Electric spark machining method of silicon carbide
The method addresses inefficiencies in silicon carbide machining by forming a dense abrasive layer on a single electrode to remove recast layers, enhancing processing efficiency and avoiding surface damage.
Patent Information
- Application Number
- CN202510724331.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-30
- Publication Date
- 2025-07-15
AI Technical Summary
Traditional mechanical processing methods are difficult to efficiently process silicon carbide, and the surface recast layer needs to be chemically mechanically polished and easily damaged, and the process is complicated.
The tool electrode and silicon carbide workpiece are filled with abrasive particle matrix powder, and the abrasive particle matrix layer is formed by polar exchange electric spark processing, the recast layer is removed, and the molten aluminum powder bonded diamond powder is used to form a dense layer on the electrode surface, and grinding is performed.
The process flow is simplified, the electrodes and platforms are replaced across platforms are avoided, and the efficient removal of the surface recast layer of silicon carbide is achieved, reducing surface damage.
Smart Images
Figure CN120306741A_ABST
Abstract
Description
Technical Field
[0001] The present invention mainly relates to the field of electrical discharge machining, and particularly relates to a method for electrical discharge machining of silicon carbide. Background Art
[0002] Silicon carbide has characteristics such as high hardness and high brittleness. Traditional mechanical machining methods are difficult to efficiently machine it, and it is prone to machining cracks. Electrical discharge machining can break through the hardness limit of traditional mechanical machining and erode materials through pulsed discharge to generate instantaneous high temperature and high pressure. There is no mechanical stress in this process, which can avoid crack propagation. Therefore, electrical discharge machining is a commonly used process technology in the machining of silicon carbide.
[0003] After electrical discharge machining of silicon carbide, there is a recast layer on the surface. Therefore, surface treatment processes such as chemical mechanical polishing (CMP) etc. are required for its surface, but this process has a long machining time and is prone to causing surface damage to it. The operation is rather cumbersome and requires changing equipment for operation. Summary of the Invention
[0004] In view of the above problems, the present application is proposed to provide a method and device for GPU resource virtualization computing power scheduling that overcomes the above problems or at least partially solves the above problems, including:
[0005] A method for electrical discharge machining of silicon carbide, including steps:
[0006] Perform electrical discharge machining on the silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer;
[0007] Fill the tool electrode and the rough workpiece with abrasive matrix powder;
[0008] Exchange the polarities of the tool electrode and the rough workpiece, and perform discharge machining on the rough workpiece to obtain an abrasive matrix layer on the tool electrode;
[0009] Remove the recast layer through the abrasive matrix layer to obtain the target workpiece.
[0010] Further, the step of performing electrical discharge machining on the silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer includes:
[0011] Connect the silicon carbide workpiece to the positive pole of the pulsed power supply, and connect the tool electrode to the negative pole of the pulsed power supply;
[0012] Adjust the machining parameters according to the machining depth and size of the target workpiece, and perform electrical discharge machining on the silicon carbide workpiece in a positive polarity manner according to the machining parameters to obtain the rough workpiece.
[0013] Further, the step of filling the recast layer with the abrasive matrix powder includes:
[0014] Mixing aluminum powder and diamond powder according to a preset ratio to obtain the abrasive matrix powder; wherein, the proportion of the aluminum powder is less than that of the diamond powder;
[0015] Filling the abrasive matrix powder between the tool electrode and the silicon carbide;
[0016] Shaking the tool electrode to make the abrasive matrix powder evenly distributed between the tool electrode and the silicon carbide workpiece.
[0017] Further, in the step of filling the tool electrode and the rough workpiece with the mixture of aluminum powder and diamond powder, the mixing mass ratio of the aluminum powder to the diamond powder is 1:2 - 4.
[0018] Further, the step of swapping the polarities of the tool electrode and the rough workpiece and performing electrical discharge machining on the rough workpiece to obtain the abrasive matrix layer includes:
[0019] Connecting the silicon carbide workpiece to the negative electrode of the pulse power supply and connecting the tool electrode to the positive electrode of the pulse power supply;
[0020] Performing electro-discharge machining on the rough workpiece in a negative polarity mode to make the aluminum powder in a molten state, and bonding the diamond powder through the molten aluminum powder to obtain the abrasive matrix;
[0021] Attaching the abrasive matrix to the surface of the tool electrode through electrical discharge machining to obtain the abrasive matrix layer.
[0022] Further, the step of removing the recast layer with the abrasive matrix layer to obtain the target workpiece includes:
[0023] Adjusting the distance between the tool electrode and the rough workpiece to form a contact pressure between the tool electrode and the rough workpiece;
[0024] Grinding the surface of the rough workpiece by rotating and shaking the tool electrode to remove the recast layer and obtain the target workpiece.
[0025] Further, it further includes:
[0026] Preprocessing the silicon carbide workpiece according to the structure of the target workpiece.
[0027] Further, it further includes: placing the tool electrode and the silicon carbide workpiece in a working fluid for processing; wherein, the working fluid is kerosene.
[0028] Further, it further includes: post-processing the target workpiece according to preset conditions.
[0029] The present application has the following advantages:
[0030] In an embodiment of the present application, aiming at the disadvantages in the prior art that after electrical discharge machining of silicon carbide, it is necessary to remove the recast layer across platforms, and chemical mechanical machining is prone to damage the surface of the workpiece, the present application provides a method for electrical discharge machining of silicon carbide, including the steps of: performing electrical discharge machining on a silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer; filling the tool electrode and the rough workpiece with abrasive matrix powder; exchanging the polarities of the tool electrode and the rough workpiece, and performing discharge machining on the rough workpiece to obtain an abrasive matrix layer on the tool electrode; removing the recast layer through the abrasive matrix layer to obtain a target workpiece. Through electrical discharge machining, aluminum powder is turned into a molten state, and the diamond powder is bonded by the molten aluminum powder to obtain an abrasive matrix; at the same time, under the action of discharge energy, the molten aluminum powder coats the above-mentioned abrasive matrix on the electrode surface, thereby forming a dense abrasive matrix layer on the electrode surface. The recast layer on the surface of silicon carbide is removed through the grinding action of the abrasive matrix layer. It is not necessary to replace the electrode and the machining platform, and only one electrode is required to complete the electrical discharge machining of silicon carbide and the elimination of its surface recast layer. The process is simple and convenient. Description of the Drawings
[0031] In order to more clearly illustrate the technical solutions of the present application, the drawings required for the description of the present application will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0032] Figure 1 is a flowchart of the steps of a method for electrical discharge machining of silicon carbide provided by an embodiment of the present application;
[0033] Figure 2 is a schematic diagram before workpiece machining of a method for electrical discharge machining of silicon carbide provided by an embodiment of the present application;
[0034] Figure 3 is a schematic diagram after electrical discharge machining of a workpiece of a method for electrical discharge machining of silicon carbide provided by an embodiment of the present application;
[0035] Figure 4 is a schematic diagram of filling abrasive matrix powder of a method for electrical discharge machining of silicon carbide provided by an embodiment of the present application;
[0036] Figure 5It is a schematic diagram of the negative polarity machining of a silicon carbide electrical discharge machining method provided by an embodiment of the present application;
[0037] Figure 6 It is a schematic diagram of the completion of workpiece machining of a silicon carbide electrical discharge machining method provided by an embodiment of the present application. Detailed implementation manners
[0038] To make the objectives, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the accompanying drawings and specific implementation manners. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts shall fall within the scope of protection of the present application.
[0039] The inventors found through analysis of the prior art that: there is a recast layer on the surface after electrical discharge machining of SiC, so surface treatment processes such as chemical mechanical polishing (CMP) etc. are required for its surface, but this process has a long processing time and is prone to subsurface damage.
[0040] Refer to Figure 1 , which shows a step flow chart of a silicon carbide electrical discharge machining method provided by an embodiment of the present application, including steps:
[0041] S110. Perform electrical discharge machining on the silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer;
[0042] S120. Fill the tool electrode and the rough workpiece with abrasive matrix powder;
[0043] S130. Exchange the polarities of the tool electrode and the rough workpiece, and perform discharge machining on the rough workpiece to obtain an abrasive matrix layer on the tool electrode;
[0044] S140. Remove the recast layer through the abrasive matrix layer to obtain a target workpiece.
[0045] In an embodiment of the present application, aiming at the disadvantages in the prior art that after electrical discharge machining of silicon carbide, it is necessary to remove the recast layer across platforms, and chemical mechanical machining is likely to damage the surface of the workpiece, the present application provides a method for electrical discharge machining of silicon carbide, including the steps of: performing electrical discharge machining on a silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer; filling the tool electrode and the rough workpiece with abrasive matrix powder; exchanging the polarities of the tool electrode and the rough workpiece, and performing discharge machining on the rough workpiece to obtain an abrasive matrix layer on the tool electrode; removing the recast layer through the abrasive matrix layer to obtain a target workpiece. Under the action of the discharge capacity, the aluminum powder is turned into a molten state, and the diamond powder is bonded by the molten aluminum powder to obtain an abrasive matrix; at the same time, under the action of the discharge energy, the molten aluminum powder coats the above-mentioned abrasive matrix on the electrode surface, thereby forming a dense abrasive matrix layer on the electrode surface. The recast layer on the surface of silicon carbide is removed through the grinding action of the abrasive matrix layer. It is not necessary to replace the electrode and the machining platform, and only one electrode is required to complete the electrical discharge machining of silicon carbide and the elimination of its surface recast layer. The process is simple and convenient.
[0046] It should be noted that in this solution, the positive polarity method is adopted to machine the silicon carbide workpiece during electrical discharge machining. When removing the recast layer in the post-treatment, the negative polarity machining is adopted to attach the abrasive matrix to the tool electrode to achieve the grinding and removal of the recast layer.
[0047] Next, a method for electrical discharge machining of silicon carbide in this exemplary embodiment will be further described.
[0048] As described in step S110 above, as Figures 2-3 shown, perform electrical discharge machining on the silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer.
[0049] It should be noted that the silicon carbide workpiece can be machined by a conventional electrical discharge machining scheme to machine a cavity on the silicon carbide workpiece, and a recast layer will be formed on the surface of the silicon carbide workpiece during the machining process.
[0050] In an embodiment of the present invention, the specific process of "performing electrical discharge machining on the silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer" described in step S120 can be further described in combination with the following description.
[0051] As described in the following steps, connect the silicon carbide workpiece to the positive pole of the pulse power supply, and connect the tool electrode to the negative pole of the pulse power supply;
[0052] As described in the following steps, adjust the machining parameters according to the machining depth and size of the target workpiece, and perform electrical discharge machining on the silicon carbide workpiece in a positive polarity manner according to the machining parameters to obtain the rough workpiece.
[0053] It should be noted that during the electrical discharge machining process, the positive polarity machining is adopted. The silicon carbide workpiece is connected to the positive electrode of the power supply, and the tool electrode is connected to the negative electrode of the power supply. The machining conditions are set as preset conditions according to the cavity structure of the target workpiece. The power supply is turned on, and the silicon carbide workpiece is machined according to the preset machining conditions to obtain a rough workpiece of the silicon carbide workpiece with the target structure.
[0054] As described in the above step S120, as Figure 4 shown, the recast layer is filled with the abrasive matrix powder.
[0055] It should be noted that the abrasive matrix powder is made by mixing the powder with grinding effect and the powder with adsorption effect. The powder with adsorption effect fixes the powder with grinding effect to the electrode, and the electrode shakes to achieve the grinding effect.
[0056] In a specific implementation, the abrasive matrix powder is made by mixing aluminum powder and diamond powder.
[0057] In an embodiment of the present invention, the specific process of "filling the recast layer with the abrasive matrix powder" described in step S120 can be further described in combination with the following description.
[0058] As described in the following steps, the abrasive matrix powder is obtained by mixing aluminum powder and diamond powder according to a preset ratio; wherein, the proportion of the aluminum powder is less than the proportion of the diamond powder;
[0059] As described in the following steps, the abrasive matrix powder is filled between the tool electrode and the silicon carbide;
[0060] As described in the following steps, the tool electrode is shaken to make the abrasive matrix powder evenly distributed between the tool electrode and the silicon carbide workpiece.
[0061] It should be noted that after the electrical discharge machining, the pulse power supply is turned off to stop the electrical discharge between the tool electrode and the silicon carbide workpiece. The aluminum powder and the diamond powder are mixed according to a certain ratio, with the aluminum powder accounting for a smaller proportion and the diamond powder accounting for a larger proportion. Under the action of its own gravity, the aluminum powder and the diamond powder are filled into the gap between the tool electrode and the SiC to form an initial abrasive layer. By slightly shaking the tool electrode, it is ensured that the aluminum powder and the diamond powder can be evenly distributed between the tool electrode and the SiC workpiece, realizing the filling of the abrasive matrix powder.
[0062] In an embodiment of the present application, in the step of filling the tool electrode and the rough workpiece with the mixture of aluminum powder and diamond powder, the mixing mass ratio of the aluminum powder to the diamond powder is 1:2 - 4.
[0063] It should be noted that the mixing mass ratio of the aluminum powder to the diamond powder is generally between 1:2 and 1:4, and the optimal mixing ratio is 1:2.
[0064] As described in step S130 above, as Figure 5 shown, the polarities of the tool electrode and the rough workpiece are exchanged, and the rough workpiece is subjected to electrical discharge machining to obtain an abrasive matrix.
[0065] In an embodiment of the present invention, the specific process of "exchanging the polarities of the tool electrode and the rough workpiece, subjecting the rough workpiece to electrical discharge machining, and obtaining an abrasive matrix layer on the tool electrode" described in step S130 can be further described in combination with the following description.
[0066] As described in the following steps, the silicon carbide workpiece is connected to the negative electrode of the pulse power supply, and the tool electrode is connected to the positive electrode of the pulse power supply;
[0067] As described in the following steps, the rough workpiece is subjected to electro-discharge machining in a negative polarity mode to make the aluminum powder become molten, and the diamond powder is bonded by the molten aluminum powder to obtain an abrasive matrix;
[0068] As described in the following steps, the abrasive matrix is attached to the surface of the tool electrode through electrical discharge machining to obtain an abrasive matrix layer.
[0069] It should be noted that the abrasive matrix powder is composed of powders with adhesive effects, such as aluminum powder, and powders with grinding effects, such as diamond powder. During the processing, the powders with adhesive effects bond the powders with grinding effects to the surface of the tool electrode to form an abrasive matrix layer.
[0070] The rough workpiece is subjected to electro-discharge machining in a negative polarity mode. Under the action of the discharge energy, the aluminum powder becomes molten, and the diamond powder is bonded by the molten aluminum powder to obtain an abrasive matrix; at the same time, under the action of the discharge energy, the molten aluminum powder coats the above-mentioned abrasive matrix on the electrode surface, thereby forming a dense abrasive matrix layer on the electrode surface. The recast layer on the surface of silicon carbide can be eliminated through the grinding action of the electrode with the abrasive matrix layer.
[0071] In a specific implementation, the silicon carbide workpiece is connected to the negative electrode of the pulse power supply, the tool electrode is connected to the positive electrode of the pulse power supply, and the silicon carbide workpiece is subjected to electro-discharge machining using negative polarity machining. Under the action of the discharge energy, the aluminum powder changes from a solid state to a molten state. The molten aluminum powder bonds the diamond powder to the surface of the tool electrode, thereby forming an abrasive matrix layer on the electrode surface.
[0072] As described in step S140 above, as Figure 6As shown, the recast layer is removed by the abrasive matrix to obtain the target workpiece.
[0073] In an embodiment of the present invention, the description of "removing the recast layer by the abrasive matrix to obtain the target workpiece" in step S140 can be further explained in combination with the following description.
[0074] As described in the following steps, the distance between the tool electrode and the rough workpiece is adjusted to form a contact pressure between the tool electrode and the rough workpiece.
[0075] As described in the following steps, the surface of the rough workpiece is ground by the rotation and shaking of the tool electrode to remove the recast layer and obtain the target workpiece.
[0076] It should be noted that since there is a gap between the tool electrode and the silicon carbide workpiece in electric discharge machining, the tool electrode needs to be adjusted downward by a certain distance so that the abrasives in the abrasive matrix layer on the outer surface of the tool electrode, such as diamond, can be in full contact with the surface of the silicon carbide workpiece to form a contact pressure to ensure smooth grinding. Then, the surface of the SiC workpiece after electric discharge machining is ground by the rotation and shaking of the tool electrode.
[0077] In an embodiment of the present invention, it further includes: preprocessing the silicon carbide workpiece according to the structure of the target workpiece.
[0078] It should be noted that preprocessing the silicon carbide workpiece according to the state of the silicon carbide workpiece and the structure of the target workpiece facilitates subsequent electric discharge machining.
[0079] In an embodiment of the present invention, it further includes: processing the tool electrode and the silicon carbide workpiece in a working fluid; wherein, the working fluid is kerosene.
[0080] In an embodiment of the present invention, it further includes: post-processing the target workpiece according to preset conditions.
[0081] It should be noted that the target workpiece is post-processed, such as cleaned and plated, according to the use of the target workpiece.
[0082] Although the preferred embodiments of the embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present application.
[0083] Finally, it should also be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or terminal device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or terminal device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or terminal device comprising the said element.
[0084] The above has introduced in detail a method for electrical discharge machining of silicon carbide provided by this application. Specific examples are used in this text to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.
Claims
1. A method for electrical discharge machining of silicon carbide, characterized in that, Including the steps of: Performing electrical discharge machining on the silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer; Filling the tool electrode and the rough workpiece with abrasive matrix powder; Exchanging the polarities of the tool electrode and the rough workpiece, and performing electrical discharge machining on the rough workpiece to obtain an abrasive matrix layer on the tool electrode; Removing the recast layer through the abrasive matrix layer to obtain the target workpiece.
2. The method according to claim 1, wherein The step of performing electrical discharge machining on the silicon carbide workpiece according to preset conditions to obtain a rough workpiece with a recast layer includes: Connecting the silicon carbide workpiece to the positive pole of the pulse power supply and connecting the tool electrode to the negative pole of the pulse power supply; Adjusting the machining parameters according to the machining depth and size of the target workpiece, and performing electrical discharge machining on the silicon carbide workpiece in a positive polarity manner according to the machining parameters to obtain the rough workpiece.
3. The method according to claim 1, characterized in that The step of filling the recast layer with abrasive matrix powder includes: Mixing aluminum powder and diamond powder according to a preset ratio to obtain abrasive matrix powder; wherein, the proportion of the aluminum powder is less than the proportion of the diamond powder; Filling the abrasive matrix powder between the tool electrode and the silicon carbide; Shaking the tool electrode to make the abrasive matrix powder evenly distributed between the tool electrode and the silicon carbide workpiece.
4. The method according to claim 3, wherein In the step of filling the tool electrode and the rough workpiece with a mixture of aluminum powder and diamond powder, the mixing mass ratio of the aluminum powder and the diamond powder is 1:2 - 4.
5. The method according to claim 1, characterized in that, The step of exchanging the polarities of the tool electrode and the rough workpiece, performing electrical discharge machining on the rough workpiece, and obtaining an abrasive matrix layer on the tool electrode includes: Connecting the silicon carbide workpiece to the negative pole of the pulse power supply and connecting the tool electrode to the positive pole of the pulse power supply; Performing electrical discharge machining on the rough workpiece in a negative polarity manner to make the aluminum powder in a molten state, and bonding the diamond powder through the molten aluminum powder to obtain an abrasive matrix; Attaching the abrasive matrix to the surface of the tool electrode through electrical discharge machining to obtain an abrasive matrix layer.
6. The method according to claim 1, characterized in that, The step of removing the recast layer through the abrasive matrix layer to obtain the target workpiece includes: Adjusting the distance between the tool electrode and the rough workpiece to form a contact pressure between the tool electrode and the rough workpiece; Grinding the surface of the rough workpiece by rotating and shaking the tool electrode to remove the recast layer and obtain the target workpiece.
7. The method according to claim 1, characterized in that, It also includes: Performing pretreatment on the silicon carbide workpiece according to the structure of the target workpiece.
8. The method according to claim 1, wherein It also includes: Placing the tool electrode and the silicon carbide workpiece in a working fluid for machining; wherein, the working fluid is kerosene.
9. The method according to claim 1, characterized in that It also includes: Performing post-treatment on the target workpiece according to preset conditions.