Device and method for protecting bulk blade from electrolytic processing stray corrosion

Abstract

The application provides a protection device and method for electrolytic machining of a bulk blade, and belongs to the field of electrolytic machining of a bulk blade. The bulk blade is clamped on a numerical control electrolytic machining machine tool with multi-axis linkage function. In the electrolytic machining process, the machining area and part of the non-machining area of the bulk blade are immersed in electrolyte. The main power supply and the third phase protection power supply are synchronously connected. The protection device for stray corrosion forms a wrapped type "U" type protection structure for the non-machining area of the bulk blade, can absorb the stray potential field generated in the electrolytic machining of the bulk blade, and greatly reduces the influence of stray corrosion on the non-machining area (the bulk body and the machined blade) of the bulk blade due to the existence of the stray potential field. Through the application, the influence of stray corrosion on the non-machining area of the bulk blade can be effectively reduced, the surface quality of the non-machining area is improved, and the risk of part scrapping caused by the influence of stray corrosion is avoided.

Description

Technical Field

[0001] This invention relates to a protective device and method for stray corrosion during electrolytic machining of integral bladed disk sleeves for aero-engines, belonging to the field of integral bladed disk electrolytic machining. Background Technology

[0002] Integral bladed disk (IBD) structures are widely used in the structural design of compressors and fans for third-generation and above aero-engines. The integrated structure of IBD replaces the traditional connection method of blades and hubs, which not only improves the overall reliability of aero-engines and reduces the weight of the bladed disk, but also eliminates the loss caused by airflow overflow in the tenons and grooves during engine operation, greatly improving the working efficiency of aero-engines. Therefore, the use of IBD structures can significantly improve the thrust-to-weight ratio of aero-engines. At the same time, the IBD structure has become a new technology in the structural and aerodynamic layout design of next-generation aero-engines and a landmark key technology of advanced aero-engines.

[0003] The materials used for integral bladed disks are mostly high-strength and difficult-to-machine materials such as high-temperature alloys and titanium alloys. Traditional machining processes result in severe tool wear, high processing costs, and low processing efficiency. Electrolytic machining of integral bladed disks is a typical machining process. It achieves the shaping of the blade profile by using a pre-formed cathode hole structure with an airfoil cross-section. Electrolytic machining of integral bladed disks is not affected by the strength of the material being machined and has many advantages such as high processing efficiency, no tool and cathode wear, and no processing stress. Therefore, electrolytic machining of integral bladed disks is particularly suitable for the mass production of high-strength and difficult-to-machine integral bladed disk parts.

[0004] To ensure stability during the electrolytic machining of integral bladed disks, an electrolyte immersion method is generally used. This means that during the electrolytic machining of the blades, a localized area of ​​the entire bladed disk is also immersed in the electrolyte. Due to the potential difference between the tool cathode and the integral bladed disk, electric fields of varying strengths exist throughout the electrolyte. The closer the tool cathode cutting edge is to the integral bladed disk, the stronger the electric field; the farther away, the weaker the electric field. Therefore, the machining area of ​​the integral bladed disk blades is closest to the tool cathode cutting edge, resulting in the strongest electric field—this is the main area for dissolving the anode parts. Meanwhile, the bladed disk... Even though the disk is partially immersed in the electrolyte, it is still affected by the electric field. Since the non-machined area of ​​the bladed disk is much farther away than the machined area of ​​the blades, the electric field strength is much weaker. The closer the non-machined area of ​​the bladed disk is to the tool cathode cutting edge, the stronger the stray electric field effect is. The farther away from the tool cathode cutting edge, the smaller the stray electric field effect is. Therefore, under the action of the stray electric potential field in the electrolyte-immersed area, the entire non-machined area of ​​the bladed disk is affected by the combined effect of the stray electric field and the flow field. The stray corrosion of the bladed disk is most affected when it is close to the blade machining area, and least affected when it is far away from the blade machining area. For integral bladed disks, if the disk body is the final shape, stray corrosion will cause parts with out-of-tolerance dimensions to be scrapped. If the disk body has a machining allowance, but the disk body is generally used as the reference for subsequent machining, stray corrosion will destroy the reference, and additional machining reference processes will be required. This will make the machining process of the bladed disk complicated and extend the machining cycle. Furthermore, if there are uneven and deep corrosion pits in some areas, the impact of stray corrosion may even lead to the risk of parts being scrapped due to out-of-tolerance. Therefore, it is urgent to develop anti-stray corrosion technology for the integral bladed disk casing electrolytic machining disk body. Summary of the Invention

[0005] The purpose of this patent is to address the issue that impeller disks are susceptible to stray corrosion during the electrolytic machining process of integral impeller disks. It proposes a device and method for preventing stray corrosion during the electrolytic machining of integral impeller disks, which can effectively reduce stray corrosion in the non-machined areas and the disk body of the integral impeller disk.

[0006] A protective device for stray corrosion of an integral bladed disk is characterized by comprising stray corrosion protection components and a circuit section; wherein the stray corrosion protection components include a bottom stray corrosion protection plate, a blade basin-side stray corrosion protection plate, and a blade back-side stray corrosion protection plate; the bottom stray corrosion protection plate has a tool cathode channel opening in the middle; the bottom stray corrosion protection plate is fixed and insulated to the tool cathode body base by an insulating plate and insulating screws; the blade basin-side stray corrosion protection plate and the blade back-side stray corrosion protection plate are located on both sides of the tool cathode channel opening and are connected to the bottom stray corrosion protection plate by conductive screws. The aforementioned stray corrosion protection plates on the blade basin side, blade back side, and bottom are connected by conductive screws to form a conductive integrated potential. The circuit includes the main power supply, the main power switch, the third-phase protection power supply, and the third-phase protection power switch. The negative terminal of the main power supply is connected to the tool cathode body, and the positive terminal of the main power supply is divided into two paths. One path is connected to the overall blade disk through the main power switch, and the other path is connected to the negative terminal of the third-phase protection power supply. The positive terminal of the third-phase protection power supply is connected to the aforementioned stray corrosion protection components through the third-phase protection power switch.

[0007] The protection method for stray corrosion of the integral bladed disk is characterized by the following process: The program is started, and electrolyte enters the tool cathode tank through the electrolyte supply channel, immersing both the machining area and part of the non-machining area of ​​the integral bladed disk in the electrolyte; the main power switch and the third-phase protection power switch are simultaneously turned on, and the blades to be machined on the integral bladed disk begin electrolytic machining according to the CNC multi-axis linkage program until machining is completed. The integral bladed disk then moves out of the tool cathode tank via multi-axis linkage, and the integral bladed disk and tool cathode return to the initial setting position. Upon receiving the blade indexing command, the integral bladed disk performs indexing and sequential machining of the other blades; during machining, the additional potential of the third-phase protection power supply is used to ensure the tool cathode... The potential difference between the electrode and the stray corrosion protection component is always higher than the potential difference between the tool cathode and the workpiece. Therefore, under the influence of the stray electric field and flow field during the electrolytic machining process, the anode of the stray corrosion protection component with a high potential difference is always higher than the non-machined area of ​​the anode part with a low potential difference. Thus, this method is used to prevent the non-machined surface of the integral bladed disk from being stray corroded under the influence of the stray corrosion electric field. After all blades of the integral bladed disk are machined, the electrolyte control system stops the supply of electrolyte, the main power switch and the third phase protection power switch of the equipment are disconnected, and the CNC system of the equipment controls the integral bladed disk and the tool cathode to safely retract to the safe waiting area. The indexing blades of the integral bladed disk indexing shaft return to the first blade position, and the electrolytic machining of the integral bladed disk is completed.

[0008] The protective device for stray corrosion of the integral bladed disk is characterized in that: the bottom stray corrosion protection plate is composed of a bottom left stray corrosion protection plate and a bottom right stray corrosion protection plate; and the tool cathode channel opening is located between the two; the blade basin side stray corrosion protection plate spans the tool cathode channel opening and is connected to the bottom left stray corrosion protection plate and the bottom right stray corrosion protection plate respectively through conductive screws; the blade back side stray corrosion protection plate spans the tool cathode channel opening and is connected to the bottom left stray corrosion protection plate and the bottom right stray corrosion protection plate respectively through conductive screws.

[0009] The protective device for stray corrosion of the integral bladed disk is characterized in that: the stray corrosion protection sheet on the blade basin side and the stray corrosion protection sheet on the blade back side are fan-shaped structures.

[0010] The beneficial technical effects of this invention are reflected in the following aspects: (1) It can effectively reduce or even eliminate stray corrosion of the bladed disk body and the processed blades during the overall bladed disk immersion electrolytic processing. The stray corrosion protection device provided by the present invention can effectively utilize the fact that the potential difference between the protection device and the cathode is larger than that between the overall bladed disk body and the surrounding non-electrolytic processing area to effectively absorb the stray electric field on the protection device, thus playing a good role in protecting the overall bladed disk body and the surrounding non-electrolytic processing area.

[0011] (2) Improve the surface quality of the non-machined area of ​​the integral bladed disk electrolytic machining. The protective device provided by the present invention reduces or avoids the stray corrosion effect of the stray electric field between the integral bladed disk parts and the cathode plate, effectively protects the integrity and surface gloss of the non-machined area of ​​the integral bladed disk electrolytic machining, effectively reduces the machining reference surface process of the non-machined area caused by electrolytic machining, and improves the engineering application level of integral bladed disk electrolytic machining.

[0012] (3) Improve the maturity of the overall bladed disk immersion electrolytic machining technology. The protective device and method provided by the present invention can effectively reduce or avoid the occurrence of stray pitting or corrosion pits in the immersion area (processed blades and disk body) of the overall bladed disk, ensure that the blades of the overall bladed disk are not locally etched away in the already formed dimensions, and ensure the quality stability of the overall bladed disk electrolytic machining. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the electrolytic machining process for integral bladed disk sleeves; Figure 2 Schematic diagram of stray corrosion protection device Figure 1 ; Figure 3 Schematic diagram of stray corrosion protection device Figure 2 Figure 4 Schematic diagram of the insulating board structure; Figure 5 This is a schematic diagram of the power supply connection structure for the electrolytic machining of an integral bladed disk.

[0014] The labels in the diagram are as follows: 1. Integral bladed disk, 2. Blade, 3. Tool cathode groove, 4. Tool cathode body, 5. Stray corrosion protection plate on the blade basin side, 6. Insulation plate, 7. Stray corrosion protection plate on the blade back side, 8. Stray corrosion protection plate on the bottom left side, 9. Stray corrosion protection plate on the bottom right side, 10. Tool cathode channel opening, 11. Main power supply of the equipment, 12. Third phase protection power supply, 13. Main power switch of the equipment, 14. Third phase protection power switch, 15. Cathode channel opening. Detailed Implementation

[0015] The embodiments of the present invention will be described in detail below. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope and application of the present invention.

[0016] When using immersion electrolytic machining to process the blade profile of an integral bladed disk, in order to reduce or avoid stray corrosion of the non-machined areas of the disk and the machined blades by stray electric potential fields, the specific implementation plan for the stray corrosion protection device of the integral bladed disk can be implemented as follows. The detailed steps are as follows: Step 1: The integral bladed disk 1 is installed on the rotation and translation shaft of the electrolysis equipment. The rotation and translation shaft can be linked to move through a CNC platform and connected to the positive terminal of the main power supply 11 of the equipment through the electrolysis power transmission mechanism.

[0017] Step 2: The tool cathode body 4 is connected to the X1 axis of the equipment through the tool cathode conduction mechanism and the clamping mechanism. The X1 axis of the equipment is connected to the negative terminal of the main power supply 11 of the equipment through the equipment power conduction device.

[0018] Step 3: The stray corrosion protection plate 5 on the blade basin side is connected to the stray corrosion protection plate 8 on the bottom left and the stray corrosion protection plate 9 on the bottom right by metal screws. The stray corrosion protection plate 7 on the blade back side is connected to the stray corrosion protection plate 8 on the bottom left and the stray corrosion protection plate 9 on the bottom right by metal screws. The stray corrosion protection plate 5 on the blade basin side, the stray corrosion protection plate 7 on the blade back side, the stray corrosion protection plate 8 on the bottom left and the stray corrosion protection plate 9 on the bottom right form a conductive integrated potential through metal screws, and its protection structure for the entire blade disk is U-shaped. The entire stray corrosion protection device is fixed and insulated to the tool cathode body base by insulating plate and insulating screws. The entire blade disk stray corrosion protection device is connected to the third phase protection power supply and the positive terminal of the main power supply of the equipment through the stray corrosion protection plate 7 on the blade back side.

[0019] Step 4: The program starts, and the electrolyte enters the tool cathode tank 3 through the electrolyte supply channel. The tool cathode tank is a typical U-shaped tank. The electrolyte can quickly fill the tool cathode tank 3, so that the processing area of ​​the whole bladed disk and some non-processing areas are immersed in the electrolyte. The main power switch 13 and the third phase protection power switch (14) of the equipment are turned on simultaneously. The blades to be processed on the whole bladed disk start to be electrolytically processed according to the CNC multi-axis linkage program until the processing is completed. The whole bladed disk moves out of the tool cathode tank 3 through multi-axis linkage. The whole bladed disk and the tool cathode return to the initial setting position. When the blade indexing command is issued, the whole bladed disk realizes the indexing and processing of the other blades in sequence.

[0020] Step 5: After all blades of the integral bladed disk are processed, the electrolyte control system stops the supply of electrolyte, the main power switch 13 and the third phase protection power switch 14 are disconnected, the CNC system controls the integral bladed disk and the tool cathode to safely retract to the safe waiting area, the indexing shaft of the integral bladed disk returns to the first blade position, and the electrolytic processing of the integral bladed disk is completed.

[0021] The above description, in conjunction with specific / preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various substitutions or modifications can be made to these described embodiments without departing from the inventive concept, and all such substitutions or modifications should be considered within the scope of protection of the present invention.

Claims

1. A protective device for stray corrosion of an integral bladed disk, characterized in that: Including stray corrosion protection components and circuitry; The stray corrosion protection components include a bottom stray corrosion protection plate, a blade basin side stray corrosion protection plate (5), and a blade back side stray corrosion protection plate (7). The bottom stray corrosion protection sheet has a tool cathode channel opening (10) in the middle; the bottom stray corrosion protection sheet is fixed and insulated to the tool cathode body base by an insulating plate and insulating screws; The stray corrosion protection sheet (5) on the blade basin side and the stray corrosion protection sheet (7) on the blade back side are located on both sides of the tool cathode channel opening (10) and are connected to the bottom stray corrosion protection sheet by conductive screws; The above-mentioned leaf basin side stray corrosion protection sheet (5), leaf back side stray corrosion protection sheet (7), and bottom stray corrosion protection sheet form a conductive integrated potential through conductive screws; The circuit section includes the main power supply of the equipment (11), the main power switch of the equipment (13), the third phase protection power supply (12), and the third phase protection power switch (14). The negative terminal of the main power supply (11) is connected to the tool cathode body (4). The positive terminal of the main power supply (11) is divided into two paths. One path is connected to the overall bladed disk through the main power supply switch (13). The other path is connected to the negative terminal of the third phase protection power supply (12). The positive terminal of the third phase protection power supply (12) is connected to the above-mentioned stray corrosion protection component through the third phase protection power supply switch (14). The bottom stray corrosion protection sheet consists of a bottom left stray corrosion protection sheet (8) and a bottom right stray corrosion protection sheet (9); and the tool cathode channel opening (10) is located between the two. The leaf basin side stray corrosion protection plate (5) spans the tool cathode channel opening (10) and is connected to the bottom left stray corrosion protection plate (8) and the bottom right stray corrosion protection plate (9) respectively by conductive screws; The stray corrosion protection sheet (7) on the back side of the blade spans the tool cathode channel opening (10) and is connected to the stray corrosion protection sheet on the bottom left and the stray corrosion protection sheet on the bottom right respectively by conductive screws.

2. The protective device for stray corrosion of integral bladed disks according to claim 1, characterized in that: The above-mentioned leaf basin side stray corrosion protection sheet (5) and leaf back side stray corrosion protection sheet (7) are fan-shaped structures.

3. The protection method for the integral bladed disk stray corrosion protection device according to claim 1, characterized in that... Includes the following processes: When the program starts, the electrolyte enters the tool cathode tank (3) through the electrolyte supply channel, so that the processing area of ​​the whole bladed disk and some non-processing areas are immersed in the electrolyte. The main power switch (13) and the third phase protection power switch (14) of the equipment are turned on simultaneously. The blades to be processed on the whole bladed disk start to be electrolytically processed according to the CNC multi-axis linkage program until the processing is completed. The whole bladed disk moves out of the tool cathode tank (3) in multi-axis linkage. The whole bladed disk and the tool cathode return to the initial setting position. When the blade indexing command is issued, the whole bladed disk realizes the indexing and processing of the other blades in sequence. During the processing, the additional potential of the third-phase protection power supply (12) is used to ensure that the potential difference between the tool cathode and the stray corrosion protection component is always higher than the potential difference between the tool cathode and the workpiece. Therefore, under the action of the stray electric field and flow field in the electrolytic processing, the anode of the stray corrosion protection component with a high potential difference is always higher than the non-processed area of ​​the anode part with a low potential difference. Therefore, this method is used to ensure that the non-processed surface of the overall bladed disk is not strayed under the action of the stray corrosion electric field. Once all blades of the integral bladed disk have been processed, the electrolyte control system stops supplying electrolyte, the main power switch (13) and the third-phase protection power switch (14) of the equipment are disconnected, the CNC system of the equipment controls the integral bladed disk and the tool cathode to safely retract to the safe waiting area, the indexing shaft of the integral bladed disk returns to the first blade position, and the electrolytic processing of the integral bladed disk is completed.

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