 - 0.030 mm; Among them, step S1 is implemented by using a gas - heated ten - die wire drawing machine described in any one of claims 1 - 5.

7. A high-performance tungsten wire drawing process according to claim 6, characterized in that, The tungsten wire obtained in step S3 has a strength ≥ 6500 MPa and a photovoltaic cutting wire breakage rate ≤ 2%.

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