A method for preparing discrete tool electrodes for spin electrochemical machining

Abstract

This invention provides a method for fabricating discrete tool electrodes for spin electrochemical machining, relating to the field of discrete tool electrode forming technology. Discrete tool electrode fabrication methods can be divided into two approaches: first, 3D printing an insulating substrate, then casting a conductive material; or first, 3D printing a conductive substrate, then casting an insulating material, and finally removing excess casting material by machining, thus obtaining a discrete tool electrode. This invention uses a combination of 3D printing and casting processes to manufacture discrete tool electrodes, which can reduce processing difficulty, improve processing efficiency, and, moreover, ensure molding quality and processing accuracy more easily through both 3D printing and casting processes.

Description

Technical Field

[0001] This invention relates to the field of discrete tool electrode forming technology, and in particular to a method for preparing discrete tool electrodes for spin electrolytic machining. Background Technology

[0002] As common rotating parts, aero-engine casing components have complex surface structures and are typically made of high-temperature alloys or high-hardness alloys. Traditional machining methods result in high tool wear, long machining cycles, high costs, and significant residual stress after machining, making the workpiece prone to deformation and requiring complex heat treatment processes to eliminate the deformation. Spin-print electrolytic machining technology can achieve one-time machining of complex surfaces, and this technology uses only a single rotating tool electrode. The patent "Electrolytic Machining Method for Thin-Walled Aero-Engine Casings (Publication No. CN104384643 A)" proposes a constant-rotation-speed spin-print electrolytic machining technique that can be used to machine "island"-shaped bosses. This method is not limited by the shape of the boss and does not generate machining stress.

[0003] Stray corrosion, an unavoidable phenomenon in electrochemical machining, can severely affect machining accuracy. The patent "Discrete Rotary Tool Electrode and Method for Spin Printing Electrochemical Machining (Publication No. CN 114473088A)" proposes a new tool electrode electrochemical machining method. This method can effectively improve the localization of the electrochemical machining process, thereby reducing stray corrosion in the spin printing electrochemical machining process. The higher the degree of discreteness of the tool electrode, the higher the forming accuracy.

[0004] Since discrete tool electrodes not only include alternating conductive blocks and insulating strips, but also have hollow windows with complex shapes on their surfaces, they incur high labor and time costs when using traditional machining methods. Furthermore, the more discrete conductive blocks there are in the cathode, the more difficult the machining and assembly become.

[0005] For discrete tool electrode structures that meet the conditions for spin-printing electrolytic machining, it is necessary to propose a discrete electrode fabrication method with advantages of low cost and high efficiency. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing discrete tool electrodes for spin electrolytic machining, so as to solve the problems existing in the prior art. By combining 3D printing and casting processes to manufacture discrete tool electrodes, the processing difficulty can be reduced and the processing efficiency can be improved. Moreover, 3D printing and casting processes make it easier to ensure molding quality and processing accuracy.

[0007] To achieve the above objectives, the present invention provides the following solution:

[0008] A method for fabricating a discrete tool electrode for spin electrochemical machining, the discrete tool electrode comprising a plurality of conductive blocks distributed along a circular trajectory, an insulating strip being disposed between adjacent conductive blocks, and at least one of the conductive blocks having a hollow window; the method for fabricating the discrete tool electrode includes the following steps:

[0009] S11. An insulating substrate is obtained by 3D printing, the insulating substrate including the insulating strips spaced apart along a circular trajectory;

[0010] S12. Place the insulating substrate into a casting container and pour in molten conductive material until the molten conductive material submerges the insulating strip;

[0011] S13. Let stand until the molten conductive material cools and solidifies, then remove it to obtain the first product;

[0012] S14. Remove material from the first article to obtain the discrete tool electrode;

[0013] Alternatively, the method for fabricating the discrete tool electrode includes the following steps:

[0014] S21. A conductive substrate is obtained by 3D printing, the conductive substrate comprising the conductive blocks spaced apart along a circular trajectory;

[0015] S22. Place the conductive substrate into a casting container and pour in liquid insulating material until the liquid insulating material submerges the conductive block;

[0016] S23. Let stand until the liquid insulating material cools and solidifies, then remove it to obtain the second product;

[0017] S24. Remove the material from the second article to obtain the discrete tool electrode.

[0018] In one embodiment, in S11, the melting point of the insulating substrate is higher than 250°C, and the melting point of the conductive material for casting is 100°C to 200°C.

[0019] As one embodiment, the insulating material is polyimide.

[0020] As one embodiment, the conductive material is a bismuth-tin alloy.

[0021] As one embodiment, the casting container used in S12 is a tin furnace, and the temperature of the tin furnace is maintained at 100°C to 200°C during the pouring of the molten conductive material.

[0022] In one embodiment, in S13, after standing at room temperature for 24h to 48h, the first product is taken out.

[0023] As one implementation, in step S14, the conductive material at the hollow window location is removed by drilling.

[0024] As one implementation, in S21, the conductive substrate is made of stainless steel, and in S22, the cast insulating material is liquid epoxy resin potting compound.

[0025] In one embodiment, in S23, after standing at room temperature for 24h to 48h, the second product is taken out.

[0026] In one embodiment, in S24, the insulating material at the location of the hollow window is removed by drilling.

[0027] The present invention has the following technical advantages over the prior art:

[0028] This invention uses a combination of 3D printing and casting processes to manufacture discrete tool electrodes, which can reduce processing difficulty and improve processing efficiency. Moreover, 3D printing and casting processes make it easier to ensure molding quality and processing accuracy. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments 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.

[0030] Figure 1 This is a schematic diagram of the rotary electrolytic machining principle in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure of the 3D-printed insulating substrate in an embodiment of the present invention;

[0032] Figure 3 for Figure 2 Top view;

[0033] Figure 4 This is a schematic diagram of the casting process of the insulating substrate in an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the discrete tool electrode structure after removing excess conductive material in an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of the 3D-printed conductive substrate in an embodiment of the present invention (both the top and bottom ends have excess conductive material to be removed);

[0036] Figure 7 This is a schematic diagram of the casting process of the conductive substrate in an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of the discrete tool electrode structure after removing some of the excess insulating material in an embodiment of the present invention (excess material at the hollow window has not been removed).

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Discrete tool electrode; 2. Conductive block; 3. Insulating strip; 4. Hollow window; 5. Casting container; 6. Connecting shaft; 7. Workpiece to be processed; 8. Protrusion. Detailed Implementation

[0040] 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, and 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.

[0041] The purpose of this invention is to provide a method for preparing discrete tool electrodes for spin electrolytic machining, so as to solve the problems existing in the prior art. By combining 3D printing and casting processes to manufacture discrete tool electrodes, the processing difficulty can be reduced and the processing efficiency can be improved. Moreover, 3D printing and casting processes make it easier to ensure molding quality and processing accuracy.

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] like Figures 1 to 8 As shown, this embodiment provides a method for fabricating a discrete tool electrode for spin-printing electrolytic machining. The discrete tool electrode 1 includes multiple conductive blocks 2 distributed along a circular trajectory, with insulating strips 3 between adjacent conductive blocks 2, and at least one conductive block 2 has a hollow window 4. Since the number of conductive blocks 2 and insulating strips 3 is relatively large and their thickness is thin (for example, the diameter of the discrete tool electrode 1 is 30mm, the width of a single conductive block 2 is approximately 2mm, and the width of the insulating strip 3 is 0.2mm to 0.3mm), and processing the hollow window 4 further complicates the fabrication of the discrete tool electrode 1 using traditional methods. Therefore, this embodiment employs a combination of 3D printing and casting to fabricate the discrete tool electrode 1, which significantly reduces the processing difficulty, improves the processing quality of the discrete tool electrode 1, and increases processing efficiency. The fabrication method of the discrete tool electrode 1 can be divided into two types: first, 3D printing the insulating substrate and then casting the conductive material; or first, 3D printing the conductive substrate and then casting the insulating material.

[0044] The method for fabricating a discrete tool electrode 1 by first 3D printing an insulating substrate and then casting a conductive material includes the following steps:

[0045] S11. An insulating substrate is obtained through 3D printing. The insulating substrate includes insulating strips 3 spaced along a circular trajectory. The thickness of the insulating strips 3 is 0.2mm to 0.3mm. At least one insulating strip 3 has a notch, and the notch contour is the same as the contour of the hollow window 4. During the printing process, a connecting shaft 6 can be printed simultaneously. The connecting shaft 6 serves as the substrate for multiple insulating strips 3, such as... Figure 2 , Figure 3 As shown.

[0046] S12. Place the insulating substrate into the casting container 5, and pour in the molten conductive material, such as... Figure 4 As shown, the molten conductive material is poured until it submerges the insulating strip 3. During operation, the molten conductive material can be used to fill the cavity of the casting container 5 until it overflows. In this embodiment, the melting point of the insulating substrate is higher than that of the conductive material to prevent the insulating substrate from softening or even melting under the high temperature of the molten conductive material. For example, in this embodiment, the melting point of the insulating substrate is higher than 250°C, and the melting point of the conductive material used for casting is 100°C to 200°C. Specifically, the insulating material can be polyimide, and the conductive material can be a bismuth-tin alloy. To ensure the fluidity of the molten conductive material during the pouring process, so that it can fully fill the cavity in the insulating substrate, this embodiment uses a temperature-controlled tin furnace as the casting container 5, and maintains the temperature of the tin furnace at 100°C to 200°C.

[0047] S13. Place at room temperature for 24h to 48h until the molten conductive material cools and solidifies, and then remove it to obtain the first product composed of an insulating matrix and a conductive material.

[0048] S14. Since the conductive material completely fills the cavity in the casting container 5 and also fills the hollow window 4, it is necessary to remove the excess conductive material to obtain a discrete tool electrode 1 with a hollow window 4, a regular shape, and a smooth surface. Figure 5 As shown. Excess conductive material around the insulating substrate can be removed by cutting or grinding; conductive material at the hollow window 4 can be removed by drilling, and finally, surface polishing can be performed.

[0049] The method for fabricating a discrete tool electrode 1 by first 3D printing a conductive substrate and then casting an insulating material includes the following steps:

[0050] S21. A conductive substrate is obtained by 3D printing. The conductive substrate includes conductive blocks 2 spaced apart along a circular trajectory. The conductive blocks 2 usually have notches, and the contour of the notches is the same as the contour of the hollow window 4. The material of the conductive substrate can be stainless steel. During printing, excess material is printed at the top and bottom of the conductive substrate, and the excess material serves as the substrate for the multiple spaced conductive blocks 2.

[0051] S22. Place the conductive substrate into the casting container 5, and pour in the liquid insulating material, such as... Figure 7 As shown, the liquid insulating material is poured until it submerges the conductive block 2; during operation, the liquid insulating material can be used to fill the cavity of the casting container 5 until it overflows. The liquid insulating material poured in is liquid epoxy resin potting compound. When preparing the liquid epoxy resin potting compound, use a digital display constant speed timer electric mixer to thoroughly mix components A and B of the potting compound. The speed is adjusted to 200 rpm to 500 rpm, and the mixer is continuously stirred for 10 min to 20 min to ensure that components A and B are evenly mixed.

[0052] S23. After the liquid insulating material fills the 5th cavity of the casting container, let it stand for 24h to 48h until the liquid insulating material cools and solidifies, and then take it out to obtain the second product.

[0053] S24. Since the insulating material completely fills the cavity in the casting container 5 and also fills the hollow window 4, it is necessary to remove the excess conductive material to obtain a discrete tool electrode 1 with a hollow window 4, a regular shape, and a smooth surface. Figure 8 As shown. Excess insulating material around the conductive substrate can be removed by cutting or grinding; insulating material at the hollow window 4 can be removed by drilling, and finally, surface polishing can be performed.

[0054] This embodiment uses a combination of 3D printing and casting processes to manufacture discrete tool electrodes 1, which can reduce processing difficulty, ensure processing accuracy, and improve processing efficiency.

[0055] The principle of spin electrolytic machining using discrete tool electrode 1 is well known to those skilled in the art. Here, this embodiment only briefly explains the principle of electrolytic machining as follows:

[0056] The power supply anode is connected to the workpiece 7 to be processed, and the power supply cathode is connected to the discrete tool electrode 1, ensuring that the 1-2 conductive blocks 2 of the discrete tool electrode 1 closest to the workpiece 7 are charged. Simultaneously, the discrete tool electrode 1 is rotated via the connecting shaft 6, and an electrolyte is sprayed from the spray pipe into the gap between the workpiece 7 and the discrete tool electrode 1. Under electrolysis, the workpiece 7 at the anode is gradually electrolyzed, while the portion of the workpiece 7 corresponding to the hollow window 4 on the discrete tool electrode 1 is not electrolyzed, thus forming a protrusion 8 that matches the shape of the hollow window 4. After electrolysis, the workpiece 7 is processed into a workpiece with the protrusion 8.

[0057] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0058] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for preparing a discrete tool electrode for spin electrochemical machining, the discrete tool electrode comprising a plurality of conductive blocks distributed along a circular trajectory, an insulating strip being disposed between adjacent conductive blocks, and at least one of the conductive blocks having a hollow window; characterized in that, The method for preparing the discrete tool electrode includes the following steps: S11. An insulating substrate is obtained by 3D printing, the insulating substrate including the insulating strips spaced apart along a circular trajectory; S12. Place the insulating substrate into a casting container and pour in molten conductive material until the molten conductive material submerges the insulating strip; S13. Let stand until the molten conductive material cools and solidifies, then remove it to obtain the first product; S14. Remove material from the first article to obtain the discrete tool electrode; Alternatively, the method for fabricating the discrete tool electrode includes the following steps: S21. A conductive substrate is obtained by 3D printing, the conductive substrate comprising the conductive blocks spaced apart along a circular trajectory; S22. Place the conductive substrate into a casting container and pour in liquid insulating material until the liquid insulating material submerges the conductive block; S23. Let stand until the liquid insulating material cools and solidifies, then remove it to obtain the second product; S24. Remove the material from the second article to obtain the discrete tool electrode.

2. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 1, characterized in that, In S11, the melting point of the insulating substrate is higher than 250°C, and the melting point of the conductive material for casting is 100°C to 200°C.

3. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 2, characterized in that, In S11, the insulating substrate is made of polyimide.

4. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 2, characterized in that, In S12, the molten conductive material is a bismuth-tin alloy.

5. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 2, characterized in that, The casting vessel used in S12 is a tin furnace, and the temperature of the tin furnace is maintained at 100°C to 200°C during the pouring of the molten conductive material.

6. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 1, characterized in that, In S13, after standing at room temperature for 24 to 48 hours, the first product is taken out.

7. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 1, characterized in that, In step S14, the conductive material at the hollow window location is removed by drilling.

8. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 1, characterized in that, In S21, the conductive substrate is made of stainless steel, and in S22, the cast insulating material is liquid epoxy resin potting compound.

9. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 8, characterized in that, In S23, after standing at room temperature for 24h to 48h, the second product is taken out.

10. The method for preparing a discrete tool electrode for spin electrochemical machining according to claim 8, characterized in that, In S24, the insulating material at the location of the hollow window is removed by drilling.

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