Magnetoelectrochemical polishing apparatus, apparatus system and method for polishing both sides of an alloy strip

Abstract

The application provides a magnetoelectrochemical polishing device, a device system and a method for polishing both sides of an alloy strip, the magnetoelectrochemical polishing device comprising an electrolyte circulating tank, an electromagnet and an electrode arranged in the electrolyte circulating tank; the electromagnet comprises a first part, a second part, a third part and a conductive coil connected in sequence, the first part and the third part are oppositely arranged, and the second part is perpendicularly arranged with the first part and the third part; the first part, the second part and the third part are all made of magnet material, and the conductive coil is wound around the first part and the third part; the electrode is arranged in a region between the first part and the third part; the electrode comprises a first sub-electrode and a second sub-electrode; the first sub-electrode and the second sub-electrode are arranged on both sides of the alloy strip. The application can avoid the situation of edge over-polishing, improve polishing uniformity, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of polishing technology, and in particular to a magneto-electrochemical polishing apparatus, a system and method for double-sided polishing of alloy strips. Background Technology

[0002] With the rapid development of high-temperature superconducting technology, second-generation high-temperature superconducting tapes have attracted widespread attention in the field of materials science due to their excellent high-field performance at 77K. These superconducting tapes typically exhibit a multilayer film structure, generally consisting of a metal substrate, a buffer (isolation) layer, a superconducting layer, and a protective layer. The metal substrate not only serves as the mechanical support for the entire structure but also as the key substrate for the subsequent growth of functional thin films; its surface quality has a decisive influence on the film quality and final performance of the superconducting layers.

[0003] Therefore, surface polishing of metal substrates is considered one of the key processes for preparing high-performance second-generation high-temperature superconducting tapes.

[0004] The fabrication of second-generation high-temperature superconducting tapes can be divided into four main parts: a metal substrate, a buffer layer, a superconducting film layer, and a protective layer. In this structural system, the main functions of the metal substrate include: 1. providing a highly consistent physical and chemical substrate for the subsequent epitaxial growth of each functional layer; 2. providing the necessary mechanical strength for practical applications. Currently commonly used metal substrate materials include C-276 Hastelloy, stainless steel, and nickel-tungsten alloys, with typical thicknesses ranging from 50 to 100 μm and widths generally between 1 and 10 cm.

[0005] Given the complex multilayer structure of coated conductors, with each layer typically ranging from nanometers to micrometers in thickness, not only are good crystal orientation and microstructure required for each layer, but the substrate surface also needs to possess extremely high roughness. Even minute changes in surface roughness can lead to discontinuities in subsequent film growth, defect formation, or even a decrease in superconducting performance.

[0006] Therefore, the requirements for the surface roughness of metal substrates are extremely strict at present. They usually need to meet the following: the root mean square surface roughness (Rrms) should be less than 2nm within the scanning range of an atomic force microscope of 5μm×5μm.

[0007] To achieve the aforementioned technical specifications, pretreatment of the Hastelloy substrate surface is necessary. Currently, the most widely used and effective treatment method is electrochemical polishing. This process involves applying an appropriate current to an electrolyte with a specific composition, causing preferential anodic dissolution of microscopic protrusions on the metal surface, thereby achieving surface smoothing. However, during electrochemical polishing, the electric field strength at the edges is significantly higher than in the center, easily leading to over-polishing at the edges. This results in thinning of the substrate edge, weakening its resistance to mechanical tearing, and making it prone to crack propagation from the edges in subsequent processes.

[0008] Therefore, there is an urgent need to develop an improved polishing process that effectively avoids over-polishing of the edges. Summary of the Invention

[0009] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a magneto-electrochemical polishing device, a device system and method for double-sided polishing of alloy strips. By using a magneto-electrochemical polishing device, the polishing efficiency can be improved, the polishing area can be controlled, the surface quality can be improved, the polishing uniformity can be improved, and the local over-polishing can be reduced, which has broad application prospects.

[0010] To achieve this objective, the present invention adopts the following technical solution:

[0011] In a first aspect, the present invention provides a magneto-electrochemical polishing apparatus, comprising an electrolyte circulation tank and an electromagnet and electrodes disposed within the electrolyte circulation tank. The electromagnet comprises a first part, a second part, a third part, and a conductive coil connected sequentially. The first and third parts are disposed opposite to each other, and the second part is disposed perpendicular to both the first and third parts. The first, second, and third parts are all made of magnetic material, and the conductive coil is wound around the first and third parts. The electrodes are disposed in the region between the first and third parts. The electrodes include a first sub-electrode and a second sub-electrode. The first and second sub-electrodes are disposed on opposite sides of an alloy strip.

[0012] Magneto-electropolishing (MEG) is a novel surface treatment technology that combines magnetic field control with electrochemical polishing principles; its full name is usually magnetic field-assisted electrolytic polishing. It primarily utilizes the magnetohydrodynamic (MHD) effect generated by the introduction of a magnetic field. The presence of current in the electrolyte, combined with the Lorentz force generated by the applied magnetic field, agitates the electrolyte, accelerating its flow across the electrode surface. This thins the diffusion layer, enhances ion transport, and promotes more uniform dissolution. The electrochemical reaction generates bubbles on the workpiece surface; the magnetic field agitates the liquid, making these bubbles easier to detach and preventing uneven polishing caused by localized bubble formation. In areas with micro-protrusions and micro-pits, where local current densities differ, the fluid disturbance differences become more pronounced with the magnetic field. MEG helps to "smooth out" protrusions more quickly, increasing the smoothing rate. It further improves polishing efficiency, controls the polishing area, improves surface quality, enhances polishing uniformity, and reduces localized over-polishing.

[0013] Preferably, the electrodes include at least one set of cathodes and at least one set of anodes. Each set of cathodes and anodes is equipped with an electromagnet.

[0014] Preferably, when the electrode is a cathode, the first sub-electrode is a first sub-cathode, the second sub-electrode is a second sub-cathode, the first sub-cathode and the second sub-cathode are arranged in a mirror symmetrical manner, and an alloy strip is disposed between them, forming a cathode region between the first sub-cathode and the second sub-cathode.

[0015] Preferably, when the electrode is an anode, the first sub-electrode is a first sub-anode, the second sub-electrode is a second sub-anode, the first sub-anode and the second sub-anode are arranged in a mirror symmetrical manner, and an alloy strip is disposed between them, forming an anode region between the first sub-anode and the second sub-anode.

[0016] Preferably, the cathode and anode are alternately arranged in the electrolyte circulation tank.

[0017] Preferably, the conductive coil is made of copper.

[0018] Preferably, the number of turns of the conductive coil is 1000 to 3000 turns, for example, it can be 1000 turns, 1220 turns, 1440 turns, 1660 turns, 1800 turns, 2100 turns, 2300 turns, 2500 turns, 2700 turns or 3000 turns, etc.

[0019] Preferably, the second and third parts are cuboid structures.

[0020] Preferably, the width of the first, second and third parts of the electromagnet is independently 2 to 10 cm, for example, it can be 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm or 10 cm, etc.

[0021] Preferably, the thickness of the first, second and third parts of the electromagnet is independently 2 to 10 cm, for example, it can be 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm or 10 cm, etc.

[0022] Preferably, the lengths of the first, second, and third parts of the electromagnet are each independently 15-50cm, for example, 15cm, 19cm, 23cm, 27cm, 31cm, 35cm, 39cm, 43cm, 47cm, or 50cm.

[0023] Preferably, the conductive coil can be directly wound around the second and third parts.

[0024] Preferably, the electromagnet further includes a cylindrical structure disposed on the inner sides of the second and third parts.

[0025] Preferably, when the electromagnet further includes a cylindrical structure on the inner side of the second and third parts, the conductive coil is directly wound around the cylindrical structure.

[0026] Preferably, the magneto-electrochemical polishing device further includes an electromagnet protective housing disposed outside the electromagnet.

[0027] Preferably, the protective housing of the electromagnet is made of polytetrafluoroethylene.

[0028] Preferably, the anode is made of a titanium inner layer and a platinum layer disposed outside the titanium inner layer.

[0029] Preferably, the cathode is made of titanium.

[0030] Preferably, the electrolyte circulation tank is made of polytetrafluoroethylene.

[0031] In a second aspect, the present invention provides an apparatus system for double-sided polishing of alloy strips, the apparatus system comprising the magneto-electrochemical polishing apparatus described in the first aspect.

[0032] Preferably, along the production direction of the alloy strip, the device system includes, in sequence, an unwinding section, a first ultrasonic rough washing tank, a water washing tank, a first air knife groove, a magneto-electrochemical polishing device, a first rinsing tank, a passivation tank, a second rinsing tank, a second ultrasonic cleaning tank, a second air knife groove, a drying device, a roughness detector, and a winding section.

[0033] Thirdly, the present invention provides a method for double-sided polishing of alloy strips, wherein the method is performed using the magneto-electrochemical polishing apparatus described in the first aspect, and / or the method is performed using the double-sided polishing apparatus system for alloy strips described in the second aspect.

[0034] Preferably, the method includes:

[0035] Electrolytic polishing solution is added to the electrolyte circulation tank, and the alloy strip is fed between two electrodes in the magneto-electrochemical polishing device. Under the action of the magnetic field and electric field formed by the electrode current and the current of the conductive coil, magnetic field-assisted electrolytic double-sided polishing is performed.

[0036] Preferably, the electrolytic polishing solution comprises, by percentage, 20%~30% sulfuric acid, 65%~75% phosphoric acid, 1%~5% glycerol, 1%~2% thiourea, 0.05%~0.2% ammonium citrate, 0.5%~2% citric acid monohydrate, 0.002%~0.01% diethylenetriaminepentaacetic acid, 0.1%~0.5% ammonium sulfate, and 1%~5% water.

[0037] Specifically, the electrolytic polishing solution comprises 20% to 30% sulfuric acid, for example, 20%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%.

[0038] Phosphoric acid 65%~75%, for example, it can be 65%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74% or 75%, etc.

[0039] Glycerin 1%~5%, for example, it can be 1%, 1.5%, 1.9%, 2.4%, 2.8%, 3.3%, 3.7%, 4.2%, 4.6% or 5%, etc.

[0040] Thiourea is 1% to 2%, for example, it can be 1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2%, etc.

[0041] Ammonium citrate is 0.05%~0.2%, for example, it can be 0.05%, 0.07%, 0.09%, 0.1%, 0.12%, 0.14%, 0.15%, 0.17%, 0.19% or 0.2%, etc.

[0042] Citric acid monohydrate is 0.5% to 2%, for example, it can be 0.5%, 0.7%, 0.9%, 1%, 1.2%, 1.4%, 1.5%, 1.7%, 1.9% or 2%, etc.

[0043] Diethylenetriaminepentaacetic acid (DTA) is 0.002% to 0.01%, for example, it can be 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, 0.01%, or 0.01%, etc.

[0044] Ammonium sulfate is 0.1% to 0.5%, for example, it can be 0.1%, 0.15%, 0.19%, 0.24%, 0.28%, 0.33%, 0.37%, 0.42%, 0.46%, or 0.5%, etc.

[0045] Water content can be 1% to 5%, for example, 1%, 1.5%, 1.9%, 2.4%, 2.8%, 3.3%, 3.7%, 4.2%, 4.6%, or 5%, etc.

[0046] Preferably, the concentration of the sulfuric acid is ≥90wt%, for example, it can be 90wt%, 91wt%, 92wt%, 93wt%, 94wt%, 95wt%, 96wt%, 97wt%, 98wt%, or 98wt%, etc.

[0047] Preferably, the concentration of phosphoric acid is ≥85wt%, for example, it can be 85wt%, 86wt%, 87wt%, 88wt%, 89wt%, 90wt%, 91wt%, or 92wt%, etc.

[0048] Preferably, the electrode current is 100~120A, for example, it can be 100A, 103A, 105A, 107A, 109A, 112A, 114A, 116A, 118A or 120A, etc.

[0049] The present invention preferably controls the electrode current within the above-mentioned range, which can better improve the polishing effect. Specifically, when the electrode current is low, the improvement effect on edge over-polishing is limited; when the electrode current is high, it is easy to cause over-polishing.

[0050] Preferably, the current of the conductive coil is 20~70A, for example, it can be 20A, 25A, 29A, 34A, 38A, 43A, 47A, 52A, 56A or 60A, etc.

[0051] The present invention preferably controls the current of the conductive coil within the above-mentioned range, which can better improve the polishing effect. When the current of the conductive coil is low, the improvement on over-polishing of the edges is limited; when the current of the conductive coil is high, it leads to over-polishing, and the roughness increases instead of decreasing.

[0052] Preferably, the magnetic field strength is 0.01~0.3T, for example, it can be 0.01T, 0.05T, 0.1T, 0.13T, 0.15T, 0.17T, 0.19T, 0.22T, 0.24T, 0.26T, 0.28T or 0.3T, etc.

[0053] Preferably, the temperature of the electrolytic polishing solution is 50~70℃, for example, it can be 50℃, 53℃, 55℃, 57℃, 59℃, 62℃, 64℃, 66℃, 68℃ or 70℃, etc.

[0054] Preferably, the conveying speed of the alloy strip in the magneto-electrochemical polishing apparatus is 0.5~1.5 m / min, for example, it can be 0.5 m / min, 0.7 m / min, 0.8 m / min, 0.9 m / min, 1 m / min, 1.1 m / min, 1.2 m / min, 1.3 m / min, 1.4 m / min or 1.5 m / min, etc.

[0055] Preferably, the circulation time of the electrolytic polishing solution in the magneto-electrochemical polishing device is 4 to 6 hours, for example, it can be 4 hours, 4.3 hours, 4.5 hours, 4.7 hours, 4.9 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours or 6 hours.

[0056] Preferably, the method includes:

[0057] S1. Unwind the alloy strip and sequentially perform the first ultrasonic coarse washing, the first rinsing, and the first air drying.

[0058] S2. Perform magnetic field-assisted electrolytic double-sided polishing on the first air-dried alloy strip.

[0059] S3. The alloy strip after step S2 is subjected to a second rinse, passivation, second ultrasonic cleaning, second air drying, and oven drying in sequence.

[0060] S4. Perform roughness testing and winding on the alloy strip dried in step S3.

[0061] Preferably, the degreasing agent used in the first ultrasonic coarse cleaning in step S1 includes, by mass percentage: 40%~60% ethanol, 1%~5% sodium dodecylbenzenesulfonate, 10%~40% acetone, 1%~5% sodium hydroxide and 10%~20% water.

[0062] Specifically, the degreasing agent, by mass percentage, includes: 40% to 60% ethanol, for example, 40%, 43%, 45%, 47%, 49%, 52%, 54%, 56%, 58%, or 60%, etc.

[0063] Sodium dodecylbenzenesulfonate is 1% to 5%, for example, it can be 1%, 1.5%, 1.9%, 2.4%, 2.8%, 3.3%, 3.7%, 4.2%, 4.6% or 5%, etc.

[0064] Acetone content can range from 10% to 40%, for example, it can be 10%, 14%, 17%, 20%, 24%, 27%, 30%, 34%, 37%, or 40%, etc.

[0065] Sodium hydroxide is 1% to 5%, for example, it can be 1%, 1.5%, 1.9%, 2.4%, 2.8%, 3.3%, 3.7%, 4.2%, 4.6% or 5%, etc.

[0066] Water content is 10% to 20%, for example, it can be 10%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%, etc.

[0067] Preferably, water is used for the first rinsing in step S1.

[0068] Preferably, the passivating agent used in step S3 includes nitric acid.

[0069] Preferably, the concentration of the nitric acid is 4 to 10 wt%, for example, it can be 4 wt%, 4.7 wt%, 5.4 wt%, 6 wt%, 6.7 wt%, 7.4 wt%, 8 wt%, 8.7 wt%, 9.4 wt%, or 10 wt%.

[0070] Preferably, in step S3, the second rinsing and the second ultrasonic cleaning each use water independently.

[0071] Preferably, the drying temperature in step S3 is 150℃~180℃, for example, it can be 150℃, 154℃, 157℃, 160℃, 164℃, 167℃, 170℃, 174℃, 177℃ or 180℃, etc.

[0072] Preferably, the alloy strip is made of Hastelloy, stainless steel, or nickel-tungsten alloy.

[0073] Preferably, the thickness of the alloy strip is 50~100μm, for example, it can be 50μm, 55μm, 60μm, 62μm, 65μm, 68μm, 70μm, 75μm, 80μm, 85μm, 90μm, 95μm or 100μm, etc.

[0074] Preferably, the width of the alloy strip is 1 to 10 cm, for example, it can be 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm or 10 cm, etc.

[0075] Compared with the prior art, the present invention has at least the following beneficial effects:

[0076] (1) The magneto-electrochemical polishing device provided by the present invention improves the current distribution through magnetic field, avoiding local over-corrosion or incomplete polishing; the roughness (Ra) of the polished alloy strip can be significantly reduced, the surface is close to mirror level, and the edge consistency is good, with little difference in polishing effect between the edge and the middle of the strip;

[0077] (2) The magnetic field in the magneto-electrochemical polishing device provided by the present invention can promote the flow of electrolyte, accelerate the detachment of reactants and bubbles, and achieve a fast polishing rate; the polishing time is shortened, the processing efficiency is high, and it is suitable for continuous production.

[0078] (3) The double-sided polishing method of alloy strip provided by the present invention can eliminate micro-defects and improve surface integrity; reduce surface stress concentration areas, which helps to improve corrosion resistance; after polishing, the surface activity is reduced and the corrosion resistance is significantly improved, which is especially suitable for harsh working conditions. Attached Figure Description

[0079] Figure 1 This is a schematic diagram of the magneto-electrochemical polishing apparatus provided in Example 1.

[0080] Figure 2 This is a schematic diagram of the design of the electrodes and electromagnets in the magneto-electrochemical polishing apparatus provided in Example 1.

[0081] Figure 3 This is a winding method for the electromagnet provided in Example 1.

[0082] Figure 4 The magnetic field distribution diagram during the simulation experiment of the first type of electromagnet provided in Example 1.

[0083] Figure 5 This is a winding method for the electromagnet provided in Example 2.

[0084] Figure 6 The magnetic field distribution diagram is shown when the second type of electromagnet provided in Example 2 is used in a simulation experiment.

[0085] Figure 7 This is a schematic diagram of the apparatus system for double-sided polishing of alloy strips provided in Example 3.

[0086] In the figure: 1. Unwinding section; 2. First ultrasonic rough cleaning tank; 3. Water washing tank; 4. Magneto-electrochemical polishing device; 41. Electromagnet; 42. Alloy strip; 43. Anode; 44. Cathode; 5. First rinsing tank; 6. Passivation tank; 7. Second rinsing tank; 8. Second ultrasonic cleaning tank; 9. Drying device; 10. Roughness detector; 11. Rewinding section. Detailed Implementation

[0087] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0088] It should be understood that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0089] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0090] Example 1

[0091] This embodiment provides a magneto-electrochemical polishing device, such as... Figure 1 As shown, the magneto-electrochemical polishing device 4 includes an electrolyte circulation tank and an electromagnet 41 and electrodes disposed in the electrolyte circulation tank.

[0092] like Figures 2-3 As shown, the electromagnet 41 is U-shaped and includes a first part, a second part, a third part, and a conductive coil connected in sequence. The first part and the third part are arranged opposite to each other, and the second part is arranged perpendicular to the first part and the third part, respectively. The first part, the second part, and the third part are all made of magnetic material, and the conductive coil is directly wound on the first part and the third part. The electrode is arranged in the area between the first part and the third part. The electrode includes a first sub-electrode and a second sub-electrode. The first sub-electrode and the second sub-electrode are arranged on both sides of the alloy strip 42.

[0093] The electrodes include at least one set of cathodes 44 and at least one set of anodes 43; each set of cathodes 44 and anodes 43 is equipped with an electromagnet 41.

[0094] When the electrode is a cathode 44, the first sub-electrode is a first sub-cathode 44, the second sub-electrode is a second sub-cathode 44, the first sub-cathode 44 and the second sub-cathode 44 are arranged in a mirror symmetrical manner, and an alloy strip 42 is provided between them, forming a cathode 44 region between the first sub-cathode 44 and the second sub-cathode 44; when the electrode is an anode 43, the first sub-electrode is a first sub-anode 43, the second sub-electrode is a second sub-anode 43, the first sub-anode 43 and the second sub-anode 43 are arranged in a mirror symmetrical manner, and an alloy strip 42 is provided between them, forming an anode 43 region between the first sub-anode 43 and the second sub-anode 43.

[0095] The cathode 44 and anode 43 are alternately arranged in the electrolyte circulation tank.

[0096] The conductive coil is made of copper; the number of turns on one side of the conductive coil is 1800; the width of the first, second and third parts of the electromagnet 41 is 5cm; the thickness of the first, second and third parts of the electromagnet 41 is 5cm; and the length of the first, second and third parts of the electromagnet 41 is 30cm.

[0097] The magneto-electrochemical polishing device 4 also includes a protective shell for the electromagnet 41 disposed outside the electromagnet 41; the protective shell for the electromagnet 41 is made of polytetrafluoroethylene; the anode 43 is made of a titanium inner layer and a platinum layer disposed outside the titanium inner layer; the cathode 44 is made of titanium; and the electrolyte circulation tank is made of polytetrafluoroethylene.

[0098] like Figure 2 As shown, electrodes are distributed on both sides of the base strip (i.e., alloy strip 42). A U-shaped electromagnet 41 encloses the electrodes and the base strip. The electric field is in the horizontal direction of the base strip, and the magnetic field is in the vertical direction of the base strip. The direction of motion of the base strip is perpendicular to the paper and inwards. Charged ions will spiral / gyroscopic trajectories around the magnetic field lines. Their gyrocenter drifts laterally at a velocity VE×B, and the spiral radius gradually changes with acceleration by the electric field. If a sheath exists on the material surface, the ions are directed towards the workpiece by a strong electric field within the sheath, resulting in a final impact angle that is biased towards the normal but still carries a lateral component caused by the transverse E×B. This is the physical source of the more uniform ion incidence distribution in magneto-electropolishing.

[0099] The magneto-electrochemical polishing tank mainly includes an electrolyte circulation tank, parallel cathodes 44, parallel anodes 43, and a U-shaped electromagnet; such as Figure 1As shown, the smaller one is the anode 43, and the larger one is the cathode 44. Two anodes 43 are mirror-symmetrically arranged side by side in the electrolyte circulation tank to form the anode 43 region, and two cathodes 44 are mirror-symmetrically arranged side by side in the electrolyte circulation tank to form the cathode 44 region. The cathode 44 region and the anode 43 region are alternately arranged in the electrolyte circulation tank. The strip passes through the alternating regions of the anode 43 region and the cathode 44 region in sequence. Each pair of cathodes 44 / anodes 43 corresponds to a U-shaped electromagnet. The U-shaped electromagnet is movable in the direction of the electric field. When attaching the base strip, it can be moved to one side of the electrode. After attaching the base strip, it can be moved to the top of the base strip. The U-shaped electromagnet consists of a U-shaped electromagnet 41 and a copper solenoid. By changing the magnitude and direction of the current, the magnitude and direction of the magnetic field can be changed.

[0100] The distribution diagram of the magnetic field for magneto-electrochemical polishing during the simulation experiment of the magneto-electrochemical polishing device provided in Example 1 is shown below. Figure 4 As shown, when the current is 60A, simulation calculations show that... Figure 4 As shown, the strongest magnetic field can reach 0.51T, and the magnetic field in the electrode working range is 0.15T~0.25T.

[0101] Example 2

[0102] This embodiment provides a magneto-electrochemical polishing device, which differs from Embodiment 1 only in that, Figure 5 As shown, the electromagnet also includes a cylindrical structure disposed on the inner side of the second and third parts, and the conductive coil is directly wound on the cylindrical structure. The rest is the same as in Embodiment 1, and will not be described again here.

[0103] The distribution diagram of the magneto-electrochemical polishing magnetic field during the simulation experiment of the magneto-electrochemical polishing device provided in Example 2 is shown below. Figure 6 As shown.

[0104] Example 3

[0105] This embodiment provides a device system for double-sided polishing of alloy strips, such as... Figure 7 As shown, along the production direction of alloy strip 42, the device system includes an unwinding section 1, a first ultrasonic coarse washing tank 2, a water washing tank 3, a first air knife groove, a magneto-electrochemical polishing device 4 provided in Example 1, a first rinsing tank 5, a passivation tank 6, a second rinsing tank 7, a second ultrasonic cleaning tank 8, a second air knife groove, a drying device 9, a roughness detector 10, and a winding section 11, wherein the magneto-electrochemical polishing device 4 is the magneto-electrochemical polishing device 4 in Example 1.

[0106] Example 4

[0107] This embodiment provides a method for double-sided polishing of alloy strips. The method uses the apparatus system of Embodiment 3 and specifically includes:

[0108] S1. The alloy strip (C276 semi-hard Hastelloy alloy strip, 0.07mm thick, 30mm wide, with 304 stainless steel strip of 0.07mm thickness and 30mm width used as traction strip at the front and rear welded parts of the Hastelloy alloy strip) is unwound and sequentially subjected to the first ultrasonic rough washing, the first rinsing and the first air drying; the unwinding tension is 20N / m.

[0109] The first ultrasonic coarse cleaning uses a degreasing agent comprising, by weight percentage: 50% ethanol, 5% sodium dodecylbenzene sulfonate, 30% acetone, 3% sodium hydroxide, and 12% water; the first rinsing uses water.

[0110] S2. Perform magnetic field-assisted electrolytic double-sided polishing on the first air-dried alloy strip.

[0111] The magnetic field-assisted electrolytic double-sided polishing includes: adding an electrolytic polishing solution at a temperature of 60°C to an electrolyte circulation tank, and feeding the alloy strip between two electrodes in a magneto-electrochemical polishing device at a conveyor speed of 0.8 m / min. Under the action of a magnetic field and an electric field of 0.1~0.2T formed by a 100A electrode current and a 50A conductive coil current, magnetic field-assisted electrolytic double-sided polishing is performed, and the circulation time of the electrolytic polishing solution is 5 hours.

[0112] The electrolytic polishing solution comprises, by percentage, 25% concentrated sulfuric acid (98wt%), 70% concentrated phosphoric acid (85wt%), 2% glycerol, 1% thiourea, 0.1% ammonium citrate, 0.5% citric acid monohydrate, 0.0051% diethylenetriaminepentaacetic acid, 0.4% ammonium sulfate, and 0.9949% water.

[0113] S3. The alloy strip after step S2 is subjected to a second rinse, 60wt% nitric acid passivation, a second ultrasonic cleaning, a second air drying, and a 180°C drying.

[0114] The second rinsing and the second ultrasonic cleaning each use water independently;

[0115] S4. Perform roughness testing and winding on the alloy strip dried in step S3.

[0116] Example 5

[0117] This embodiment provides a method for double-sided polishing of alloy strips. The method uses the apparatus system of Embodiment 3 and specifically includes:

[0118] S1. The alloy strip (C276 semi-hard Hastelloy alloy strip, 0.07mm thick, 30mm wide, with 304 stainless steel strip of 0.07mm thickness and 30mm width used as traction strip at the front and rear welded parts of the Hastelloy alloy strip) is unwound and sequentially subjected to the first ultrasonic rough washing, the first rinsing and the first air drying; the unwinding tension is 20N / m.

[0119] The first ultrasonic coarse cleaning uses a degreasing agent comprising, by weight percentage: 50% ethanol, 5% sodium dodecylbenzene sulfonate, 30% acetone, 3% sodium hydroxide, and 12% water; the first rinsing uses water.

[0120] S2. Perform magnetic field-assisted electrolytic double-sided polishing on the first air-dried alloy strip.

[0121] The magnetic field-assisted electrolytic double-sided polishing includes: adding an electrolytic polishing solution at a temperature of 60°C to an electrolyte circulation tank, and feeding the alloy strip between two electrodes in a magneto-electrochemical polishing device at a conveyor speed of 1.0 m / min. Under the action of a magnetic field and an electric field of 0.15~0.25T formed by a 105A electrode current and a 60A conductive coil current, magnetic field-assisted electrolytic double-sided polishing is performed, and the circulation time of the electrolytic polishing solution is 5 hours.

[0122] The electrolytic polishing solution comprises, by percentage, 25% concentrated sulfuric acid (98wt%), 70% concentrated phosphoric acid (85wt%), 2% glycerol, 1% thiourea, 0.1% ammonium citrate, 0.5% citric acid monohydrate, 0.0051% diethylenetriaminepentaacetic acid, 0.4% ammonium sulfate, and 0.9949% water.

[0123] S3. The alloy strip after step S2 is subjected to a second rinse, 6wt% nitric acid passivation, a second ultrasonic cleaning, a second air drying, and a 180°C drying.

[0124] The second rinsing and the second ultrasonic cleaning each use water independently;

[0125] S4. Perform roughness testing and winding on the alloy strip dried in step S3.

[0126] Example 6

[0127] This embodiment provides a method for double-sided polishing of alloy strips. The method uses the apparatus system of Embodiment 3 and specifically includes:

[0128] S1. Unwind the alloy strip (C276 semi-hard Hastelloy alloy strip, 0.09mm thick, 35mm wide, with 304 stainless steel strip of 0.09mm thickness and 35mm width used as traction strip at the front and rear welded parts of the Hastelloy alloy strip) and sequentially perform the first ultrasonic rough cleaning, the first rinsing and the first air drying; the unwinding tension is 20N / m.

[0129] The first ultrasonic coarse cleaning uses a degreasing agent comprising, by weight percentage: 40% ethanol, 1% sodium dodecylbenzenesulfonate, 40% acetone, 5% sodium hydroxide, and 14% water; the first rinsing uses water.

[0130] S2. Perform magnetic field-assisted electrolytic double-sided polishing on the first air-dried alloy strip.

[0131] The magnetic field-assisted electrolytic double-sided polishing includes: adding an electrolytic polishing solution at a temperature of 50°C to an electrolyte circulation tank, and feeding the alloy strip between two electrodes in a magneto-electrochemical polishing device at a conveyor speed of 0.5 m / min. Under the action of a magnetic field and an electric field of 0.05~0.1T formed by a 120A electrode current and a 20A conductive coil current, magnetic field-assisted electrolytic double-sided polishing is performed, and the circulation time of the electrolytic polishing solution is 6 hours.

[0132] The electrolytic polishing solution comprises, by percentage, 28.44% concentrated sulfuric acid (98wt%), 65% concentrated phosphoric acid (85wt%), 1% glycerol, 2% thiourea, 0.05% ammonium citrate, 2% citric acid monohydrate, 0.01% diethylenetriaminepentaacetic acid, 0.5% ammonium sulfate, and 0.9949% water.

[0133] S3. The alloy strip after step S2 is subjected to a second rinse, 10wt% nitric acid passivation, a second ultrasonic cleaning, a second air drying, and a 150°C drying.

[0134] The second rinsing and the second ultrasonic cleaning each use water independently;

[0135] S4. Perform roughness testing and winding on the alloy strip dried in step S3.

[0136] Example 7

[0137] This embodiment provides a method for double-sided polishing of alloy strips. The method uses the apparatus system of Embodiment 3 and specifically includes:

[0138] S1. The alloy strip (C276 semi-hard Hastelloy alloy strip, 0.06mm thick, 28mm wide, with 304 stainless steel strip of 0.06mm thickness and 28mm width used as traction strip at the front and rear welded parts of the Hastelloy alloy strip) is unwound and sequentially subjected to the first ultrasonic rough cleaning, the first rinsing and the first air drying; the unwinding tension is 20N / m.

[0139] The first ultrasonic coarse cleaning uses a degreasing agent comprising, by weight percentage: 60% ethanol, 5% sodium dodecylbenzenesulfonate, 24% acetone, 1% sodium hydroxide, and 10% water; the first rinsing uses water.

[0140] S2. Perform magnetic field-assisted electrolytic double-sided polishing on the first air-dried alloy strip.

[0141] The magnetic field-assisted electrolytic double-sided polishing includes: adding an electrolytic polishing solution at a temperature of 70°C to an electrolyte circulation tank, and feeding the alloy strip between two electrodes in a magneto-electrochemical polishing device at a conveyor speed of 1.5 m / min. Under the action of a magnetic field and an electric field of 0.15~0.25T formed by a 100A electrode current and a 60A conductive coil current, magnetic field-assisted electrolytic double-sided polishing is performed, and the circulation time of the electrolytic polishing solution is 4 hours.

[0142] The electrolytic polishing solution comprises, by percentage, 20% concentrated sulfuric acid (98wt%), 70.698% concentrated phosphoric acid (85wt%), 5% glycerol, 1.5% thiourea, 0.2% ammonium citrate, 0.5% citric acid monohydrate, 0.002% diethylenetriaminepentaacetic acid, 0.1% ammonium sulfate, and 2% water.

[0143] S3. The alloy strip after step S2 is subjected to a second rinse, 4wt% nitric acid passivation, a second ultrasonic cleaning, a second air drying, and a 160°C drying process in sequence.

[0144] The second rinsing and the second ultrasonic cleaning each use water independently;

[0145] S4. Perform roughness testing and winding on the alloy strip dried in step S3.

[0146] Example 8

[0147] This embodiment provides a method for double-sided polishing of alloy strip. Except for the current of the conductive coil being 10A, the method is the same as that in Embodiment 4, and will not be described again here.

[0148] Example 9

[0149] This embodiment provides a method for double-sided polishing of alloy strip. Except for the current of the conductive coil being 80A, the method is the same as that in Embodiment 4, and will not be described again here.

[0150] Example 10

[0151] This embodiment provides a method for double-sided polishing of alloy strip. Except for the electrode current being 80A, the method is the same as that in Embodiment 4, and will not be described again here.

[0152] Example 11

[0153] This embodiment provides a method for double-sided polishing of alloy strip. Except for the electrode current being 140A, the method is the same as that in Embodiment 4, and will not be described again here.

[0154] Comparative Example 1

[0155] This comparative example provides a method for double-sided polishing of alloy strips. The method is the same as in Example 4, except that magnetic field-assisted electrolytic double-sided polishing is replaced with conventional electrolytic double-sided polishing, i.e., no additional magnetic field is added. Therefore, it will not be described again here.

[0156] Test method: The surface roughness of the polished alloy strip is tested using a roughness tester, with the edge area defined as within 1 mm of the edge line.

[0157] The test results of the above embodiments and comparative examples are shown in Table 1.

[0158] Table 1

[0159]

[0160] The following points can be observed from Table 1:

[0161] (1) As can be seen from the comprehensive examples 4 to 7, the double-sided polishing method of alloy strip provided by the present invention can present a mirror polishing effect after polishing the alloy strip surface. The surface is free of scratches, and the average surface roughness Ra after polishing is within 1.76 nm. The difference between the roughness Ra of each region is within 0.5 nm, indicating that the edge polishing is significantly improved.

[0162] (2) Comparing Example 4 with Examples 8-9, it can be seen that the current of the conductive coil in Example 4 is 50A, compared with 10A and 80A in Examples 8-9, respectively. The roughness of the polished area in Example 4 is within 1nm, and the difference in roughness Ra between different regions is only 0.139nm. In contrast, the differences in roughness Ra between different regions in Examples 8-9 are 1.36nm and 2.36nm, respectively. Therefore, it can be seen that the present invention preferably controls the current of the conductive coil within a reasonable range to achieve better polishing effect and polishing uniformity.

[0163] (3) Comparing Example 4 with Examples 10-11, it can be seen that the electrode current in Example 4 is 100A, compared to 80A and 140A in Examples 10-11, respectively. In Example 4, the polishing roughness is within 1nm, and the difference in roughness Ra between different regions is only 0.139nm. In contrast, the differences in roughness Ra between different regions in Examples 10-11 are 0.25nm and 0.55nm, respectively. Therefore, it can be seen that the present invention preferably controls the electrode current within a reasonable range to achieve better polishing effect and polishing uniformity.

[0164] (4) Comparing Example 1 and Comparative Example 1, it can be seen that Comparative Example 1 does not add an additional magnetic field, which leads to a significant decrease in the uniformity of polishing.

[0165] In summary, the apparatus and method for double-sided polishing of alloy strips provided by the present invention can improve polishing efficiency, control the polishing area, improve surface quality, improve polishing uniformity, and reduce local over-polishing. Under preferred conditions, the average surface roughness Ra after polishing is within 1.76 nm, and the difference in roughness Ra between different regions is within 0.5 nm.

[0166] The present invention has been illustrated with the above embodiments to illustrate its detailed features, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the selected technical features, additions of auxiliary technical features, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A magneto-electrochemical polishing apparatus, characterized in that, The magneto-electrochemical polishing device includes an electrolyte circulation tank and an electromagnet and electrodes disposed in the electrolyte circulation tank. The electromagnet includes a first part, a second part, a third part, and a conductive coil connected in sequence. The first part and the third part are arranged opposite to each other, and the second part is arranged perpendicular to the first part and the third part, respectively. The first part, the second part, and the third part are all made of magnets, and the conductive coil is wound around the first part and the third part. The electrode is disposed in the region between the first part and the third part; The electrode includes a first sub-electrode and a second sub-electrode; the first sub-electrode and the second sub-electrode are disposed on both sides of the alloy strip.

2. The magneto-electrochemical polishing apparatus according to claim 1, characterized in that, The electrode includes at least one set of cathodes and at least one set of anodes; each set of cathodes and anodes is equipped with an electromagnet. Preferably, when the electrode is a cathode, the first sub-electrode is a first sub-cathode, the second sub-electrode is a second sub-cathode, the first sub-cathode and the second sub-cathode are arranged in a mirror symmetrical manner, and an alloy strip is disposed between them, forming a cathode region between the first sub-cathode and the second sub-cathode; Preferably, when the electrode is an anode, the first sub-electrode is a first sub-anode, the second sub-electrode is a second sub-anode, the first sub-anode and the second sub-anode are arranged in a mirror symmetrical manner, and an alloy strip is disposed between them, forming an anode region between the first sub-anode and the second sub-anode; Preferably, the cathode and anode are alternately arranged in the electrolyte circulation tank.

3. The magneto-electrochemical polishing apparatus according to claim 1 or 2, characterized in that, The conductive coil is made of copper; Preferably, the conductive coil has 1000 to 3000 turns; Preferably, the width of the first, second, and third parts of the electromagnet is 2-10 cm; Preferably, the thickness of the first, second, and third parts of the electromagnet is 2-10 cm; Preferably, the lengths of the first, second, and third parts of the electromagnet are each independently 15-50 cm; Preferably, the magneto-electrochemical polishing device further includes an electromagnet protective housing disposed outside the electromagnet; Preferably, the protective housing of the electromagnet is made of polytetrafluoroethylene; Preferably, the anode is made of a titanium inner layer and a platinum layer disposed outside the titanium inner layer; Preferably, the cathode is made of titanium; Preferably, the electrolyte circulation tank is made of polytetrafluoroethylene.

4. A device system for double-sided polishing of alloy strips, characterized in that, The device system includes the magneto-electrochemical polishing apparatus according to any one of claims 1 to 3.

5. The device system according to claim 4, characterized in that, Along the production direction of the alloy strip, the device system includes, in sequence, an unwinding section, a first ultrasonic rough washing tank, a water washing tank, a first air knife groove, a magneto-electrochemical polishing device, a first rinsing tank, a passivation tank, a second rinsing tank, a second ultrasonic cleaning tank, a second air knife groove, a drying device, a roughness detector, and a winding section.

6. A method for double-sided polishing of alloy strip, characterized in that, The method is performed using the magneto-electrochemical polishing apparatus according to any one of claims 1 to 3, and / or the method is performed using the apparatus system for double-sided polishing of alloy strips according to claim 4 or 5.

7. The method according to claim 6, characterized in that, The method includes: Electrolytic polishing solution is added to the electrolyte circulation tank, and the alloy strip is fed between two electrodes in the magneto-electrochemical polishing device. Under the action of the magnetic field and electric field formed by the electrode current and the current of the conductive coil, magnetic field-assisted electrolytic double-sided polishing is performed.

8. The method according to claim 7, characterized in that, The electrolytic polishing solution comprises, by percentage, 20%–30% sulfuric acid, 65%–75% phosphoric acid, 1%–5% glycerol, 1%–2% thiourea, 0.05%–0.2% ammonium citrate, 0.5%–2% citric acid monohydrate, 0.002%–0.01% diethylenetriaminepentaacetic acid, 0.1%–0.5% ammonium sulfate, and 1%–5% water; Preferably, the concentration of the sulfuric acid is ≥90 wt%; Preferably, the concentration of the phosphoric acid is ≥85 wt%; Preferably, the electrode current is 100~120A; Preferably, the current of the conductive coil is 20~70A; Preferably, the strength of the formed magnetic field is 0.01~0.3T; Preferably, the temperature of the electrolytic polishing solution is 50~70℃; Preferably, the conveying speed of the alloy strip in the magneto-electrochemical polishing apparatus is 0.5~1.5m / min; Preferably, the circulation time of the electrolytic polishing solution in the magneto-electrochemical polishing apparatus is 4-6 hours.

9. The method according to any one of claims 6 to 8, characterized in that, The method includes: S1. Unwind the alloy strip and sequentially perform the first ultrasonic rough cleaning, the first rinsing, and the first air drying. S2. Perform magnetic field-assisted electrolytic double-sided polishing on the first air-dried alloy strip. S3. The alloy strip after step S2 is subjected to a second rinsing, passivation, second ultrasonic cleaning, second air drying and oven drying in sequence. S4. Perform roughness testing and winding on the alloy strip dried in step S3.

10. The method according to claim 9, characterized in that, The degreasing agent used in the first ultrasonic coarse cleaning in step S1 comprises, by mass percentage: 40%~60% ethanol, 1%~5% sodium dodecylbenzenesulfonate, 10%~40% acetone, 1%~5% sodium hydroxide, and 10%~20% water; Preferably, water is used for the first rinsing in step S1; Preferably, the passivating agent used in step S3 includes nitric acid; Preferably, the concentration of the nitric acid is 4-10 wt%; Preferably, in step S3, the second rinsing and the second ultrasonic cleaning each use water independently; Preferably, the drying temperature in step S3 is 150℃~180℃.

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