Titanium alloy blade electrolyte plasma polishing apparatus and method

Abstract

The application discloses a titanium alloy blade electrolyte plasma polishing device and method, and aims to solve the problems of temperature control, electrolyte flow and polishing uniformity in the polishing process of a compressor disc. The device comprises a cathode disc, an anode rotating disc, an electrolyte circulating pipe and a flat nozzle. The anode rotating disc is connected with the compressor disc and is arranged between two cathode discs, and the cathode disc is connected with a power supply device. The electrolyte circulating pipe is arranged below the disc, is connected with an external electrolyte tank and realizes electrolyte circulation through the flat nozzle. The application controls the temperature of the blade gap through low-temperature electrolyte circulation, promotes the electrolyte flow by rotating the anode rotating disc to avoid air bag aggregation, optimizes the electric field distribution by combining the upper and lower cathode discs, realizes uniform polishing of both sides of the blade, and improves the polishing effect and stability.

Description

Technical Field

[0001] This invention relates to the field of metal material surface polishing technology, and specifically to an electrolyte plasma polishing device and method for titanium alloy blades. Background Technology

[0002] In the modern aerospace field, the compressor bladed disk is one of the core components of an aero-engine, and its performance directly affects the overall performance and reliability of the engine. As aerospace technology continues to develop towards high performance and high reliability, extremely stringent requirements are placed on the manufacturing precision and surface quality of compressor bladed disks.

[0003] From a manufacturing precision perspective, even minute dimensional deviations can cause severe airflow turbulence during high-speed engine operation, reducing compressor efficiency and even leading to engine failure. High-precision manufacturing ensures optimal interaction between the blades and airflow of the impeller, improving the compressor's compression ratio and efficiency, thereby enhancing engine thrust and fuel economy. Surface quality is equally crucial. Rough surfaces increase airflow friction, reducing compressor aerodynamic performance and potentially causing stress concentration, affecting the impeller's fatigue life. Under prolonged harsh conditions such as high temperature, high pressure, and high-speed airflow impact, cracks and wear are more likely to occur, threatening the engine's safe operation.

[0004] Traditional compressor bladed disk machining processes, such as machining and electrochemical polishing, while meeting some accuracy and surface quality requirements, have numerous limitations. During machining, the mechanical contact between the tool and the workpiece inevitably generates cutting forces, leading to microscopic surface damage such as scratches and deformed layers. This damage not only affects surface roughness but also alters the surface stress state of the material, reducing the fatigue performance of the bladed disk. For complex-shaped compressor bladed disks, toolpath planning in machining is challenging, making it difficult to ensure consistent machining accuracy across different areas. While electrochemical polishing can improve surface roughness, its uniformity is poor, especially at blade edges and corners, where over-polishing or under-polishing is prone to occur. Furthermore, electrolyte treatment presents environmental pollution and high costs.

[0005] Electrolyte plasma polishing technology originated in Belarus and has gained popularity in China in recent years, offering a new opportunity to solve the aforementioned problems. Based on the principle of plasma discharge, this technology generates high-temperature, high-pressure plasma micro-regions in an electrolyte solution to achieve rapid removal and smoothing of material surfaces. Currently, this technology can polish metal surfaces such as stainless steel and copper alloys, but it is only used in civilian applications, primarily for decorative purposes.

[0006] Electrolyte plasma polishing technology and equipment for compressor bladed disks are still under development and face many unresolved issues. On the one hand, the discharge stability of the equipment is poor, easily affected by factors such as electrolyte composition, temperature, flow rate, and processing gaps, leading to uneven plasma energy distribution during polishing and consequently unstable polishing quality of the bladed disk surface. On the other hand, existing equipment lacks adaptability to the complex structure of compressor bladed disks, making it difficult to achieve precise polishing of different parts of the blades and failing to fully leverage the advantages of electrolyte plasma polishing technology.

[0007] In conclusion, developing an electrolyte plasma polishing device that can achieve stable discharge, adapt to the complex structure of compressor bladed disks, and ensure consistent polishing quality is of great practical significance for improving the manufacturing level of compressor bladed disks and promoting the development of aerospace technology. Summary of the Invention

[0008] The technical problem of this invention is: 1. Traditional devices have poor discharge stability and are easily affected by various factors such as electrolyte composition, temperature, flow rate and processing gap, resulting in uneven energy distribution of plasma during polishing and thus unstable polishing quality of the impeller surface.

[0009] 2. Traditional devices are not adaptable to the complex structure of compressor blades, making it difficult to achieve precise polishing of different parts of the blades and failing to fully utilize the advantages of electrolyte plasma polishing technology.

[0010] The purpose of this invention is: The present invention aims to develop an electrolyte plasma polishing device and method for titanium alloy blades, which achieves uniform, stable and efficient polishing of complex blade surfaces through structural optimization and process control.

[0011] The technical solution of this invention is: On one hand, the present invention provides an electrolyte plasma polishing device for titanium alloy blades. The device includes: an upper cathode disk (1), a lower cathode disk (2), an anode shaft and clamp (3), a coaxially clamped compressor blade disk (4), an annular water pipe (5), a flat nozzle (6), a rotating motor (7), and an insulating electrolytic cell (8), wherein: Preferably, the upper cathode disk (1) serves as the cathode, made of stainless steel with a thickness of 3-8 mm; a central opening allows the blade disk to pass through and for venting; a uniform electric field is formed between it and the anode blade disk; symmetrical arrangement with the lower cathode disk (2) ensures that the upper and lower parts of the blade are subjected to similar electric field strengths, avoiding over-polishing or under-polishing on one side. The cathode-anode spacing is generally 30-80 mm, with a spacing of 40-60 mm resulting in better polishing effect. A spacing of <30 mm is prone to arcing and short circuits, while a spacing of >80 mm requires a higher ignition voltage and results in uneven discharge.

[0012] Preferably, the lower cathode disk (2) serves as the cathode, made of stainless steel, with a thickness of 3-8 mm and a central opening for venting. It is arranged symmetrically with the upper cathode disk 1 to ensure that the upper and lower surfaces of the blades are subjected to similar electric field strengths. It can also be used alone during the second finishing and polishing of the blade edge. The typical cathode-anode spacing is 40-60 mm. A spacing of <30 mm is prone to arcing and short circuits, while a spacing of >80 mm requires a higher ignition voltage and results in uneven discharge.

[0013] Preferably, the anode shaft and clamp (3) mainly consists of an anode shaft (31) and a titanium alloy conductive clamp (32). The anode shaft is made of copper alloy or other conductive metal, and the outside includes insulating material (such as PTFE). It is used to coaxially clamp the impeller (4) and make the impeller the anode connected to the positive terminal of the external power supply. A rotating motor (7) is connected above the anode shaft, which can rotate and support the impeller between the upper and lower cathode disks, drive the impeller to rotate, and adjust the speed between 10 and 30 r / min. If the speed is too low, gas will easily accumulate in the flow channel, and if it is too high, splashing and liquid surface instability will occur. The anode shaft (31) drives the impeller (4) to be coaxial with the upper and lower cathode disks (1, 2), improving the uniformity of the electric field. Finally, the anode conductive connection of the impeller is realized, and the centrifugal-pumping effect is generated in the narrow flow channel of the blade by driving the electrolyte, which destroys the gas film accumulation and promotes the rapid discharge of high temperature electrolyte. The titanium alloy conductive clamp is made of titanium alloy. After connecting the impeller, the contact resistance is checked and should be <0.1Ω.

[0014] Preferably, the flat nozzle (6) is connected to a rectangular slit nozzle of 1.5×40mm shape via an annular conduit. This nozzle is located between the impeller and the lower cathode disk, directing the electrolyte into the flow channel at the root of the impeller. This creates a forced flow field along the blade extension direction, compensating for the axial unevenness of the rotating flow field, accelerating the electrolyte flow velocity between the blades, improving the electrolyte temperature uniformity control, and focusing on cooling the high-temperature zone from the blade root to the blade center. The distance between the flat nozzle water outlet and the impeller is generally 10~20mm, and the nozzle flow rate is approximately 15~25L / min. The number of nozzles is 1 / 3 to 1 / 10 of the number of blades in the impeller.

[0015] Preferably, the electrolyte circulation temperature control system (9) provides electrolyte at a set temperature to the insulated electrolytic tank. The optimal polishing window for titanium alloy is 75-85°C. Temperatures exceeding 95°C can easily lead to over-etching of the workpiece and instability of the gas film.

[0016] On the other hand, the present invention proposes a method for electrolyte plasma polishing of titanium alloy blades using the above-mentioned device, comprising the following steps: S1 Pretreatment: Clean and degrease the TC4 or TA15 titanium alloy impeller, clamp it in the titanium alloy conductive chuck (32) and confirm that the resistance between the impeller and the titanium alloy conductive chuck (32) is <0.1Ω. S2 Component Position Adjustment: Adjust the jet direction of the flat nozzle (6) to the gap between it and the blade of the blade disk or to have an angle deviation of 0° to 30°; immerse the anode shaft and clamp (3) and the blade disk in the electrolyte, adjust the height of the upper cathode disk (1) and the lower cathode disk (2) so that the distance (h2 and h3) between the lower surface of the upper cathode disk (1) and the upper surface of the lower cathode disk (2) and the blade disk is 80 to 300 mm, adjust the position of the annular water pipe and the flat nozzle (6) so that the distance between the flat nozzle (6) and the blade disk is 30 to 70 mm, and after adjustment, the components from top to bottom are the upper cathode disk (1), the anode shaft and clamp (3), the blade disk, the annular water pipe (5) and the lower cathode disk (2), and all components are coaxial.

[0017] S3 Injection and Temperature Control: Start the centrifugal rotation system (94) and temperature controller (95) in the electrolyte circulation temperature control system (9), open the flow limiter (98) to the maximum flow rate, and circulate the electrolyte between the insulated electrolytic tank (8) and the electrolyte circulation temperature control system (9). Set the temperature of the temperature controller (95) to 70-90℃, wait for the electrolyte to be fully heated to the set temperature, and after adjusting to the set temperature, set the water flow rate of the flow limiter (98) so that the water flow rate of the flat nozzle (6) is 10-30 L / min.

[0018] S4 Initial Polishing: Connect the external power supply, first apply a low voltage of 150-200V for 5-15s for pre-wetting, then increase to a working voltage of 300-340V, turn on the rotating motor (7), set the speed to 10-30r / min, the impeller rotates and drives the electrolyte to flow upward, the polishing time is 5-15min. During the polishing process, the superheated electrolyte in the insulating electrolytic tank (8) is discharged from the top drain port (81) and discharged into the electrolyte circulation temperature control system (9) for cooling to the set temperature.

[0019] S5 Process Inspection: Disconnect the power supply and observe whether the edges of the blades on the impeller are completely polished; S6 Secondary polishing: If not fully polished, disassemble the impeller, and reinstall it on the titanium alloy conductive clamp (32) with the unpolished side facing down. Immerse it in the electrolyte so that the impeller is coaxial with the annular water pipe (5) and the lower cathode plate (2). During this polishing, the upper cathode plate is no longer connected to the anode so that it no longer generates an electric field. Polish according to the steps of S5-S6, in which the polishing time in step S5 is reduced to 1~5min; S7 Polishing End and Post-processing: After the impeller is fully polished, turn off the rotating motor (7) and the electrolyte circulation temperature control system (9), move the upper cathode disk (1), the anode shaft and clamp (3) and the impeller, remove the impeller from the titanium alloy conductive chuck (32), and lower the cathode disk (2). S8. Remove the impeller, rinse with deionized water, and blow dry.

[0020] The advantages and beneficial effects of this invention are: This invention controls the blade gap temperature through low-temperature electrolyte circulation, promotes electrolyte flow by rotating the anode disk to avoid gas accumulation, and optimizes the electric field distribution by combining the upper and lower cathode disks, thereby achieving uniform polishing of both sides of the blade and improving the polishing effect and stability.

[0021] 1. Low-temperature electrolyte is connected to the external electrolyte circulation pipe, and the electrolyte is circulated through a flat nozzle. The nozzle angle is aligned with the blade direction. By adjusting the height of the nozzle and the blade disk, as well as the water flow speed of the nozzle, the electrolyte circulation and cooling in the blade gap is accelerated, and the electrolyte temperature in the blade gap is controlled.

[0022] 2. The anode turntable can achieve 360° continuous rotation. The blade angle drives the surrounding electrolyte to flow upward, promoting electrolyte flow and preventing the formation of air pockets during plasma polishing.

[0023] 3. By setting up an upper and lower set of cathode disks, the electric field distribution around the blades of the blade disk is controlled, so as to achieve uniform polishing of both sides of the blades. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of an electrolyte plasma polishing device for a compressor blade disk according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a compressor blade disk electrolyte plasma polishing device according to another embodiment of the present invention; The reference numerals in the figures include: Upper cathode plate 1, lower cathode plate 2, anode shaft and clamp 3, impeller 4, annular water pipe 5, flat nozzle 6, rotating motor 7, insulated electrolytic cell body 8, and electrolyte circulation temperature control system 9. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] This invention discloses an electrolyte plasma polishing device and method for titanium alloy blades or integral bladed disks, aiming to solve the problems of unstable discharge, runaway temperature between blades, dead zones in electrolyte flow preventing gas bag discharge, and poor polishing uniformity of complex surfaces in existing polishing devices. The device includes: an insulated electrolytic tank, upper / lower cathode disks, an anode rotary table clamp, a rotating motor, an electrolyte circulation temperature control system, and a flat nozzle assembly. The anode rotary table clamp is used to coaxially clamp the compressor bladed disk and serves as the anode connected to the positive terminal of a DC power supply. The upper and lower cathode disks are arranged parallel and symmetrically above and below the bladed disk and connected to the negative terminal of an external power supply. The electrode distance between the upper and lower cathode disks and the blades is adjustable. The electrolyte circulation temperature control system injects electrolyte at a set temperature tangentially into the blade flow channel at a set flow rate through the flat nozzle assembly below the bladed disk. The anode rotary table is continuously rotated by the rotating motor, causing the electrolyte between the blades to flow upwards. This invention controls the polishing zone temperature at 80-90°C through low-temperature electrolyte circulation and directional liquid supply from a flat nozzle group. It eliminates air pockets in the flow channel and enhances ion diffusion by rotating the anode. It achieves uniform plasma polishing of titanium alloy blades on both sides by balancing the electric field distribution on the upper and lower sides of the upper and lower cathode disks. After polishing, the surface roughness Ra can be stably reduced to below 0.1μm.

[0029] Figure 1 and Figure 2 This is a schematic diagram of the structure of an electrolyte plasma polishing device for a compressor blade disk according to an embodiment of the present invention.

[0030] like Figure 1 and Figure 2 As shown, the compressor blade disk electrolyte plasma polishing device may include: an upper cathode disk (1), a lower cathode disk (2), an anode shaft and clamp (3), a coaxially clamped compressor blade disk (4), an annular water pipe (5), a flat nozzle (6), a rotating motor (7), an insulating electrolytic cell (8), and an electrolyte circulation temperature control system (9). Wherein: The insulated electrolytic cell (8) has a drain port (81) at the top and a drain port (82) at the bottom. When the equipment is working, the superheated electrolyte is discharged from the top drain port to accelerate the flow of electrolyte. When changing the tank liquid, the electrolyte is discharged from the bottom drain port (82). The upper cathode plate (1) and the lower cathode plate (2) are both made of stainless steel and are arranged in parallel and symmetrically in the insulating electrolytic cell (8). The distance between the upper cathode plate (1) and the lower cathode plate (2) is adjustable and both are connected to the negative terminal of the external power supply. The anode shaft and clamp (3) consist of an insulating turntable body (31, i.e., the shaft, not shown in the figure) and a titanium alloy conductive chuck (32, not shown in the figure) set in its center. It is used to coaxially clamp the compressor blade disk (4) and connect the blade disk as the anode to the positive terminal of the external power supply. It is located between the upper cathode disk (1) and the lower cathode disk (2). It is connected to an external rotating motor (7) and can rotate under the control of the rotating motor (7). The annular water pipe (5) is made of insulating material. The annular shape is coaxial with the impeller and is used to introduce the electrolyte of the electrolyte circulation temperature control system (9) into the annular water pipe. Flat nozzles (6) are evenly distributed on it. The flat nozzle (6) is made of insulating material, connected by an annular water pipe (5) and evenly distributed on the annular water. The number of flat nozzles is 1 / 3 to 1 / 10 of the number of blades in the bladed disk. The flat nozzle and the annular water pipe are combined and installed below the compressor bladed disk and tilted towards the direction of blade rotation. The water jet direction of the flat nozzle is towards the blade gap of the bladed disk, and the length direction of the nozzle is the same as the length direction of the blade.

[0031] The rotating motor (7) is connected to the top of the turntable body (31). The anode shaft and the clamp (3) rotate continuously around their own axis at a set speed, ensuring that the rotating impeller drives the electrolyte to flow upward.

[0032] The electrolyte circulation temperature control system (9) includes a storage tank (91), a heating system (92), a cooling system (93), a centrifugal rotation system (94), a temperature controller (95), an outlet (96), a flow limiter (98), and an inlet (97). The storage tank (91) is used to store the electrolyte and regulate it within a specified temperature range. The temperature control system is used to detect the electrolyte temperature and control the heating system (92) and the cooling system (93), and is used to heat the electrolyte within a temperature control range of room temperature to 95°C. The centrifugal rotation system (94) is used to accelerate the uniformity of the electrolyte temperature within the storage tank (91). The inlet (97) receives the electrolyte from the drain port (81) of the insulated electrolytic cell body, and the outlet (96) is equipped with a flow limiter (98) to output electrolyte at a set temperature to the flat nozzle assembly (6).

[0033] In some embodiments, the upper cathode disk (1) and the lower cathode disk (2) are both annular flat plates with a central opening. The outer diameter is 20-50 mm larger than the maximum outer diameter (R1) of the blade disk to be polished. The distance (h2 and h3) between the lower surface of the upper cathode disk (1) and the upper surface of the lower cathode disk (2) and the blade disk is 80-300 mm. The distance between the upper and lower cathode disks can be adjusted to accommodate blade disks of different shapes.

[0034] In some embodiments, the outlet of the flat nozzle assembly (6) is a rectangular slit structure with a nozzle width of 1 to 3 mm and a nozzle length of 30% to 60% of the blade length of the impeller. The nozzle jet direction is adjusted to be directly opposite the gap between the blades of the impeller or there is a 0° to 30° included angle deviation. The rated flow rate of the nozzle is 10 to 30 L / min. The distance between the water outlet of the flat nozzle and the impeller is generally 30 to 70 mm.

[0035] In some embodiments, the rotational motor (7) is set to a speed of 10~30 r / min, and the rotation direction can cause the impeller to drive the electrolyte to flow upward.

[0036] In some embodiments, the anode shaft is connected to the titanium alloy conductive chuck (32) of the clamp (3) and the impeller to ensure that the anode conduction resistance is <0.1Ω, and the remaining parts are covered with polytetrafluoroethylene or ceramic insulating layer to prevent discharge in the non-polished area.

[0037] In some embodiments, the external power supply is a DC power supply with a continuously adjustable voltage of 0 to 400V and a maximum output current of ≥30A. The recommended polishing working voltage is 300 to 350V. During the ignition and preheating stage, a stepped voltage boosting method can be used (150V→250V→set voltage).

[0038] In some embodiments, the insulating electrolytic cell (8) is provided with drain ports at both the top and bottom. The top drain port (81) is opened during the polishing process to discharge the superheated electrolyte, and the bottom drain port (82) is used when changing the electrolyte.

[0039] In some embodiments, the electrolyte circulation temperature control system (9) maintains the electrolyte temperature entering the electrolytic cell at 70-90°C. The cell is equipped with a temperature controller (95) for real-time feedback. Initially, the heating system (92) heats the electrolyte. When the polishing temperature exceeds the limit, the cooling system (93) is activated to cool it down. When the electrolyte circulation temperature control system is activated, the centrifugal rotation system (94) is activated to accelerate the uniform temperature in the storage tank (91).

[0040] Example 1: Taking cathode disk 1 and integral bladed disk of TC4 titanium alloy (outer diameter Φ320 mm, blade length 60 mm, initial roughness Ra≈ 0.6 μm) as examples: A method for electrolyte plasma polishing of titanium alloy blades includes the following steps: S1 Pretreatment: Clean and degrease the TC4 titanium alloy impeller, clamp it in the titanium alloy conductive chuck (32), and use a multimeter to check the resistance between the impeller and the titanium alloy conductive chuck (32). It should be <0.1Ω. S2 Component Position Adjustment: Adjust the jet direction of the flat nozzle (6) so that its nozzle length is reversed and the same as the blade gap; immerse the anode shaft and clamp (3) and the blade plate in the electrolyte, adjust the height of the upper cathode plate (1) and the lower cathode plate (2) so that the height between the lower surface of the upper cathode plate (1) and the blade plate is 100mm, and the distance between the upper surface of the lower cathode plate (2) and the blade plate is 20mm; adjust the position of the annular water pipe and the flat nozzle (6) so that the distance between the flat nozzle (6) and the blade plate is 70mm. After adjustment, the components from top to bottom are the upper cathode plate (1), the anode shaft and clamp (3), the blade plate, the annular water pipe (5) and the lower cathode plate (2), and all components are coaxial.

[0041] S3 Injection and Temperature Control: Start the centrifugal rotation system (94) and temperature controller (95) in the electrolyte circulation temperature control system (9), open the flow limiter (98) to the maximum flow rate, and circulate the electrolyte between the insulated electrolytic tank (8) and the electrolyte circulation temperature control system (9). Set the temperature of the temperature controller (95) to 70-90℃, wait for the electrolyte to be fully heated to the set temperature, and after adjusting to the set temperature, set the water flow rate of the flow limiter (98) so that the water flow rate of the flat nozzle (6) is 25L / min. S5 Initial Polishing: Connect the external power supply, first apply 150V low voltage for 10s pre-wetting, then increase to 340 working voltage, turn on the rotating motor (7), set the speed to 15r / min, the impeller rotates to drive the electrolyte to flow upward, and the polishing time is 5min. During the polishing process, the superheated electrolyte in the insulating electrolytic tank (8) is discharged from the top drain port (81) and discharged into the electrolyte circulation temperature control system (9) for cooling to the set temperature.

[0042] S6 Process Inspection: Disconnect the power and observe whether the blade edges of the impeller are completely polished. The blade edges of the upper impeller are not completely polished, so a second polishing is required. S7 Secondary Polishing: Disassemble the impeller, and reinstall it on the titanium alloy conductive chuck (32) with the side that is not fully polished facing down. Immerse it in the electrolyte, so that the impeller is coaxial with the annular water pipe (5) and the lower cathode plate (2). During this polishing, the upper cathode plate is no longer connected to the anode. Connect the external power supply, first apply a low voltage of 150V for 10s for pre-wetting, and then increase it to 340V working voltage. Turn on the rotating motor (7) and set the speed to 15r / min. The impeller rotates and drives the electrolyte to flow upward. The polishing time is 2min.

[0043] After the S8 impeller is fully polished, turn off the rotating motor (7) and the electrolyte circulation temperature control system (9), move the upper cathode disk (1), the anode shaft and clamp (3) and the impeller, remove the impeller from the titanium alloy conductive chuck (32), and lower the cathode disk (2). S8. Remove the impeller, rinse with deionized water, and blow dry.

[0044] Example 2: A method for electrolyte plasma polishing of titanium alloy blades includes the following steps: 1. Clamp the bladed disk onto the anode turntable (3), press the conductive clamp against the hub, and ensure the conduction resistance is ≤ 0.1 Ω; 2. Adjust the distance between the upper and lower cathode disks (1, 2) and the outer edge of the blade disk to 50 mm; 3. Start the electrolyte circulation temperature control system and inject 0.35 mol / L NH4F + 0.35 mol / L KF neutral electrolyte into the insulated electrolytic tank (10). Set the temperature to 85 ℃ and pH = 6.2. 4. Open the flat nozzle (6) (slit 1.5 × 50 mm, tilt angle 30°, flow rate 20 L / min × 2 pieces) to direct the electrolyte into the blade channel; 5. Start the servo rotary drive mechanism (8), and the anode turntable rotates at a constant speed of 20 r / min; 6. Connect the DC power supply (7), and increase the working voltage stepwise from 150 V / 8 s → 250 V / 5 s → 320 V. Polish for 10 min, with a current density of 0.2~0.3 A / cm². 7. After power is off, continue spraying and rinsing for 20 seconds, then remove the impeller, rinse with deionized water, and blow dry.

[0045] After testing, the surface roughness Ra of the polished blade disk is 0.04 to 0.08 μm. The blade base and blade back surfaces are bright and uniform, without over-etching, pitting, or arc burn marks, meeting the surface quality requirements of aero-engine compressor blade disks.

[0046] Compared with the prior art, the advantages of the present invention include the following:

[0047] It should be emphasized that the parameters and their combinations in this invention are all optimal parameters obtained based on basic research and a large number of experiments. If one or more of them are changed, the later effects will be weakened, or even the technical problems will not be solved and the expected technical effects will not be achieved.

[0048] It should be noted that the above process operations can be combined to varying degrees. For the sake of brevity, the implementation methods of various combinations will not be elaborated here. Those skilled in the art can flexibly adjust the order of the above operation steps or flexibly combine the above steps according to actual needs.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A titanium alloy blade electrolyte plasma polishing device, characterized in that, include: The upper cathode plate (1), lower cathode plate (2), anode shaft and clamp (3), impeller (4), annular water pipe (5), flat nozzle (6), rotating motor (7), and insulated electrolytic cell (8), wherein: The upper cathode plate (1) and the lower cathode plate (2) are both made of stainless steel and are arranged in parallel and symmetrically in the insulating electrolytic cell (8). The distance between the upper cathode plate (1) and the lower cathode plate (2) is adjustable and both are connected to the negative terminal of the external power supply. The anode shaft and clamp (3) are used to coaxially clamp the blade disk (4) and make the blade disk (4) connect to the positive terminal of the external power supply as the anode. It is located between the upper cathode disk (1) and the lower cathode disk (2). An external rotating motor (7) is connected to it and it can rotate under the control of the rotating motor (7). The annular water pipe (5) is made of insulating material. The annular shape is coaxial with the impeller (4) and is used to introduce the electrolyte of the electrolyte circulation temperature control system (9) into the annular water pipe. Flat nozzles (6) are evenly distributed on it. The flat nozzle (6) is combined with the annular water pipe (5), installed below the impeller (4) and tilted towards the rotation direction of the impeller (4), with the water jet direction of the flat nozzle (6) facing the blade gap of the impeller (4); The rotating motor (7) is externally connected to the anode shaft and the clamp (3). The anode shaft and the clamp (3) rotate continuously around their own axis at a set speed of 360°, rotating the blade disk (4) and driving the electrolyte to flow upward, thereby performing electrolyte plasma polishing on the titanium alloy blade.

2. The apparatus according to claim 1, characterized in that, in: The upper cathode disk (1) serves as the cathode, with a central opening for the blade disk (4) to pass through and for exhaust; a uniform electric field is formed between it and the anode blade disk; The symmetrical arrangement with the lower cathode disk (2) can ensure that the upper and lower parts of the blade are subjected to similar electric field strength, thus avoiding over-throwing or under-throwing on one side.

3. The apparatus according to claim 1, characterized in that, in: The lower cathode disk (2) serves as the cathode, with a central opening for venting. The lower cathode disk (2) and the upper cathode disk (1) are arranged symmetrically so that the upper and lower surfaces of the blade are subjected to similar electric field strengths, and can be used alone when the blade edge is trimmed and polished for the second time.

4. The apparatus according to claim 1, characterized in that, in: The upper cathode disk (1) and the lower cathode disk (2) are used as cathodes, and the material is stainless steel with a disk thickness of 3-8mm; The distance between the cathode and anode is 40-60mm to ensure polishing effect. A distance of less than 30mm is prone to arcing and short circuits, while a distance of more than 80mm requires a higher ignition voltage and results in uneven discharge.

5. The apparatus according to claim 1, characterized in that, in: The anode shaft and clamp (3) includes: an insulating turntable body and a titanium alloy conductive chuck set in the center. The anode shaft and clamp (3) drive the pressure plate to rotate and adjust the speed between 10 and 30 r / min to prevent air from accumulating in the flow channel if the speed is too low, and splashing and unstable liquid surface if the speed is too high.

6. The apparatus according to claim 5, characterized in that, in: The anode shaft on the main body of the turntable drives the blade disk (4) to be coaxial with the upper cathode disk (1) and the lower cathode disk (2), which improves the uniformity of the electric field, realizes the conductive connection of the anode of the blade disk, and drives the electrolyte to generate a centrifugal-pumping effect in the narrow flow channel of the blade, thereby destroying the gas film accumulation and promoting the rapid discharge of high temperature electrolyte.

7. The apparatus according to claim 1, characterized in that, in: The flat nozzle (6) is made of insulating material, connected by an annular water pipe (5) and evenly distributed on the annular water. The number of flat nozzles (6) is 1 / 3 to 1 / 10 of the number of blades in the bladed disk (4). The outlet of the flat nozzle assembly (6) is a rectangular slit structure. The nozzle width is 1-3 mm and the nozzle length is 30%-60% of the blade length of the impeller. The nozzle jet direction is adjusted to be directly opposite the gap between the blades of the impeller or there is a 0°-30° included angle deviation. The rated flow rate of the nozzle is 10-30 L / min. The distance between the water outlet of the flat nozzle and the impeller is generally 30-70 mm.

8. The apparatus according to any one of claims 1-7, characterized in that, The device also includes an electrolyte circulation temperature control system (9), wherein: The electrolyte circulation temperature control system (9) includes: a storage tank (91), a heating system (92), a cooling system (93), a centrifugal rotation system (94), a temperature controller (95), an outlet (96), a flow limiter (98), and an inlet (97), wherein: The electrolyte storage tank (91) is used to store the electrolyte and regulate the electrolyte within a specified temperature range; The temperature controller (95) is used to detect the electrolyte temperature and control the heating system (92) and cooling system (93), and is used for heating electrolyte within the temperature control range of room temperature to 95°C; The centrifugal rotation system (94) is used to accelerate the uniformity of electrolyte temperature within the storage tank (91); The inlet (97) receives the electrolyte from the outlet (81) of the insulated electrolytic cell, and the outlet (96) is equipped with a flow limiter (98) to output electrolyte at a set temperature to the flat nozzle assembly (6).

9. A method for electrolyte plasma polishing of titanium alloy blades using the apparatus according to any one of claims 1 to 8, the method comprising the following steps: Injection and temperature control: Start the centrifugal rotation system (94) and temperature controller (95) in the electrolyte circulation temperature control system (9), open the flow limiter (98) to the maximum flow rate, and circulate the electrolyte between the insulated electrolytic tank (8) and the electrolyte circulation temperature control system (9). Set the temperature of the temperature controller (95) to 70-90℃, wait for the electrolyte to be fully heated to the set temperature, and after adjusting to the set temperature, set the water flow rate of the flow limiter (98) so that the water flow rate of the flat nozzle (6) is 10-30 L / min; Qi Hui Polishing: Connect the external power supply, first apply a low voltage of 150~200V for 5~15s to pre-wet, then increase to 300~340V working voltage, turn on the rotating motor (7), set the speed to 10~30r / min, the impeller rotates to drive the electrolyte to flow upward, the polishing time is 5~15min; during the polishing process, the superheated electrolyte in the insulating electrolytic tank (8) is discharged from the top drain port (81) and discharged into the electrolyte circulation temperature control system (9) to be cooled to the set temperature; Process inspection: Disconnect the power supply and observe whether the edges of the blades on the impeller are completely polished; Secondary polishing: If not fully polished, disassemble the impeller, and reinstall it on the titanium alloy conductive clamp (32) with the side that is not fully polished facing down. Immerse it in the electrolyte so that the impeller is coaxial with the annular water pipe (5) and the lower cathode plate (2). During this polishing, the upper cathode plate is no longer connected to the anode so that it no longer generates an electric field. Polish according to steps S5-S6, where the polishing time in step S5 is reduced to 1~5 minutes. Polishing completion and post-processing: After the impeller is fully polished, turn off the rotating motor (7) and the electrolyte circulation temperature control system (9), move the upper cathode disk (1), the anode shaft and clamp (3) and the impeller, remove the impeller from the titanium alloy conductive chuck (32), and lower the cathode disk (2). Remove the impeller, rinse with deionized water, and dry.

10. The method according to claim 9, characterized in that, The method also includes the following steps: Pretreatment: Clean and degrease the TC4 or TA15 titanium alloy impeller, clamp it in the titanium alloy conductive chuck (32) and confirm that the resistance between the impeller and the titanium alloy conductive chuck (32) is <0.1Ω; Component position adjustment: Adjust the jet direction of the flat nozzle (6) to the gap between it and the blade of the blade disk or to have an angle deviation of 0° to 30°; immerse the anode shaft and clamp (3) and the blade disk in the electrolyte, adjust the height of the upper cathode disk (1) and the lower cathode disk (2) so that the distance (h2 and h3) between the lower surface of the upper cathode disk (1) and the upper surface of the lower cathode disk (2) and the blade disk is 80 to 300 mm, adjust the position of the annular water pipe and the flat nozzle (6) so that the distance between the flat nozzle (6) and the blade disk is 30 to 70 mm, and after adjustment, the components from top to bottom are the upper cathode disk (1), the anode shaft and clamp (3), the blade disk, the annular water pipe (5) and the lower cathode disk (2), and all components are coaxial.

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