Electrolytic composite diamond wire saw cutting apparatus and method for Hastelloy alloys

Abstract

This invention relates to the field of electrolytic machining technology, and in particular provides an electrolytic composite diamond wire saw cutting device and method for Hastelloy alloys. The device includes a wire saw feeding mechanism, a side baffle, a liquid-blocking baffle, a base, an electrolyte circulation system, a longitudinal spray fixture, a cathode graphite electrode, an insulating baffle, an anode workpiece, a DC high-frequency pulse power supply, a conductive module fixture, a clamping mechanism, and a workpiece feeding device. The device utilizes a longitudinal spray fixture to allow the electrolyte to flow longitudinally along the wire saw during machining, reducing the impact of oblique spraying on the quality of electrolytic grinding. It uses a cleaning electrolyte instead of the original highly corrosive electrolyte and positively matches the electrolytic parameters with the mechanical grinding parameters, reducing environmental pollution while improving machining accuracy and electrolytic efficiency, reducing wear and tear on machining equipment, and achieving high-quality machining.

Description

Technical Field

[0001] This invention relates to the field of electrolytic machining technology, and in particular to an electrolytic composite diamond wire saw cutting device and method for Hastelloy alloys. Background Technology

[0002] Hastelloy X is a high-temperature alloy made by smelting nickel (Ni) as the base element and adding other elements (such as chromium (Cr), iron (Fe), molybdenum (Mo), cobalt (Co)). It has the characteristics of high strength, high hardness, high corrosion resistance and excellent high-temperature mechanical properties. Therefore, it is widely used in the aerospace field. For example, aircraft blades, engine locking plates and turbine blade tenon and groove structures made of Hastelloy X are currently widely used in various spacecraft.

[0003] However, due to the high strength and hardness of Hastelloy X, traditional machining methods are difficult to apply, often resulting in low machining accuracy, high tool wear, and the presence of damaged layers. Furthermore, with the advancement of aerospace technology, the structures of various critical components on spacecraft are becoming increasingly complex and intricate, demanding even higher precision, which traditional methods struggle to meet. Wire electrolytic cutting (EED) is a machining method that uses a wire electrode as the cathode to electrolytically process the anode workpiece. Under an electrolyte atmosphere and an applied electric field, material removal is achieved through ion exchange between the cathode, anode, and electrolyte, ultimately achieving precision machining with sub-micron to nanometer-level accuracy. Moreover, due to its non-contact nature, EED is unaffected by material properties, allowing for precision machining of Hastelloy X despite its high strength and hardness. While maintaining the material's conductivity, it offers advantages such as no damaged layer, no residual stress, no heat-affected zone, and low tool wear.

[0004] Due to the passivation properties of metals, during the electrolytic wire cutting process, a film composed of passivation film and electrolytic products will be formed on the workpiece surface of the anode (Hastelloy X). This film will hinder further processing, while also protecting the processed surface from stray corrosion. Simultaneously, as electrolytic processing continues, the electrolyte within the processing area reacts continuously, causing changes in its concentration. If the electrolyte cannot be renewed, concentration polarization will occur, affecting the efficiency and accuracy of the electrolytic processing.

[0005] Currently, most electrolytes used in electrolytic machining are strong acids, strong bases, or electrolytes with strong passivating properties. These electrolytes may produce polluting products during the reaction or cause environmental pollution through waste liquid, and they also pose hazards during processing, hindering green and sustainable processing. For neutral electrolytes, NaNO3 solution is a strong passivating electrolyte, which can easily corrode and damage machine tools, fixtures, and detection modules during processing. Furthermore, NaNO3 is a potentially explosive substance and a controlled substance; improper handling can lead to danger, and its storage and use are subject to numerous restrictions. Additionally, if the solution splashes onto the operator's skin, it can cause skin damage. Although NaNO3 solution has been proven to improve processing efficiency and quality in electrolytic machining, its environmental pollution drawbacks cannot be ignored. Summary of the Invention

[0006] In view of this, the present invention provides an electrolytic composite diamond wire saw cutting device and method for Hastelloy alloys, which improves processing accuracy and electrolytic efficiency, reduces wear and tear on processing equipment, and reduces environmental pollution.

[0007] In a first aspect, the present invention provides an electrolytic composite diamond wire saw cutting device for Hastelloy alloys, the device comprising: a wire saw feeding mechanism, a side partition, a liquid-blocking partition, a base, an electrolyte circulation system, a longitudinal liquid spraying fixture, a cathode graphite electrode, an insulating partition, an anode workpiece, a DC high-frequency pulse power supply, a conductive module fixture, a clamping mechanism, and a workpiece feeding device; the wire saw feeding mechanism includes a guide wheel, a diamond wire saw, a tension wheel, a wire winding spool, and a sliding guide rail; the electrolyte circulation system includes electrolyte and an electrolyte spraying device, the electrolyte spraying device including an electric pump, a spray pipe, and an electrolyte tank, the spray pipe including a universal joint guide tube and a nozzle; the workpiece feeding device is a feeding mechanism; the side partition and the liquid-blocking partition are fixed to the base of the machine tool body by bolts.

[0008] An insulating partition is bonded between the anode workpiece and the cathode graphite electrode to ensure insulation between the anode and cathode. Before processing, the anode workpiece, insulating partition, and cathode graphite electrode are bonded together from bottom to top and stabilized by a clamping mechanism. The clamping mechanism is equipped with threaded holes, and clamping bolts are used to fix the anode workpiece, insulating partition, and cathode graphite electrode in sequence during clamping. The positive terminal of the DC high-frequency pulse power supply is connected to the anode workpiece, and its cathode is connected to the cathode graphite electrode. The wire spool drives the diamond wire saw to reciprocate, so as to cut through the diamond wire saw. The electrolyte is sprayed out through the nozzle and flows into the electrolyte tank. The electrolyte is drawn from the electrolyte tank by an electric pump and flows through the universal joint guide tube and nozzle to form a circulation loop. The electrolyte is sprayed longitudinally along the diamond wire saw to the processing area through the electrolyte spraying device and the longitudinal spraying fixture.

[0009] Optionally, the clamping mechanism consists of an upper clamping mechanism and a lower clamping mechanism. The upper clamping mechanism is detachable, and the lower clamping mechanism is bolted to the top of the feed mechanism. The top of the feed mechanism and both the upper and lower clamping mechanisms are provided with threaded holes. The upper and lower clamping mechanisms are connected by bolts, and the anode workpiece is clamped between the upper and lower clamping mechanisms using clamping bolts. The entire clamping mechanism moves with the feed mechanism.

[0010] Optionally, the feed mechanism consists of a ball screw and nut pair, a displacement control module, and a displacement measuring element. Its housing is made of aluminum alloy, covered with a leather sheath, and painted. A force measuring element is installed in the feed mechanism to detect the numerical change trend of the grinding force. A CNC module and a manual fine-tuning knob are set in the feed mechanism to allow for simultaneous software-controlled feed and manual adjustment. The displacement accuracy of the feed mechanism is greater than or equal to 1μm, and the feed speed range is 1μm / s-10μm / s.

[0011] Optionally, the conductive module fixture consists of an end cap, a first fixture body, fixture bolts, and a pad; the conductive module fixture has a threaded hole at the top and a base plate at the bottom; the pad is connected to the first fixture body through the threaded hole and the fixture bolts, and the spacing is adjusted by rotating the fixture bolts to clamp the conductive module, while the conductive module fixture is used for conducting electricity; the conductive module consists of an anode workpiece, an insulating partition, and a cathode graphite electrode in sequence.

[0012] Optionally, the longitudinal spraying fixture includes a second fixture body, a liquid inlet, a liquid guide tube, and a longitudinal spraying wire groove; one side of the longitudinal spraying fixture is provided with a threaded hole and connected to a pneumatic connector, the other end of which is connected to the spraying tube, and the electrolyte flows into the fixture along with the pneumatic connector; the other side of the longitudinal spraying fixture is provided with a deep groove with a diameter of 2mm to place the moving diamond wire saw; the interior of the longitudinal spraying fixture is designed with two axially symmetrical liquid guide tubes, the outlets of which are located on both sides of the deep groove and inclined downward at 45°.

[0013] Optionally, the diamond wire saw has a wire diameter ranging from 0.125mm to 0.25mm, a wire feed speed ranging from 0m / s to 15m / s, and a tension range of 19N to 22N; the side baffles and liquid baffles are made of acrylic with a thickness ranging from 2mm to 3mm; the insulating baffles have a thickness ranging from 0.5mm to 1mm and are made of glass or insulating plastic.

[0014] Secondly, the present invention provides a method for electrolytic composite diamond wire saw cutting of Hastelloy alloys, the method comprising:

[0015] Step 1: Adhere the anode workpiece, insulating partition, and cathode graphite electrode together, and fix them to the clamping mechanism using a conductive module clamp; connect the positive terminal of the DC high-frequency pulse power supply to the anode workpiece, and connect the cathode of the DC high-frequency pulse power supply to the cathode graphite electrode; spray the electrolyte longitudinally onto the diamond wire saw through the spray pipe and longitudinal spray clamp, and control the flow rate and velocity of the electrolyte spray through the electrolyte tank; turn on the wire winding drum to make it rotate cyclically, driving the diamond wire saw to reciprocate the wire feeding motion; set the tension wheel to the tensioned state; set the mechanical grinding parameters of the feed mechanism to make it move in the X / Y direction to drive the anode workpiece to feed; turn on the DC high-frequency pulse power supply and adjust the electrical discharge machining parameters;

[0016] Step 2: Based on the settings in Step 1, process the anode workpiece, and adjust the electrical discharge machining parameters and machining parameters; when the processing progress reaches 50%, pause the processing of the anode workpiece; use hot melt adhesive and paraffin wax to bond the processed surface, and then continue processing the anode workpiece;

[0017] Step 3: After completing the machining of the anode workpiece in Step 2, the diamond wire saw continues to reciprocate for 1 minute, then stops the movement of the feed mechanism and the delivery of electrolyte, turns off the DC high-frequency pulse power supply, cleans the workpiece and cleans the device.

[0018] Optionally, the electrolyte is a binary electrolyte prepared by combining a potassium dihydrogen phosphate solution (KH₂PO₄) of 1.3 mol / L to 1.5 mol / L and a potassium chloride solution (KCl) of 0.3 mol / L to 0.6 mol / L.

[0019] The technical solution provided by this invention includes a wire saw feeding mechanism, a side partition, a liquid-blocking partition, a base, an electrolyte circulation system, a longitudinal spray fixture, a cathode graphite electrode, an insulating partition, an anode workpiece, a DC high-frequency pulse power supply, a conductive module fixture, a clamping mechanism, and a workpiece feeding device. This device constructs a conductive module by bonding the cathode graphite electrode, the insulating partition, and the anode workpiece together, and uses an electrolyte spray method in the processing area to achieve circuit conductivity during diamond wire saw electrolytic grinding wire cutting. The longitudinal spray fixture allows the electrolyte to flow longitudinally along the wire saw during processing, reducing the impact of oblique spraying on the electrolytic grinding quality. Using a cleaning electrolyte instead of the original highly corrosive electrolyte and positively matching the electrolytic parameters with the mechanical grinding parameters reduces environmental pollution while improving processing accuracy and electrolytic efficiency, reducing wear and tear on processing equipment, and achieving high-quality processing. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, 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.

[0021] Figure 1 This is a structural diagram of the electrolytic composite diamond wire saw cutting device provided in an embodiment of the present invention;

[0022] Figure 2 A partial view of the electrolytic composite diamond wire saw cutting device provided in an embodiment of the present invention;

[0023] Figure 3 This is a structural diagram of the conductive module fixture provided in an embodiment of the present invention;

[0024] Figure 4a This is a schematic diagram of a longitudinal spraying fixture provided in an embodiment of the present invention;

[0025] Figure 4b A perspective view of the longitudinal spraying fixture provided in an embodiment of the present invention;

[0026] Figure 5 The electrochemical polarization curves provided in the embodiments of the present invention;

[0027] Figure 6a This is a schematic diagram of a workpiece being processed according to an embodiment of the present invention;

[0028] Figure 6b This is a schematic diagram of the workpiece surface provided in an embodiment of the present invention.

[0029] In the diagram: 1-Wire guide wheel; 2-Side partition; 3-Diamond wire saw; 4-Liquid baffle; 5-Tension wheel; 6-Wire winding spool; 7-Sliding guide rail; 8-Base; 9-Spray pipe; 10-Longitudinal spray clamp; 101-Second clamp body; 102-Liquid inlet; 103-Liquid guide pipe; 104-Longitudinal spray line groove; 11-Cathode graphite electrode; 12-Insulating partition; 13-Anode workpiece; 14-DC high-frequency pulse power supply; 15-Conductive module clamp; 151-End cap; 152-First clamp body; 153-Clamp bolt; 154-Padded block; 16-Upper part of clamping mechanism; 17-Lower part of clamping mechanism; 18-Feeding mechanism; 19-Circulating electrolyte tank; Clamp bolt 20. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0031] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0032] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in the embodiments of this invention are also intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0034] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0035] Figure 1 The structural diagram of the electrolytic composite diamond wire saw cutting device provided in the embodiment of the present invention is as follows: Figure 1As shown, the device includes: a wire saw feeding mechanism, a side partition 2, a liquid-blocking partition 4, a base 8, an electrolyte circulation system, a longitudinal spraying fixture 10, a cathode graphite electrode 11, an insulating partition 12, an anode workpiece 13, a DC high-frequency pulse power supply 14, a conductive module fixture 15, a clamping mechanism, and a workpiece feeding device; the wire saw feeding mechanism includes a guide wheel 1, a diamond wire saw 3, a tension wheel 5, a wire winding spool 6, and a sliding guide rail 7; the electrolyte circulation system includes electrolyte and an electrolyte spraying device, the electrolyte spraying device includes an electric pump, a spray pipe 9, and an electrolyte tank 19, the spray pipe 9 includes a universal joint guide tube and a nozzle; the workpiece feeding device is a feeding mechanism 18; the side partition 2 and the liquid-blocking partition 4 are fixed to the base 8 of the machine tool body by bolts.

[0036] An insulating partition 12 is bonded between the anode workpiece 13 and the cathode graphite electrode 11 to ensure insulation between the anode and cathode. Before processing, the anode workpiece 13, insulating partition 12, and cathode graphite electrode 11 are bonded together from bottom to top and stabilized by a clamping mechanism. The clamping mechanism is provided with threaded holes. During clamping, the anode workpiece 13, insulating partition 12, and cathode graphite electrode 11 are fixed in sequence by clamping bolts 20. The positive terminal of the DC high-frequency pulse power supply 14 is connected to the anode workpiece 13, and its cathode is connected to the cathode graphite electrode 11. The wire winding drum 6 drives the diamond wire saw 3 to reciprocate to cut through the diamond wire saw 3. The electrolyte is sprayed out through the nozzle and flows into the electrolyte tank 19. The electrolyte is drawn from the electrolyte tank 19 by an electric pump and flows through the universal joint guide tube and nozzle to form a circulation loop. The electrolyte spraying device and the longitudinal spraying fixture 10 spray the electrolyte longitudinally along the diamond wire saw 3 to the processing area.

[0037] In this embodiment of the invention, the lateral baffle 2 and the liquid-blocking baffle 4 effectively prevent electrolyte splashing and thus prevent corrosion damage to the machine tool; the circulation loop continuously sprays electrolyte into the processing area, maintaining the stability of the electrolyte atmosphere during the processing. The positive terminal of the DC high-frequency pulse power supply 14 is connected to the anode workpiece 13, and its cathode is connected to the cathode graphite electrode 11. An ammeter and a current detection module are connected in the circuit. By measuring the magnitude of the inter-electrode current and the number of short circuits during the electrolysis process, the processing quality and stability of the electrolytic grinding wire EDM are controlled.

[0038] In this embodiment of the invention, during the processing, electrolyte is sprayed onto the processing area, and the worktable drives the workpiece to feed. When the diamond wire saw 3 begins to cut the anode workpiece 13 and the cathode graphite electrode 11, current flows through the anode workpiece 13, the diamond wire saw 3, and the cathode graphite electrode 11 to form a circuit, thereby achieving the purpose of making the anode workpiece 13 conductive. At this time, the diamond wire saw 3 performs electrolytic wire cutting on the anode workpiece 13 and generates a passivation film on the surface. Simultaneously, the grinding action of the diamond wire saw 3 removes the passivation film in the feed direction, allowing the electrolytic grinding wire cutting process to continue.

[0039] In embodiments of the present invention, such as Figure 2 As shown, the clamping mechanism consists of two parts: an upper clamping mechanism 16 and a lower clamping mechanism 17. The upper clamping mechanism 16 is detachable, and the lower clamping mechanism 17 is bolted to the top of the feed mechanism 18. The top of the feed mechanism 18 and both the upper clamping mechanism 16 and the lower clamping mechanism 17 are provided with threaded holes. The upper clamping mechanism 16 and the lower clamping mechanism 17 are connected by bolts, and the anode workpiece 13 is clamped between the upper clamping mechanism 16 and the lower clamping mechanism 17 by clamping bolts 20. The entire clamping mechanism moves with the feed mechanism 18, ensuring the accuracy of movement and the horizontality of the device.

[0040] In this embodiment of the invention, the feed mechanism 18 consists of a ball screw and nut pair, a displacement control module, and a displacement measuring element. Its outer shell is made of aluminum alloy, covered with a leather sheath, and painted. A force measuring element is installed in the feed mechanism 18 to detect the numerical change trend of the grinding force. A CNC module and a manual fine-tuning knob are provided in the feed mechanism 18 to allow for simultaneous software-controlled feed and manual adjustment. The displacement accuracy of the feed mechanism 18 is greater than or equal to 1 μm, and the feed speed selection range is 1 μm / s-10 μm / s.

[0041] In this embodiment of the invention, the housing of the feed mechanism 18 is made of aluminum alloy, covered with a leather sheath and painted to resist the corrosive effect of the electrolyte on the device during processing. By controlling the magnitude of the grinding force, the feed mechanism 18 can ultimately control the service life and final processing quality of the diamond wire saw 3.

[0042] In embodiments of the present invention, such as Figure 3 As shown, the conductive module clamp 15 consists of an end cap 151, a first clamp body 152, clamp bolts 153, and a pad 154. The conductive module clamp 15 has a threaded hole at the top and a base plate at the bottom to increase the clamping area and thus ensure clamping stability. The pad 154 is connected to the first clamp body 152 through the threaded hole and the clamp bolts 153, and the spacing is adjusted by rotating the clamp bolts 153 to clamp the conductive module. At the same time, the conductive module clamp 15 is used for conducting electricity. The conductive module consists of an anode workpiece 13, an insulating partition 12, and a cathode graphite electrode 11 in sequence.

[0043] In this embodiment of the invention, the conductive module clamp 15 not only serves to conduct electricity, but also reduces the difficulty of installing the current loop.

[0044] In embodiments of the present invention, such as Figure 4a and Figure 4bAs shown, the longitudinal spraying fixture 10 includes a second fixture body 101, a liquid inlet 102, a liquid guide pipe 103, and a longitudinal spraying groove 104. One side of the longitudinal spraying fixture 10 is provided with a threaded hole and connected to a pneumatic connector. The other end of the pneumatic connector is connected to the spraying pipe 9, and the electrolyte flows into the fixture along with the pneumatic connector. The other side of the longitudinal spraying fixture 10 is provided with a deep groove with a diameter of 2 mm to place the moving diamond wire saw 3. The longitudinal spraying fixture 10 is designed with two axially symmetrical liquid guide pipes 103 inside. The outlet of the liquid guide pipes 103 is located on both sides of the deep groove and is inclined downward at 45°.

[0045] In this embodiment of the invention, the longitudinal spraying fixture 10 is manufactured by 3D printing, and the material used is acrylic. The overall volume of the fixture is less than 30mm*20mm*15mm.

[0046] During the machining process, the diamond wire saw 3, the spray pipe 9, and the longitudinal spray fixture 10 do not move. Only the feed mechanism 18 moves the anode workpiece 13. Therefore, the diamond wire saw 3 will not damage the longitudinal spray fixture 10. The liquid guide pipe 103 is inclined downwards at 45° to eliminate the axial momentum brought by the spray and to ensure that the electrolyte flows longitudinally with the wire saw. This eliminates the adverse effects of stray corrosion and excessive electrolysis on one side of the cut caused by the direct oblique spray from the spray pipe 9. By modifying the longitudinal spray fixture 10, the electrolyte can be updated in a timely manner during the machining process. The electrolyte flow rate between the electrodes is uniform, the concentration gradient distribution is reasonable, the current density is at an appropriate level, and the generated passivation film structure is dense, which is beneficial to the machining accuracy of electrolytic grinding wire EDM.

[0047] In this embodiment of the invention, the diamond wire saw 3 has a wire diameter ranging from 0.125mm to 0.25mm, a wire feed speed ranging from 0m / s to 15m / s, and a tension range of 19N to 22N; the side baffle 2 and the liquid-blocking baffle 4 are both made of acrylic with a thickness ranging from 2mm to 3mm; the insulating baffle 12 has a thickness ranging from 0.5mm to 1mm and is made of glass or insulating plastic.

[0048] In this embodiment of the invention, an electrolytic composite diamond wire saw cutting method for Hastelloy alloys is provided, the method comprising:

[0049] Step 1: Adhere the anode workpiece 13, insulating partition 12, and cathode graphite electrode 11 together, and fix them to the clamping mechanism using conductive module clamp 15; connect the positive terminal of the DC high-frequency pulse power supply 14 to the anode workpiece 13, and connect the cathode of the DC high-frequency pulse power supply 14 to the cathode graphite electrode 11; spray the electrolyte longitudinally onto the diamond wire saw 3 through the spray pipe 9 and longitudinal spray clamp 10, and control the flow rate and velocity of the electrolyte spray through the electrolyte tank 19; turn on the wire winding drum 6 to make it rotate cyclically, driving the diamond wire saw 3 to reciprocate the wire feeding motion; set the tension wheel 5 to be in a tensioned state; set the mechanical grinding parameters of the feed mechanism 18 to make it move in the X / Y direction to drive the anode workpiece 13 to feed; turn on the DC high-frequency pulse power supply 14 and adjust the electrical discharge machining parameters.

[0050] Step 2: Based on the settings in Step 1, process the anode workpiece 13, and adjust the electrical discharge machining parameters and machining parameters; when the processing progress reaches 50%, pause the processing of the anode workpiece 13; use hot melt adhesive and paraffin to bond the processed surface, and then continue processing the anode workpiece 13.

[0051] In this embodiment of the invention, hot melt adhesive and paraffin wax are used to bond the processed surface, preventing it from falling off and protecting the processed surface from stray corrosion.

[0052] Step 3: After completing the processing of the anode workpiece 13 in Step 2, the diamond wire saw 3 continues to reciprocate for 1 minute, then stops the movement of the feed mechanism 18 and the delivery of electrolyte, turns off the DC high-frequency pulse power supply 14, cleans the workpiece and cleans the device.

[0053] In this embodiment of the invention, the electrolyte is a binary electrolyte prepared by combining a potassium dihydrogen phosphate solution (KH2PO4) of 1.3 mol / L to 1.5 mol / L and a potassium chloride solution (KCl) of 0.3 mol / L to 0.6 mol / L.

[0054] In this embodiment of the invention, the voltage range during processing is 8V-9V, the pulse frequency range is 20kHz-25kHz, and the duty cycle range is 20%-30%.

[0055] In this embodiment of the invention, the modified electrolytic composite diamond wire saw cutting device is controlled by this method to obtain the processing procedure, which can meet the requirements of clean processing for electrolytic grinding wire cutting of diamond wire saws. In the electrolytic grinding wire cutting process of Hastelloy X alloy, the electrolytic processing accounts for approximately 90%, and the mechanical grinding process accounts for approximately 10%. The mechanical grinding process mainly serves to remove the passivation film generated in the feed direction of the cathode wire saw during the electrolytic processing; the removal of material during the processing mainly relies on the electrolytic processing.

[0056] In this embodiment of the invention, a clean electrolyte is used as the environmental atmosphere for electrolytic processing, including using a weakly acidic potassium dihydrogen phosphate solution (KH₂PO₄) instead of a neutral sodium nitrate (NaNO₃) solution. The KH₂PO₄ solution used is widely used in daily life; it is a practical fertilizer currently widely applied in agricultural planting. Using a clean electrolyte for electrolytic processing does not harm the environment or processing personnel, making it a safe and environmentally friendly electrolytic processing method.

[0057] In this embodiment of the invention, to achieve the same or even better processing effect as traditional electrolytes, the concentration and component ratio of the electrolyte need to be modified and optimized. In electrochemical processing, the conductivity of the electrolyte determines the superiority of the solution's electrical conductivity. The aforementioned non-clean electrolytes, as typical electrolytes used in electrochemical processing, exhibit excellent conductivity. For example, a NaNO3 solution with a concentration of 1 mol / L and a temperature of 25°C has a conductivity of 160.6 mS / cm. Under the same conditions, a 1 mol / L KH2PO4 solution has a conductivity of 127.6 mS / cm. Analyzing the conductivity values, clean electrolytes have weaker conductivity than traditional electrolytes, resulting in poorer performance when used as electrolytes in electrochemical processing. To eliminate the influence of conductivity, the concentration of the KH₂PO₄ solution needs to be increased. During use, a binary electrolyte solution consisting of 1.3-1.5 mol / L KH₂PO₄ and 0.3-0.4 mol / L KCl solution should be prepared for electrolytic machining. Related studies have shown that the ion concentration in the electrolyte affects the formation rate and density of the passivation film on the Hastelloy X alloy during electrolytic grinding wire EDM. To prevent secondary corrosion caused by stray current during electrolytic grinding wire EDM, which would degrade the surface quality, the ion concentration in the solution must be maintained within a certain range. This ensures the formation rate and density of the passivation film on the Hastelloy X alloy surface, thus protecting the machined surface during the electrolytic grinding wire EDM process.

[0058] In this embodiment of the invention, the electrochemical polarization curve of Hastelloy X in the binary electrolyte of the present invention is as follows: Figure 5As shown, Hastelloy X exhibits a significant passivation region in a binary electrolyte solution composed of a 1.5 mol / L KH₂PO₄ solution and a 0.4 mol / L KCl solution. When the voltage is between 0.1V and 1.2V, the surface of Hastelloy X remains passivated, forming a passivation film and resulting in a decrease in current density. This demonstrates the existence of a distinct passivation region for Hastelloy X in the binary electrolyte solution. Under suitable processing parameters, this binary electrolyte solution can meet the cleaning requirements for diamond wire saw electrolytic grinding and wire cutting using Hastelloy X.

[0059] During electrochemical machining, the current density within the micro-machining region between the anode and cathode significantly affects the machining quality. Too low a current density results in low material removal; too high a current density leads to over-passivation, causing the passivation film to rupture. Furthermore, excessive current density can also cause passivation film rupture and stray corrosion, degrading the surface quality of the machined surface. Therefore, it is crucial to control the inter-electrode current density during machining. The machining parameters are shown in Table 1.

[0060] Table 1

[0061]

[0062] The matching of electrolysis parameters and grinding parameters during the machining process will affect the final machining quality of the workpiece. Excessive electrolysis parameters will lead to stray corrosion and poor forming accuracy, while excessive grinding parameters will result in surface scratches and a damaged layer, causing a decrease in machining accuracy. Therefore, it is necessary to adjust the electrolysis parameters and grinding parameters to achieve a proper match during machining, ensuring that the thickness of the passivation film generated by electrolysis is equal to the feed distance during wire saw grinding, and guaranteeing an appropriate inter-electrode current density to eliminate the impact of stray corrosion on the machined surface. Under the premise of the electrolysis parameters specified above, the specific grinding parameter values ​​are shown in Table 2.

[0063] Table 2

[0064]

[0065] An electrolyte spraying device circuit is equipped with a flow detection module to check the electrolyte spray velocity during the processing and to regulate the electrolyte flow rate, adjust the flow field gradient between the anode and cathode, and reduce the negative impact of concentration polarization on electrolytic grinding wire cutting.

[0066] In embodiments of the present invention, such as Figure 6a As shown, the pentagram is an inscribed pentagram with a radius of 1 mm; as Figure 6b As shown, its surface roughness parameters are: Ra value is 0.299, and Sa value is 0.345μm.

[0067] This invention uses a diamond wire saw 3 as a cathode machining tool to electrolytically erode the Hastelloy X workpiece in the machining area under a clean electrolyte atmosphere, thereby achieving electrolytic wire cutting of the workpiece; the reciprocating diamond wire saw mechanically grinds away the passivation film generated on the surface of the Hastelloy X workpiece during the electrolytic machining process at a certain feed speed, thereby eliminating the obstructive effect of the passivation film on the electrolytic wire cutting process.

[0068] This invention is applicable to the processing requirements of Hastelloy X alloy, helps to improve the stability of the processing, ensures processing quality while being environmentally friendly, and can be widely used in the precision special processing of Hastelloy X alloy.

[0069] Compared with the prior art, the present invention has the following beneficial effects:

[0070] 1. This invention applies electrolytic grinding wire cutting technology to Hastelloy X alloy for precision special machining. Compared with traditional electrical discharge wire cutting, electrolytic grinding wire cutting has advantages such as no heat-affected zone, low residual stress, no hot recast layer, and high machining accuracy. Compared with diamond wire sawing, it has advantages such as low grinding force, low tool electrode wear, and less demanding material performance requirements. It also has significant advantages in terms of machining accuracy, material utilization, equipment size, and environmental pollution control.

[0071] 2. This invention designs a modification scheme for electrolytic grinding wire EDM equipment used with Hastelloy X alloy, which helps to improve the surface quality, cathode tool life and processing stability of electrolytic grinding. The modification of workpiece conductivity is simple, easy to install and clamp stably, with minimal impact on processing accuracy and no damage to the machine tool body. At the same time, the machine tool spraying method is modified by installing a longitudinal spraying fixture to reduce the impact of stray corrosion caused by oblique spraying on workpiece processing accuracy and ensure uniform distribution and real-time updating of electrolyte between electrodes during processing.

[0072] 3. This invention uses a clean electrolyte instead of traditional strong passivation or corrosive electrolytes. A binary electrolyte, consisting of a 1.3 mol / L-1.5 mol / L KH₂PO₄ solution and a 0.3 mol / L-0.4 mol / L KCl solution, is used instead of NaNO₃ solution, achieving clean electrolytic grinding wire EDM. Simultaneously, the parameter range for diamond wire saw electrolytic grinding wire EDM with the clean electrolyte has been calibrated, achieving a perfect match for the process. While ensuring machining accuracy and surface quality, this invention achieves the goals of minimal environmental pollution and low harm to machine tools and operators. Furthermore, the electrolyte is easily recyclable after processing, reducing processing costs.

[0073] 4. In the modification scheme of the diamond wire saw electrolytic grinding wire cutting processing device provided by this invention, the dimensions of each component can be modified according to actual processing needs, expanding the scope of application and optimizing the spatial distribution of the equipment. Based on the above advantages, this disclosure can be widely applied to the processing of high-quality gear involute templates.

[0074] The technical solution provided by this invention includes a wire saw feeding mechanism, a side partition, a liquid-blocking partition, a base, an electrolyte circulation system, a longitudinal spray fixture, a cathode graphite electrode, an insulating partition, an anode workpiece, a DC high-frequency pulse power supply, a conductive module fixture, a clamping mechanism, and a workpiece feeding device. This device constructs a conductive module by bonding the cathode graphite electrode, the insulating partition, and the anode workpiece together, and uses an electrolyte spray method in the processing area to achieve circuit conductivity during diamond wire saw electrolytic grinding wire cutting. The longitudinal spray fixture allows the electrolyte to flow longitudinally along the wire saw during processing, reducing the impact of oblique spraying on the electrolytic grinding quality. Using a cleaning electrolyte instead of the original highly corrosive electrolyte and positively matching the electrolytic parameters with the mechanical grinding parameters reduces environmental pollution while improving processing accuracy and electrolytic efficiency, reducing wear and tear on processing equipment, and achieving high-quality processing.

[0075] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0076] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electrolytic composite diamond wire saw cutting device for Hastelloy alloys, characterized in that, The device includes: a wire saw feeding mechanism, a side partition (2), a liquid-blocking partition (4), a base (8), an electrolyte circulation system, a longitudinal spraying fixture (10), a cathode graphite electrode (11), an insulating partition (12), an anode workpiece (13), a DC high-frequency pulse power supply (14), a conductive module fixture (15), a clamping mechanism, and a workpiece feeding device; the wire saw feeding mechanism includes a guide wheel (1), a diamond wire saw (3), a tension wheel (5), a wire winding spool (6), and a sliding guide rail (7); the electrolyte circulation system includes an electrolyte and an electrolyte spraying device, the electrolyte spraying device includes an electric pump, a spray pipe (9), and an electrolyte tank (19), the spray pipe (9) includes a universal joint guide tube and a nozzle; the workpiece feeding device is a feeding mechanism (18); the side partition (2) and the liquid-blocking partition (4) are fixed to the base (8) of the machine tool base by bolts; An insulating partition (12) is bonded between the anode workpiece (13) and the cathode graphite electrode (11) to ensure insulation between the anode and cathode. Before processing, the anode workpiece (13), insulating partition (12), and cathode graphite electrode (11) are bonded together from bottom to top and stabilized by a clamping mechanism. The clamping mechanism is provided with threaded holes. During clamping, the anode workpiece (13), insulating partition (12), and cathode graphite electrode (11) are fixed in sequence by clamping bolts (20). DC high-frequency pulse power supply ( The positive electrode of 14) is connected to the anode workpiece (13), and its cathode is connected to the cathode graphite electrode (11); the wire winding drum (6) drives the diamond wire saw (3) to reciprocate to cut through the diamond wire saw (3); the electrolyte is sprayed out through the nozzle and flows into the electrolyte tank (19), and the electrolyte is drawn from the electrolyte tank (19) by the electric pump, and flows through the universal joint guide tube and the nozzle to form a circulation loop; the electrolyte spraying device and the longitudinal spraying fixture (10) spray the longitudinal flow of the diamond wire saw (3) to the processing area.

2. The electrolytic composite diamond wire saw cutting device according to claim 1, characterized in that, The clamping mechanism consists of two parts: the upper end (16) and the lower end (17). The upper end (16) is detachable, and the lower end (17) is bolted to the top of the feed mechanism (18). The top of the feed mechanism (18) and both the upper end (16) and the lower end (17) of the clamping mechanism are provided with threaded holes. The upper end (16) and the lower end (17) of the clamping mechanism are connected by bolts, and the anode workpiece (13) is clamped between the upper end (16) and the lower end (17) of the clamping mechanism by clamping bolts (20). The entire clamping mechanism moves with the feed mechanism (18).

3. The electrolytic composite diamond wire saw cutting device according to claim 1, characterized in that, The feed mechanism (18) consists of a ball screw and nut pair, a displacement control module, and a displacement measuring element. Its outer shell is made of aluminum alloy, covered with a leather sheath, and painted. A force measuring element is installed in the feed mechanism (18) to detect the numerical change trend of the grinding force. A CNC module and a manual fine-tuning knob are provided in the feed mechanism (18) to allow for simultaneous software-controlled feed and manual adjustment. The displacement accuracy of the feed mechanism (18) is greater than or equal to 1 μm, and the feed speed selection range is 1 μm / s. 10μm / s.

4. The electrolytic composite diamond wire saw cutting device according to claim 1, characterized in that, The conductive module clamp (15) consists of an end cap (151), a first clamp body (152), a clamp bolt (153), and a pad (154). The conductive module clamp (15) has a threaded hole at the top and a base plate at the bottom. The pad (154) is connected to the first clamp body (152) through the threaded hole and the clamp bolt (153), and the spacing is adjusted by rotating the clamp bolt (153) to clamp the conductive module. At the same time, the conductive module clamp (15) is used to conduct electricity. The conductive module consists of an anode workpiece (13), an insulating partition (12), and a cathode graphite electrode (11) in sequence.

5. The electrolytic composite diamond wire saw cutting device according to claim 1, characterized in that, The longitudinal spray fixture (10) includes a second fixture body (101), a liquid inlet (102), a liquid guide pipe (103), and a longitudinal spray groove (104). The longitudinal spray fixture (10) has a threaded hole on one side and is connected to a pneumatic connector. The other end of the pneumatic connector is connected to the spray pipe (9), and the electrolyte flows into the fixture along with the pneumatic connector. The other side of the longitudinal spray fixture (10) has a deep groove with a diameter of 2 mm to place the moving diamond wire saw (3). The longitudinal spray fixture (10) has two axially symmetrical liquid guide pipes (103) inside. The outlet of the liquid guide pipe (103) is located on both sides of the deep groove and is inclined downward at 45°.

6. The electrolytic composite diamond wire saw cutting device according to claim 1, characterized in that, The diamond wire saw (3) has a wire diameter range of 0.125mm-0.25mm, a wire feed speed range of 0m / s-15m / s, and a tension range of 19N-22N. The side baffle (2) and the liquid baffle (4) are made of acrylic with a thickness range of 2mm-3mm. The insulating baffle (12) has a thickness range of 0.5mm-1mm and is made of glass or insulating plastic.

7. A method for electrolytic composite diamond wire saw cutting of Hastelloy alloys, characterized in that, The method includes: Step 1: Adhere the anode workpiece (13), insulating partition (12), and cathode graphite electrode (11) together, and fix them on the clamping mechanism with conductive module clamp (15); connect the positive terminal of DC high-frequency pulse power supply (14) to the anode workpiece (13), and connect the cathode of DC high-frequency pulse power supply (14) to the cathode graphite electrode (11); spray the electrolyte longitudinally onto the diamond wire saw (3) through the spray pipe (9) and longitudinal spray clamp (10), and control the flow rate and velocity of the electrolyte spray through the electrolyte tank (19); turn on the wire winding drum (6) to make it rotate in a cycle, driving the diamond wire saw (3) to reciprocate the wire feeding motion; set the tension wheel (5) to be in a tensioned state; set the mechanical grinding parameters of the feed mechanism (18) to make it move in the X / Y direction to drive the anode workpiece (13) to feed; turn on the DC high-frequency pulse power supply (14) and adjust the electrical discharge machining parameters; Step 2: Based on the settings in Step 1, process the anode workpiece (13), and adjust the electrical discharge machining parameters and mechanical machining parameters; when the processing progress reaches 50%, pause the processing of the anode workpiece (13); use hot melt adhesive and paraffin wax to bond the processed surface, and then continue to process the anode workpiece (13); Step 3: After completing the processing of the anode workpiece (13) in step 2, the diamond wire saw (3) continues to reciprocate for 1 minute, then stops the movement of the feed mechanism (18) and the delivery of electrolyte, turns off the DC high-frequency pulse power supply (14), cleans the workpiece and cleans the device.

8. The electrolytic composite diamond wire saw cutting method according to claim 7, characterized in that, The electrolyte is a binary electrolyte prepared by combining a 1.3 mol / L to 1.5 mol / L potassium dihydrogen phosphate (KH2PO4) solution with a 0.3 mol / L to 0.6 mol / L potassium chloride (KCl) solution.

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