Electrochemical discharge assisted grinding apparatus

Abstract

This invention discloses an electrochemical discharge-assisted grinding (EDG) equipment, characterized in that the EEG equipment includes a frequency converter, a power supply, a spindle, an electric current supply device, a tool electrode chuck, a tool electrode, a nozzle, a workpiece, a workpiece fixture, an electrolyte, a water pump, a filter, cooling water, and a collection tank; the tool electrode is composed of the following components in parts by weight: 30-100 parts of novel alloy powder, 5-70 parts of copper powder, and 5-20 parts of diamond abrasive; the tool electrode used in the EEG equipment of this invention has a high melting point, resistance to electrical erosion, strength and hardness, high-temperature mechanical properties, wear resistance, and corrosion resistance; it can effectively reduce the electrical erosion loss of the diamond tool electrode and abrasive wear during EEG grinding.

Description

Technical Field

[0001] This invention belongs to the field of electrical discharge machining technology, specifically relating to an electrochemical discharge-assisted grinding equipment and tool electrode. Background Technology

[0002] Metal matrix composites (MMCs) are multiphase material systems formed by combining a metallic matrix with reinforcing phases such as metals and ceramics. Common MMCs include aluminum-based silicon carbide composites (SiCp / Al) and magnesium-based silicon carbide composites (SiCp / Mg). Among them, aluminum-based silicon carbide composites are widely used in aerospace, aviation, automotive, optical precision devices, and electronics industries due to their high strength, high modulus, high toughness, and low density.

[0003] To meet application requirements, metal matrix composites typically require secondary processing. However, the significant difference in mechanical properties between the metal matrix and the reinforcing phase makes them extremely difficult to process. Currently, processing methods for metal matrix composites are mainly categorized into traditional processing, special processing, and composite processing. Traditional processing primarily includes turning, milling, drilling, and grinding. Special processing mainly includes electrical discharge machining (EDM), laser processing, and abrasive waterjet machining. Taking aluminum-based silicon carbide as an example, traditional processing methods offer advantages such as simple operation and mature technology, but they struggle to process high-hardness silicon carbide particles, leading to severe tool wear and impacting processing efficiency and surface quality. While laser processing and abrasive waterjet machining can efficiently remove material without tool wear, the processed surface is often accompanied by severe machining defects and is difficult to use for machining parts with complex three-dimensional shapes. Although electrical discharge machining (EDM) can machine parts with complex three-dimensional shapes, it is difficult to vaporize or melt high-melting-point, non-conductive silicon carbide particles. Furthermore, as machining progresses, debris is difficult to remove in time within the narrow discharge gap, leading to poor machining stability and affecting both machining efficiency and surface quality. Electrochemical discharge machining (ECM) is a machining method that combines electrolysis and electrical discharge effects. Its discharge gap can be 5-10 times larger than that of EDM, which is more conducive to debris removal. Therefore, it can achieve material removal efficiency far higher than that of EDM and electrolytic machining. However, due to the presence of electrical discharge effects, defects such as recast layers and electrolytic pits still exist on the processed surface.

[0004] To improve the processing efficiency and surface quality of metal matrix composites, industry researchers have proposed incorporating grinding into electrical discharge machining (EDM). For example, patent CN202010112088.1 proposes a novel electrode—a bronze-bonded diamond tool electrode—for EDM-assisted grinding of metal matrix composites. This tool electrode is sintered from diamond abrasive and a bronze binder. During processing, grinding, electrolytic machining, and EDM are performed simultaneously. EDM can erode the matrix material and reinforcing phases at high temperatures, creating pits and heat-affected zones (HAZs). Simultaneously, the high temperature softens the material, significantly increasing grinding efficiency. Furthermore, grinding can remove pits and HAZs generated by EDM, as well as surface passivation layers produced by electrolytic machining, improving surface quality while ensuring the continuous operation of electrolytic machining. Electrolytic machining can electrolytically remove electro-erosion pits and recast layers, thereby improving surface quality. However, this method currently suffers from significant electrode wear problems: on the one hand, due to the presence of electrical discharge, the tool electrode inevitably experiences electro-erosion, especially when high-current machining is used to pursue higher processing efficiency, resulting in more pronounced electro-erosion and a significantly shortened electrode life; on the other hand, the high-melting-point, high-hardness reinforcing phase will wear down the tool electrode. These two wear mechanisms make the tool electrode prone to deformation or even breakage during machining, severely impacting processing efficiency, surface quality, and machining accuracy, while also increasing processing costs. Summary of the Invention

[0005] To address the electrode wear problem in electrical discharge assisted grinding (EDG), this invention proposes an electrochemical EEG-assisted grinding device. The tool electrode utilizes a special material design and preparation method, transforming the metal raw material into a novel alloy with high melting point, resistance to electrical erosion, high strength, hardness, wear resistance, high-temperature stability, and resistance to high-temperature creep. Diamond tool electrodes prepared using this novel alloy or its copper-based composite material can reduce electrical erosion loss and wear, thereby ensuring processing efficiency, surface quality, and processing accuracy.

[0006] The purpose of this invention is to provide an electrochemical discharge assisted grinding equipment, which includes a frequency converter (1), a power supply (2), a spindle (3), an electric current supply device (4), a tool electrode chuck (5), a tool electrode (6), a nozzle (7), a workpiece (8), a workpiece fixture (9), an electrolyte (10), a water pump (11), a filter (12), cooling water (13), and a collection tank (14); the frequency converter (1) is used to control the rotational speed of the spindle (3); the cooling water (13) circulates the cooling water through the spindle (3) during operation. Cooling; the tool electrode (6) is clamped on the tool electrode chuck (5); the positive terminal of the power supply (2) is connected to the workpiece (8), and the workpiece (8) is fixed by the workpiece clamp (9); the negative terminal of the power supply (2) is connected to the tool electrode (6) via the power supply device (4), and as the spindle (3) feeds downward, the tool electrode (6) is immersed in the electrolyte (10); the water pump (11) draws the used electrolyte (10) and filters it through the filter (12) and stores it in the collection tank (14), and the water pump (11) and the nozzle (7) laterally flush the machining surface of the workpiece (8);

[0007] Furthermore, the tool electrode (6) is a hollow or solid electrode, and its structure is cylindrical or milling cutter-shaped, etc.

[0008] Furthermore, the tool electrode (6) is composed of the following components in parts by weight: 30-100 parts of novel alloy powder, 5-70 parts of copper powder, and 5-20 parts of diamond abrasive.

[0009] The novel alloy powder is prepared by mixing four or more elements selected from Cu, Cr, Fe, Mn, Ni, Al, Co, Zn, Mg, Mo, and W in a molar ratio of (0.05-1.5):(0.05-1.5), with a particle size of 5-100 μm.

[0010] The diamond abrasive is one of uncoated diamond, W-coated diamond, and Ti-coated diamond, with a particle size of 10-400 μm. The particle size of the diamond abrasive of this invention helps improve machining accuracy and surface quality because it allows for easier penetration into the workpiece's microstructure for cutting. Excessively small abrasive grains may increase the conductivity of the electrolyte and lead to heat accumulation during machining, thereby affecting machining efficiency and workpiece surface quality.

[0011] Furthermore, the method for preparing the tool electrode includes the following steps:

[0012] (1) Weigh the new alloy powder according to the required weight parts, and ball mill the new alloy powder under an argon / nitrogen atmosphere for 5-50 hours with a ball-to-material ratio of (10-30):1 and a rotation speed of 200-500 rpm.

[0013] (2) Weigh out copper powder and diamond abrasive according to the required weight proportions, mix them with the new alloy powder obtained in step (1) and ball mill them. The ball mill speed is 200-450 r / min, the ball milling time is 1-5 h, the protective atmosphere is argon or nitrogen, and the total volume of raw materials does not exceed 2 / 3 of the volume of the ball milling tank.

[0014] (3) The mixed material obtained in step (2) is placed into a hard alloy cold pressing mold with a size of Φ30mm and cold pressing is performed to obtain a blank. The compaction density of the blank is 40-60%, the cold pressing pressure is 100-250MPa, and the cold pressing time is 5min.

[0015] (4) The above-obtained blank is hot-pressed and sintered, heated to 750-1450℃ at a heating rate of 20-100℃ / min, held for 5-40min, the sintering pressure during the heating stage is 20-100MPa, the protective atmosphere is argon or nitrogen, and cooled to room temperature with the furnace to obtain the discharge machining tool electrode.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The electrochemical discharge-assisted grinding equipment of this invention uses a high-entropy alloy abrasive electrode, which has a high melting point, resistance to electrical erosion, strength, hardness, high-temperature mechanical properties, wear resistance, and corrosion resistance. It can effectively reduce the electrical erosion loss and abrasive wear of the diamond tool electrode during discharge-assisted grinding, thereby ensuring efficient, high-quality, and high-precision processing of materials. Compared with the diamond tool electrodes currently used in discharge-assisted grinding, the designed diamond tool electrode based on the new alloy has a higher melting point and better resistance to electrical erosion, and can better meet the environmental conditions in discharge-assisted grinding, reducing the electrical erosion loss of the diamond tool electrode. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the electrochemical discharge-assisted grinding equipment of the present invention.

[0019] Figure 2 This is a schematic diagram illustrating the principle of electrochemical discharge-assisted grinding in this invention.

[0020] Figure 3 The present invention includes (a) a blank sample of a novel alloy-coated W-diamond abrasive and (b) a sample of a novel alloy-coated W-diamond abrasive electrode.

[0021] Figure 4 This is a SEM image of the surface of the novel alloy-coated W-diamond abrasive electrode of this invention.

[0022] Figure 5 The wear and average material removal rate of the two tool electrodes in Embodiment 2 of the present invention are shown.

[0023] Figure 6 The wear and average material removal rate of the two tool electrodes in Example 3 of the present invention are shown.

[0024] Figure 7 The images show the processing results of high-entropy alloy abrasive electrodes with different compositions according to the present invention.

[0025] Figure 8 The XRD patterns of the high-entropy alloy FeCrCoNiMo mixed metal powder (before ball milling) and the molded sample in Example 4 of this invention are shown.

[0026] Figure 9 This is the macroscopic morphology of the tool electrode tip after multiple processing steps of the high-entropy alloy abrasive electrode and the copper-based abrasive electrode in Embodiment 4 of the present invention.

[0027] Figure 10 The present invention is constructed as a cylindrical or milling cutter-shaped hollow tool electrode.

[0028] Explanation of reference numerals in the attached figures:

[0029] In the diagram: 1. Frequency converter; 2. Power supply; 3. Spindle; 4. Power supply device; 5. Tool electrode chuck; 6. Tool electrode; 7. Nozzle; 8. Workpiece; 9. Workpiece fixture; 10. Electrolyte; 11. Water pump; 12. Filter; 13. Cooling water; 14. Liquid collection tank; 15. New alloy matrix; 16. Diamond abrasive grains; 17. Hydrogen bubbles; 18. Electrical discharge machining; 19. Diamond particles; 20. Recast layer; 21. Metal matrix; 22. Reinforcing particles; 23. Flushing hole; 24. Machining clearance. Detailed Implementation

[0030] The following is a description of the embodiments and appendices. Figure 1-10 The present invention will be described in further detail below.

[0031] Example 1

[0032] An electrochemical discharge assisted grinding equipment includes a frequency converter (1), a power supply (2), a spindle (3), an electric current supply device (4), a tool electrode chuck (5), a tool electrode (6), a nozzle (7), a workpiece (8), a workpiece fixture (9), an electrolyte (10), a water pump (11), a filter (12), cooling water (13), and a collection tank (14). The frequency converter (1) is used to control the rotational speed of the spindle (3). The cooling water (13) is used to cool the spindle (3) during operation. The tool electrode (6) is clamped on the tool electrode chuck (5); the positive terminal of the power supply (2) is connected to the workpiece (8), which is fixed by the workpiece fixture (9); the negative terminal of the power supply (2) is connected to the tool electrode (6) via the power supply device (4), and as the spindle (3) feeds downward, the tool electrode (6) is immersed in the electrolyte (10); the water pump (11) draws the used electrolyte (10) and filters it through the filter (12) and stores it in the collection tank (14), and the water pump (11) and the nozzle (7) laterally flush the machined surface of the workpiece (8);

[0033] Through such Figure 1 The discharge-assisted grinding equipment shown is used to process metal matrix composites. The novel alloy-bonded diamond tool electrode (6) proposed in this invention is clamped on the tool electrode chuck (5). The positive terminal of the power supply (2) is connected to the workpiece (8) to be processed, and the negative terminal of the power supply (2) is connected to the novel alloy-bonded diamond tool electrode (6) via the power supply device (4). As the spindle (3) feeds downward, the tool electrode (6) is immersed in the electrolyte.

[0034] Figure 2This is a schematic diagram illustrating the principle of discharge-assisted grinding of metal matrix composites using a novel alloy-bonded diamond tool electrode (6). After the power supply (2) is turned on, the workpiece (8) and the tool electrode (6) begin to undergo an electrochemical reaction in the electrolyte (10). According to Faraday's law of electrolysis, the workpiece (8), acting as the anode, gradually dissolves, and the tool electrode (6), acting as the cathode, begins to generate hydrogen bubbles (17) on its surface. As the reaction proceeds, the resistance between the tool electrode (6) and the surface of the workpiece (8) within the machining gap continuously increases due to the hydrogen bubbles (17) generated by the electrochemical reaction, and the voltage between the two electrodes also increases with the increase in resistance. When the voltage between the electrodes reaches the voltage required to break down the bubbles (17) and generate a discharge, an electric spark discharge (18) in the form of an electric arc is generated. The localized instantaneous high temperature generated by the discharge melts and vaporizes the metal material, ultimately completing the discharge removal of the workpiece material. In the electrical discharge machining debris generated during this process, a large number of molten debris will reshape around the discharge erosion pits, eventually forming a recast layer (20) on the machining surface, which seriously affects the machining quality. The novel tool electrode proposed in this invention is a tool electrode with a novel alloy matrix (15) and diamond abrasive grains (16). After powder metallurgy and wire cutting, a large number of diamond abrasive grains (16) are randomly exposed on the surface of the tool electrode (6). Under the rotation of the spindle (3), the diamond abrasive grains (16) exposed on the surface of the tool electrode will mechanically grind the workpiece during the machining process. The metal matrix (21) in the metal matrix composite workpiece is directly removed by the grinding action of the diamond abrasive grains (16), while the removal of the reinforcing particles (22) is carried out by crushing or pulling out as a whole. Due to the softening of the high temperature workpiece matrix material (21) generated by the electrical discharge effect, the grinding effect of the diamond abrasive grains (16) is further improved. Meanwhile, the non-conductive properties of the diamond abrasive grains (16) eliminate the risk of short circuits due to micro-grinding contact during machining, ensuring uninterrupted and stable machining operations. As machining continues, new diamond grains (19) can continue to be exposed from inside the tool electrode (6) under the effects of electrical discharge and electrochemical processes, forming new cutting edges and thus maintaining the grinding effect of the machining.

[0035] The increase in the rotational speed of the tool electrode (6) helps to enhance the grinding effect and improve the chip removal effect. The preferred spindle (3) has a maximum speed of 24,000 rpm. The speed of the spindle (3) is controlled by the frequency converter (1). At the same time, in order to achieve high precision of the spindle (3) even when it is running at high speed, the preferred spindle precision is 0.003 mm. Cooling water (13) is used to cool the spindle (3) in the working state.

[0036] For the electrolyte (10) after processing, the electrolyte circulation system can draw the used electrolyte by the water pump (11) and filter it through the filter (12) and store it in the collection tank (14). The water pump (11) and the nozzle (7) are used to laterally flush the processed surface of the workpiece (8) to complete the recycling of the electrolyte.

[0037] Figure 10 The present invention is constructed as a hollow tool electrode, such as a cylindrical or milling cutter shape. Figure 10 (a) is a three-dimensional view of the tool electrode 6 in operation. Figure 10 (b) is a top view of the tool electrode 6 in operation. The hollow tool electrode (6) is provided with a flushing hole (23). When electrical discharge machining is performed, the electrolyte (10) can enter from the top of the tool electrode through the flushing hole (23) and then flow into the machining gap (24) at the bottom of the tool electrode, which can achieve the effect of machining and electrolysis at the same time. In addition, by setting the tool electrode to the shape of a milling cutter, the workpiece can be milled and ground in a comprehensive way during the electrical discharge machining process, and the machining effect will be better.

[0038] Example 2

[0039] The preparation method of the tool electrode (6) includes the following steps:

[0040] (1) Cr, Fe, Ni, Al, Co powder (particle size 10 μm) were weighed in a molar ratio of 1:1:1:1:1 and ball-milled for 50 h in an argon atmosphere with a ball-to-material ratio of 20:1.

[0041] (2) Take 90 parts of new alloy powder, 20 parts of copper powder and 10 parts of diamond abrasive (particle size 40μm), put them in a ball mill and mix them. The ball mill speed is 300rpm and the ball milling time is 5h.

[0042] (3) The mixed powder obtained above is placed into a cemented carbide cold pressing mold for cold pressing. The cold pressing pressure is 220MPa and the cold pressing time is 5min to obtain a blank with a compaction density of 55%.

[0043] (4) The above-obtained billet is subjected to protective atmosphere hot pressing sintering. The billet is heated to 1200℃ at a heating rate of 80℃ / min and held for 20min. At the same time, a pressure of 60MPa is applied. After cooling in the furnace, a new alloy-diamond bulk material is obtained.

[0044] Testing revealed that the alloy material exhibited a hardness greater than 800 Hv, a compressive strength greater than 1400 MPa, good wear resistance, and a 94.4% improvement in resistance to electrolytic corrosion compared to pure Cu. Diamond tool electrodes were fabricated from the prepared bulk material using wire electrical discharge machining (EDM), mounted on a machining equipment, and used in electrochemical discharge assisted grinding and drilling of high-volume-fraction aluminum-based silicon carbide composite materials (50 vol.% SiCp). Results showed that the wear of the novel alloy diamond tool electrode was significantly lower than that of the pure Cu-bonded diamond tool, while the average material removal rate of the novel alloy diamond tool electrode was significantly higher than that of the pure Cu-bonded diamond tool electrode (see...). Figure 5 (As shown). In summary, the obtained novel alloy diamond tool electrode exhibits high wear resistance, electrical corrosion resistance, and processing efficiency.

[0045] Figure 3 The present invention relates to a novel alloy-coated diamond sintered block sample and a novel alloy-coated diamond tool electrode sample prepared by the inventor. The prepared sintered block is a cylinder with a diameter of 3 mm and a height of 10 mm.

[0046] Figure 4 SEM and EDS surface scan images of a novel alloy-coated W-diamond tool electrode sample.

[0047] Example 3

[0048] The preparation method of the tool electrode (6) includes the following steps:

[0049] (1) Cr, Fe, Ni, Al, Co powder (particle size 10 μm) were weighed in a molar ratio of 1:1:1:1:1 and ball-milled for 50 h in an argon atmosphere with a ball-to-material ratio of 20:1.

[0050] (2) Take 70 parts of new alloy powder, 40 parts of Cu powder and 10 parts of diamond abrasive (particle size 40μm), put them in a ball mill and mix them. The ball mill speed is 300rpm and the ball milling time is 5h.

[0051] (3) The mixed powder obtained above is placed into a cemented carbide cold pressing mold for cold pressing. The cold pressing pressure is 220MPa and the cold pressing time is 5min to obtain a blank with a compaction density of 60%.

[0052] (4) The above-obtained billet is subjected to protective atmosphere hot pressing sintering. The billet is heated to 1100℃ at a heating rate of 80℃ / min and held for 20min. At the same time, a pressure of 60MPa is applied. After cooling in the furnace, a new alloy-diamond bulk material is obtained.

[0053] Testing revealed that the alloy material exhibited a hardness greater than 645 Hv, a compressive strength greater than 1200 MPa, good wear resistance, and a 68.4% improvement in resistance to electrolytic corrosion compared to pure Cu. Diamond tool electrodes were fabricated from the prepared bulk material using wire electrical discharge machining (EDM), mounted on a machining equipment, and used in electrochemical discharge assisted grinding and drilling of low-volume-fraction aluminum-based silicon carbide composite materials (20 vol.% SiCp). Results showed that the wear of the novel alloy / copper bonded diamond tool electrode was significantly lower than that of the pure Cu bonded diamond tool electrode, while the average material removal rate of the novel alloy / copper bonded diamond tool electrode was significantly higher than that of the pure Cu bonded diamond tool electrode (see...). Figure 6 (As shown). In summary, the novel alloy / copper bonded diamond tool electrode exhibits high wear resistance, electrical corrosion resistance, and processing efficiency.

[0054] Example 4

[0055] The preparation method of the tool electrode (6) includes the following steps:

[0056] (1) Cr, Fe, Ni, Co and Mo powder (particle size 10 μm) were weighed in a molar ratio of 1:1:1:1:1 and ball-milled for 50 h in an argon atmosphere with a ball-to-material ratio of 20:1.

[0057] (2) Take 70 parts of new alloy powder, 40 parts of Cu powder and 10 parts of diamond abrasive (particle size 40μm), put them in a ball mill and mix them. The ball mill speed is 300rpm and the ball milling time is 5h.

[0058] (3) The mixed powder obtained above is placed into a cemented carbide cold pressing mold for cold pressing. The cold pressing pressure is 220MPa and the cold pressing time is 5min to obtain a blank with a compaction density of 60%.

[0059] (4) The above-obtained billet is subjected to protective atmosphere hot pressing sintering. The billet is heated to 1100℃ at a heating rate of 80℃ / min and held for 20min. At the same time, a pressure of 60MPa is applied. After cooling in the furnace, a new alloy-diamond bulk material is obtained.

[0060] In the preparation of the high-entropy alloy FeCrCoNiMo sample, the mixed metal powder is ball-milled in a planetary ball mill. At the same time, the hard balls of different sizes and masses collide at high speed in the ball mill jar and generate heat. After continuous collision and cold welding, the alloy powder undergoes plastic deformation, resulting in large lattice distortion of the powder. This promotes solid solution between the atoms of each element. Therefore, the mixed powder after ball milling is verified to have high entropy. Finally, it is sintered by powder metallurgy process to become the high-entropy alloy sample used in this invention. Figure 8XRD patterns of the high-entropy alloy FeCrCoNiMo sample prepared for the experiments in this chapter and XRD patterns of the mixed metal powder before ball milling are shown. Figure 8 As can be seen, it is difficult to detect the diffraction peaks of each element in the XRD pattern of the formed high-entropy alloy FeCrCoNiMo sample. This indicates that the high-entropy alloy sample has undergone a high-entropy process, forming an FCC structure FeCrCoNiMo high-entropy alloy. At the same time, there are three diffraction peaks in the XRD pattern, corresponding to the three crystal planes (111), (200) and (220) of the face-centered cubic solid solution (FCC).

[0061] Figure 9 The images show the macroscopic morphology of the tool electrode tips after multiple machining operations for a high-entropy alloy abrasive electrode (Hea / C electrode) and a copper-based abrasive electrode, respectively. Figure 9 As observed in (a), the center of the processed high-entropy alloy abrasive electrode tip bulges. This is because the wear in the area near the sidewall of the tip is greater than that in the center area. It is worth noting that... Figure 9 In (b), the copper-based abrasive electrode, after processing, has a larger diameter at its tip than the rest of its length, and exhibits a compressed, flattened shape extending outwards. As can be observed in the figure, the outer edge of the tip is bright red. Observation of the number of diamond abrasive grains on the end face reveals that the number of diamond abrasive grains on the end face and outer edge is significantly less than on the rest of the electrode's sidewall. This electrode morphology is believed to be caused by the rapid re-condensation of a large amount of molten copper during processing due to the cooling effect of the working fluid, forming a shape resembling... Figure 9 (b) shows the abnormal electrode morphology. Furthermore, during the experiment, it was found that this abnormal electrode morphology worsened with continued machining, and a carbon layer in solid solution form rapidly formed on the electrode surface during EDM, reducing the number of diamond particles participating in auxiliary grinding and ultimately leading to decreased material removal efficiency. More importantly, the abnormal electrode tip morphology resulted in larger apertures in the experimentally prepared pores, severely affecting machining accuracy and threatening machining stability. Therefore, compared to copper-based abrasive electrodes, high-entropy alloy-based abrasive electrodes are more suitable for G-ECDM machining of aluminum-based silicon carbide composite materials.

[0062] Example 5

[0063] The preparation method of the tool electrode (6) includes the following steps:

[0064] (1) Cr, Fe, Ni, Al, Co, MO and W powders (particle size 10 μm) were weighed in a molar ratio of 1:1:1:1:1 and ball-milled for 50 h in an argon atmosphere with a ball-to-material ratio of 20:1.

[0065] (2) Take 90 parts of new alloy powder, 20 parts of copper powder and 10 parts of diamond abrasive (particle size 40μm), put them in a ball mill and mix them. The ball mill speed is 300rpm and the ball milling time is 5h.

[0066] (3) The mixed powder obtained above is placed into a cemented carbide cold pressing mold for cold pressing. The cold pressing pressure is 220MPa and the cold pressing time is 5min to obtain a blank with a compaction density of 55%.

[0067] (4) The above-obtained billet is subjected to protective atmosphere hot pressing sintering. The billet is heated to 1200℃ at a heating rate of 80℃ / min and held for 20min. At the same time, a pressure of 60MPa is applied. After cooling in the furnace, a new alloy-diamond bulk material is obtained.

[0068] Example 6

[0069] The preparation method of the tool electrode (6) includes the following steps:

[0070] (1) Cr, Fe, Ni, Al, Co and Mn powders (particle size 10 μm) were weighed in a molar ratio of 1:1:1:1:1 and ball-milled for 50 h in an argon atmosphere with a ball-to-material ratio of 20:1.

[0071] (2) Take 90 parts of new alloy powder, 20 parts of copper powder and 10 parts of diamond abrasive (particle size 40μm), put them in a ball mill and mix them. The ball mill speed is 300rpm and the ball milling time is 5h.

[0072] (3) The mixed powder obtained above is placed into a cemented carbide cold pressing mold for cold pressing. The cold pressing pressure is 220MPa and the cold pressing time is 5min to obtain a blank with a compaction density of 55%.

[0073] (4) The above-obtained billet is subjected to protective atmosphere hot pressing sintering. The billet is heated to 1200℃ at a heating rate of 80℃ / min and held for 20min. At the same time, a pressure of 60MPa is applied. After cooling in the furnace, a new alloy-diamond bulk material is obtained.

[0074] like Figure 7In this invention, the workpiece being processed is an aluminum-based silicon carbide composite material with a particle-reinforced phase volume fraction of 60%. During electrochemical discharge machining (G-ECDM), FeCoNiCrAl, as a typical high-entropy alloy electrode, did not perform well, exhibiting the lowest MRR and the highest TWR among the selected high-entropy alloy electrodes. However, comparative experiments revealed that the high-entropy alloy FeCoNiCrMo and FeCoNiCrMoW abrasive electrodes demonstrated higher material removal rates in G-ECDM, along with lower wear rates than the other abrasive electrodes tested. However, the FeCoNiCrMoW abrasive electrode experienced electrode breakage, resulting in tool wear far exceeding the TWR observed during normal machining.

[0075] Comparative Example 1

[0076] The only difference between Comparative Example 1 and Example 2 is that the same weight proportions of Cu powder are used instead of the novel alloy powder.

[0077] Comparative Example 2

[0078] The only difference between Comparative Example 2 and Example 3 is that the same weight parts of Cu powder are used instead of abrasive.

[0079] Comparative Example 3

[0080] The only difference between Comparative Example 3 and Example 2 is that the particle size of the novel alloy powder is 120 μm;

[0081] Comparative Example 4

[0082] The only difference between Comparative Example 4 and Example 3 is that the diamond abrasive particle size is 450 μm;

[0083] Comparative Example 5

[0084] The only difference between Comparative Example 5 and Example 2 is that the particle size of the novel alloy powder is 120 μm;

[0085] Comparative Example 6

[0086] The only difference between Comparative Example 6 and Example 3 is that the diamond abrasive particle size is 450 μm;

[0087] Comparative Example 7

[0088] The only difference between Comparative Example 7 and Example 2 is that the same weight parts of Cr, Fe, Ni powder were used instead of Cr, Fe, Ni, Al, Co powder.

[0089] Comparative Example 8

[0090] The only difference between Comparative Example 8 and Example 3 is that the same weight parts of Cr, Fe, Ni powder were used instead of Cr, Fe, Ni, Al, Co powder.

[0091] The above test data are recorded in Table 1.

[0092] Table 1

[0093]

[0094]

[0095] As can be seen from Table 1, the particle size and composition of the novel alloy powder and the particle size of the diamond abrasive also have a certain impact on the electrode wear and material removal rate. Among them, the change in the composition of the novel alloy powder has a relatively large impact on these effects. Compared with the electrodes in Comparative Examples 1-2, the tool electrode of the present invention has excellent performance.

[0096] The above description represents the best specific implementation of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An electrochemical discharge-assisted grinding processing device, characterized in that, The electrochemical discharge assisted grinding equipment includes a frequency converter (1), a power supply (2), a spindle (3), an electric current device (4), a tool electrode chuck (5), a tool electrode (6), a nozzle (7), a workpiece (8), a workpiece fixture (9), an electrolyte (10), a water pump (11), a filter (12), cooling water (13), and a collection tank (14); the frequency converter (1) is used to control the rotational speed of the spindle (3); the cooling water (13) cools the spindle (3) during operation; the tool electrode (6) The workpiece (8) is clamped on the tool electrode chuck (5); the positive terminal of the power supply (2) is connected to the workpiece (8), which is fixed by the workpiece clamp (9); the negative terminal of the power supply (2) is connected to the tool electrode (6) via the power supply device (4). As the spindle (3) feeds downward, the tool electrode (6) is immersed in the electrolyte (10); the water pump (11) draws the used electrolyte (10) and filters it through the filter (12) and stores it in the collection tank (14). The water pump (11) and the nozzle (7) are used to laterally flush the machining surface of the workpiece (8). The tool electrode (6) is a hollow or solid electrode, and its structure is cylindrical; The tool electrode (6) is composed of the following components in parts by weight: 30-100 parts of novel alloy powder, 5-70 parts of copper powder, and 5-20 parts of diamond abrasive. The novel alloy powder is composed of four or more elements selected from Cu, Cr, Fe, Mn, Ni, Al, Co, Zn, Mg, Mo, and W. The elements composing the novel alloy powder are weighed in a molar ratio of 1:1, and the particle size of the novel alloy powder is 5-100 μm. The diamond abrasive is one of uncoated diamond, W-coated diamond, and Ti-coated diamond, with a particle size of 10-400 μm.

2. The electrochemical discharge-assisted grinding equipment as described in claim 1, characterized in that, The preparation method of the tool electrode (6) includes the following steps: (1) Weigh the new alloy powder according to the required weight parts, and place the new alloy powder in an argon / nitrogen atmosphere for ball milling for 5-50 hours. The ball-to-material ratio is (10-30):1, and the rotation speed is 200-500 r / min. (2) Weigh out copper powder and diamond abrasive according to the required weight proportions, mix them with the new alloy powder obtained in step (1) and ball mill them. The ball mill speed is 200-450 r / min, the ball milling time is 1-5 h, the protective atmosphere is argon or nitrogen, and the total volume of raw materials does not exceed 2 / 3 of the volume of the ball milling tank. (3) The mixed material obtained in step (2) is placed into a hard alloy cold pressing mold with a size of Φ 30mm for cold pressing to obtain a blank. The compaction density of the blank is 40-60%, the cold pressing pressure is 100-250MPa, and the cold pressing time is 5min. (4) The above-obtained blank is hot-pressed and sintered, heated to 750-1450℃ at a heating rate of 20-100℃ / min, held for 5-40min, the sintering pressure during the heating stage is 20-100MPa, the protective atmosphere is argon or nitrogen, and cooled to room temperature with the furnace to obtain the discharge machining tool electrode.

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