Annular honeycomb burr-free machining method

Abstract

The annular honeycomb burr-free machining method comprises the following steps that a conductive grinding wheel is connected with the negative electrode of a power source and horizontally placed in an annular workpiece, and electrolyte nozzles are placed on the two sides of the grinding wheel; the conductive grinding wheel rotates at a preset rotating speed; the conductive grinding wheel is fed at a preset speed in the annular feeding direction, so that the annular workpiece reaches the required machining depth under the continuous action of the conductive grinding wheel and the direct-current power supply; and when parameters such as the size of the annular workpiece meet requirements, rotation and feeding of the conductive grinding wheel are stopped, it is detected that no burrs exist and the size precision reaches the standard, and machining is completed. The method has the advantage of solving the problems of many burrs and low precision in the traditional method. Machining deviation is corrected in real time through online detection and feedback closed loop, and the percent of pass of parts is increased to 95% or above. And protective measures are taken for a non-machining area, so that the damage rate is reduced to below 1%, and the requirement of high-end equipment for part integrity is met. Burr-free machining of the honeycomb surface is achieved, and the application range of the electrolytic machining technology is expanded.

Description

Technical Field

[0001] This invention relates to the field of special processing technology, and in particular to a burr-free processing method for annular honeycomb. Background Technology

[0002] Nickel-based superalloys exhibit excellent fatigue strength, yield strength, tensile strength, corrosion resistance, and oxidation resistance in environments ranging from 600℃ to 1100℃, making them a commonly used material in aero-engines. However, due to their dispersed precipitation hardening and stable interatomic bonding, traditional machining methods are difficult to handle, easily leading to severe work hardening, tool sticking, and poor machinability, thus limiting their application in the aerospace field. Annular honeycomb sealing structures often utilize this nickel-based superalloy material, with a core lattice of 0.8 mm-1.6 mm and a wall thickness of 0.03 mm-0.05 mm. This advanced structure is widely used for sealing between rotors and stators in modern aero-engines, gas turbines, steam turbines, and space shuttles, providing a wear-resistant layer that serves as a buffer, protection, and seal. It is widely distributed and numerous. However, the dense lattice structure and high hardness of this material, along with the thin core lattice walls, weak rigidity, and single / double wall distribution of the honeycomb sealing surface, present significant challenges to its machining.

[0003] Currently, common methods for machining annular honeycomb structures made of nickel-based superalloys include ultrasonic-assisted machining and electrical discharge grinding. Ultrasonic-assisted machining utilizes a high-frequency vibrating tool to reduce friction between the workpiece and the tool by altering the material removal mechanism, thereby improving material removal efficiency, reducing cutting forces, and minimizing tool wear, thus increasing machining accuracy. However, this method requires regular maintenance of components such as the ultrasonic generator, and due to hardware limitations, it is not suitable for machining large parts. Furthermore, machining can easily produce burrs, affecting the surface quality.

[0004] Electrical discharge grinding (EDG) offers advantages such as high precision and low grinding force in machining high-temperature alloy annular honeycomb structures. However, the recast layer generated by EDM during machining remains a surface defect that needs to be addressed. Furthermore, EDM machining causes significant wear on the cathode grinding wheel, increasing machining costs and process complexity.

[0005] A novel processing method for high-temperature alloy annular honeycomb, characterized by high processing efficiency, low maintenance cost, and high processing accuracy, is proposed—electrolytic grinding composite processing technology.

[0006] Electrolytic grinding composite machining technology is a composite machining method that combines electrolytic action with mechanical grinding action. When an inter-electrode voltage is applied, the workpiece surface undergoes electrochemical dissolution, being oxidized into a very thin passivation film. This film is then scraped away by the abrasive protruding from the surface of the conductive grinding wheel, exposing a new metal surface for continued electrolysis. Under the alternating action of electrochemical dissolution and mechanical grinding, the workpiece surface is continuously processed until a certain dimensional accuracy and surface roughness are achieved. Although electrolytic grinding composite machining technology can achieve efficient removal, it faces three major problems: First, poor matching of machining parameters easily leads to burrs or insufficient removal (low dimensional accuracy); second, grinding wheel wear and part dimensional drift cannot be monitored in real time, resulting in uncontrolled machining accuracy; third, non-machined areas are susceptible to stray current corrosion, and the cutting performance cannot be restored online after grinding wheel wear, seriously affecting the part qualification rate and machining efficiency.

[0007] This invention proposes an integrated solution that achieves burr-free, high-dimensional precision, and stable machining of 0.8 mm lattice high-temperature alloy annular honeycomb through the coordinated design of parameter optimization, online detection, damage protection, and grinding wheel dressing. Summary of the Invention

[0008] This invention provides a method for electrolytic grinding of annular honeycomb materials to address the problems of existing technologies, effectively improving the processing efficiency and surface quality of high-temperature alloy annular honeycomb materials. A cubic boron nitride conductive grinding wheel is used as the cathode, and a pulsed DC power supply is applied to the annular workpiece for electrolytic grinding. Under the combined action of electrolysis and mechanical grinding, efficient dissolution and leveling of the annular honeycomb material are achieved. This processing method, through processing parameter design, online detection technology for parts and grinding wheels, damage protection in non-processed areas, and online grinding wheel dressing, can achieve efficient, high-quality, and high-precision annular honeycomb processing, solving the problems of work hardening, low efficiency, and numerous surface defects in traditional nickel-based high-temperature alloy annular honeycomb processing.

[0009] This invention provides a method for processing annular honeycomb by electrolytic grinding, which solves the problems existing in the prior art and can effectively improve the processing efficiency and surface quality of high-temperature alloy annular honeycomb.

[0010] A burr-free machining method for annular honeycomb workpieces includes the following steps: Step 1: Apply insulating adhesive to the non-machined area of ​​the annular honeycomb workpiece and allow it to cure. Connect the annular workpiece to the positive terminal of a DC power supply, connect a conductive grinding wheel to the negative terminal of the power supply, and place it horizontally inside the annular workpiece. Place electrolyte nozzles on both sides of the grinding wheel. Step 2: Open the electrolyte nozzles to allow the electrolyte to enter the machining area. Set the DC power supply voltage and turn on the power supply. Simultaneously, rotate the conductive grinding wheel at a preset speed. Step 3: Cut the conductive grinding wheel radially into the annular workpiece. After reaching a predetermined cutting depth, feed the conductive grinding wheel along the annular feed direction at a preset speed, and electrolyze the electrolyte. The process involves electrochemically dissolving the surface of the ring-shaped workpiece. Cubic boron nitride abrasive grains on the conductive grinding wheel remove insoluble substances and electrochemical products from the surface of the ring-shaped workpiece, improving electrolytic machining efficiency and surface quality. Step 4: Repeat step 3 to allow the ring-shaped workpiece to reach the required machining depth under the continuous action of the conductive grinding wheel and DC power supply. Step 5: When the dimensions and other parameters of the ring-shaped workpiece meet the requirements, stop the rotation and feed of the conductive grinding wheel, turn off the DC power supply and the electrolyte nozzle, remove the ring-shaped workpiece and the conductive grinding wheel and clean them, remove the insulating adhesive, clean the residual electrolyte, and check to confirm that there are no burrs and the dimensional accuracy meets the standards. The machining is then complete.

[0011] The specific technical solution is as follows: 1) Design of processing parameters for annular honeycomb Electrochemical parameters Voltage: A pulsed DC power supply is used, with the voltage set between 15 V and 25 V. Low voltage (<15 V) can lead to insufficient material removal, while high voltage (>25 V) can cause stray corrosion. The pulse parameter can reduce the accumulation of electrolytic products and avoid short circuits in the honeycomb pore walls.

[0012] Electrolyte: A 1%-5% NaNO3 solution is selected, with the temperature controlled at 25℃-30℃. The nozzle is positioned at approximately 30°-60° to the tangent of the annular workpiece processing area, with a flow velocity of 3 m / s-10 m / s and a flow rate of 8 L / min-12 L / min. This concentration ensures uniform corrosion of the honeycomb surface while suppressing stray reactions in non-processed areas. The constant temperature and high flow rate effectively remove electrolytic products, preventing clogging within the pores.

[0013] Mechanical parameters Grinding wheel speed: 1000 rpm-1500 rpm (metal-bonded conductive grinding wheel, abrasive is cubic boron nitride (CBN), grit size 100-200 mesh). Too low a speed will result in untimely removal of the passivation film, while too high a speed will easily cause vibration and deformation of the honeycomb wall.

[0014] Workpiece rotation speed: 0.15 rpm-0.23 rpm for large depths of cut (0.25 mm-0.65 mm) (rotation of the annular honeycomb around its own axis), feed rate 150 mm / min-250 mm / min. For small depths of cut (0.1 mm-0.25 mm), 0.23 rpm-0.52 rpm (rotation of the annular honeycomb around its own axis), feed rate 250 mm / min-550 mm / min. Low-speed rotation ensures uniform machining of each honeycomb hole, and low feed rate avoids burrs caused by excessive instantaneous current.

[0015] Matching relationship The parameter coupling rules were determined through orthogonal experiments: when the voltage increases by 1V, the grinding wheel speed needs to be reduced by 50rpm, and the feed rate needs to be increased by 15 mm / min (0.25 mm-0.65 mm depth of cut) and 30 mm / min (0.1 mm-0.25 mm depth of cut), respectively, in order to balance the removal rate of electrochemical corrosion and mechanical grinding. By using a large depth of cut in roughing and a small depth of cut in finishing, burr-free machining (burr height ≤ 5 μm) and dimensional accuracy (hole diameter tolerance ±0.08 mm) can be achieved.

[0016] 2) Online inspection of parts and grinding wheels Construct a closed-loop control system with "dual detection and dual feedback" to correct processing deviations in real time: Online inspection of part dimensions A laser profile sensor is installed on the side of the machining spindle. The sensor is triggered once every 10-15 honeycomb holes are machined to collect data on the diameter and depth of the holes.

[0017] Setting accuracy threshold: When the deviation between the detected value and the theoretical value exceeds ±0.05 mm, the system automatically adjusts the feed speed (the feed linear speed decreases by 0.7 mm / min for every 0.01 mm increase in deviation) and at the same time fine-tunes the voltage (the voltage increases by 1 V for every 0.01 mm increase in deviation, not exceeding the upper limit of 25 V).

[0018] Grinding wheel condition inspection Current monitoring: The current value is collected in real time by a Hall sensor connected in series in the electrolysis circuit. When the current fluctuation exceeds ±1 A (corresponding to grinding wheel wear >0.02 mm), the grinding wheel is determined to be faulty and the online dressing program is triggered.

[0019] 3) Damage protection in non-processing areas For the non-processed areas of the ring-shaped honeycomb, a dual protection system is employed: "insulating coating protection + electrolyte concentration and processing distance control". ① Insulating coating protection Apply a high-temperature resistant (>200℃) insulating adhesive (such as polyimide-based adhesive) to non-processed areas. The coating thickness is 0.1 mm-0.2 mm, and the insulation resistance after curing is >10 Ω·cm. 10 Ω. After processing, it can be dissolved and removed with a special solvent (such as N-methylpyrrolidone), leaving no residue.

[0020] ② Control the electrolyte concentration and processing distance The electrolyte is controlled to be a 1%-5% NaNO3 solution, the processing distance is controlled to be more than 4 mm, and there are no scattered corrosion marks on the honeycomb side and honeycomb support surface.

[0021] 4) Online dressing of grinding wheels To avoid decreased machining performance due to grinding wheel wear, an online dressing module is integrated: Design an online electrolytic spark dressing device for conductive grinding wheels. A stainless steel vise is installed at the worktable position where the grinding wheel cuts into the workpiece. A copper cathode plate is clamped in the jaws of the vise for online dressing of the grinding wheel after wear. The vise rotates with the worktable. When dressing of the conductive grinding wheel is required during machining, the wheel can be moved to the dressing fixture position on the worktable. Without disassembling the wheel, a negative voltage is applied, with the fixture acting as the cathode and the grinding wheel as the anode, allowing for direct dressing. The dressed wheel can then be reused.

[0022] ① Timing of repair Triggered by the electrode status detection system, it automatically executes once when the current fluctuation exceeds ±1 A.

[0023] ② Repair methods The dressing process of a conductive grinding wheel can be divided into two processes: dressing the lower end face and dressing the outer cylindrical face. When dressing the lower end face, the lower end face of the grinding wheel is brought into contact with the upper surface of the copper cathode. The grinding wheel spindle reciprocates left and right along the X-axis and feeds downwards along the Z-axis. One reciprocating motion of the grinding wheel constitutes one cycle. Before each movement along the X-axis, the spindle cuts downwards along the Z-axis by 1 μm-2 μm, completing one cycle of grinding wheel dressing. When dressing the outer cylindrical face, the grinding wheel reciprocates up and down along the Z-axis and feeds forward along the X-axis. One reciprocating motion of the grinding wheel constitutes one cycle. Before each movement along the Z-axis, the spindle cuts forwards along the X-axis by 1 μm-2 μm, completing one cycle of grinding wheel dressing. Both dressing processes are performed by setting a machine tool cycle program until the specified dimensions are achieved.

[0024] After finishing, the part is verified by current detection: if the laser detection part size deviation is ≤ ±0.05 mm, the finishing is deemed qualified and processing continues; otherwise, the finishing is repeated (up to 3 times, if it is still unqualified, the grinding wheel is prompted to be replaced).

[0025] This invention proposes a method for electrolytic grinding of annular honeycomb. The method utilizes electrolysis to dissolve the material on the anode surface of the workpiece to form a passivation layer. The passivation layer is then removed by the grinding action of a conductive grinding wheel, and insoluble substances on the material surface are cleaned to ensure the continuous electrolytic processing and achieve the effect of surface smoothing.

[0026] Electrolytic grinding composite machining technology involves an electrochemical dissolution process. During the grinding process of thin-walled honeycomb structures, machining defects such as swarf and burrs undergo anodic dissolution and are promptly removed, resulting in a honeycomb metal surface free of swarf and burrs. Its machining accuracy and surface roughness are superior to ordinary electrolytic machining, and its production efficiency is higher than mechanical grinding. Compared to pure grinding, the addition of electrolysis reduces mechanical grinding forces and increases feed rate and depth of cut, thereby improving production efficiency. Compared to pure electrolytic machining, the grinding action removes insoluble substances from the surface and smooths the surface, thus reducing surface roughness.

[0027] During the processing, the conductive grinding wheel rotates at high speed around its axis and slowly makes circular motions on the inner surface of the annular workpiece in the same direction of rotation, thereby increasing the surface linear velocity of the conductive grinding wheel.

[0028] During the processing, the electrolyte is sprayed into the processing area at high speed, which serves to continuously provide reaction conditions for electrolysis, remove the electrolytic products generated during processing and the fine grinding debris generated by the grinding action, and promptly dissipate the heat generated by electrolysis and grinding.

[0029] This invention achieves burr-free machining of 0.8 mm lattice high-temperature alloy annular honeycomb through parameter co-optimization, with a dimensional accuracy of ±0.08 mm, solving the problems of numerous burrs and low accuracy in traditional methods.

[0030] Online inspection and feedback loop can correct processing deviations in real time, increasing the part qualification rate to over 95%.

[0031] Protective measures in non-processing areas reduce the damage rate to below 1%, meeting the requirements of high-end equipment for part integrity.

[0032] Online grinding wheel dressing extends grinding wheel life (by 20%-30%), reduces downtime for replacement, and increases processing efficiency by 20%-30%.

[0033] Advantages of this invention: This invention proposes a method for electrolytic grinding of annular honeycomb, which simultaneously applies electrolytic and grinding actions to the machined surface. Through parameter synergistic optimization, burr-free machining of 0.8 mm lattice high-temperature alloy annular honeycomb is achieved with a dimensional accuracy of ±0.08 mm, solving the problems of excessive burrs and low precision in traditional methods. Real-time correction of machining deviations through online detection and feedback closed-loop increases the part qualification rate to over 95%. Protective measures for non-machined areas reduce the damage rate to below 1%, meeting the integrity requirements of high-end equipment. Online grinding wheel dressing extends wheel life, reduces downtime for replacement, and increases machining efficiency by 20%-30%. Utilizing a combined electrolytic grinding and machining method improves the surface quality and dimensional accuracy of the annular honeycomb, achieving burr-free machining of the honeycomb surface and expanding the application scope of electrolytic machining technology. However, the above description should not be construed as limiting this invention. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the conductive grinding wheel infeed stage of the electrolytic grinding method for machining annular honeycomb proposed in this invention. Figure 2 This is a schematic diagram of the conductive grinding wheel annular feed machining stage in the electrolytic grinding annular honeycomb machining method proposed in this invention. The labels in the diagram are as follows: 1. Ring-shaped workpiece; 2. DC power supply; 3. Conductive grinding wheel; 4. Electrolyte nozzle; 5. Cubic boron nitride abrasive grains; 6. Insoluble substance; 7. Electrochemical product; 8. Electrolyte; 9. Radial cutting direction; 10. Grinding wheel rotation direction; 11. Circular feed direction. Figure 3 This is a schematic diagram of a dual-sided electrolyte supply proposed in this invention; Figure 4 This is a schematic diagram of a conductive grinding wheel dressing process proposed in this invention. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings.

[0036] The process flow for the composite machining of annular honeycomb electrolytic grinding is as follows: pretreatment → parameter setting → machining and inspection → real-time dressing of grinding wheel → post-processing.

[0037] 1) Preprocessing The 0.8 mm lattice high-temperature alloy annular honeycomb blank is cleaned, and insulating glue is applied to the non-machined area and cured. It is then installed on the CNC rotary table and connected to the positive terminal of the power supply. The grinding wheel is installed on the spindle and connected to the negative terminal of the power supply and the dressing module.

[0038] 2) Parameter settings Initialize the electrolysis voltage (15 V-25 V), grinding wheel speed (1000 rpm-1500 rpm), grinding wheel parameters (metal-bonded conductive grinding wheel, abrasive is cubic boron nitride (CBN), grit size 100-200 mesh), and electrolyte parameters (1%-5% NaNO3, 25℃-30℃, the nozzles are horizontally arranged on the left and right sides of the conductive grinding wheel, and the electrolyte is sprayed into the processing area at the same time during processing. The tangent direction of the nozzles to the processing area of ​​the annular workpiece is about 30°-60°. The flow rate and flow rate of the electrolyte should be controlled at 3m / s-10 m / s and 8 L / min-12 L / min, respectively).

[0039] For roughing with a large depth of cut (0.25 mm-0.65 mm), the feed rate is 0.15 rpm-0.23 rpm (the annular honeycomb rotates around its own axis), with a feed rate of 150 mm / min-250 mm / min. For finishing with a small depth of cut (0.1 mm-0.25 mm), the feed rate is 0.23 rpm-0.52 rpm (the annular honeycomb rotates around its own axis), with a feed rate of 250 mm / min-550 mm / min.

[0040] 3) Processing and testing Open the electrolyte nozzle to allow electrolyte to enter the processing area. A schematic diagram of dual-sided electrolyte supply is shown below. Figure 1 As shown, when the electrolyte is supplied from both sides, the electrolyte distribution in the flow field is uniform, the flow rate is stable, and the eddy current phenomenon is weakened, thus avoiding the problem of insufficient electrolyte supply from one side and ensuring the stability of the electrolyte supply.

[0041] Set the DC power supply voltage and turn on the power to start machining. The conductive grinding wheel rotates at a preset speed at high speed, and the wheel feeds into the machining area. A schematic diagram of the conductive grinding wheel infeed stage of the electrolytic grinding ring honeycomb machining method is shown below. Figure 2 As shown. The conductive grinding wheel 3 cuts into the annular workpiece 1 radially to achieve a preset cutting depth; the electrolyte 8 is sprayed into the processing area at high speed through the electrolyte nozzles 4 on both sides of the conductive grinding wheel 3 to maintain the continuous electrolysis; the cubic boron nitride abrasive grains 5 adhering to the surface of the conductive grinding wheel 3 remove the surface material through the grinding action; the large amount of fresh electrolyte 8 carries away the insoluble substances 6 and electrochemical products 7 generated during the processing, while also cooling the grinding action. The conductive grinding wheel is radially inserted into the annular workpiece. After reaching the predetermined depth of cut, the conductive grinding wheel feeds along the annular feed direction at a preset speed. Electrolysis causes electrochemical dissolution of the annular workpiece surface. The cubic boron nitride abrasive grains on the conductive grinding wheel remove insoluble substances and electrochemical products from the annular workpiece surface, improving electrolytic machining efficiency and surface quality. A schematic diagram of the conductive grinding wheel annular feed machining stage in the electrolytic grinding annular honeycomb machining method is shown below. Figure 3As shown, the conductive grinding wheel 3 processes the inner circular surface of the annular workpiece 1 along the annular feed direction 11; the rotation direction 10 of the grinding wheel is the same as the annular feed direction 11, so that the surface linear velocity of the conductive grinding wheel 3 is superimposed and increased, thereby enhancing the grinding effect and improving the surface quality of the electrolytic grinding process.

[0042] The laser sensor checks the part size every 10-15 holes, the current sensor monitors the grinding wheel status in real time, and the data is fed back to the control system to dynamically adjust the parameters.

[0043] 4) Real-time dressing of grinding wheels When a grinding wheel failure is detected, the system automatically executes a dressing procedure. If the dressing is successful, processing continues. A schematic diagram of the conductive grinding wheel dressing process is shown below. Figure 4 As shown. When dressing the lower end face of the grinding wheel, the lower end face of the grinding wheel is brought into contact with the upper surface of the copper cathode. The grinding wheel spindle reciprocates left and right along the X-axis and feeds downward along the Z-axis. One reciprocating motion of the grinding wheel constitutes one cycle. Before each movement along the X-axis, the spindle cuts downward 1 μm-2 μm along the Z-axis, completing one cycle of grinding wheel dressing. When dressing the outer cylindrical surface of the grinding wheel, the grinding wheel reciprocates up and down along the Z-axis and feeds forward along the X-axis. One reciprocating motion of the grinding wheel constitutes one cycle. Before each movement along the Z-axis, the spindle cuts forward 1 μm-2 μm along the X-axis, completing one cycle of grinding wheel dressing. Both dressing processes are performed by setting the machine tool cycle program until the specified dimensions are achieved.

[0044] After finishing, the part is verified by current detection: if the laser detection part size deviation is ≤ ±0.05 mm, the finishing is deemed qualified and processing continues; otherwise, the finishing is repeated (up to 3 times, if it is still unqualified, the grinding wheel is prompted to be replaced).

[0045] 5) Post-processing When the dimensions and other parameters of the ring-shaped workpiece meet the requirements, stop the rotation and feed of the conductive grinding wheel, turn off the DC power supply and the electrolyte nozzle, remove the ring-shaped workpiece and the conductive grinding wheel, and clean them. After processing, remove the workpiece, remove the insulating adhesive with a special solvent, clean the residual electrolyte, and finally check to confirm that there are no burrs (burr height ≤ 5 μm) and the dimensional accuracy meets the standard (tolerance within ±0.08 mm).

[0046] Matters not covered in this invention are common knowledge.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method of burr-free machining of annular honeycomb, characterized by: The annular honeycomb burr-free processing method comprises the following steps: Step one: coat the non-processing area of the annular honeycomb workpiece with insulating glue and solidify, connect the annular workpiece to the positive pole of a direct current power supply, connect the conductive grinding wheel to the negative pole of the power supply, and horizontally place the grinding wheel inside the annular workpiece, with electrolyte nozzles placed on both sides of the grinding wheel; Step two: open the electrolyte nozzles, make the electrolyte enter the processing area, set the voltage of the direct current power supply and turn on the power supply, and rotate the conductive grinding wheel at a preset speed; Step three: cut the conductive grinding wheel into the annular workpiece along the radial direction, when the preset cutting depth is reached, feed the conductive grinding wheel along the annular feeding direction at a preset speed, the electrolytic action causes the surface of the annular workpiece to be electrochemically dissolved, the cubic boron nitride abrasive grains on the conductive grinding wheel remove the insoluble substances and electrochemical products on the surface of the annular workpiece, and the electrolytic processing efficiency and surface quality are improved; Step four: repeat step three, so that the annular workpiece reaches the required processing depth under the continuous action of the conductive grinding wheel and the direct current power supply; Step five: when the size and other parameters of the annular workpiece meet the requirements, stop the rotation and feeding of the conductive grinding wheel, turn off the direct current power supply and the electrolyte nozzles, remove the annular workpiece and the conductive grinding wheel, and clean them, remove the insulating glue, clean the residual electrolyte, detect and confirm that there is no burr and the size precision meets the standard, and the processing is completed.

2. The annular honeycomb burr-free processing method according to claim 1, wherein the annular honeycomb processing parameters comprise: electrochemical parameters voltage: pulse direct current power supply, voltage set to 15 V-25 V; low voltage <15 V leads to insufficient material removal, and high voltage >25 V can cause stray corrosion; pulse parameters can reduce electrolytic product accumulation and avoid short circuit of the honeycomb hole wall; electrolyte: select a NaNO3 solution with a concentration of 1%-5%, control the temperature at 25℃-30℃, the nozzle and the tangent direction of the annular workpiece processing area are about 30°-60°, the flow rate is 3 m / s-10 m / s, and the flow rate is 8 L / min-12 L / min; under this concentration, uniform corrosion of the honeycomb surface can be ensured, and stray reactions in the non-processing area can be inhibited; constant temperature and high flow rate can remove electrolytic products in time to prevent hole blockage; mechanical parameters grinding wheel speed: 1000 rpm-1500 rpm metal bond conductive grinding wheel, abrasive is cubic boron nitride, particle size is 100-200 mesh; too low speed will lead to delayed removal of the passivation film, and too high speed will easily cause deformation of the honeycomb wall; workpiece speed: 0.15 rpm-0.23 rpm for large cutting depth of 0.25 mm-0.65 mm, the annular honeycomb rotates around its own axis, and the feeding line speed is 150 mm / min-250 mm / min; 0.23 rpm-0.52 rpm for small cutting depth of 0.1 mm-0.25 mm, and the feeding line speed is 250 mm / min-550 mm / min; low speed rotation ensures uniformity of each honeycomb hole processing, and low feeding amount avoids excessive instantaneous current to produce burrs; matching relationship: ​ The parameter coupling rule is determined by orthogonal test. When the voltage is increased by 1 V, the grinding wheel speed needs to be reduced by 50 rpm, and the feed speed is increased by 15 mm / min and 30 mm / min respectively, so as to balance the removal rate of electrochemical corrosion and mechanical grinding, realize burr-free machining and size precision through rough machining with large cutting depth and fine machining with small cutting depth, and realize hole diameter tolerance of ±0.08 mm.

3. The burr-free machining method of the annular honeycomb according to claim 1, characterized in that: On-line detection of parts and grinding wheels: A "double detection-double feedback" closed-loop control system is constructed to correct machining deviation in real time: On-line detection of part size A laser profile sensor is installed on the side of the machining spindle, and detection is triggered once every 10-15 honeycomb holes are machined, and the aperture diameter and depth data are collected; The accuracy threshold is set: when the deviation between the detected value and the theoretical value exceeds ±0.05 mm, the system automatically adjusts the feed speed, and the feed speed is reduced by 0.7 mm / min for every 0.01 mm of deviation, and the voltage is adjusted at the same time, and the voltage is increased by 1 V for every 0.01 mm of deviation, not exceeding the upper limit of 25 V; Grinding wheel state detection: current monitoring: the current value is collected in real time by a Hall sensor connected in series in the electrolysis loop, and when the current fluctuation exceeds ±1 A, the grinding wheel wear is greater than 0.02 mm, the grinding wheel is determined to be invalid, and the on-line dressing program is triggered.

4. The burr-free machining method of the annular honeycomb according to claim 1, characterized in that: Damage protection of non-machining area: For the non-machining area of the annular honeycomb, double protection of "insulating coating protection + electrolyte concentration and machining distance control" is adopted: Insulating coating protection: In the non-processing area, high-temperature-resistant (>200℃) insulating glue is coated, the coating thickness is 0.1 mm-0.2 mm, and the insulation resistance after curing is >10 10 Ω; after processing is completed, it can be removed by dissolving with special solvent, without residue; Control of electrolyte concentration and machining distance The electrolyte is controlled to be 1%-5% concentration NaNO3 solution, and the machining distance is controlled to be more than 4 mm, and there is no stray corrosion mark on the side surface of the honeycomb and the honeycomb support surface.

5. The burr-free machining method of the annular honeycomb according to claim 1, characterized in that: On-line dressing of grinding wheel: In order to avoid the decline of machining performance caused by grinding wheel wear, an on-line dressing module is integrated: An on-line electrolytic spark dressing device for conductive grinding wheel is designed; a stainless steel metal clamp is installed at the position of the workbench in the direction of the grinding wheel cutting into the workpiece, the jaws of the clamp are clamped with a red copper cathode plate, which is used to dress the grinding wheel on-line after the grinding wheel is worn out; the clamp can rotate with the workbench, when the conductive grinding wheel needs to be dressed during machining, the conductive grinding wheel is moved to the position of the dressing clamp of the workbench, without disassembling the grinding wheel, setting a negative voltage, that is, the clamp acts as a cathode and the grinding wheel acts as an anode, directly performing the dressing work of the grinding wheel, and the dressed grinding wheel can continue to be used; Dressing opportunity: Triggered by the electrode state detection system, automatic execution once when the current fluctuation exceeds ±1 A; Dressing method: The conductive grinding wheel dressing process is divided into lower end surface dressing and outer cylindrical surface dressing; when dressing the lower end surface of the grinding wheel, the lower end surface of the grinding wheel is in contact with the upper surface of the red copper cathode, the grinding wheel spindle reciprocates along the X axis direction, and feeds downward along the Z axis; one cycle of the grinding wheel reciprocation along the X axis direction is one cycle, before each movement along the X axis direction, the spindle cuts in 1 μm-2 μm downward along the Z axis, and one cycle of the grinding wheel dressing is completed; when dressing the outer cylindrical surface of the grinding wheel, the grinding wheel reciprocates upward and downward along the Z axis, and feeds forward along the X axis; one cycle of the grinding wheel reciprocation upward and downward along the Z axis is one cycle, before each movement along the Z axis, the spindle cuts in 1 μm-2 μm forward along the X axis, and one cycle of the grinding wheel dressing is completed; through setting the machine tool cycle program, the two dressing processes are performed until the specified size is reached; After dressing, the current detection is used for verification: if the size deviation of the laser detection part is ≤±0.05 mm, it is determined that the dressing is qualified, and the machining is continued; otherwise, the dressing is repeated, at most 3 times, and if it is still unqualified, the grinding wheel is replaced.

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