A method for electrolytic machining of a flexible cathode mask with a curved surface microstructure and an implementation device thereof

Abstract

The present invention discloses a method and an implementation device for electrolytic machining of a flexible cathode mask with a curved surface microstructure, belonging to the technical field of electrolytic machining. It includes a liquid replenishing cavity, a liquid inlet cavity, set screws, a liquid distribution plate, a high-resilience sponge, socket head cap screws, a flexible cathode, a mask plate, and a workpiece. Its characteristics are that by combining the flexible cathode with the high-resilience sponge, it can meet the needs of mask electrolytic machining for different curvature curved surface microstructures, breaking through the bottleneck problem that it is difficult to electrolytic machine large-area curved surface microstructures; the flexible cathode generates self-adaptive deformation according to the curved surface shape of the workpiece, and the flexible cathode makes a small amount of reciprocating motion in the vertical direction, having a good pressing and fitting effect on the mask plate, which can inhibit the stray corrosion of mask electrolytic machining, strengthen mass transfer in the machining area, and eliminate the machining missing of curved surface microstructures; by introducing high-pressure electrolyte inside the liquid replenishing cavity, it inhibits the excessive loss of low-pressure electrolyte from the gaps of the flexible cathode, ensuring the stable implementation of the mask electrolytic machining process.

Description

Technical Field

[0001] The present invention relates to a method and an implementation device for electrolytic machining of a flexible cathode mask with a curved surface microstructure, belonging to the technical field of electrolytic machining. Background Art

[0002] Improving the friction performance of the surface of moving parts and reducing their contact wear are important research directions in the fields of tribology and mechanical manufacturing. In traditional cognition, the smaller the roughness value of the part surface and the smoother the surface, the more the friction coefficient can be reduced and the service life can be improved. In recent years, with the cross-integration of disciplines such as bionics, tribology, and mechanical manufacturing technology, researchers have found that preparing microstructures of organisms or plants on the surface of parts can often obtain better friction and wear performance than smooth surfaces. At present, the technologies for preparing microstructures on the surface of parts mainly include micro-cutting machining, biological template machining, picosecond laser machining, and mask electrolytic machining. Compared with other machining methods, mask electrolytic machining can theoretically remove materials at the ion scale and does not generate thermal stress and mechanical cutting force, and is particularly suitable for machining large-area microstructures on the surfaces of parts made of difficult-to-machine materials.

[0003] The mask electrolytic machining method covers an insulating mask plate with a hollow pattern on the surface of a metal workpiece, and realizes the localized removal of materials by means of the electrochemical dissolution effect on the workpiece surface, so as to machine large-area microstructures. Traditional mask electrolytic machining usually adopts a flow field form with lateral flow of the electrolyte. The workpiece and the tool cathode remain stationary, and the forming process of the surface microstructure is controlled by adjusting the power-on time of the power supply. This method can stably obtain microstructures, but due to the uneven distribution of the electrolyte conductivity, it is difficult to ensure the dimensional consistency of the microstructures. In order to further improve the machining performance of the surface microstructure, researchers have introduced a low-rigidity porous cathode into mask electrolytic machining from the perspectives of electrolyte transport and tool cathode structure optimization, and delivered high-speed electrolyte through the porous cathode to the workpiece surface by means of jet flow, eliminating the edge effect of the electric field on the workpiece surface, reducing the electrolyte conductivity fluctuation, and significantly improving the machining consistency and machining localization of the surface microstructure, and has been widely used on flat and cylindrical workpieces.

[0004] It should be noted that although the mask electrolytic machining method can achieve high-localization machining of microstructures on the surfaces of different metal materials, the workpiece surface is usually limited to regular surfaces such as flat surfaces and cylindrical surfaces, and there is still little attention paid to the machining of complex curved surface microstructures such as engine blade surfaces and die cavity surfaces. At present, the mask electrolytic machining method is also difficult to be used for the preparation of complex curved surface microstructures. Summary of the Invention

[0005] 1. In view of the shortcomings of the existing curved surface microstructure mask electrochemical processing technology, the present invention proposes a curved surface microstructure flexible cathode mask electrochemical processing method and implementation device, breaking through the bottleneck problem that large-area curved surface microstructures are difficult to electrochemically process, and providing a new technical path for the processing of complex curved surface microstructures such as engine blade surfaces and mold cavity surfaces.

[0006] 2. In order to achieve the above-mentioned purpose of the invention, the technical solution of the present invention is: a method for electrolytic machining of curved microstructures with a flexible cathode mask, wherein a flexible cathode and a mask plate are used to electrolytically machine the curved microstructure of a workpiece, the liquid inlet cavity and the workpiece are respectively connected to the negative and positive poles of the power supply, and the electric field energy is conducted to the machining area formed by the flexible cathode, the mask plate and the workpiece; the liquid inlet cavity is driven by the machine tool spindle to perform a vertical feed motion relative to the workpiece until the high-rebound sponge, the flexible cathode and the mask plate are aligned with the curved surface of the workpiece. Adaptive tight fit; low-pressure electrolyte with an inlet pressure of 0.05-0.1MPa flows into the top of the liquid inlet cavity and fills the high-rebound sponge. The flexible cathode makes a micro-reciprocating motion of 0.05-0.2mm from the position tightly fitted with the mask plate, and the electrolyte filled in the high-rebound sponge is periodically squeezed into the processing area; high-pressure electrolyte with an inlet pressure of 0.5-1MPa flows into the liquid replenishment cavity and flows through the side wall of the flexible cathode, inhibiting the low-pressure electrolyte from losing too quickly from the gaps in the flexible cathode.

[0007] Another technical purpose of the present invention is to provide a device for implementing electrolytic processing of curved microstructure flexible cathode mask, including a liquid replenishment cavity, a liquid inlet cavity, a tightening screw, a liquid separator plate, a high-rebound sponge, a hexagon socket screw, a flexible cathode, a mask plate, and a workpiece. A high-rebound sponge is provided at the bottom of the liquid inlet cavity, the top of the high-rebound sponge is tightly fitted with the bottom of the liquid separator plate, and the side wall of the liquid separator plate is fastened to the liquid inlet cavity by a tightening screw; the bottom of the high-rebound sponge is covered with a flexible cathode, and the flexible cathode is fastened to the bottom of the liquid inlet cavity by a hexagon socket screw and a gasket; the non-hollow area of the mask plate is tightly bonded to the curved surface of the workpiece by double-sided tape, and its hollow area is tightly fitted with the curved surface of the workpiece by the pressing force of the high-rebound sponge and the flexible cathode; the liquid replenishment cavity adopts a hollow structure, and its side walls are symmetrically provided with liquid inlet holes, and the liquid inlet cavity and the liquid replenishment cavity are fastened by tightening screws.

[0008] The flexible cathode is made of silver fabric, cotton fabric and polyester fabric are base materials of the silver fabric, a conductive layer is prepared on the surface of the base material by chemical silver plating method, and the square resistance of the silver fabric is 20-50Ω / sq.

[0009] The mask plate is made of epoxy resin material, and a hollow area is processed in the middle position of the mask plate by using a picosecond laser method. The electrolyte flowing into the top of the liquid inlet cavity flows to the workpiece surface through the hollow area of the mask plate.

[0010] Four liquid separation holes are evenly arranged at the middle position of the liquid separation plate, and the electrolyte flowing in from the top of the liquid inlet cavity fills the high-resilience sponge evenly through the liquid separation holes.

[0011] 3. The beneficial effects of the present invention are as follows: (1) The present invention combines a flexible cathode and a high-resilience sponge, which is applicable to the mask electrolytic machining of microstructures with different curvature surfaces, breaking through the bottleneck problem that it is difficult to electrolytically machine large-area curved surface microstructures; (2) The flexible cathode and high-resilience sponge adopted in the present invention can generate adaptive deformation according to the curved surface shape of the workpiece, and have a good pressing and fitting effect on the mask plate, eliminating the machining defects of curved surface microstructures; (3) By introducing high-pressure electrolyte into the liquid replenishing cavity, the present invention inhibits the rapid loss of low-pressure electrolyte from the gaps of the flexible cathode, maintains the sufficient supply of electrolyte in the machining area, and ensures the stable implementation of the mask electrolytic machining process. Description of the Drawings

[0012] Figure 1 It is a schematic diagram of a half-section of the overall structure of the device for realizing mask electrolytic machining with a flexible cathode of the present invention.

[0013] Figure 2 It is a schematic diagram of a half-section of the structure of the liquid inlet cavity of the present invention.

[0014] Figure 3 It is a schematic diagram of the structure of the flexible cathode of the present invention.

[0015] Figure 4 It is a schematic diagram of the structure of the mask plate of the present invention.

[0016] In the figure: 1. Liquid replenishing cavity, 2. Liquid inlet cavity, 3. Set screw, 4. Liquid separation plate, 5. High-resilience sponge, 6. Hexagon socket head cap screw, 7. Flexible cathode, 8. Mask plate, 9. Workpiece. Detailed Embodiments

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] Figure 1Schematic diagram of the overall structure of the flexible cathode mask electrolytic machining device in half-section. The device includes: a liquid replenishing cavity 1, a liquid inlet cavity 2, a set screw 3, a liquid distribution plate 4, a high-resilience sponge 5, an internal hexagonal screw 6, a flexible cathode 7, a mask plate 8, and a workpiece 9. The liquid replenishing cavity 1 has a hollow structure, and liquid inlet holes are symmetrically arranged on both sides thereof. High-pressure electrolyte with an inlet pressure of 0.5 - 1 MPa flows into the interior of the liquid replenishing cavity 1 and flows through the side wall of the flexible cathode 7 to prevent the low-pressure electrolyte from flowing out too quickly through the gaps of the flexible cathode 7. The liquid inlet cavity 2 is connected to the liquid replenishing cavity 1 as a whole through the set screw 3. A high-resilience sponge 5 is arranged at the bottom of the liquid inlet cavity 2, and the bottom of the high-resilience sponge 5 wraps the flexible cathode 7. The flexible cathode 7 is firmly connected to the bottom of the liquid inlet cavity 2 through the internal hexagonal screw 6 and a gasket. The top of the high-resilience sponge 5 is in close contact with the bottom of the liquid distribution plate 4, and the liquid distribution plate 4 is connected to the liquid inlet cavity 2 as a whole through the set screw 3. Four liquid distribution holes are evenly arranged at the top of the liquid distribution plate 4. Low-pressure electrolyte with an inlet pressure of 0.05 - 0.1 MPa flows into the liquid distribution holes from the top of the liquid inlet cavity 2 and evenly fills the high-resilience sponge 5. During the mask electrolytic machining process, the liquid inlet cavity 2 makes a linear feed towards the workpiece 9 driven by the machine tool spindle until the high-resilience sponge 5, the flexible cathode 7, the mask plate 8 and the curved surface of the workpiece 9 are adaptively and tightly fitted. Then, the flexible cathode 7 makes a micro reciprocating motion of 0.05 - 0.2 mm from the position where it is in close contact with the mask plate 8, and periodically squeezes the electrolyte absorbed in the high-resilience sponge 5 into the machining area.

[0019] Figure 2 Schematic diagram of the structure of the liquid inlet cavity in half-section. The liquid inlet cavity 2 has a hollow structure, and four threaded holes are evenly arranged along the circumference at its bottom, and two threaded holes are also symmetrically arranged on the side wall. The interior of the liquid inlet cavity 2 adopts a stepped hole form. The lower end of the stepped hole is filled with the high-resilience sponge 5, and the upper end of the stepped hole is in close contact with the side wall of the liquid distribution plate 4 and serves as the liquid inlet for the low-pressure electrolyte.

[0020] Figure 3 Schematic diagram of the structure of the flexible cathode. Four through holes are evenly arranged along the circumference of the flexible cathode 7 to facilitate the firm connection with the bottom of the liquid inlet cavity 2. The flexible cathode 7 is made of silver fabric and can be adaptively fitted according to the change of the curvature of the curved surface of the workpiece 9. Cotton fabric and polyester fabric are the base materials of the silver fabric, and a conductive coating is prepared on the surface of the base materials by electroless silver plating. The sheet resistance of the silver fabric is 20 - 50 Ω / sq.

[0021] Figure 4 Schematic diagram of the mask plate structure. The mask plate 8 is made of epoxy resin material and has a thickness of 0.05 - 0.1 mm. A groove array, a round hole array and other hollow areas are machined at the middle position of the mask plate 8 by means of picosecond laser. The electrolyte flowing in from the top of the liquid inlet cavity 2 reaches the surface of the workpiece 9 through the hollow areas of the mask plate 8.

[0022] The specific application ways of the present invention are numerous. The above description is only the preferred embodiment of the present invention. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technology and the protection of rights of the present invention.

Claims

1. An apparatus for realizing the electrolytic machining of a flexible cathode mask with a curved surface microstructure, comprising a liquid replenishing cavity (1), a liquid inlet cavity (2), a set screw (3), a liquid distribution plate (4), a highly resilient sponge (5), an internal hexagonal screw (6), a flexible cathode (7), a mask plate (8), and a workpiece (9), characterized in that: A high-resilience sponge (5) is provided at the bottom of the liquid inlet cavity (2). The top of the high-resilience sponge (5) is in close contact with the bottom of the liquid distribution plate (4). The side wall of the liquid distribution plate (4) is fixedly connected to the liquid inlet cavity (2) by set screws (3). The bottom of the high-resilience sponge (5) wraps the flexible cathode (7). The flexible cathode (7) is fixedly connected to the bottom of the liquid inlet cavity (2) by socket head cap screws (6) and gaskets. The flexible cathode (7) is made of silver fabric. Cotton fabric and polyester fabric are the base materials of the silver fabric. A conductive layer is prepared on the surface of the base materials by electroless silver plating. The sheet resistance of the silver fabric is 20 - 50 Ω / sq. The non-perforated area of the mask plate (8) is tightly adhered to the curved surface of the workpiece (9) by double-sided tape. Its perforated area is in close contact with the curved surface of the workpiece (9) under the pressing force of the high-resilience sponge (5) and the flexible cathode (7). The liquid replenishing cavity (1) has a hollow structure. Liquid inlet holes are symmetrically provided on its side wall. The outer wall of the liquid inlet cavity (2) is fixedly connected to the liquid replenishing cavity (1) by set screws (3).

2. The device for realizing the electrolytic machining of a flexible cathode mask with a curved surface microstructure according to claim 1, wherein: The mask plate (8) is made of epoxy resin material. A perforated area is machined in the middle position of the mask plate (8) by means of picosecond laser. The electrolyte flowing into the top of the liquid inlet cavity (2) flows to the surface of the workpiece (9) through the perforated area of the mask plate (8). Four liquid distribution holes are evenly provided in the middle position of the liquid distribution plate (4). The electrolyte flowing into the top of the liquid inlet cavity (2) evenly fills the high-resilience sponge (5) through the liquid distribution holes.

3. A method for electrolytic machining of a flexible cathode mask with a curved surface microstructure, which uses a device for electrolytic machining of a flexible cathode mask with a curved surface microstructure as described in any one of claims 1-2, characterized in that: Electrolytic machining of the curved surface microstructure of the workpiece (9) is carried out using the flexible cathode (7) and the mask plate (8). The liquid inlet cavity (2) and the workpiece (9) are respectively connected to the negative electrode and the positive electrode of the power supply, and the electric field energy is conducted to the machining area formed by the flexible cathode (7), the mask plate (8) and the workpiece (9). The liquid inlet cavity (2) makes a vertical feeding movement relative to the workpiece (9) driven by the machine tool spindle until the high-resilience sponge (5), the flexible cathode (7) and the mask plate (8) are adaptively and tightly attached to the curved surface of the workpiece (9). Low-pressure electrolyte with an inlet pressure of 0.05 - 0.1 MPa flows into the top of the liquid inlet cavity (2) and fills the high-resilience sponge (5). The flexible cathode (7) makes a small reciprocating movement of 0.05 - 0.2 mm from the position in close contact with the mask plate (8), and periodically squeezes the electrolyte filled inside the high-resilience sponge (5) into the machining area. High-pressure electrolyte with an inlet pressure of 0.5 - 1 MPa flows into the inside of the liquid replenishing cavity (1) and flows through the side wall of the flexible cathode (7) to inhibit the rapid loss of the low-pressure electrolyte from the gaps of the flexible cathode (7).

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