Electrolytic polishing system for titanium alloy ultrafine wires and polishing method of electrolytic polishing system

Abstract

The electrolytic polishing system comprises an electrolytic tank, the electrolytic tank is internally provided with a cathode tube, the cathode tube is provided with a plurality of layers of cylindrical barrels which are coaxially arranged in a sleeved mode and are different in diameter, and the cathode tube is arranged in the horizontal direction of the central axis; the potential of the cathode tube is higher than that of the titanium alloy ultrafine wire to be polished; the two insulated supporting nets are arranged at the two ends of the cathode tube; each supporting net comprises an inner circular ring and an outer circular ring which are concentrically arranged, a plurality of supporting rods are arranged between the inner circular ring and the outer circular ring in the radius direction of the supporting nets, and buckles are arranged at the positions, intersecting with the cylinder bodies, of the supporting rods; the buckles are used for clamping the corresponding barrels; the cathode sliding conducting strip is located on the outer side of one supporting net and used for being connected with a cathode of the direct-current power source; the anode guide wheel is located on the outer side of the other supporting net and used for being connected with an anode of a direct-current power source. The problems that an existing titanium alloy ultrafine wire cannot be subjected to online electrolytic polishing, and the diameter reduction of the polished wire is not uniform are solved.

Description

[Technical field]

[0001] The invention belongs to the technical field of surface treatment of titanium alloy ultrafine wires, and particularly relates to an electrolytic polishing system and a polishing method for titanium alloy ultrafine wires. [Background technology]

[0002] In the medical field, with the growing demand for high-precision, high-purity medical devices, TC4 titanium alloy ultrafine wire has become a key material for manufacturing precision medical implants and devices due to its excellent mechanical properties, excellent corrosion resistance and good biocompatibility. However, the surface treatment of this ultrafine wire, especially the realization of a highly bright and uniform surface, has become a technical challenge. Traditional mechanical polishing methods are difficult to meet medical grade requirements because they are prone to wire deformation and breakage, and it is difficult to achieve the ideal surface finish.

[0003] In this context, electropolishing, as an advanced surface treatment technology, has gradually emerged in the surface treatment of TC4 titanium alloy ultrafine wires for medical use. The advantage of electropolishing is that it can evenly and efficiently remove the microscopic unevenness and oxide layer on the surface of the material without direct contact with the workpiece, thus avoiding deformation and damage caused by mechanical stress. In addition, electropolishing can significantly improve the surface finish and corrosion resistance of the material, reduce the risk of bacterial adhesion, and improve the biocompatibility and service life of medical devices.

[0004] In particular, for TC4 titanium alloy ultrafine wire, electrolytic polishing technology can accurately control the polishing process, avoid excessive corrosion or the generation of local corrosion pits, and ensure that the diameter and performance of the wire remain stable during the polishing process. At the same time, electrolytic polishing also has the advantages of high production efficiency, high degree of automation, and low environmental pollution, which meets the needs of modern medical manufacturing industry for efficient, environmentally friendly, and high-quality production.

[0005] Since ultrafine wires have a huge specific surface area due to their extremely fine diameter, and the surface oxide layer exhibits extremely strong adhesion properties, these characteristics significantly increase the complexity and difficulty of achieving surface brightening treatment, resulting in electrolytic polishing being a major technical bottleneck for ultrafine wires. [Summary of the invention]

[0006] The purpose of the present invention is to provide an electrolytic polishing system for titanium alloy ultrafine wires to solve the problems that the existing titanium alloy ultrafine wires cannot be electrolytically polished online and the wire diameter reduction is uneven after polishing.

[0007] The present invention adopts the following technical scheme: an electrolytic polishing system for titanium alloy ultrafine wires, comprising an electrolytic cell, wherein the electrolytic cell is provided with:

[0008] A cathode tube having multiple coaxially sleeved cylindrical bodies of different diameters, which are arranged horizontally along the central axis; the potential of the cathode tube is higher than the potential of the titanium alloy ultrafine wire to be polished;

[0009] Two insulating support nets are arranged at both ends of the cathode tube; each support net comprises an inner ring and an outer ring arranged concentrically, a plurality of support rods are arranged between the inner ring and the outer ring along the radial direction thereof, and buckles are arranged on each support rod at the intersection with each layer of the cylinder; the buckles are used to clamp the corresponding cylinder;

[0010] A cathode sliding conductive sheet, located outside one of the support nets, used to connect to the cathode of a DC power source;

[0011] an anode guide wheel, located outside the other support mesh, for connecting the anode of the DC power supply;

[0012] The cathode sliding conductive sheet includes a conductive connecting rod fixed on the inner wall of the electrolytic cell, which is connected to the cathode of the DC power supply, and the conductive connecting rod is parallel to and does not contact the supporting net; a sliding guide rod is provided on the conductive connecting rod, which can move back and forth along the conductive connecting rod; the sliding guide rod is connected to a conductive sheet, and the conductive sheet points to the inside of the cathode tube; the conductive sheet is used to contact and conduct electricity with cylinders of different radii on the cathode tube in sequence during the process of following the movement of the sliding guide rod;

[0013] Among them, the cylinder with the smallest diameter in the cathode tube is used for the passage of the titanium alloy ultrafine wire to be polished; the cathode tube is used to select one layer of the cylinder to contact and conduct electricity with the conductive sheet during the sliding process of the sliding guide rod; the anode guide wheel is used to contact and conduct electricity with the titanium alloy ultrafine wire to be polished; the cathode cylinder and a section of the titanium alloy ultrafine wire to be polished located in the cathode tube and the electrolyte form a dynamic and complete electrolysis circuit.

[0014] Furthermore, the electrolytic polishing device also includes a DC power supply, which is located outside the electrolytic cell, with its anode connected to the anode guide wheel and its cathode connected to the conductive connecting rod.

[0015] Furthermore, a pair of middle guide wheels are arranged on the outer side of the cathode sliding conductive sheet.

[0016] Furthermore, a tension wheel and a retractable wire wheel are sequentially arranged on the side of the centering guide wheel away from the cathode tube.

[0017] Furthermore, a tension wheel and a take-up and pay-off wheel are sequentially arranged on the side of the anode guide wheel away from the cathode tube.

[0018] Furthermore, an ultrasonic cleaning tank is arranged on one side of the electrolytic cell close to the wire output.

[0019] Furthermore, the diameter of the titanium alloy ultrafine wire to be polished is d, the outer diameter of the cylinder connected to the cathode is D=(20-500)d, the spacing between adjacent cylinders is 0.1-10mm, and the ratio of the outer diameter of a single-layer cylinder to its wall thickness is 20-50.

[0020] The present invention also provides an electrolytic polishing method of an electrolytic polishing system for titanium alloy ultrafine wires, based on the electrolytic polishing system for titanium alloy ultrafine wires, comprising the following contents:

[0021] Step 1, the titanium alloy ultrafine wire to be polished passes through the anode guide wheel, passes into the cylinder with the smallest diameter in the cathode tube, passes through the cathode tube, passes through the centering guide wheel, enters the electrolytic cell, passes through the electrolytic cell, passes through the ultrasonic cleaning cell, and is finally collected by the pay-off and take-up wheel;

[0022] Step 2, adjusting the sliding guide rod on the cathode sliding conductive sheet and connecting it to the cylinder with an outer diameter of D in the cathode tube to obtain a closed loop; wherein D = (20-500) d, d is the diameter of the titanium alloy ultrafine wire to be polished;

[0023] Step 3: Adjust the centering guide wheel, two tension wheels and anode guide wheel; confirm that the ultra-fine titanium alloy wire to be polished fits tightly with the anode guide wheel during operation without shaking;

[0024] Step 4: Turn on the electrolyte circulation pump to fully immerse the cathode tube in the electrolyte, and confirm the electrolyte temperature;

[0025] Step 5, set the DC power supply voltage to 5-80V, turn on the DC power supply, adjust the DC power supply voltage to cover the contact voltage drop of the anode guide wheel, and start electrolytic polishing;

[0026] At the same time, the wire-retracting and -releasing device is turned on, and the ultrasonic cleaning pool is turned on to obtain the electrolytically polished titanium alloy ultrafine wire after cleaning.

[0027] Furthermore, in step 1, the tension of the two tension wheels is ≤ (1-5%) of the tensile strength, the retracting and releasing line speed is 1-5 m / min, and the running speed of the titanium alloy ultrafine wire to be polished is 1-50 m / min.

[0028] Furthermore, in step 4, the electrolyte temperature is less than 80° C. and the pH value is in the range of 1-6.

[0029] The beneficial effects of the present invention are as follows: the present invention uses a cathode tube with a multi-layer cylindrical barrel structure as a polishing cathode. During the electrolysis process, the curved surface of the cathode tube and the curved surface of the wire material achieve the same curvature and equidistant distance. Then, electrolysis is performed according to the optimal spacing determined by the Hull cell experiment, thereby achieving the multi-directional synergy of the wire material during the electrolytic polishing process. This process can not only fully guarantee the polishing effect on the surface of the wire material, but also ensure that the wire material has the same diameter reduction at different positions due to the uniform electric field distribution and ion distribution in the tube-mounted cathode. The present invention designs the cathode tube as a multi-layer cylindrical barrel structure, and the barrels are not connected. According to the wire diameter of the titanium alloy ultrafine wire connected to the anode, the size of the barrel connected to the cathode is adjusted accordingly, which can meet the polishing requirements of materials with different surface areas, expand the scope of electrolytic polishing, improve usability, and fully guarantee the polishing effect.

Brief Description of the Drawings

[0030] Figure 1 It is a structural schematic diagram of the electrolytic polishing system of the titanium alloy ultrafine wire of the present invention;

[0031] Figure 2 for Figure 1 An enlarged schematic diagram of the middle support net;

[0032] Figures 3 to 5 The surface quality test result diagrams of wires of different specifications are obtained for Examples 1 to 3 respectively.

[0033] Among them, 1. Centering guide wheel; 2. Anode guide wheel; 3. Cathode tube; 31. Cylinder; 4. Operating table; 5. Ultrasonic cleaning tank; 6. Tension wheel; 7. Retracting and releasing wheel; 8. Support net; 81. Inner ring; 82. Outer ring; 83. Support rod; 84. Buckle; 9. Cathode sliding conductive sheet; 91. Conductive connecting rod; 92. Sliding guide rod; 93. Conductive sheet; 10. Electrolytic cell; 11. DC power supply. [Specific implementation method]

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] The present invention provides an electrolytic polishing system for titanium alloy ultrafine wires, wherein the diameter of the titanium alloy ultrafine wires to be polished is 0.1-0.5 mm. Figure 1As shown, the electrolytic polishing system includes an electrolytic cell 10 filled with an electrolyte. The electrolyte is an alkyd system, which is composed of perchloric acid, methanol and ethanol, wherein perchloric acid: methanol: ethylene glycol = 1-10: 5-10: 1-5, the voltage range during the electrolysis process is 0-100V, the pH value is 1-6, and the liquid temperature during the process should be maintained at 0-80°C. The electrolyte is transported from the reservoir to the electrolytic cell 10 via a circulation pump, and a replaceable filter element is provided in the reservoir. The electrolytic cell 10 is provided with a temperature and concentration sensor, which can be read and controlled by the operating console 4. When the electrolyte temperature is higher than the set temperature, the cooling circulation pump can be turned on by the operating console 4.

[0036] The electrolytic cell 10 is provided with a cathode tube 3, two insulating support nets 8, a cathode sliding conductive sheet 9 and an anode guide wheel 2. The specific structure is as follows:

[0037] The cathode tube 3 has multiple layers of coaxially sleeved cylindrical barrels 31 of different diameters, which are arranged horizontally along the central axis; the potential of the cathode tube 3 is higher than the potential of the titanium alloy ultrafine wire to be polished; the cathode tube 3 is composed of multiple layers of thin-walled barrels 31, and the radius of the barrels 31 increases layer by layer from the inside to the outside.

[0038] The principle of electrolytic polishing is to use the electrolytic cell anode to dissolve to remove impurities and oxides on the anode surface. During the electrolytic polishing process, when the current passes through the anode, the anode will dissolve, the metal atoms will lose electrons and release positive ions. These positive ions then undergo an oxidation reaction with the negatively charged ions in the electrolyte to generate corresponding metal salts near the anode. At the same time, the cathode obtains electrons, causing the positively charged ions in the electrolyte to undergo a reduction reaction on the cathode surface to generate reduction products. The anode and cathode of the electrolytic cell gain and lose electrons through the ions in the electrolyte, forming a closed electrolytic loop. Therefore, according to the type of titanium alloy ultrafine wire to be polished, the cathode tube material in the present invention needs to use a material with a higher potential than the titanium alloy ultrafine wire to be polished. For example, platinum is used to make the cathode tube 3, which has a higher potential than titanium and titanium alloy materials and has good conductivity.

[0039] Two insulating support nets 8 are arranged at both ends of the cathode tube 3; each support net 8 comprises an inner ring 81 and an outer ring 82 which are arranged concentrically, a plurality of support rods 83 are arranged between the inner ring 81 and the outer ring 82 along the radial direction thereof, and buckles 84 are arranged on each support rod 83 at the intersection with each layer of the cylinder 31; the buckles 84 are used to clamp the corresponding cylinder 31;

[0040] A cathode sliding conductive sheet 9 is located outside one of the support nets 8 and is used to connect the cathode of the DC power supply; an anode guide wheel 2 is located outside the other support net 8 and is used to connect the anode of the DC power supply. The anode guide wheel 2 is made of graphite, coke or carbon ink, with a resistivity of 1 to 5, a guide wheel hardness of 30 to 35 Hv, a contact voltage drop of 0 to 20 V, and a friction coefficient of 0 to 0.5 mm.

[0041] The cathode sliding conductive sheet 9 and the anode guide wheel 2 are arranged on both sides of the cathode tube 3 respectively. This distribution can increase the closed loop length of the electrolytic cell, make the movement range of ions in the electrolyte cover the movement range of the wire, and make the electrolysis process more uniform.

[0042] Among them, the cathode sliding conductive sheet 9 includes a conductive connecting rod 91 fixed on the inner wall of the electrolytic cell 10, which is connected to the cathode of the DC power supply, and the conductive connecting rod 91 is parallel to and does not contact the support net 8; the conductive connecting rod 91 is provided with a sliding guide rod 92 that can move back and forth along it; the sliding guide rod 92 is connected to a conductive sheet 93, and the conductive sheet 93 points to the inside of the cathode tube 3; the conductive sheet 93 is used to contact and conduct electricity with the cylinders 31 of different radii on the cathode tube 3 in sequence during the process of following the movement of the sliding guide rod 92.

[0043] Among them, the cylinder 31 with the smallest diameter in the cathode tube 3 is used for the titanium alloy ultrafine wire to be polished to pass through; the cathode tube 3 is used to select one layer of the cylinder 31 to contact and conduct electricity with the conductive sheet 93 during the sliding process of the sliding guide rod 92; the anode guide wheel 2 is used to contact and conduct electricity with the titanium alloy ultrafine wire to be polished; the cathode cylinder 31 and a section of the titanium alloy ultrafine wire to be polished and the electrolyte located in the cathode tube 3 form a dynamic and complete electrolysis circuit.

[0044] Since the anode titanium alloy ultrafine wire to be polished is always in a moving state, only a section of the titanium alloy ultrafine wire to be polished located inside the cathode tube 3, the cylinder 31 connected to the cathode and the electrolyte constitute a closed electrolytic circuit, and the titanium alloy ultrafine wire to be polished located inside the cathode tube 3 can be polished and electrolyzed. The electrolytic circuit is dynamically changing, because when the titanium alloy ultrafine wire to be polished is sent out from the cathode tube 3, the titanium alloy ultrafine wire to be polished located outside the cathode tube does not form an electrolytic circuit. This dynamic process realizes the online electrolytic polishing of the wire, and the wire length is not limited by the length of the electrolytic polishing pool, and the effective processing length can be ≥2000m.

[0045] The titanium alloy ultrafine wire to be polished is used as the anode in the electrolytic cell 10, and the cathode tube 3 is used as the cathode. After the DC power supply is turned on, an electrolytic reaction occurs to achieve the purpose of removing the oxide layer on the surface of the wire. The cathode tube 3 is designed as a multi-layer thin-walled cylinder structure in the present invention. By adjusting the position of the sliding conductive sheet, a certain layer of the cylinder 31 to be connected is selected according to the size of the wire diameter of the titanium alloy ultrafine wire to be polished, that is, the spacing between the anode and cathode is determined, which can minimize the diameter reduction of the wire during the polishing process and improve the yield rate of the product.

[0046] The present invention designs the cathode tube 3 as a multi-layer cylinder structure, and the spacing between the cathode and cathode can be adjusted according to the wire diameter of the titanium alloy ultrafine wire to be polished, which can minimize the diameter reduction of the titanium alloy ultrafine wire to be polished during the polishing process. The present invention uses a multi-layer coaxial cylindrical cylinder 31 as a cathode tube. During the electrolysis process, the curved surface of the cathode is the same as the curved surface and curvature of the titanium alloy ultrafine wire to be polished, and the spacing distance is equal. The electric field distribution and ion distribution in the cathode tube 3 are uniform, which can ensure that the diameter reduction of the titanium alloy ultrafine wire to be polished is consistent when electrolyzed at different positions, and fully ensure the polishing effect of the wire surface.

[0047] In some embodiments, the electrolytic polishing device also includes a DC power supply 11, which is located outside the electrolytic cell 10, whose anode is connected to the anode guide wheel 2, and whose cathode is connected to the conductive connecting rod 91.

[0048] In some embodiments, a pair of centering guide wheels 1 are arranged outside the cathode sliding conductive sheet 9. The centering guide wheel 1 is a deep V-shaped guide wheel, and the guide wheel bearing is fixed on an adjustable support frame. The centering guide wheel 1 can be adjusted up and down and forward and backward to ensure that the titanium alloy ultrafine wire to be polished is stably in a coaxial position with the cathode tube 3.

[0049] In some embodiments, a tension wheel 6 and a retracting and releasing wheel 7 are sequentially arranged on the side of the centering guide wheel 1 away from the cathode tube 3. During the adjustment of the tension wheel 6, it is necessary to ensure that the titanium alloy ultrafine wire to be polished is closely fitted with the anode guide wheel 2, and the titanium alloy ultrafine wire to be polished is always in a coaxial position with the cathode tube 3, so that the distance from the circumference of the cathode tube 3 to the inner wall of the cathode tube 3 is equal.

[0050] Through the coordinated adjustment of the center guide wheel 1 and the tension wheel 6, the titanium alloy ultrafine wire to be polished is in a tension pre-tightened state, and the tension it bears is less than 1-5% Rm. At the same time, it keeps a close fit with the anode guide wheel 2, maintains the anode voltage in a stable state, and can run stably at a high speed. The polishing speed reaches 50m / min, which is much greater than the approximately 5m / min of an ordinary belt polisher.

[0051] In some embodiments, a tension wheel 6 and a retracting and releasing wheel 7 are sequentially arranged on a side of the anode guide wheel 2 away from the cathode tube 3 .

[0052] Several small guide wheels are arranged between the anode guide wheel 2 and the adjacent tension wheel 6, and several small guide wheels are also arranged between the centering guide wheel 1 and the adjacent tension wheel 6. Through the arrangement and coordination of the small guide wheels, the possible shaking of the wire under the action of tension can be effectively reduced, so that the ultra-fine wire enters the electrolytic cell evenly and stably under the action of tension, and the electrolyte completely immerses the wire.

[0053] In some embodiments, an ultrasonic cleaning tank 5 is provided on the side of the electrolytic tank 10 close to the wire outlet. The cleaning frequency of the ultrasonic cleaning tank 5 is 10-100 Hz.

[0054] In some embodiments, the diameter of the titanium alloy ultrafine wire to be polished is d, the diameter of the cylinder 31 connected to the cathode is D=(20-500)d, the spacing between adjacent cylinders 31 is 0.1-10mm, and the ratio of the outer diameter of the single-layer cylinder 31 to its wall thickness is 20-50.

[0055] The positions of the layers of cylinders 31 in the cathode tube 3 are supported by an insulating support net 8, and the head and tail of the multi-layer cylinder 31 are fixed by the support net 8. The inner ring 81 and the outer ring 82 on the support net 8 are coaxial with the multi-layer cylinder 31. The inner ring 81 and the outer ring 82 are evenly distributed with multiple buckles 84 along the radial direction. The multi-layer cylinder 31 is fixed from the inside to the outside to the position of the buckle 84 to ensure that the spacing between the multi-layer cylinders 31 meets the requirement of 0.1-10mm.

[0056] It also includes an operating table, which is equipped with an electrolytic cell temperature, concentration sensor and electrolyte circulation cooling and filtering pump. Detection and recording are carried out along with the electrolysis process. The circulating cooling pump realizes the circulation of the electrolyte. The filter element in the liquid storage tank filters the oxide and cools the electrolyte at the same time to ensure the constant temperature of the electrolyte, achieve uniformity of the electrolyte during the electrolysis process, and achieve consistency between the beginning and the end of the wire polishing process.

[0057] The present invention also provides an electrolytic polishing method of an electrolytic polishing system for titanium alloy ultrafine wires, comprising the following contents:

[0058] Step 1, the titanium alloy ultrafine wire to be polished passes through the anode guide wheel 2, passes into the cylinder 31 with the smallest diameter in the cathode tube 3, passes through the centering guide wheel 1 after passing through the cathode tube 3, passes through the electrolytic cell 10 after passing through the electrolytic cell 10, passes through the ultrasonic cleaning cell 5 after passing through the electrolytic cell 10, and is finally collected by the pay-off and take-up wheel 7;

[0059] Step 2, adjusting the sliding guide rod 92 on the cathode sliding conductive sheet 9, and connecting it to the cylinder 31 with an outer diameter of D in the cathode tube 3, so as to obtain a closed loop; wherein D = (20-500) d, d is the diameter of the titanium alloy ultrafine wire to be polished;

[0060] Step 3, adjust the centering guide wheel 1, the two tension wheels 6 and the anode guide wheel 2; observe the online operation of the titanium alloy superfine wire to be polished passing through the anode guide wheel 2, and confirm that the titanium alloy superfine wire to be polished is closely attached to the anode guide wheel 2 during operation without shaking;

[0061] Step 4, turn on the electrolyte circulation pump to fully immerse the cathode tube 3 in the electrolyte, and confirm the electrolyte temperature;

[0062] Step 5, set the DC power supply voltage to 5-80V, turn on the DC power supply 11, adjust the voltage of the DC power supply 11 to cover the contact voltage drop of the anode guide wheel 2, and start electrolytic polishing;

[0063] At the same time, the wire-reeling device is turned on, and the ultrasonic cleaning pool 5 is turned on. Deionized water is used for ultrasonic cleaning to clean the electrolyte remaining on the surface of the titanium alloy ultrafine wire to be polished, so as to obtain the cleaned electrolytically polished titanium alloy ultrafine wire.

[0064] In some embodiments, in step 1, the tension of the two tension wheels 6 is ≤ (1-5%) of the tensile strength, the retracting and releasing line speed is 1-5 m / min, and the running speed of the ultrafine titanium alloy wire to be polished is 1-50 m / min. The tensile strength is measured during the polishing process.

[0065] In some embodiments, in step 4, the electrolyte temperature is less than 80° C. and the pH value is in the range of 1-6.

[0066] Example

[0067] The present invention carries out Examples 1 to 3 according to the following method, and the parameters in each example are shown in Table 1.

[0068] Step 1, the titanium alloy ultrafine wire to be polished passes through the anode guide wheel 2, passes into the cylinder 31 with the smallest diameter in the cathode tube 3, passes through the centering guide wheel 1 after passing through the cathode tube 3, passes through the electrolytic cell 10 after passing through the electrolytic cell 10, passes through the ultrasonic cleaning cell 5 after passing through the electrolytic cell 10, and is finally collected by the pay-off and take-up wheel 7;

[0069] Step 2, adjusting the sliding guide rod 92 on the cathode sliding conductive sheet 9, and connecting it to the cylinder 31 with an outer diameter of D in the cathode tube 3, so as to obtain a closed loop; wherein D = (20-500) d, d is the diameter of the titanium alloy ultrafine wire to be polished;

[0070] Step 3, adjust the centering guide wheel 1, the two tension wheels 6 and the anode guide wheel 2; confirm that the titanium alloy ultrafine wire to be polished is tightly fitted with the anode guide wheel 2 during operation without shaking;

[0071] Step 4, turn on the electrolyte circulation pump to fully immerse the cathode tube 3 in the electrolyte, and confirm the electrolyte temperature;

[0072] Step 5, turning on the DC power supply 11, adjusting the voltage of the DC power supply 11 to cover the contact voltage drop of the anode guide wheel 2, and electrolytic polishing begins;

[0073] At the same time, the wire-reeling and -releasing device is turned on, and the ultrasonic cleaning pool 5 is turned on to obtain the electrolytically polished titanium alloy ultrafine wire after cleaning.

[0074] Table 1 Process parameters involved in three embodiments

[0075]

[0076]

[0077] The electrolytic polishing length of conventional materials is limited by the length of the equipment, and the electrolytic polishing length is equal to the cathode length of the equipment. However, the lengths of the titanium alloy ultrafine wires to be polished processed by the above three embodiments are all over 2000m, and the wire length is not limited by the length of the electrolytic polishing pool, thus realizing online electrolytic polishing of the wire.

[0078] The three specifications of wires polished in Examples 1 to 3 were sampled for surface quality testing, and the surface quality test results of wires of different specifications were as follows: Figures 3 to 5 ,As can be seen from the figure, the surface quality of the three specifications of wires is bright.

[0079] Since conventional electrolysis equipment uses a structure in which an anode wire and a cathode plate cooperate for electrolysis, and the cathode plate is a flat plate structure, there is a difference in distance between the side of the wire close to the cathode plate and the side far from the cathode plate, and the size of the difference distance is the diameter of the polished wire, resulting in the same electrolytic polishing parameters. The polishing degree of the side close to the cathode plate is higher than the side far from the cathode plate, so the surface quality after the final electrolysis is not as uniform as the electrolysis effect using a cathode tube. In the present invention, due to the tubular structure adopted by the cathode tube 3, the electrolyte can evenly wrap the wire to be polished and the cathode tube, the wire and the cathode tube are concentric, and at different positions under the same curvature, the distance between the cathode tube and the wire to be polished is equal, which can effectively improve the uniformity of the diameter reduction of the titanium alloy ultrafine wire polishing, and can also accurately control the diameter of the bright wire.

[0080] The diameters of the titanium alloy ultrafine wires after polishing in the three embodiments are measured at random multiple points, for example, the diameters are measured at 10 positions of the titanium alloy ultrafine wires at random, and the measurement results are shown in Table 2. From the results in Table 2, it can be seen that the diameters of the titanium alloy ultrafine wires after polishing in the three embodiments are uniform, without melting, indicating that the diameter reduction is uniform during the electrolytic polishing process.

[0081] Table 2 Diameter statistics of titanium alloy ultrafine wires after polishing in three embodiments

[0082]

[0083] The present invention uses a cathode tube with a multi-layer cylindrical structure as a polishing cathode. During the electrolysis process, the curved surface of the cathode tube and the curved surface of the wire material achieve the same curvature and equidistance, and then electrolysis is performed according to the optimal spacing determined by the Hull cell experiment, so as to achieve multi-directional synergy of the wire material during the electrolytic polishing process. This process can not only fully guarantee the polishing effect of the wire surface, but also ensure that the wire material has the same diameter reduction at different positions due to the uniform electric field distribution and ion distribution in the tube-mounted cathode.

[0084] The cathode tube of the present invention is designed as a multi-layer cylindrical barrel structure, and the barrels are not connected. According to the wire diameter of the titanium alloy ultrafine wire connected to the anode, the size of the barrel connected to the cathode is adjusted accordingly, which can meet the polishing requirements of materials with different surface areas, expand the scope of electrolytic polishing, improve usability, and fully guarantee the polishing effect.

[0085] The present invention focuses on the application of electrolytic polishing technology in the surface treatment of 0.1-0.5mm TC4 titanium alloy ultrafine wires for medical use, aiming to further improve the surface quality and production efficiency of ultrafine wires by optimizing the electrolytic polishing process parameters, and to provide a more reliable and efficient solution for the manufacture of medical devices.

Claims

1. An electrolytic polishing system for titanium alloy ultrafine wires, characterized in that: The invention comprises an electrolytic cell (10), wherein the electrolytic cell (10) is provided with: A cathode tube (3) having a plurality of coaxially sleeved cylindrical barrels (31) of different diameters, which are arranged horizontally along the central axis; the potential of the cathode tube (3) is higher than the potential of the titanium alloy ultrafine wire to be polished; Two insulating support nets (8) are arranged at both ends of the cathode tube (3); each support net (8) comprises an inner ring (81) and an outer ring (82) which are arranged concentrically, a plurality of support rods (83) are arranged between the inner ring (81) and the outer ring (82) along their radial direction, and buckles (84) are arranged on each of the support rods (83) at the intersection with each layer of the cylinder (31); the buckles (84) are used to clamp the corresponding cylinder (31); a cathode sliding conductive sheet (9), located outside one of the supporting nets (8) and used for connecting to the cathode of a DC power source; an anode guide wheel (2), located outside the other supporting mesh (8), used for connecting the anode of the DC power supply; The cathode sliding conductive sheet (9) comprises a conductive connecting rod (91) fixed to the inner wall of the electrolytic cell (10), which is connected to the cathode of the DC power supply, and the conductive connecting rod (91) is parallel to and does not contact the supporting net (8); the conductive connecting rod (91) is provided with a sliding guide rod (92) which can reciprocate along the conductive connecting rod; the sliding guide rod (92) is connected to a conductive sheet (93), and the conductive sheet (93) points to the inside of the cathode tube (3); the conductive sheet (93) is used to contact and conduct electricity with cylinders (31) of different radii on the cathode tube (3) in sequence in the process of following the movement of the sliding guide rod (92); The cylinder (31) with the smallest diameter in the cathode tube (3) is used for the passage of the titanium alloy ultrafine wire to be polished; the cathode tube (3) is used to select one layer of the cylinder (31) to contact with the conductive sheet (93) for electrical conduction during the sliding process of the sliding guide rod (92); the anode guide wheel (2) is used to contact with the titanium alloy ultrafine wire to be polished for electrical conduction; the cathode cylinder (31) and a section of the titanium alloy ultrafine wire to be polished located in the cathode tube (3) and the electrolyte constitute a dynamic and complete electrolytic circuit.

2. The electrolytic polishing system for titanium alloy ultrafine wire according to claim 1, characterized in that: The electrolytic polishing device also includes a DC power supply (11), which is located outside the electrolytic cell (10), its anode is connected to the anode guide wheel (2), and its cathode is connected to the conductive connecting rod (91).

3. An electrolytic polishing system for titanium alloy ultrafine wires as claimed in claim 1 or 2, characterized in that: A pair of middle guide wheels (1) are arranged outside the cathode sliding conductive sheet (9).

4. The electrolytic polishing system for titanium alloy ultrafine wire according to claim 3, characterized in that: A tension wheel (6) and a retractable wire wheel (7) are sequentially arranged on a side of the centering guide wheel (1) away from the cathode tube (3).

5. The electrolytic polishing system for titanium alloy ultrafine wire according to claim 1 or 2, characterized in that: A tension wheel (6) and a retractable wire wheel (7) are sequentially arranged on a side of the anode guide wheel (2) away from the cathode tube (3).

6. An electrolytic polishing system for titanium alloy ultrafine wires as claimed in claim 1 or 2, characterized in that: An ultrasonic cleaning tank (5) is arranged on the side of the electrolytic tank (10) close to the wire output.

7. An electrolytic polishing system for titanium alloy ultrafine wires as claimed in claim 1 or 2, characterized in that: The diameter of the titanium alloy ultrafine wire to be polished is d, the outer diameter D of the cylinder (31) connected to the cathode is (20-500) d, the spacing between adjacent cylinders (31) is 0.1-10 mm, and the ratio of the outer diameter of a single-layer cylinder (31) to its wall thickness is 20-50.

8. An electrolytic polishing method of an electrolytic polishing system for titanium alloy ultrafine wires, characterized in that: The electrolytic polishing system of the titanium alloy ultrafine wire according to any one of claims 1 to 7 comprises the following contents: Step 1, passing the titanium alloy ultrafine wire to be polished through the anode guide wheel (2), passing into the cylinder (31) with the smallest diameter in the cathode tube (3), passing through the centering guide wheel (1) after passing through the cathode tube (3), passing through the electrolytic cell (10), passing through the ultrasonic cleaning cell (5) after passing through the electrolytic cell (10), and finally being collected by the pay-off and take-up wheel (7); Step 2, adjusting the sliding guide rod (92) on the cathode sliding conductive sheet (9) and connecting it to the cylinder (31) with an outer diameter of D in the cathode tube (3) to obtain a closed loop; wherein D = (20-500) d, d is the diameter of the titanium alloy ultrafine wire to be polished; Step 3, adjusting the centering guide wheel (1), the two tension wheels (6) and the anode guide wheel (2); confirming that the ultrafine titanium alloy wire to be polished is tightly fitted to the anode guide wheel (2) during operation without shaking; Step 4, turning on the electrolyte circulation pump to fully immerse the cathode tube (3) in the electrolyte, and confirming the electrolyte temperature; Step 5, setting the DC power supply voltage to 5-80V, turning on the DC power supply (11), adjusting the voltage of the DC power supply (11) to cover the contact voltage drop of the anode guide wheel (2), and starting electrolytic polishing; At the same time, the wire-reeling and -releasing device is turned on, and the ultrasonic cleaning pool (5) is turned on to obtain the electrolytically polished titanium alloy ultrafine wire after cleaning.

9. The electrolytic polishing method according to claim 8, characterized in that: In the step 1, the tension of the two tension wheels (6) is ≤ (1-5%) of the tensile strength, the retracting and releasing line speed is 1-5 m / min, and the running speed of the titanium alloy ultrafine wire to be polished is 1-50 m / min.

10. The electrolytic polishing method according to claim 9, characterized in that: In step 4, the electrolyte temperature is less than 80° C. and the pH value is in the range of 1-6.

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