Ultrasonic-assisted electrolytic machining apparatus and method for abrasive reciprocating polishing

Abstract

This invention discloses an ultrasonic-assisted electrolytic machining apparatus and method for reciprocating abrasive polishing, belonging to the field of electrolytic machining. The apparatus includes an ultrasonic-assisted electrolytic machining device, an electrolyte sealing fixture, and an electrolyte reciprocating control system. The ultrasonic-assisted electrolytic machining device controls the cathode to vibrate ultrasonically while performing periodic reciprocating motion, and the reciprocating polishing system realizes the reciprocating flow of abrasive grains within the machining area. During machining, when the cathode vibrates close to the workpiece, the abrasive grains are collected in the abrasive grain cavity, and the cathode ultrasonic cavitation removes the machining product layer. Simultaneously, the ultrasonic disturbance of the flow field promotes the uniform distribution of bubbles and temperature. When the cathode moves away from the workpiece, the workpiece does not dissolve, and the abrasive grains reciprocate, achieving polishing removal of insoluble phases under ultrasonic action. This invention can control cavitation by adjusting the ultrasonic power, removing the machining product layer and improving the uniformity of the flow field. Ultrasonic force can also improve the grinding effect of abrasive grains, remove insoluble phases from the machined surface, and achieve high-precision, high-surface-quality precision machining.

Description

Technical Field

[0001] This invention relates to an ultrasonic-assisted electrochemical machining apparatus and method for reciprocating abrasive polishing, belonging to the field of electrochemical machining. Background Technology

[0002] Electrochemical machining (ECM) is a processing technology based on electrochemical principles to dissolve metal materials, enabling the production of parts with specific shapes. Compared to conventional machining, ECM offers advantages such as better workpiece surface quality, higher batch production efficiency, and lower processing costs, making it suitable for machining integral components such as integral bladed disks for aero-engines.

[0003] In traditional electrolytic machining of bladed disk-type integral components, the electrolyte is introduced from both sides of the flange. This method provides separate electrolyte supply for the blade basin and blade back flow channels, resulting in good flow field controllability. However, due to the accumulation of bubbles, temperature, and electrolytic products along the flow path under unidirectional flow, the physical field within the machining gap becomes unevenly distributed, leading to poor uniformity of electrolyte conductivity and affecting molding accuracy. During electrolytic machining, a passivation layer and highly adsorbent flocculent electrolytic products are generated on the workpiece surface, causing uneven dissolution of the material. Simultaneously, the presence of insoluble phases such as carbides in the material severely impacts surface quality.

[0004] Based on this, researchers have proposed a variable flow electrolytic machining method (active control electrolyte flow method and electrolyte circulation system in blade machining, application number CN200810020457.3, publication number CN101249577B). By switching the electrolyte flow through an electrolyte reversing valve, the electrolyte inlet channel and outlet channel for blade basin machining, as well as the electrolyte inlet channel and outlet channel for blade back machining, can be switched, which helps to improve the forming accuracy of electrolytic machining. Meanwhile, researchers have proposed an abrasive flow-assisted electrolytic finishing method (vibration-assisted abrasive flow electrolytic micro-grinding composite finishing method, application number CN201710733206.9, publication number CN107442874A). By introducing an electrolyte mixed with abrasive particles of different sizes and shapes into the flow channel at a certain speed and pressure, the electrolyte drives the abrasive particles to flow, producing a micro-grinding effect on the passivation film and protrusions on the workpiece surface, causing the protrusions to undergo electrolytic dissolution, thereby achieving a macroscopic smoothness on the workpiece surface.

[0005] In summary, current precision electrochemical machining methods cannot further improve machining accuracy and surface quality. Given the urgent need for precision electrochemical machining of integral components such as aero-engine bladed disks, a new precision electrochemical machining device and method are required to achieve high-precision, high-surface-quality manufacturing of these components. Summary of the Invention

[0006] This invention addresses the precision electrolytic machining of integral bladed disk components by proposing an ultrasonic-assisted electrolytic machining device and method for reciprocating abrasive polishing, thereby achieving high-precision and high-surface-quality manufacturing of integral bladed disk components.

[0007] An ultrasonic-assisted electrolytic machining device for abrasive reciprocating polishing includes an ultrasonic-assisted electrolytic machining device, an electrolyte sealing fixture, and an electrolyte reciprocating control system; characterized in that: the ultrasonic-assisted electrolytic machining device includes a first ultrasonic amplitude transformer and a first ultrasonic transducer sequentially connected to the cathode of the blade basin, a second ultrasonic amplitude transformer and a second ultrasonic transducer sequentially connected to the cathode of the blade back, and further includes an ultrasonic generator and an anode workpiece; wherein the first ultrasonic transducer and the second ultrasonic transducer are respectively connected to the first feed axis and the second feed axis of the machine tool, and are controlled by the ultrasonic generator; the electrolyte sealing fixture includes a fixture body, the fixture body being located at the current... A first abrasive cavity is set at the corresponding position at the end of the blade, a second abrasive cavity is set on the outer side of the cathode on the blade back, and a third abrasive cavity is set on the outer side of the cathode on the blade base. A micro-filter is set between the first, second, and third abrasive cavities and the connector of the electrolyte system. The electrolyte reciprocating control system mainly includes several solenoid valves and controllers, which allows the electrolyte inlet and electrolyte outlet to switch between the following two modes: Mode 1: The electrolyte inlet is connected to the second and third abrasive cavities, and the electrolyte outlet is connected to the first abrasive cavity; Mode 2: The electrolyte inlet is connected to the first abrasive cavity, and the second and third abrasive cavities are connected to the electrolyte outlet.

[0008] The ultrasonic-assisted electrolytic machining device for reciprocating abrasive polishing is characterized in that: the electrolyte reciprocating control system includes a first normally closed solenoid valve, a first normally open solenoid valve, a second normally open solenoid valve, a second normally closed solenoid valve, a safety valve, and a controller; wherein the electrolyte inlet is connected to the second abrasive chamber and the third abrasive chamber through the first normally open solenoid valve, and the first abrasive chamber is connected to the electrolyte outlet through the second normally open solenoid valve; wherein the electrolyte inlet is connected to the first abrasive chamber through the second normally closed solenoid valve, and the second and third abrasive chambers are connected to the electrolyte outlet through the first normally closed solenoid valve; a safety valve (20) is provided at the electrolyte inlet for safety protection of the electrolyte reciprocating control system.

[0009] The method of the ultrasonic-assisted electrolytic machining device for reciprocating abrasive polishing is characterized by the following: during electrolytic machining, under the control of an ultrasonic generator, the blade-side cathode and the blade-back cathode undergo ultrasonic vibration; the first and second feed axes on both sides of the machine tool control the blade-side cathode and the blade-back cathode to feed towards each other while performing periodic reciprocating motion along the feed direction; when the blade-side cathode and the blade-back cathode vibrate and approach the workpiece along the positive feed direction, electrolytic machining is initiated, the reciprocating polishing system is shut down, and the abrasive particles are collected in the first abrasive particle cavity; the tool cathode undergoes ultrasonic cavitation, generating shock waves and micro-jet effects to remove the product layer on the machined surface and promote the uniform dissolution of the material; simultaneously, the ultrasonic waves affect the flow field within the gap. The disturbance effect ensures a uniform distribution of air bubbles and temperature physical field within the machining gap, improving machining accuracy. When the cathode vibrates away from the workpiece along the negative feed direction, the electrolytic power supply is disconnected, and the reciprocating polishing system is activated. Under ultrasonic action, the fine abrasive particles adhere to the workpiece surface to produce a grinding effect, achieving polishing removal of insoluble phases on the machined surface and improving surface quality. The controller periodically turns on and off, and the electrolyte periodically switches between the first and second flow directions, with the fine abrasive particles flowing back and forth within the machining area. The first flow direction is when the electrolyte flows from the second and third abrasive cavity to the first abrasive cavity, and the second flow direction is when the electrolyte flows from the first abrasive cavity to the second and third abrasive cavity.

[0010] The method of the ultrasonic-assisted electrolytic machining device for reciprocating abrasive polishing is characterized in that: the cavitation intensity generated by the cathode ultrasound is controlled by adjusting the output power of the ultrasonic generator, thereby controlling the distribution of physical fields, including bubbles and temperature, in the gap during the machining process and improving machining accuracy.

[0011] The advantages of using this invention are:

[0012] This invention can control the uniformity of the physical field distribution within the machining gap, thereby improving machining accuracy. During electro-machining, hydrogen gas and Joule heat are continuously generated within the gap and accumulate along the electrolyte flow direction, causing uneven distribution of bubbles and temperature field within the gap, thus reducing machining accuracy. The cavitation effect generated by ultrasonic waves at the tool cathode disturbs the flow field within the gap, promoting a more uniform distribution of bubbles and temperature field. By adjusting the ultrasonic power, the cavitation intensity can be controlled, thereby controlling the uniformity of the physical field distribution and improving machining accuracy.

[0013] This invention can remove the product layer on the machined surface and promote the uniform dissolution of the material. During electrolytic machining, the dissolution of the material generates a large number of insoluble flocculent products, which adsorb onto the machined surface to form a product layer, inhibiting the uniform dissolution of the material. The ultrasonic cavitation of the tool cathode generates shock waves and micro-jets, which remove the product layer on the machined surface and promote the uniform dissolution of the material.

[0014] This invention helps remove insoluble phases from workpiece surfaces, improving surface quality. The presence of insoluble phases such as carbides and oxides in the workpiece material hinders the improvement of processing quality. During the power-off zone, the tool cathode undergoes ultrasonic vibration, and abrasive grains reciprocate within the processing area. Under ultrasonic action, the abrasive grains adhere to the workpiece surface, generating a grinding effect, thus achieving polishing removal of insoluble phases and improving surface quality.

[0015] The micro-abrasives used in this invention are recyclable, and the device is simple and applicable. In this invention, the micro-abrasives only flow back and forth within the processing area and do not enter the electrolyte circulation system, achieving graded and independent filtration of abrasives and products. The micro-abrasives are recyclable, and the device is simple, applicable, and highly adaptable. Attached Figure Description

[0016] Figure 1 A schematic diagram of an ultrasonic-assisted electrolytic machining device for reciprocating polishing of abrasive particles flowing downwards;

[0017] Figure 2 Schematic diagram of an ultrasonic-assisted electrolytic machining device for reciprocating polishing of abrasive particles flowing downwards;

[0018] Figure 3 This is a schematic diagram of a reciprocating polishing control device;

[0019] Labels in the diagram: 1. First feed shaft, 2. First ultrasonic transducer, 3. First ultrasonic amplitude transformer, 4. Blade basin cathode, 5. Electrolyte sealing clamp, 6. First abrasive chamber, 7. Ultrasonic generator, 8. Blade back cathode, 9. Second ultrasonic amplitude transformer, 10. Second ultrasonic transducer, 11. Second feed shaft, 12. Second abrasive chamber, 13. Anode workpiece, 14. Micro abrasive grains, 15. Third abrasive chamber, 16. First normally closed solenoid valve, 17. First normally open solenoid valve, 18. Second normally open solenoid valve, 19. Second normally closed solenoid valve, 20. Safety valve, 21. Electrolyte inlet, 22. Electrolyte outlet, 23. Controller. Detailed Implementation

[0020] Combined with appendix Figure 1 , 2 3. The electrolytic processing process of the present invention is described in detail below:

[0021] The anode workpiece 13 is installed on a special electrolytic machining machine tool. The electrolyte sealing fixture 5 is installed. The blade cathode 4, the first ultrasonic amplitude transformer 3 and the first ultrasonic transducer 2 are connected in sequence and then installed on the first feed shaft 1. The blade back cathode 8, the second ultrasonic amplitude transformer 9 and the second ultrasonic transducer 10 are connected in sequence and then installed on the second feed shaft 11.

[0022] The anode workpiece 13 is connected to the power supply anode, the blade basin cathode 4 and the blade back cathode 8 are connected to the power supply cathode, and the first ultrasonic transducer 2 and the second ultrasonic transducer 10 are controlled by the ultrasonic generator 7.

[0023] Add fine abrasive particles 14 to the second abrasive chamber 12 and the third abrasive chamber 15, and start the electrolyte circulation system;

[0024] The ultrasonic generator 7 generates high-frequency electrical energy, which is transmitted to the first ultrasonic transducer 2 and the second ultrasonic transducer 10. The transducers convert the received electrical energy into mechanical energy, which is then amplified by the first ultrasonic amplitude transformer 3 and the second ultrasonic amplitude transformer 9 and transmitted to the blade cathode 4 and the blade back cathode 8. The tool cathode achieves continuous ultrasonic vibration.

[0025] When the dedicated power supply for electrolytic machining is turned on, the cathodes 4 on both sides of the blade basin and the cathodes 8 on the back of the blade move in opposite directions and vibrate and reciprocate under the control of the first feed axis 1 and the second feed axis 11 of the machine tool, and the blade begins to be processed.

[0026] During a single dissolution cycle, when the blade-bowl cathode 4 and blade-back cathode 8 vibrate close to the anode workpiece 13 along the positive feed direction, energizing is applied, and the material dissolves. The reciprocating polishing system shuts down, and the abrasive particles are collected in the first abrasive particle chamber 6, where cathode ultrasound generates cavitation. When the blade-bowl cathode 4 and blade-back cathode 8 vibrate away from the anode workpiece 13 along the negative feed direction, the power is disconnected, the electrolyte supply is maintained, the material does not dissolve, and the reciprocating polishing system starts. Under the action of the reciprocating polishing control device, the controller 23 periodically opens and closes, controlling the electrolyte to periodically switch between flow direction 1 and flow direction 2, and the micro-abrasive particles 14 reciprocate within the processing area.

[0027] As processing continues, the dissolution process within a single cycle occurs repeatedly, and the blade is gradually eroded and shaped.

[0028] Once the cathode reaches its final position, feeding stops, and the blade is shaped. After electrolytic machining is complete, the power is disconnected, the ultrasonic generator and reciprocating polishing system are turned off, and the electrolyte circulation system is shut down, thus completing the electrolytic machining of the blade.

Claims

1. An ultrasonic-assisted electrolytic machining device for abrasive reciprocating polishing, comprising an ultrasonic-assisted electrolytic machining device, an electrolyte sealing fixture, and an electrolyte reciprocating control system; characterized in that: The ultrasonic-assisted electrolytic machining device includes a first ultrasonic amplitude transformer (3) and a first ultrasonic transducer (2) connected in sequence to the blade cathode (4), a second ultrasonic amplitude transformer (9) and a second ultrasonic transducer (10) connected in sequence to the blade back cathode (8), and also includes an ultrasonic generator (7) and an anode workpiece (13); wherein the first ultrasonic transducer (2) and the second ultrasonic transducer (10) are respectively connected to the first feed axis (1) and the second feed axis (11) of the machine tool, and are controlled by the ultrasonic generator (7); The electrolyte sealing fixture (5) includes a fixture body, which has a first abrasive cavity (6) at the corresponding position of the end of the blade being processed, a second abrasive cavity (12) on the outside of the back cathode (8) of the blade, and a third abrasive cavity (15) on the outside of the base cathode (4); a micro-filter is provided between the first abrasive cavity (6), the second abrasive cavity (12), the third abrasive cavity (15) and the connector of the electrolyte system; The electrolyte reciprocating control system mainly includes several solenoid valves and controllers, enabling the electrolyte inlet and outlet to switch between the following two modes: Mode 1: The electrolyte inlet is connected to the second and third abrasive chambers, and the electrolyte outlet is connected to the first abrasive chamber; Mode 2: The electrolyte inlet is connected to the first abrasive chamber, and the second and third abrasive chambers are connected to the electrolyte outlet. The electrolyte reciprocating control system includes a first normally closed solenoid valve (16), a first normally open solenoid valve (17), a second normally open solenoid valve (18), a second normally closed solenoid valve (19), a safety valve (20), and a controller (23). The electrolyte inlet is connected to the second and third abrasive chambers via the first normally open solenoid valve (17), and the first abrasive chamber is connected to the electrolyte outlet via the second normally open solenoid valve (18). The electrolyte inlet is also connected to the first abrasive chamber through the second normally closed solenoid valve (19), and the second and third abrasive chambers are connected to the electrolyte outlet through the first normally closed solenoid valve (16). A safety valve (20) is installed at the electrolyte inlet for safety protection of the electrolyte reciprocating control system.

2. The method of the ultrasonic-assisted electrolytic machining apparatus for reciprocating abrasive polishing according to claim 1, characterized in that: During the electrolytic processing, the blade basin cathode (4) and the blade back cathode (8) undergo ultrasonic vibration under the control of the ultrasonic generator (7); The first feed axis (1) and the second feed axis (11) on both sides of the machine tool control the blade head cathode (4) and the blade back cathode (8) to feed towards each other while performing periodic reciprocating motion along the feed direction; When the blade basin cathode (4) and the blade back cathode (8) vibrate and approach the workpiece in the positive feed direction, electrolytic machining is performed, the reciprocating polishing system is shut down, and the abrasive particles are collected in the first abrasive particle cavity (6); the tool cathode undergoes ultrasonic cavitation, generating shock waves and micro-jet effects, removing the product layer on the machining surface and promoting the uniform dissolution of the material; at the same time, the ultrasonic waves disturb the flow field in the gap, making the bubbles and temperature physical field in the machining gap uniformly distributed, thus improving the machining accuracy; When the cathode vibrates away from the workpiece along the negative feed direction, the electrolytic power supply is disconnected, the reciprocating polishing system is started, and the fine abrasive particles adhere to the workpiece surface under ultrasonic action to generate a grinding effect, thereby achieving the polishing removal of the insoluble phase on the processed surface and improving the surface quality; wherein, the controller (23) is periodically turned on and off, and the electrolyte is periodically switched between the first flow direction and the second flow direction, and the fine abrasive particles (14) flow back and forth in the processing area; the first flow direction is that the electrolyte flows from the second abrasive cavity (12) and the third abrasive cavity (15) to the first abrasive cavity (6), and the second flow direction is that the electrolyte flows from the first abrasive cavity (6) to the second abrasive cavity (12) and the third abrasive cavity (15).

3. The method of the ultrasonic-assisted electrolytic machining apparatus for reciprocating abrasive polishing according to claim 2, characterized in that: The cavitation intensity generated by the cathode ultrasound is controlled by adjusting the output power of the ultrasonic generator, thereby controlling the distribution of physical fields, including bubbles and temperature, within the gap during processing and improving processing accuracy.

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