Titanium-steel composite plate small hole electrolytic electric spark combined machining device and method

Abstract

This invention belongs to the field of electrolytic machining equipment and process technology, and provides an electrolytic electrical discharge machining (EDM) device and method for small-hole machining of titanium-steel composite plates. The device includes a clamping assembly with a fastening fixture for clamping the titanium-steel composite plate, the fastening fixture having a vertical adjustment mechanism for adjusting its height; a hole forming assembly with a first and second tube electrode, located on opposite sides of the titanium-steel composite plate, the first tube electrode being positioned closer to the titanium side and the second tube electrode closer to the steel side, each with a lateral adjustment mechanism for adjusting the horizontal distance between itself and the titanium-steel composite plate; and an electrolyte circulation device including a supply tank, with the first and second tube electrodes connected to the supply tank via two sets of electrolyte connecting pipes. This invention is adaptable to the characteristics of titanium-steel composite plates and solves the problems of recast layer defects and hole diameter deviations caused by existing single EDM machining.

Description

Technical Field

[0001] This invention belongs to the field of electrolytic processing equipment and process technology, and particularly relates to an electrolytic electric spark composite processing equipment and method for small holes in titanium-steel composite plates. Background Technology

[0002] Titanium-steel composite plates are a type of composite material with unique properties and significant advantages in the field of materials engineering. Through a metallurgical composite process, they organically integrate the performance advantages of titanium and steel, retaining the excellent corrosion resistance and high strength of titanium and its compounds while also possessing the high rigidity, good plasticity, and cost-effectiveness of steel and its compounds. They have been widely used in high-end manufacturing fields such as aerospace, marine engineering, and chemical equipment.

[0003] In industrial production, titanium-steel composite plate components often require the machining of various functional hole structures. Among these, the machining quality of small holes significantly affects the performance of the components. Therefore, achieving high-precision machining of small holes in titanium-steel composite plates is not only a key step in leveraging the material's performance advantages, but also a technological foundation for expanding its applications in the field of precision equipment.

[0004] In current industry, electrical discharge machining (EDM) has become one of the important methods for machining small holes in titanium-steel composite plates due to its non-contact machining characteristics. It utilizes the localized high temperature generated by pulsed discharge to erode the material, effectively machining high-hardness, high-toughness, and conductive materials. However, this method has inherent limitations: a recast layer (i.e., a heat-affected zone) forms on the machined surface, leading to a decrease in hole wall performance; simultaneously, due to the differences in melting point (titanium 1668℃ / steel 1538℃) and thermal conductivity (titanium 21.9 W / (m·K) / steel 45 W / (m·K)), the uneven distribution of discharge energy between the two materials can cause differences in the machined hole diameter, affecting machining accuracy.

[0005] Therefore, electrical discharge machining alone cannot meet the synergistic requirements of titanium-steel composite plates in terms of processing efficiency, hole diameter consistency, surface quality, and overall cost for small holes. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for electrolytic electrical discharge machining of small holes in titanium-steel composite plates, so as to solve the problems of recast layer defects and hole diameter deviations caused by existing single electrical discharge machining.

[0007] To achieve the above objectives, the present invention provides the following solution: a device for electrolytic electrical discharge machining of small holes in titanium-steel composite plates, comprising: The clamping assembly includes a fastening clamp for clamping a titanium-steel composite plate, and the fastening clamp is provided with a vertical adjustment mechanism for adjusting the height of the fastening clamp; The hole forming assembly includes a first tube electrode and a second tube electrode. The first tube electrode and the second tube electrode are respectively located on both sides of the titanium-steel composite plate. The first tube electrode is disposed closer to the titanium side metal, and the second tube electrode is disposed closer to the steel side metal. The first tube electrode and the second tube electrode are respectively provided with a lateral adjustment mechanism for adjusting the horizontal distance between them and the titanium-steel composite plate. An electrolyte circulation device includes a supply tank, wherein the first tube electrode and the second tube electrode are respectively connected to the supply tank through two sets of electrolyte connection pipes; A processing power supply, wherein the processing power supply is used to provide pulse voltage.

[0008] Preferably, the positive terminal of the processing power supply is connected to the fastening fixture via a first positive wire, so that the titanium-steel composite plate is electrically connected to the positive terminal of the processing power supply, and the negative terminal of the processing power supply is electrically connected to the first tube electrode and the second tube electrode via a first negative wire and a second negative wire, respectively.

[0009] Preferably, the vertical adjustment mechanism includes a third rotary feed shaft, and the top of the fastening clamp is fixedly connected to the telescopic end of the third rotary feed shaft; The lateral adjustment mechanism includes a first rotary feed shaft and a second rotary feed shaft arranged horizontally. The ends of the first tube electrode and the second tube electrode away from the titanium-steel composite plate are respectively fixedly connected to the telescopic ends of the first rotary feed shaft and the second rotary feed shaft.

[0010] Preferably, the system also includes a frame, with the third rotary feed shaft vertically fixedly connected to the top of the frame, and the first and second rotary feed shafts horizontally fixedly connected to two opposite side walls of the frame.

[0011] Preferably, the liquid supply tank includes a clear liquid tank, and the ends of the two electrolyte connecting pipes away from the first tube electrode and the second tube electrode are connected to a three-way interface. A pump is provided in the clear liquid tank, and the outlet end of the pump is connected to the two electrolyte connecting pipes through the three-way interface.

[0012] Preferably, the liquid supply tank further includes a solution tank, which is located below the titanium-steel composite plate. The solution tank is connected to a turbid liquid tank through a liquid outlet opened in the side wall, and the turbid liquid tank is connected to the clear liquid tank through a filter.

[0013] Preferably, the cross-sectional shape of the inner cavity of the first tube electrode and the second tube electrode can be selected from one or more of the following shapes: circular, elliptical, or triangular. The materials of the first and second tube electrodes can be one or more combinations of pure copper, brass, or copper-tungsten alloy.

[0014] A method for electrolytic electro-spark composite machining of small holes in titanium-steel composite plates includes the following steps: The power supply for controlling the machining is electrically connected to the titanium-steel composite plate, the first tube electrode, and / or the second tube electrode. When the processing power supply is electrically connected to the titanium-steel composite plate and the first tube electrode, the processing power supply and electrolyte circulation device are started, the first tube electrode moves from the titanium side metal to the steel side metal, and after the small hole processing is completed, the processing power supply is turned off and the first tube electrode is retracted. When the machining power supply is electrically connected to the titanium-steel composite plate and the second tube electrode, the machining power supply and electrolyte circulation device are started. The second tube electrode moves from the steel side metal to the titanium side metal. After the small hole machining is completed, the machining power supply is turned off and the second tube electrode is retracted. When the processing power supply is electrically connected to the titanium-steel composite plate, the first tube electrode, and the second tube electrode, the processing power supply and electrolyte circulation device are started. The first tube electrode processes the titanium side metal, and the second tube electrode processes the steel side metal. After the small holes of the two electrodes are aligned, the processing is completed.

[0015] Preferably, when processing the power supply to connect the titanium-steel composite plate, the first tube electrode, and the second tube electrode, the feed time of the first tube electrode is t1, and the feed time of the second tube electrode is t2. If t1 < t2, the first electrode disconnects from the processing power supply and retracts; the second electrode completes processing, turns off the processing power supply, and retracts. If t1 > t2, the second tube electrode disconnects from the machining power supply and retracts; the first tube electrode completes machining, shuts off the machining power supply, and retracts. If t1=t2, turn off the machining power supply, and the first and second electrodes retract simultaneously.

[0016] Preferably, when the processing power supply is electrically connected to the titanium-steel composite plate and the first tube electrode, the parameters of the processing power supply remain unchanged; When the machining power supply is electrically connected to the titanium-steel composite plate and the second tube electrode, the pulse voltage of the machining power supply gradually increases. When the machining power supply is electrically connected to the titanium-steel composite plate, the first tube electrode, and the second tube electrode, the parameters of the machining power supply remain unchanged.

[0017] Compared with the prior art, the present invention has the following advantages and technical effects: 1. This invention comprehensively considers the material properties of titanium-steel composite plates and the precision requirements for small hole machining, proposing three machining methods and formulating corresponding process strategies. Various machine tools can utilize one or more of the machining methods and their supporting strategies from this invention to perform small hole machining on titanium-steel composite plates, significantly improving the applicability of this invention to different types of machine tools.

[0018] 2. The biaxial anisotropic feed machining method proposed in this invention can simultaneously process the titanium side and the steel side of the titanium-steel composite plate, which not only significantly improves the single-axis machining efficiency, but also solves the problem of hole diameter consistency caused by the difference in material properties.

[0019] 3. This invention is designed for composite plates with different thicknesses of titanium and steel layers. It can adjust the feed and retraction strategies of the electrodes on both sides according to the difference in material removal rates on both sides, effectively avoiding overcutting or undercutting problems that may occur during processing, and significantly improving the accuracy of small hole processing in titanium-steel composite plates.

[0020] 4. This invention addresses the material properties and small-hole machining requirements of titanium-steel composite plates by integrating electrolytic machining into electrical discharge machining (EDM), effectively eliminating the recast layer problem that occurs when EDM is used alone for titanium-steel composite plates. Furthermore, by adjusting process parameters, the hole diameter variation caused by EDM machining of small holes in titanium-steel composite plates is effectively reduced, thus improving machining accuracy. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the processing apparatus of the present invention; Figure 2 This is a schematic diagram of the geometric outline of the first tube electrode of the present invention; Figure 3 This is a schematic diagram of the geometric outline of the second tube electrode of the present invention; Figure 4 This is a schematic diagram of the single-axis machining method for the titanium side of the present invention; Figure 5 This is a schematic diagram of the single-axis machining method for the steel side of the present invention; Figure 6 This is a schematic diagram of the biaxial anisotropic machining method of the present invention; The components include: 1. First rotary feed axis; 2. Second rotary feed axis; 3. Third rotary feed axis; 4. First tube electrode; 5. Second tube electrode; 6. Frame; 7. Fastening fixture; 8. Base; 9. Solution tank; 10. Electrolyte circulation device; 11. Electrolyte connecting pipe; 12. Outlet; 13. Clear liquid tank; 14. Turbid liquid tank; 15. Filter; 16. T-junction; 17. Hollow cavity of the first tube electrode; 18. Hollow cavity of the second tube electrode; 19. Processing power supply; 20. First positive electrode wire; 21. First negative electrode wire; 22. Second negative electrode wire; 23. Titanium-steel composite plate; 24. Titanium side metal; 25. Steel side metal; 26. Titanium-steel composite plate interface; 27. Flexible hose. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] Example 1: Reference Figures 1-6 This invention provides a device for electrolytic electrical discharge machining of small holes in titanium-steel composite plates, comprising: The clamping assembly includes a fastening clamp 7, which is used to clamp the titanium-steel composite plate 23. The fastening clamp 7 is provided with a vertical adjustment mechanism for adjusting the height of the fastening clamp 7. The hole forming assembly includes a first tube electrode 4 and a second tube electrode 5. The first tube electrode 4 and the second tube electrode 5 are located on both sides of the titanium-steel composite plate 23, with the first tube electrode 4 positioned closer to the titanium side metal 24 and the second tube electrode 5 positioned closer to the steel side metal 25. The first tube electrode 4 and the second tube electrode 5 are respectively provided with a lateral adjustment mechanism for adjusting the horizontal distance between them and the titanium-steel composite plate 23. The electrolyte circulation device 10 includes a supply tank, and the first tube electrode 4 and the second tube electrode 5 are respectively connected to the supply tank through two sets of electrolyte connection pipes 11. Processing power supply 19 is used to provide pulse voltage.

[0026] The main function of the fastening fixture 7 is to vertically clamp the titanium-steel composite plate 23. The vertical adjustment mechanism can adjust the height of the titanium-steel composite plate 23 by driving the fastening fixture 7, aligning its processing position with the first tube electrode 4 or the second tube electrode 5. The main function of the horizontal adjustment mechanism is to adjust the horizontal distance between the first tube electrode 4, the second tube electrode 5 and the titanium-steel composite plate 23, while simultaneously driving the first tube electrode 4 and the second tube electrode 5 to feed or retract. The main function of the electrolyte supply tank is to supply electrolyte to the first tube electrode 4 and the second tube electrode 5. The main function of the processing power supply 19 is to connect the fastening fixture 7 and the first tube electrode 4 or the second tube electrode 5, forming a pulse voltage between the electrode and the titanium-steel composite plate 23. Overall, this invention integrates electrolytic machining into the electrical discharge machining process, effectively eliminating the recast layer problem caused by single electrical discharge machining of titanium-steel composite plates. In addition, the use of electrolytic machining effectively reduces the hole diameter difference caused by single electrical discharge machining of small holes in titanium-steel composite plates, improving processing accuracy.

[0027] In a further optimized scheme, the positive terminal of the processing power supply 19 is connected to the fastening fixture 7 through the first positive terminal wire 20, so that the titanium steel composite plate 23 is electrically connected to the positive terminal of the processing power supply 19, making the titanium steel composite plate 23 the anode. The negative terminal of the processing power supply 19 is electrically connected to the first tube electrode 4 and the second tube electrode 5 through the first negative terminal wire 21 and the second negative terminal wire 22, respectively.

[0028] The scheme is further optimized. The vertical adjustment mechanism includes a third rotary feed shaft 3, and the top of the fastening clamp 7 is fixedly connected to the telescopic end of the third rotary feed shaft 3. The lateral adjustment mechanism includes a horizontally arranged first rotary feed shaft 1 and a second rotary feed shaft 2. The ends of the first tube electrode 4 and the second tube electrode 5 away from the titanium-steel composite plate 23 are respectively fixedly connected to the telescopic ends of the first rotary feed shaft 1 and the second rotary feed shaft 2.

[0029] In this embodiment, the first negative electrode wire 21 and the second negative electrode wire 22 are respectively connected to the first rotary feed shaft 1 and the second rotary feed shaft 2, thereby making the first tube electrode 4 or the second tube electrode 5 the cathode.

[0030] Further optimization of the scheme also includes a frame 6, with the third rotary feed shaft 3 vertically fixedly connected to the top of the frame 6, and the first rotary feed shaft 1 and the second rotary feed shaft 2 horizontally fixedly connected to the two opposite side walls of the frame 6.

[0031] To further optimize the solution, in this embodiment, the fastening clamp 7 is made of one or more combinations of sintered NdFeB, SmCo, and AlNiCo. When the steel side metal 25 of the titanium-steel composite plate 23 is made of magnetic materials such as ordinary carbon steel, low alloy steel, or cast iron, the titanium-steel composite plate 23 can be directly adsorbed onto the fastening clamp 7. When the steel side metal 25 of the titanium-steel composite plate is made of non-magnetic materials such as high-nickel austenitic stainless steel, high-manganese non-magnetic structural steel, or Fe-Cr-Mn-N non-magnetic stainless steel, conventional bolts and locating pins are required for installation and positioning with the fastening clamp 7.

[0032] The solution is further optimized. The liquid supply tank includes a clear liquid tank 13. The end of the two electrolyte connecting pipes 11 away from the first tube electrode 4 and the second tube electrode 5 is connected to a three-way interface 16. A pump is installed in the clear liquid tank 13. The outlet end of the pump is connected to the two electrolyte connecting pipes 11 through the three-way interface 16.

[0033] In a further optimized design, the liquid supply tank also includes a solution tank 9, which is located below the titanium-steel composite plate 23. The solution tank 9 is connected to a turbid liquid tank 14 through a liquid outlet 12 opened on the side wall. The turbid liquid tank 14 is connected to a clear liquid tank 13 through a filter 15.

[0034] In this embodiment, the main function of the filter 15 is to filter the turbid electrolyte in the turbid liquid tank 14 into a clean electrolyte that meets the processing requirements. The clear liquid tank 13 is connected to the first tube electrode cavity 17 in the first tube electrode 4 and the second tube electrode cavity 18 in the second tube electrode 5 via the electrolyte connecting pipe 11 after passing through the three-way interface 16. The turbid liquid tank 14 is connected to the outlet 12 on the lower side of the solution tank 9. The main function of the solution tank 9 is to collect the electrolyte generated during the processing.

[0035] In a further optimized design, a base 8 is fixedly connected to the bottom inner side of the frame 6, and a solution tank 9 is placed on the base 8. The position of the solution tank 9 is higher than that of the turbid liquid tank 14 so that the electrolyte can flow from the solution tank 9 to the turbid liquid tank 14.

[0036] Further optimize the plan, such as Figure 2 and Figure 3 As shown, the cross-sectional shape of the hollow cavity 17 and the hollow cavity 18 of the first tube electrode 4 and the second tube electrode 5 can be selected from one or more of the following shapes: circular, elliptical, or triangular. The materials for the first electrode 4 and the second electrode 5 can be one or more combinations of pure copper, brass, or copper-tungsten alloy.

[0037] In a further optimized design, the titanium-steel composite plate 23 is connected to the titanium-steel composite plate interface 26 via the titanium-steel composite plate interface 26.

[0038] like Figure 2 and Figure 3 As shown, the diameter of the first electrode 4 is D1, and the diameter of the second electrode 5 is D2, where D1 = d - 2Δ1, D2 = d - 2Δ2, and D1 ≠ D2. In the formula: d Δ1 represents the geometric dimensions of the hole to be processed; Δ1 represents the side clearance value during the processing of the first tube electrode, with a value range of 0.02–0.25 mm; Δ2 represents the side clearance value during the processing of the second tube electrode, with a value range of 0.02–0.25 mm.

[0039] Example 2: A method for electrolytic electro-spark composite machining of small holes in titanium-steel composite plates includes the following steps: The control processing power supply 19 is electrically connected to the titanium steel composite plate 23, the first tube electrode 4 and / or the second tube electrode 5; When the processing power supply 19 is electrically connected to the titanium-steel composite plate 23 and the first tube electrode 4, this is a single-axis processing mode on the titanium side. The processing power supply 19 and the electrolyte circulation device 10 are started, and the first tube electrode 4 moves from the titanium-side metal 24 to the steel-side metal 25. After the small hole processing is completed, the processing power supply 19 is turned off, and the first tube electrode 4 is retracted. When the machining power supply 19 is electrically connected to the titanium-steel composite plate 23 and the second tube electrode 5, this is a single-axis machining mode on the steel side. The machining power supply 19 and the electrolyte circulation device 10 are started, and the second tube electrode 5 moves from the steel side metal 25 to the titanium side metal 24. After the small hole machining is completed, the machining power supply 19 is turned off and the second tube electrode 5 is retracted. When the processing power supply 19 is electrically connected to the titanium-steel composite plate 23, the first tube electrode 4, and the second tube electrode 5, this is a biaxial anisotropic processing mode. The processing power supply 19 and the electrolyte circulation device 10 are started. The first tube electrode 4 processes the titanium-side metal 24, and the second tube electrode 5 processes the steel-side metal 25. After the small holes of the two electrodes overlap, the processing is completed.

[0040] In this embodiment, a specific processing technology is as follows: 1. For example Figure 4 The diagram shows a single-axis machining method for the titanium side, which involves single-axis machining of the titanium side metal 24 of the titanium-steel composite plate 23, including the following steps: Step 1: Connect the first positive wire 20 of the processing power supply 19 to the fastening fixture 7, and the first negative wire 21 to the first rotary feed shaft 1, so that the titanium-steel composite plate is the anode and the first tube electrode 4 is the cathode. The hollow cavity 17 of the first tube electrode is connected to the clear liquid tank 13 through the electrolyte connection pipe 11. The outlet 12 of the solution tank is connected to the turbid liquid tank 14 through the hose 27. Adjust the first rotary feed shaft 1 and the third rotary feed shaft 3 so that the distance between the first tube electrode 4 and the titanium side metal 24 of the titanium-steel composite plate is maintained within the range of 0.005 to 0.300 mm; The processing power supply 19 is a pulse power supply with a pulse frequency range of 1–500 kHz, a pulse width in the microsecond to nanosecond range, an output voltage of 0–300 V, and a current density of up to 10. 5 ~10 8 A / cm².

[0041] Step 2: Sequentially start the electrolyte circulation device 10 and the processing power supply 19. Driven by the first rotary feed shaft 1, the first tube electrode 4 processes the titanium side metal 24, the titanium-steel composite plate interface 26, and the steel side metal 25 of the titanium-steel composite plate 23 from left to right. The electrolyte flows sequentially from the clear liquid tank 13 through the hollow cavity 17 of the first tube electrode and the processing area. Then, the electrolyte containing the electrolysis products enters the solution tank 9 and finally flows into the turbid liquid tank 14. Throughout the composite processing, the processing parameters remain constant. After the small hole processing is completed, the processing power supply 19 is turned off, the first tube electrode 4 retracts, and then the electrolyte circulation device 10 is turned off. The titanium-steel composite plate 23 is removed from the fastening fixture 7, thus obtaining the titanium-steel composite plate 23 with small holes.

[0042] The retraction speed of the first tube electrode 4 is set to 10-50 mm / min, the pulse width during processing is set to 10-20 μs, the pulse interval is set to 20-40 μs, the peak current is set to 5-15 A, the conductivity of the solution is set to 1-10 mS / cm, the pulse voltage is set to 80-100 V, the rotational speed of the first rotary feed axis 1 is set to 80-120 rpm, the flushing pressure is set to 3-10 MPa, the working fluid is NaNO3 solution, and the processing temperature is set to 25℃.

[0043] When single electrical discharge machining (EDM) enters the titanium side metal 24 of the titanium-steel composite plate 23, the difference in the aperture of the small hole in the resulting titanium-steel composite plate meets the machining requirements. Therefore, for the single-axis machining method on the titanium side, the main function of electrolytic machining is to eliminate the recast layer generated by single EDM.

[0044] In the single-axis machining method of titanium side in electro-discharge machining of titanium-steel composite plates, a composite machining method can be adopted, or electro-discharge machining can be performed first and then electrolytic machining. The specific implementation is as follows: Driven by the first rotary feed axis 1, the first tube electrode 4 processes the titanium side metal 24, titanium-steel composite plate interface 26 and steel side metal 25 of the titanium-steel composite plate 23 from left to right through electro-discharge machining; then, driven by the first rotary feed axis 1, the first tube electrode 4 retracts and processes the steel side metal 25, titanium-steel composite plate interface 26 and titanium side metal 24 of the titanium-steel composite plate from right to left through electrolytic machining to remove the recast layer.

[0045] 2. For example Figure 5The diagram shows a single-axis machining method for the steel side, involving single-axis machining of the steel side metal 25 of the titanium-steel composite plate 23, including the following steps: Step 1: Connect the first positive wire 20 of the processing power supply 19 to the fastening fixture 7, and the second negative wire 22 to the second rotary feed shaft 2. The hollow cavity 18 of the second tube electrode is connected to the clear liquid tank 13 through the electrolyte connection pipe 11. The outlet 12 of the solution tank is connected to the turbid liquid tank 14 through the electrolyte connection pipe 11. Adjust the second rotary feed shaft 2 and the third rotary feed shaft 3 to maintain the distance between the second tube electrode 5 and the steel side metal 25 of the titanium-steel composite plate within the range of 0.005 to 0.300 mm; The processing power supply 19 is a pulse power supply with a pulse frequency range of 1–500 kHz, a pulse width in the microsecond to nanosecond range, an output voltage of 0–300 V, and a current density of up to 10. 5 ~10 8 A / cm².

[0046] Step 2: Sequentially start the electrolyte circulation device 10 and the processing power supply 19. Driven by the second rotary feed shaft 2, the second tube electrode 5 processes the steel side metal 25, the titanium-steel composite plate interface 26, and the titanium side metal 24 of the titanium-steel composite plate 23 from right to left. The electrolyte flows sequentially from the clear liquid tank 13 through the hollow cavity 18 of the second tube electrode and the processing area, then enters the solution tank 9, and finally flows into the turbid liquid tank 14. During the entire composite processing, the pulse voltage gradually increases. After the small hole processing is completed, the processing power supply 19 is turned off, the second tube electrode 5 retracts, and then the electrolyte circulation device 10 is turned off. The titanium-steel composite plate 23 is removed from the fastening fixture 7, thus obtaining the titanium-steel composite plate 23 with small holes.

[0047] The retraction speed of the second electrode 5 is set to 10–50 mm / min, the pulse width to 10–20 μs, the pulse interval to 20–40 μs, the peak current to 5–15 A, the conductivity of the solution to 1–10 mS / cm, the pulse voltage to 80–100 V, the rotational speed of the second rotary feed axis to 80–120 rpm, the flushing pressure to 3–10 MPa, the working fluid to be NaNO3 solution, and the processing temperature to 25 °C.

[0048] The pulse voltage of the processing power supply 19 can be increased in a step-by-step manner, dividing the voltage into several stages. Each stage maintains a constant voltage value, and after reaching the set time or processing depth, it jumps to the next voltage stage.

[0049] For single-axis machining of steel, the main function of electrolytic machining is to eliminate the hole diameter differences and recast layer caused by single electrical discharge machining.

[0050] In the single-axis machining of the steel side of the titanium-steel composite plate 23 via electrical discharge machining (EDM) and electrolytic machining, a composite machining method can be adopted, or EDM can be performed first and then electrolytic machining. The specific implementation is as follows: Driven by the second rotary feed axis 2, the second tube electrode 5 processes the steel side metal 25, the titanium-steel composite plate interface 26, and the titanium side metal 24 of the titanium-steel composite plate sequentially from right to left via EDM; subsequently, driven by the second rotary feed axis 2, the second tube electrode 5 retracts, and the titanium side metal 24, the titanium-steel composite plate interface 26, and the steel side metal 25 of the titanium-steel composite plate sequentially from left to right via electrolytic machining.

[0051] 3. For example Figure 6 The diagram shows a dual-axis anisotropic machining method, which includes the following steps: Step 1: Connect the first positive wire 20 of the processing power supply 19 to the fastening fixture 7, the first negative wire 21 to the first rotary feed shaft 1, and the second negative wire 22 to the second rotary feed shaft 2; the hollow cavity 17 of the first tube electrode and the hollow cavity 18 of the second tube electrode are both connected to the clear liquid tank 13 through the electrolyte connection pipe 11, and the outlet 12 of the solution tank is connected to the turbid liquid tank 14 through the electrolyte connection pipe 11; adjust the first rotary feed shaft 1 and the third rotary feed shaft 3 to keep the distance between the first tube electrode 4 and the titanium side metal 24 of the titanium-steel composite plate within the range of 0.005 to 0.300 mm; then adjust the second rotary feed shaft 2 to keep the distance between the second tube electrode 5 and the steel side metal 25 of the titanium-steel composite plate within the range of 0.005 to 0.300 mm. The processing power supply 19 is a pulse power supply with a pulse frequency range of 1–500 kHz, a pulse width in the microsecond to nanosecond range, an output voltage of 0–300 V, and a current density of up to 10. 5 ~10 8 A / cm².

[0052] Step 2: Sequentially turn on the electrolyte circulation device 10 and the processing power supply 19. The first tube electrode 4, driven by the first rotary feed axis 1, processes the titanium side metal 24 of the titanium-steel composite plate. During the processing, the process parameters remain constant. The second tube electrode 5, driven by the second rotary feed axis 2, processes the steel side metal 25 of the titanium-steel composite plate. During the processing, the processing parameters remain constant. The retraction speed of the first electrode 4 and the second electrode 5 are both set to 10-50 mm / min, the pulse width is set to 10-20 μs, the pulse interval is set to 20-40 μs, the peak current is set to 5-15 A, the conductivity of the solution is set to 1-10 mS / cm, the pulse voltage is set to 80-100 V, the speed of the first rotary feed axis is set to 80-120 rpm, the speed of the second rotary feed axis is set to 80-120 rpm, the flushing pressure is set to 3-10 MPa, the working fluid is NaNO3 solution, and the processing temperature is 25℃.

[0053] For biaxial anisotropic machining, the main function of electrolytic machining is to eliminate the recast layer produced by single electrical discharge machining.

[0054] In the biaxial anisotropic machining method of EDM / Electrolytic machining of titanium-steel composite plates, a composite machining method can be adopted, or EDM can be performed first and then EDM. Specific implementation details are as follows: Using electrical discharge machining (EDM), the first tube electrode 4, driven by the first rotary feed axis 1, begins machining from the titanium side metal 24 of the titanium-steel composite plate; simultaneously, the second tube electrode 5, driven by the second rotary feed axis 2, begins machining from the steel side metal 25 of the titanium-steel composite plate; subsequently, using electrolytic machining, the first tube electrode 4, driven by the first rotary feed axis 1, retracts to its initial position; simultaneously, the second tube electrode 5, driven by the second rotary feed axis 2, retracts to its initial position.

[0055] Step 3: The small hole formed by the electrolytic discharge machining of the first electrode 4 is precisely aligned with the small hole formed by the electrolytic discharge machining of the second electrode 5. After processing is complete, the electrolyte circulation device 10 is shut off, and the titanium-steel composite plate 23 is removed from the fastening fixture 7, thus obtaining the titanium-steel composite plate 23 with the small hole.

[0056] Further optimization of the scheme: the thickness of the titanium-steel composite plate 23 is h, the thickness of the titanium-side metal 24 is h1, and the thickness of the steel-side metal 25 is h2. The feed speed v1 of the first rotary feed axis 1 is set to 0.1~50mm / min, and the feed speed v2 of the second rotary feed axis 2 is set to 0.1~50mm / min. When the machining power supply 19 is electrically connected to the titanium-steel composite plate 23, the first tube electrode 4, and the second tube electrode 5, the feed time of the first tube electrode 4 is t1, and the feed time of the second tube electrode 5 is t2. Therefore, the feed time t1 of the first tube electrode 4 is h1 / v1, and the feed time t2 of the second tube electrode 5 is h2 / v2. If t1 < t2, the first tube electrode 4 disconnects from the processing power supply 19 and retracts, and the second tube electrode 5 shuts off the processing power supply 19 and retracts after completing the processing. Specifically, if t1 < t2, after completing the small hole machining of the titanium side metal 24, disconnect the connection between the first negative electrode wire 21 of the machining power supply and the first rotary feed shaft 1, and the first tube electrode 4 retracts at a speed of 10 to 50 mm / min; after the second tube electrode 5 is fed to the precise overlap of the small holes on both sides, turn off the machining power supply 19, and the second tube electrode 5 quickly retracts at a speed of 10 to 50 mm / min.

[0057] If t1 > t2, the second tube electrode 5 disconnects from the processing power supply 19 and retracts, and the first tube electrode 4 shuts off the processing power supply 19 and retracts after completing the processing. Specifically, if t1 > t2, after completing the small hole machining of the steel side metal 25, disconnect the connection between the second negative electrode wire 22 on the machining power supply 19 and the second rotary feed shaft 2, and retract the second tube electrode 5 at a speed of 10-50 mm / min; after the first tube electrode 4 has been fed to precisely overlap the small holes on both sides, turn off the machining power supply 19 and quickly retract at a speed of 10-50 mm / min. If t1=t2, turn off the processing power supply 19, and the first tube electrode 4 and the second tube electrode 5 will retract simultaneously.

[0058] Specifically, if t1=t2, the first tube electrode 4 and the second tube electrode 5 are fed to precisely overlap the small holes on both sides. Then the processing power supply 19 is disconnected, and the first tube electrode 4 and the second tube electrode 5 retract simultaneously at a retraction speed of 10-50 mm / min.

[0059] The dual-axis anisotropic machining method adopts dual-axis anisotropic feed machining, which can simultaneously process the titanium side metal 24 and the steel side metal 25 of the titanium-steel composite plate 23. Compared with single-axis feed machining, it not only improves efficiency, but also solves the problem of hole diameter consistency caused by material performance differences.

[0060] Further optimization of the scheme: the end face gap of the first tube electrode 4 during the processing is Δ1, and the end face gap of the second tube electrode 5 during the processing is Δ2, and Δ1+Δ2≥h-h1-h2, that is, the sum of the end face gaps of the first tube electrode 4 and the second tube electrode 5 during the processing is not less than the thickness of the titanium-steel composite plate interface 26, so as to ensure that the micro-holes on both sides of the titanium-steel composite plate 23 are completely connected.

[0061] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0062] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A device for electrolytic electrical discharge machining of small holes in titanium-steel composite plates, characterized in that, include: The clamping assembly includes a fastening clamp (7) for clamping a titanium-steel composite plate (23), and the fastening clamp (7) is provided with a vertical adjustment mechanism for adjusting the height of the fastening clamp (7); The hole forming assembly includes a first tube electrode (4) and a second tube electrode (5). The first tube electrode (4) and the second tube electrode (5) are respectively located on both sides of the titanium-steel composite plate (23). The first tube electrode (4) is set close to the titanium side metal (24), and the second tube electrode (5) is set close to the steel side metal (25). The first tube electrode (4) and the second tube electrode (5) are respectively provided with a lateral adjustment mechanism for adjusting the horizontal distance between them and the titanium-steel composite plate (23). The electrolyte circulation device (10) includes a supply tank, and the first tube electrode (4) and the second tube electrode (5) are respectively connected to the supply tank through two sets of electrolyte connection pipes (11); The processing power supply (19) is used to provide pulse voltage.

2. The device for small-hole electrolytic electrical discharge machining of titanium-steel composite plates according to claim 1, characterized in that: The positive terminal of the processing power supply (19) is connected to the fastening fixture (7) through the first positive terminal wire (20) so that the titanium steel composite plate (23) is electrically connected to the positive terminal of the processing power supply (19). The negative terminal of the processing power supply (19) is electrically connected to the first tube electrode (4) and the second tube electrode (5) through the first negative terminal wire (21) and the second negative terminal wire (22) respectively.

3. The electrolytic discharge machining device for small holes in titanium-steel composite plates according to claim 1, characterized in that: The vertical adjustment mechanism includes a third rotary feed shaft (3), and the top of the fastening clamp (7) is fixedly connected to the telescopic end of the third rotary feed shaft (3); The lateral adjustment mechanism includes a horizontally arranged first rotary feed shaft (1) and a second rotary feed shaft (2). The ends of the first tube electrode (4) and the second tube electrode (5) away from the titanium-steel composite plate (23) are respectively fixedly connected to the telescopic ends of the first rotary feed shaft (1) and the second rotary feed shaft (2).

4. The electrolytic discharge machining device for small holes in titanium-steel composite plates according to claim 3, characterized in that: It also includes a frame (6), the third rotary feed shaft (3) is vertically fixed to the top of the frame (6), and the first rotary feed shaft (1) and the second rotary feed shaft (2) are horizontally fixed to the two opposite side walls of the frame (6).

5. The electrolytic discharge machining device for small holes in titanium-steel composite plates according to claim 1, characterized in that: The liquid supply tank includes a clear liquid tank (13). The two electrolyte connecting pipes (11) are connected to a three-way interface (16) at one end away from the first tube electrode (4) and the second tube electrode (5). A pump is installed in the clear liquid tank (13). The outlet end of the pump is connected to the two electrolyte connecting pipes (11) through the three-way interface (16).

6. The electrolytic discharge machining device for small holes in titanium-steel composite plates according to claim 5, characterized in that: The liquid supply tank also includes a solution tank (9), which is located below the titanium steel composite plate (23). The solution tank (9) is connected to a turbid liquid tank (14) through a liquid outlet (12) opened on the side wall. The turbid liquid tank (14) is connected to the clear liquid tank (13) through a filter (15).

7. The electrolytic discharge machining device for small holes in titanium-steel composite plates according to claim 1, characterized in that: The inner cross-sectional shape of the first tube electrode (4) and the second tube electrode (5) can be selected from one or more of the following shapes: circular, elliptical, or triangular. The materials of the first tube electrode (4) and the second tube electrode (5) can be one or more combinations of pure copper, brass or copper-tungsten alloy.

8. A method for electrolytic discharge machining of small holes in titanium-steel composite plates, based on the electrolytic discharge machining apparatus for small holes in titanium-steel composite plates as described in claim 1, characterized in that... The following steps are included: Control the processing power supply (19) to electrically connect the titanium steel composite plate (23), the first tube electrode (4) and / or the second tube electrode (5). When the processing power supply (19) is electrically connected to the titanium-steel composite plate (23) and the first tube electrode (4), the processing power supply (19) and the electrolyte circulation device (10) are started. The first tube electrode (4) moves from the titanium side metal (24) to the steel side metal (25). After the small hole processing is completed, the processing power supply (19) is turned off and the first tube electrode (4) is retracted. When the processing power supply (19) is electrically connected to the titanium-steel composite plate (23) and the second tube electrode (5), the processing power supply (19) and the electrolyte circulation device (10) are started. The second tube electrode (5) moves from the steel side metal (25) to the titanium side metal (24). After the small hole processing is completed, the processing power supply (19) is turned off and the second tube electrode (5) is retracted. When the processing power supply (19) is electrically connected to the titanium-steel composite plate (23), the first tube electrode (4) and the second tube electrode (5), the processing power supply (19) and the electrolyte circulation device (10) are started. The first tube electrode (4) processes the titanium side metal (24), and the second tube electrode (5) processes the steel side metal (25). After the small holes of the two electrodes overlap, the processing is completed.

9. The method for electrolytic discharge machining of small holes in a titanium-steel composite plate according to claim 8, characterized in that: When the processing power supply (19) is electrically connected to the titanium steel composite plate (23), the first tube electrode (4) and the second tube electrode (5), the feed time of the first tube electrode (4) is t1 and the feed time of the second tube electrode (5) is t2. If t1 < t2, the first tube electrode (4) disconnects from the machining power supply (19) and retracts, and the second tube electrode (5) shuts off the machining power supply (19) and retracts after completing the machining; If t1 > t2, the second tube electrode (5) disconnects from the machining power supply (19) and retracts, and the first tube electrode (4) shuts off the machining power supply (19) and retracts after completing the machining. If t1=t2, turn off the processing power supply (19), and the first tube electrode (4) and the second tube electrode (5) retract simultaneously.

10. The method for small-hole electrolytic electrical discharge machining of titanium-steel composite plates according to claim 8, characterized in that: When the processing power supply (19) is electrically connected to the titanium steel composite plate (23) and the first tube electrode (4), the parameters of the processing power supply (19) remain unchanged; When the processing power supply (19) is electrically connected to the titanium steel composite plate (23) and the second tube electrode (5), the pulse voltage of the processing power supply (19) gradually increases; When the processing power supply (19) is electrically connected to the titanium-steel composite plate (23), the first tube electrode (4), and the second tube electrode (5), the parameters of the processing power supply (19) remain unchanged.

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