An ultrasonic wave cooperates with micro-bubble electrochemical polishing device and polishing method

Abstract

The application discloses an ultrasonic wave and micro-bubble coordinated electrochemical polishing device and polishing method. The polishing device comprises an electrochemical polishing cabin; a workbench for placing a workpiece and a clamp for fixing the workpiece on the workbench are arranged in the electrochemical polishing cabin; the electrochemical polishing cabin is provided with an electrolyte circulating loop, the outlet of the electrolyte circulating loop is communicated with the inlet through the circulating loop, a micro-bubble generating device and a supply pump are arranged on the electrolyte circulating loop; the polishing device further comprises a pressure booster for pressurizing the electrochemical polishing cabin, a bubble monitoring device for monitoring the micro-bubble concentration in the electrolyte and an ultrasonic wave generating device; the ultrasonic wave probe of the ultrasonic wave generating device and the workpiece are connected with a power supply. The polishing method can simultaneously consider high polishing efficiency, high consistency and excellent surface integrity of the workpiece.

Description

Technical Field

[0001] This invention relates to an ultrasonic-assisted microbubble electrochemical polishing apparatus, and also to a polishing method based on the above-mentioned polishing apparatus. Background Technology

[0002] Electrochemical polishing, also known as electrolytic polishing, is a precision surface treatment technology for metals that originated in the 1930s. Its core mechanism involves the selective dissolution of the metal workpiece in an electrolyte solution, acting as the anode to preferentially remove microscopic protrusions on the surface, thereby significantly reducing surface roughness and improving finish. Traditional electrochemical polishing typically relies on a single electrochemical action, resulting in relatively low polishing efficiency.

[0003] To improve the efficiency of electrochemical polishing, researchers have proposed an ultrasonic-assisted electrochemical polishing technique. This technique significantly enhances the efficiency of electrochemical polishing. Ultrasonic waves can induce cavitation, forming microbubbles. The microjet streams and shock waves generated during the bursting of these bubbles help to break down the microscopic protrusions on the workpiece surface, thereby improving the polishing effect. However, current ultrasonic-assisted electrochemical polishing techniques lack the ability to effectively and precisely control the microbubbles during the polishing process. This makes it difficult to simultaneously achieve high efficiency, high consistency, and excellent surface integrity when processing high-precision, complex structures. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide an electrochemical polishing device that uses ultrasound in conjunction with microbubbles; another purpose of this invention is to provide an electrochemical polishing method based on the above-mentioned polishing device, which can simultaneously achieve high polishing efficiency, high consistency and excellent surface integrity of the workpiece.

[0005] Technical Solution: The ultrasonic-assisted microbubble electrochemical polishing device of the present invention includes an electrochemical polishing chamber; the electrochemical polishing chamber is provided with a worktable for placing workpieces and a clamp for fixing workpieces on the worktable; the electrochemical polishing chamber is provided with an electrolyte circulation loop, the outlet of which is connected to the inlet through the circulation loop, and a microbubble generating device and a supply pump are provided on the electrolyte circulation loop; it also includes a booster for pressurizing the electrochemical polishing chamber, a bubble monitoring device for monitoring the concentration of microbubbles in the electrolyte, and an ultrasonic generator; the ultrasonic probe and the workpiece of the ultrasonic generator are both connected to a power source.

[0006] The electrochemical polishing method based on the above polishing device includes the following steps:

[0007] (1) Fix the workpiece on the fixture and inject electrolyte into the electrochemical polishing chamber to the working level; turn on the supply pump and microbubble generation device, and monitor the concentration of microbubbles in the electrolyte in real time through the bubble monitoring device;

[0008] (2) When the concentration of microbubbles in the electrolyte reaches the preset value, close the detachable sealing cover to ensure that the electrochemical polishing chamber is completely sealed; turn on the booster to pressurize the air pressure in the chamber to the preset value.

[0009] (3) After pressurization is completed, start the ultrasonic generator and power supply, adjust the frequency and power of the ultrasonic generator, and start polishing; the ultrasonic probe is immersed in the electrolyte and close to the workpiece to act as the cathode. The high-frequency vibration of the ultrasonic probe generates cavitation bubbles in the electrolyte and forces the microbubbles and cavitation bubbles to work together to impact the micro protrusions of the anode workpiece, further enhancing the ultrasonic cavitation effect and making the electrochemical polishing process more complete.

[0010] (4) Depending on the metal workpiece to be polished, after polishing for 300~3600s, remove the workpiece. Polishing is complete. Take out the polished workpiece and perform ultrasonic cleaning and drying.

[0011] In step (1), the electrolyte is at least one of ethanol, ethylene glycol, methanol, or perchloric acid; the working level of the electrolyte should be 5-10 cm above the upper surface of the fixture; the horizontal height of the inlet is lower than the working level; the horizontal height of the outlet is lower than the horizontal height of the inlet; the height difference between the two holes promotes the flow of the electrolyte, so that the electrolyte in the polishing gap is fully cooled and renewed; by limiting the height relationship between the working level, the inlet and the outlet, the full flow of the electrolyte is ensured and the required microbubble concentration is maintained.

[0012] In step (1), the maximum flow rate of the electrolyte in the circulation loop is not less than 4500 L / h; in the microbubble generating device, the flow rate of air introduced into the electrolyte is 5~300 mL / min. Through the coordinated regulation of the electrolyte flow rate, the flow rate of air introduced into the electrolyte, and the air pressure inside the chamber, the concentration of microbubbles in the electrolyte is always kept within the preset range.

[0013] In step (2), once the concentration of microbubbles in the electrolyte reaches the preset value, the concentration of microbubbles in the electrolyte is 3 × 10⁻⁶. 8 ~10×10 8 The microbubble density is 100 micrometers or less per mL. The internal pressure is increased to a preset value of 1 to 2 atmospheres.

[0014] In step (3), the frequency of the ultrasonic generator is 20~40kHz, the power is 50~100W, and the current density is 0.1~1.5A / cm. 2 .

[0015] Beneficial effects: This invention introduces microbubbles of a specific concentration into the electrolyte, which can effectively enhance ultrasonic cavitation. The ultrasonic motion generates cavitation bubbles in the electrolyte and forces the microbubbles and cavitation bubbles to impact the microscopic protrusions of the anode workpiece, making the electrochemical polishing process more thorough. This significantly improves polishing efficiency, resulting in low surface roughness and high gloss of the workpiece. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the polishing device of the present invention.

[0017] Figure 2 Industrial microscope images and surface profile curves derived from a roughness tester for A100 steel plates before polishing.

[0018] Figure 3 The images show industrial microscope images and surface profile curves derived from a roughness tester of the A100 steel plate after polishing in Example 1.

[0019] Figure 4 The images show industrial microscope images and surface profile curves derived from a roughness tester of an A100 steel plate after polishing, as shown in Comparative Example 1. Detailed Implementation

[0020] like Figure 1 As shown, the electrochemical polishing device of the present invention, which utilizes ultrasonic synergy with microbubbles, includes an electrochemical polishing chamber 1. The electrochemical polishing chamber 1 is equipped with a worktable for placing a workpiece 9 and a clamp 102 for fixing the workpiece 9 to the worktable. The electrochemical polishing chamber 1 includes an inlet 103 and an outlet 104, with the outlet 104 connected to the inlet 103 via an electrolyte circulation loop. A microbubble generating device 3 and a supply pump 4 are provided on the electrolyte circulation loop. The polishing device also includes a booster 2 for pressurizing the electrochemical polishing chamber 1, a bubble monitoring device 5 for monitoring the concentration of microbubbles in the electrolyte, and an ultrasonic generator 6. The ultrasonic probe 601 of the ultrasonic generator 6 and the workpiece 9 are respectively connected to the cathode and anode of a power supply 7. The electrochemical polishing chamber 1 also includes a detachable sealing cover 101, with three openings at the top for connecting the booster tube of the booster 2, the probe 501 of the bubble monitoring device 5, and the ultrasonic probe 601 of the ultrasonic generator 6.

[0021] Two A100 steel plates (A100 steel plate size is 20 mm*10 mm*3 mm, surface roughness Ra is 1.297 μm) were polished according to Example 1 and Comparative Example 1 respectively.

[0022] Example 1

[0023] The electrochemical polishing method using the above-mentioned polishing apparatus includes the following steps:

[0024] (1) Fix the workpiece to be polished (A100 steel plate) on the fixture, inject electrolyte (ethanol) into the electrochemical polishing chamber to the working level, which is 10cm higher than the upper surface of the fixture; turn on the supply pump and microbubble generating device, and in the circulation loop, the flow rate of electrolyte is 4500L / h; in the microbubble generating device, the flow rate of air introduced into the electrolyte is 200mL / min, and the concentration of microbubbles in the electrolyte is monitored in real time by the bubble monitoring device.

[0025] (2) When the concentration of microbubbles in the electrolyte reaches the preset value (5×10⁻⁶), 8 After (number of cells / mL), close the removable sealing cap to ensure the electrochemical polishing chamber is completely sealed; turn on the pressurizer to pressurize the air pressure inside the chamber to the preset value (1.5 atmospheres).

[0026] (3) After pressurization is completed, start the ultrasonic generator and power supply. The frequency of the ultrasonic generator is 30kHz and the power is 80W. After starting the power supply, the current density is 1A / cm. 2 An ultrasonic probe positioned 1 cm above the workpiece acts as the cathode, while the workpiece acts as the anode, and polishing begins. The high-frequency vibration of the ultrasonic probe generates cavitation bubbles in the electrolyte and forces microbubbles to work together with the cavitation bubbles to impact the microscopic protrusions of the anode workpiece, further enhancing the ultrasonic cavitation effect and making the electrochemical polishing process more thorough.

[0027] (4) After polishing for 3600s, take out the polished workpiece and perform ultrasonic cleaning and drying.

[0028] pass Figures 2-3 As can be seen from the comparison, after polishing with the present invention, the roughness Ra of A100 steel plate decreased from 1.297μm to 0.680μm.

[0029] Comparative Example 1

[0030] An electrochemical polishing method includes the following steps:

[0031] (1) Fix the workpiece to be polished (A100 steel plate) on the fixture, and inject electrolyte (ethanol) into the electrochemical polishing chamber to the working level, which is 10cm higher than the upper surface of the fixture;

[0032] (2) Start the ultrasonic generator and power supply. The frequency of the ultrasonic generator is 30kHz and the power is 80W. After starting the power supply, the current density is 1A / cm. 2 An ultrasonic probe positioned 1 cm above the workpiece acts as the cathode, while the workpiece acts as the anode, and polishing begins.

[0033] (4) After polishing for 5600s, take out the polished workpiece and perform ultrasonic cleaning and drying.

[0034] pass Figure 2 and Figure 4 The comparison shows that after polishing in Comparative Example 1, the surface roughness Ra of the A100 steel plate decreased from 1.297 μm to 0.813 μm.

Claims

1. An ultrasonic-assisted microbubble electrochemical polishing device, characterized in that: The device includes an electrochemical polishing chamber (1); the electrochemical polishing chamber (1) is provided with a worktable for placing workpieces (9) and a fixture (102) for fixing workpieces (9) on the worktable; the electrochemical polishing chamber (1) is provided with an electrolyte circulation loop, and its outlet (104) is connected to the inlet (103) through the circulation loop. A microbubble generating device (3) and a supply pump (4) are provided on the electrolyte circulation loop; the device also includes a booster (2) for pressurizing the electrochemical polishing chamber (1), a bubble monitoring device (5) for monitoring the concentration of microbubbles in the electrolyte, and an ultrasonic generator (6); the ultrasonic probe (601) of the ultrasonic generator (6) and the workpiece (9) are both connected to a power supply (7).

2. The electrochemical polishing method based on the polishing apparatus of claim 1, characterized in that, Includes the following steps: (1) Fix the workpiece on the fixture and inject electrolyte into the electrochemical polishing chamber to the working level; turn on the supply pump and microbubble generation device, and monitor the concentration of microbubbles in the electrolyte in real time through the bubble monitoring device; (2) When the concentration of microbubbles in the electrolyte reaches the preset value, close the electrochemical polishing chamber; turn on the booster to pressurize the air pressure in the chamber to the preset value; (3) After pressurization is completed, start the ultrasonic generator and power supply, adjust the frequency and power of the ultrasonic generator, and start polishing; (4) After polishing, remove the workpiece.

3. The electrochemical polishing method according to claim 2, characterized in that: In step (1), the electrolyte is at least one of ethanol, ethylene glycol, methanol or perchloric acid.

4. The electrochemical polishing method according to claim 2, characterized in that: In step (1), the working electrolyte level should be 5-10 cm above the upper surface of the fixture, the horizontal height of the inlet should be lower than the working level, and the horizontal height of the outlet should be lower than the horizontal height of the inlet.

5. The electrochemical polishing method according to claim 2, characterized in that: In step (1), the flow rate of the electrolyte in the circulation loop is not less than 4500 L / h; in the microbubble generating device, the flow rate of air introduced into the electrolyte is 5~300 mL / min.

6. The electrochemical polishing method according to claim 2, characterized in that: In step (2), once the concentration of microbubbles in the electrolyte reaches the preset value, the concentration of microbubbles in the electrolyte is 3 × 10⁻⁶. 8 ~10×10 8 The number of microbubbles per mL is no more than 100 micrometers.

7. The electrochemical polishing method according to claim 2, characterized in that: In step (2), the air pressure inside the cabin is increased to a preset value, which is 1 to 2 atmospheres.

8. The electrochemical polishing method according to claim 2, characterized in that: In step (3), the frequency of the ultrasonic generator is 20~40kHz and the power is 50~100W.

9. The electrochemical polishing method according to claim 2, characterized in that: In step (3), the current density is 0.1~1.5A / cm. 2 .

10. The electrochemical polishing method according to claim 2, characterized in that: In step (4), the polishing time is 300~3600s.

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