A device and method for cold drawing nickel-titanium alloy micro wires

Abstract

This invention provides a cold drawing device and method for nickel-titanium alloy microwires. The nickel-titanium alloy microwire cold drawing device includes: a frame, comprising a base, a frame body, and a guide rail; an XY bidirectional fine-tuning platform fixed on the base; a drawing platform mounted on the upper surface of the XY bidirectional fine-tuning platform via a connecting plate, the upper surface of the drawing platform having a groove; a drawing die installed in the groove, having a die hole through which the nickel-titanium alloy microwire passes; a lifting plate mounted on the guide rail; and a microwire chuck mounted on the lifting plate via a force gauge, used to clamp the nickel-titanium alloy microwire from above the drawing die and draw it under the drive of the lifting plate. A through hole for the nickel-titanium alloy microwire to pass through is also provided below the groove. The upper surface of the XY bidirectional fine-tuning platform is a movable worktable surface, used to fine-tune the position of the upper surface according to the real-time measurement data of the force gauge to adjust the position of the drawing die, so that the exit direction of the nickel-titanium alloy microwire is parallel to the axis of the drawing die.

Description

Technical Field

[0001] This invention relates to the field of materials processing technology, specifically to a device and method for cold drawing nickel-titanium alloy microwires. Background Technology

[0002] Nickel-titanium alloys are typical shape memory alloys, possessing excellent properties such as shape memory effect, superelasticity, high damping, biocompatibility, and high corrosion resistance, and are widely used in aerospace, electronics, energy, and construction. Traditional nickel-titanium alloys are coarse-grained, fine-grained, or nanocrystalline materials, exhibiting poor fatigue resistance and their mechanical behavior is greatly affected by ambient temperature. Transforming the internal structure of nickel-titanium alloys from a purely crystalline to an amorphous / nanocrystalline composite structure can significantly improve their fatigue resistance and reduce the influence of temperature on their mechanical behavior.

[0003] Cold drawing combined with annealing is a commonly used method for preparing amorphous / nanocrystalline composite nickel-titanium alloys. Cold drawing involves drawing nickel-titanium alloy wires at room temperature to achieve large plastic deformation and obtain an amorphous structure. Unlike hot drawing, cold drawing of nickel-titanium alloy materials does not involve intermediate annealing, leading to a gradual increase in the material's hardness and brittleness. Nickel-titanium alloy microwires often experience breakage during cold drawing, making it difficult to achieve a large reduction in surface area and thus hindering the full amorphization of the wire structure. This is due to two main reasons: firstly, the microwire tip is difficult to pass through the die; and secondly, the wire's exit direction deviates from the centerline of the drawing die, resulting in excessive drawing force and breakage. Summary of the Invention

[0004] This invention is made to solve the above-mentioned problems, and its purpose is to provide a cold drawing device and method for nickel-titanium alloy micro wires.

[0005] This invention provides a cold drawing device for nickel-titanium alloy microwires, characterized by comprising: a frame, including a base, a frame body disposed on the base, and a guide rail disposed on the frame body; an XY bidirectional fine-tuning platform fixed on the base; a drawing platform mounted on the upper surface of the XY bidirectional fine-tuning platform via a connecting plate, the upper surface of the drawing platform having a groove; a drawing die, installed in the groove, having a die hole through which the nickel-titanium alloy microwires pass; a lifting plate, mounted on the guide rail, for longitudinal lifting movement; and a microwire chuck, mounted on the lifting plate via a force gauge, for clamping the nickel-titanium alloy microwires from above the drawing die and drawing the nickel-titanium alloy microwires under the drive of the lifting plate. The groove also has a through hole for the nickel-titanium alloy microwires to pass through. The upper surface of the XY bidirectional fine-tuning platform is a movable worktable surface, used for fine-tuning the position of the upper surface according to real-time measurement data from the force gauge, thereby adjusting the position of the drawing die so that the exit direction of the nickel-titanium alloy microwires is parallel to the axis of the drawing die.

[0006] The nickel-titanium alloy micro-wire cold drawing device provided by the present invention may also have the following feature: the drawing platform is further provided with two quick clamps, and the drawing die is fixed in position by the quick clamps after being placed in the groove.

[0007] The nickel-titanium alloy micro-wire cold drawing device provided by the present invention may also have the following feature: the lifting plate is controlled to lift by an external drive structure or manually.

[0008] The present invention also provides a method for cold drawing of nickel-titanium alloy micro wires, using the above-mentioned nickel-titanium alloy micro wire cold drawing device, characterized by the following steps: Step S1, take the solution-treated nickel-titanium alloy micro wire, take the two ends of the nickel-titanium alloy micro wire as end A and end B respectively, immerse end B of the nickel-titanium alloy micro wire into the etching solution at a uniform speed, take it out after immersion for a period of time and clean it.

[0009] Step S2: Place the drawing die into the groove and fix the drawing die with a quick clamp. Pass the B end of the nickel-titanium alloy micro wire through the lower part of the drawing platform and through the through hole into the drawing die, and then pass the end of the nickel-titanium alloy micro wire through the die.

[0010] Step S3: After the end of the die is passed through, keep the clamped state and control the lifting plate to move slowly upward. According to the real-time measurement data of the force measuring instrument, fine-tune the XY bidirectional fine-tuning platform to minimize the real-time measurement data of the force measuring instrument. Then control the lifting plate to move quickly upward to pull until the nickel-titanium alloy micro wire has completely passed through the drawing die.

[0011] Step S4: Repeat steps S1 to S3 to perform multiple cold drawing passes until the desired nickel-titanium alloy microwire with the required area reduction ratio is obtained.

[0012] The cold drawing method for nickel-titanium alloy microwires provided by the present invention may also have the following features: in step S1, the total immersion length of the nickel-titanium alloy microwire in the corrosion solution is 20 mm to 50 mm, and the total immersion time is 5 min to 30 min.

[0013] The cold drawing method for nickel-titanium alloy microwires provided by this invention may also have the following feature: In step S2, when threading the end of the nickel-titanium alloy microwire through the die, the following sub-steps are included:

[0014] Step S2-1: Control the lifting plate to move to a position where the micro-wire chuck can hold the B end of the nickel-titanium alloy micro-wire. The micro-wire chuck is used to hold the nickel-titanium alloy micro-wire at a position 5mm from the end of the B end of the nickel-titanium alloy micro-wire. After holding, it moves upward 5mm.

[0015] Step S2-2: Release the microwire chuck, control the lifting plate to move downward, and clamp the nickel-titanium alloy microwire again through the microwire chuck. The clamping position is 15mm away from the B end of the nickel-titanium alloy microwire. After clamping, move upward 15mm.

[0016] Step S2-3: Release the microwire chuck again, control the lifting plate to move downward, and clamp the nickel-titanium alloy microwire again through the microwire chuck. The clamping position is 30mm away from the B end of the nickel-titanium alloy microwire. After clamping, move upward 20mm.

[0017] Step S2-4: Release the microwire chuck, control the lifting plate to move downwards, and clamp the nickel-titanium alloy microwire through the microwire chuck. The clamping position is 50mm away from the B end of the nickel-titanium alloy microwire, completing the end die-through of the nickel-titanium alloy microwire.

[0018] The method for cold drawing of nickel-titanium alloy micro wires provided by the present invention may also have the following features: in step S3, the speed of the lifting plate when it moves slowly upward is 10 mm / min to 50 mm / min, and the speed of the lifting plate when it moves quickly upward is 300 mm / min to 500 mm / min.

[0019] The cold drawing method for nickel-titanium alloy microwires provided by this invention may also have the following characteristics: when the diameter of the nickel-titanium alloy microwire before drawing is 0.2 mm to 0.3 mm, the reduction rate per pass must be less than 40%; when the diameter of the nickel-titanium alloy microwire before drawing is 0.11 mm to 0.2 mm, the reduction rate per pass must be less than 30%; and when the diameter of the nickel-titanium alloy microwire before drawing is less than 0.11 mm, the reduction rate per pass must be less than 20%.

[0020] The role and effect of invention

[0021] This invention relates to a cold drawing device and method for nickel-titanium alloy microwires. It utilizes a force gauge to measure the tension data of the microwire chuck in real time, and then fine-tunes the position of the drawing die using an XY bidirectional fine-tuning platform. This minimizes the real-time measurement data from the force gauge, ensuring that the microwire's exit direction is parallel to the die's axis, effectively solving the problem of the microwire's exit direction deviating from the die's centerline. Furthermore, this invention employs gradient etching of the microwire's end with an etchant, and uses the microwire chuck to repeatedly clamp and move the end of the microwire to complete the die-cutting process, effectively solving the problem of difficulty in cutting the microwire's end through the die. Therefore, this invention solves the problems of difficulty in cutting the microwire's end through the die and deviation of the microwire's exit direction from the die's centerline. Using the nickel-titanium alloy microwire cold drawing device and method of this invention, a reduction in surface area of ​​nearly 90% can be achieved, a significant improvement compared to the 40%–60% reduction achieved by existing technologies. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the nickel-titanium alloy micro-wire cold drawing device in an embodiment of the present invention;

[0023] Figure 2 This is a 1 / 4 sectional view of the pulling platform in an embodiment of the present invention;

[0024] Figure 3 This is a schematic flowchart of the cold drawing method for nickel-titanium alloy microwires in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the end corrosion of nickel-titanium alloy microwires in an embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the end die insertion and cold drawing process of the nickel-titanium alloy microwire cold drawing device in an embodiment of the present invention. Detailed Implementation

[0027] To make the technical means, creative features, objectives and effects of this invention easier to understand, the following embodiments are described in detail with reference to the accompanying drawings.

[0028] <Example>

[0029] Figure 1 This is a schematic diagram of the structure of the nickel-titanium alloy micro-wire cold drawing device in an embodiment of the present invention.

[0030] like Figure 1 As shown, the nickel-titanium alloy micro-wire cold drawing device 100 of this embodiment includes a frame 10, an XY bidirectional fine adjustment platform 20, a drawing platform 30, a drawing die 40, a lifting plate 50, a force gauge 60, and a micro-wire chuck 70.

[0031] The frame 10 includes a horizontally placed base 11, a frame 12 vertically arranged on the base 11, and a guide rail 13 arranged on the surface of the frame 12.

[0032] The XY bidirectional fine-tuning platform 20 is fixed on the base 11. This XY bidirectional fine-tuning platform 20 is existing technology, directly available commercially, with product model number LY60-LM, and adjustment accuracy of 0.01mm.

[0033] In this embodiment, the XY bidirectional fine-tuning platform 20 includes a base 21, an intermediate platform 22, and an upper plane 23. The base 21 is fixed on the base 11, and a first displacement guide rail is provided inside the base 21. The intermediate platform 22 is movably mounted on the base 21 via the first displacement guide rail. A second displacement guide rail is provided on the intermediate platform 22, and the upper plane 23 is movably mounted on the intermediate platform 22 via the second displacement guide rail.

[0034] The intermediate platform 22 is also provided with a first fixed block and an X-axis adjustment handle 221 on one side along the X-axis direction. The X-axis adjustment handle 221 is set in the fixing part connected to the base. The X-axis adjustment handle 221 is a micro head. The front end of the X-axis adjustment handle 221 is connected to the first fixed block. When adjusting the X-axis position, the intermediate platform 22 is driven to move along the first displacement guide rail by rotating the X-axis adjustment handle 221 to make displacement in the X-axis direction.

[0035] A second fixed block and a Y-axis adjustment handle 231 are also provided on one side of the upper plane 23 along the Y-axis direction. The Y-axis adjustment handle 231 is set in the fixed part connected to the intermediate platform 22. The Y-axis adjustment handle 231 is a micro head. The front end of the Y-axis adjustment handle 231 is connected to the second fixed block. When adjusting the Y-axis position, the upper plane 23 is moved along the second displacement guide rail by rotating the Y-axis adjustment handle 231 to move in the Y-axis direction. Thus, the upper plane 23 can be controlled to move in the XY plane by rotating the X-axis adjustment handle 221 and the Y-axis adjustment handle 231.

[0036] The pulling platform 30 is mounted on the upper plane 23 of the XY bidirectional fine-tuning platform 20 via the connecting plate 31, and thus moves accordingly as the upper plane 23 of the XY bidirectional fine-tuning platform 20 moves.

[0037] Figure 2 This is a 1 / 4 sectional view of the pulling platform in an embodiment of the present invention.

[0038] like Figure 2 As shown, the upper surface of the drawing platform 30 is provided with a groove, and a through hole is provided below the groove for passing through the nickel-titanium alloy micro wire. The lower part of the drawing platform 30 is provided with a gap, and the groove is correspondingly set above the gap and communicates with the gap through the through hole.

[0039] The drawing die 40 is installed in a groove and has a die hole through which nickel-titanium alloy microwires pass.

[0040] The drawing platform 30 is equipped with two quick clamps 32, which are arranged opposite each other on both sides of the groove. After the drawing die 40 is placed into the groove, it is fixed in position by the quick clamps 32.

[0041] In this embodiment, the quick clamp 32 is a vertical quick clamp, which uses a handle and a pressure rod connected to the handle via a linkage structure to achieve position fixation. When it is necessary to fix the drawing die 40, the handle is pulled upward to control the pressure rod to move downward, so that the pressure rod contacts and presses the drawing die 40 downward to fix it in the groove. When it is necessary to remove the drawing die 40, the handle is pushed downward to control the pressure rod to move upward and remove the drawing die 40. By controlling the quick clamp 32, the replacement and fixation of drawing dies 40 with different hole diameters can be completed quickly and conveniently.

[0042] The lifting plate 50 is mounted on the guide rail 13 and is used for vertical lifting movement.

[0043] The lifting plate 50 can be controlled by external drive structures such as motors and lead screws, or by manually pushing it up and down.

[0044] The force gauge 60 is mounted on the lifting plate 50, and the micro wire chuck 70 is mounted at the end of the force gauge 60. The micro wire chuck 70 clamps the nickel-titanium alloy micro wire from above the drawing die 40 and draws the nickel-titanium alloy micro wire under the drive of the lifting plate 50. At the same time, the force gauge 60 can measure and obtain the real-time tension data of the micro wire chuck 70.

[0045] In this embodiment, the force gauge 60 is also provided with a data display window 61 for displaying real-time measurement data.

[0046] The upper plane of the XY bidirectional fine-tuning platform 20 is finely adjusted according to the real-time measurement data of the force measuring instrument 60, thereby adjusting the position of the drawing die 40 so that the exit direction of the nickel-titanium alloy micro wire is parallel to the axis of the drawing die 40. At this time, the real-time measurement data of the force measuring instrument 60 is minimized.

[0047] Figure 3 This is a schematic flowchart of the cold drawing method for nickel-titanium alloy microwires in an embodiment of the present invention.

[0048] like Figure 3 As shown, the cold drawing method for nickel-titanium alloy microwires in this embodiment is performed using a nickel-titanium alloy microwire cold drawing device 100, and includes the following steps:

[0049] Step S1, as follows Figure 4As shown, before placing the drawing die 40 for drawing, a glass cup can be placed in the groove. The glass cup 80 containing the etching solution is placed in the groove. A nickel-titanium alloy microwire (initial diameter of 0.3 mm) after solution treatment is taken. The two ends of the nickel-titanium alloy microwire are designated as end A and end B, respectively. End A of the nickel-titanium alloy microwire is clamped by the microwire chuck 70, and the position of the lifting plate 50 is adjusted so that end B of the nickel-titanium alloy microwire contacts the etching solution and is immersed in the etching solution at a uniform speed. The immersion length is 30 mm. After the immersion process is maintained for 30 minutes, the microwire chuck is released, the nickel-titanium alloy microwire is taken out of the etching solution, and then cleaned.

[0050] In step S1, the etching solution is a corrosive solution capable of corroding nickel-titanium alloy microwires. Preferably, in this embodiment, the etching solution is a hydrofluoric acid and nitric acid solution, and the ratio of hydrofluoric acid, nitric acid and water is 1:4:20.

[0051] Step S2, as follows Figure 5 As shown, the glass cup is removed from the groove, the drawing die 40 is placed into the groove, and the drawing die 40 is fixed with the quick clamp 32. The B end of the nickel-titanium alloy micro wire is passed through the lower part of the drawing platform 30 and through the through hole into the drawing die 40, and then the end of the nickel-titanium alloy micro wire is threaded through the die.

[0052] Step S2, which involves threading the end of the nickel-titanium alloy microwire through a die, includes the following sub-steps:

[0053] Step S2-1: Control the lifting plate 50 to move to a position where the micro wire chuck 70 can clamp the B end of the nickel-titanium alloy micro wire. The micro wire chuck 70 clamps the nickel-titanium alloy micro wire at a position 5mm from the end of the B end of the nickel-titanium alloy micro wire, and then moves it upward 5mm after clamping.

[0054] Step S2-2: Release the micro-wire chuck 70, control the lifting plate 50 to move downward, and clamp the nickel-titanium alloy micro-wire again through the micro-wire chuck 70. The clamping position is 15mm away from the B end of the nickel-titanium alloy micro-wire. After clamping, move upward 15mm.

[0055] Step S2-3: Release the microwire chuck 70 again, control the lifting plate 50 to move downward, and clamp the nickel-titanium alloy microwire again through the microwire chuck 70. The clamping position is 30mm away from the B end of the nickel-titanium alloy microwire. After clamping, move upward 20mm.

[0056] Step S2-4: Loosen the micro-wire chuck 70, control the lifting plate 50 to move downward, and clamp the nickel-titanium alloy micro-wire through the micro-wire chuck 70. The clamping position is 50mm away from the B end of the nickel-titanium alloy micro-wire, thus completing the end-mold insertion of the nickel-titanium alloy micro-wire.

[0057] Step S3: After the end die is completed, maintain the clamping state and control the lifting plate 50 to move upward slowly (20mm / min). According to the real-time measurement data displayed by the force gauge 60, fine-tune the XY bidirectional fine-tuning platform 20 to adjust the position of the drawing die 40. When the die exit direction of the titanium alloy micro wire is parallel to the axis of the drawing die 40, and the real-time measurement data of the force gauge 60 is minimized, control the lifting plate 50 to move upward quickly (300mm / min) to draw until the nickel-titanium alloy micro wire has completely passed through the drawing die 40.

[0058] Step S4: Repeat steps S1 to S3 for a total of 7 cold drawing passes until the desired nickel-titanium alloy microwire with reduced surface area is obtained.

[0059] When the diameter of the nickel-titanium alloy microwire before drawing is 0.2mm to 0.3mm, the reduction rate per pass must be less than 40%; when the diameter before drawing is 0.11mm to 0.2mm, the reduction rate per pass must be less than 30%; and when the diameter before drawing is less than 0.11mm, the reduction rate per pass must be less than 20%.

[0060] Table 1. Parameters of each pull-down process.

[0061]

[0062]

[0063] In this embodiment, as shown in Table 1, a total of 7 cold drawing passes were performed. In each pass, the immersion length of the nickel-titanium alloy microwire in the etching solution was 30 mm. The immersion times for passes 1 to 7 were 30 min, 20 min, 15 min, 12 min, 10 min, 8 min, and 5 min, respectively. The drawing die orifices used for passes 1 to 7 were 0.25 mm, 0.2 mm, 0.17 mm, 0.15 mm, 0.13 mm, 0.11 mm, and 0.1 mm, respectively. The nickel-titanium alloy microwire with an initial diameter of 0.3 mm was reduced to 0.1 mm after 7 cold drawing passes, achieving a total reduction in surface area of ​​88.9%.

[0064] The role and effect of the embodiments

[0065] The nickel-titanium alloy micro-wire cold drawing apparatus and method involved in this embodiment uses a force gauge to measure the tensile force data of the micro-wire chuck in real time, and then uses an XY bidirectional fine-tuning platform to finely adjust the position of the drawing die accordingly, minimizing the real-time measurement data of the force gauge. This ensures that the micro-wire's exit direction is parallel to the axis of the drawing die, effectively solving the problem of the micro-wire's exit direction deviating from the center line of the drawing die. Furthermore, this embodiment uses a gradient etching solution to corrode the end of the nickel-titanium alloy micro-wire, and uses the micro-wire chuck to repeatedly clamp and move the end of the nickel-titanium alloy micro-wire to complete the die-cutting process, effectively solving the problem of difficulty in cutting the micro-wire end through the die. Therefore, this embodiment solves the problems of difficulty in cutting the micro-wire end through the die and deviation of the micro-wire's exit direction from the center line of the drawing die. Using the nickel-titanium alloy micro-wire cold drawing apparatus and method of this embodiment, the cold drawing of nickel-titanium alloy micro-wires can achieve a reduction in surface area of ​​nearly 90%, which is a significant improvement compared to the 40%–60% reduction in surface area achieved by existing technologies.

[0066] The above embodiments are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A cold drawing method of a fine wire of a nickel-titanium alloy, characterized by, The nickel-titanium alloy micro-wire cold drawing device uses a nickel-titanium alloy micro-wire cold drawing device, The nickel-titanium alloy micro-wire cold drawing device comprises a rack, an XY two-way fine adjustment platform fixed on the base, a drawing platform installed on the upper plane of the XY two-way fine adjustment platform through a connecting plate, an upper surface of the drawing platform being provided with a groove, a drawing die installed in the groove and having a die hole through which the nickel-titanium alloy micro-wire passes, a lifting plate installed on the guide rail for longitudinal lifting movement, and a micro-wire chuck installed on the lifting plate through a dynamometer for clamping the nickel-titanium alloy micro-wire above the drawing die and drawing the nickel-titanium alloy micro-wire under the driving of the lifting plate, wherein a through hole through which the nickel-titanium alloy micro-wire passes is further arranged below the groove, and the upper plane of the XY two-way fine adjustment platform is a movable workbench surface for adjusting the position of the drawing die by fine adjusting the position of the upper plane according to the real-time measurement data of the dynamometer so that the ejection direction of the nickel-titanium alloy micro-wire is parallel to the axis of the drawing die, The nickel-titanium alloy micro-wire cold drawing method comprises the following steps: Step S1, taking the nickel-titanium alloy micro-wire after solid solution treatment, taking the two ends of the nickel-titanium alloy micro-wire as A end and B end respectively, uniformly immersing the B end of the nickel-titanium alloy micro-wire into the corrosion liquid, taking out after a period of immersion and cleaning; Step S2, placing the drawing die into the groove and fixing the drawing die using a quick clamp, passing the B end of the nickel-titanium alloy micro-wire through the lower part of the drawing platform and the through hole into the drawing die, and then performing end threading of the nickel-titanium alloy micro-wire, wherein the end threading of the nickel-titanium alloy micro-wire in step S2 comprises the following sub-steps: Step S2-1, controlling the lifting plate to move to a position where the micro-wire chuck can clamp the B end of the nickel-titanium alloy micro-wire, clamping the nickel-titanium alloy micro-wire through the micro-wire chuck, the clamping position being 5mm away from the B end of the nickel-titanium alloy micro-wire, and moving upward 5mm after clamping, Step S2-2, loosening the micro-wire chuck, controlling the lifting plate to move downward, clamping the nickel-titanium alloy micro-wire through the micro-wire chuck again, the clamping position being 15mm away from the B end of the nickel-titanium alloy micro-wire, and moving upward 15mm after clamping, Step S2-3, loosening the micro-wire chuck again, controlling the lifting plate to move downward, clamping the nickel-titanium alloy micro-wire through the micro-wire chuck again, the clamping position being 30mm away from the B end of the nickel-titanium alloy micro-wire, and moving upward 20mm after clamping, Step S2-4, loosening the micro-wire chuck, controlling the lifting plate to move downward, clamping the nickel-titanium alloy micro-wire through the micro-wire chuck, the clamping position being 50mm away from the B end of the nickel-titanium alloy micro-wire, and completing the end threading of the nickel-titanium alloy micro-wire, The nickel-titanium alloy micro-wire cold drawing method comprises the following steps: Step S3, after the end of the die, keep the clamping state and control the slow upward movement of the lifting plate, according to the real-time measurement data of the load cell, fine-tune the XY two-way fine-tuning platform to make the real-time measurement data of the load cell minimum, and then control the lifting plate to move upward quickly for drawing until the nickel-titanium alloy micro-wire completely passes through the drawing die; Step S4, repeat steps S1-S3 to perform multi-pass cold drawing until the desired reduction ratio of the nickel-titanium alloy micro-wire is obtained, When the diameter of the nickel-titanium alloy micro-wire before drawing is 0.2mm-0.3mm, the pass reduction ratio needs to be less than 40%; When the diameter of the nickel-titanium alloy micro-wire before drawing is 0.11mm-0.2mm, the pass reduction ratio needs to be less than 30%; When the diameter of the nickel-titanium alloy micro-wire before drawing is 0.11mm or less, the pass reduction ratio needs to be less than 20%.

2. The cold drawing method of the nickel-titanium alloy micro-wire according to claim 1, characterized in that: wherein The drawing platform is also provided with two quick clamps, and the drawing die is fixed in position by the quick clamps after being placed in the groove.

3. The cold drawing method of the nickel-titanium alloy micro-wire according to claim 1, characterized in that: wherein The lifting plate is controlled to rise and fall by an external driving structure or manually.

4. The cold drawing method of the nickel-titanium alloy micro-wire according to claim 1, characterized in that: wherein In step S1, the total length of the nickel-titanium alloy micro-wire immersed in the etching liquid is 20mm-50mm, and the total time of the immersion process is 5min-30min.

5. The cold drawing method of the nickel-titanium alloy micro-wire according to claim 1, characterized in that: wherein, In step S3, the speed of the slow upward movement of the lifting plate is 10mm / min-50mm / min, and the speed of the fast upward movement of the lifting plate is 300mm / min-500mm / min.

Images