A solid media electrochemical polishing method with controllable material removal rate adjustment

Abstract

The application discloses a solid medium electrochemical polishing method with controllable material removal rate, and mainly comprises the following steps: using solid particles containing electrolyte as conductive medium, adjusting the content of electrolyte in the solid particles during the polishing process, so that different current densities are generated between the polished parts and the cathode, the material removal rate of the polishing process is controlled, and the polishing of surfaces with different roughness is adapted. The solid medium electrochemical polishing method with controllable material removal rate uses solid particles containing pore structures as conductive medium, the current density can be adjusted by adjusting the content of electrolyte in the solid particles, and thus the controllable adjustment of the material removal rate during the polishing process is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrochemical polishing, in particular to a solid medium electrochemical polishing method with controllable material removal rate. BACKGROUND

[0002] Polishing refers to a process of removing workpiece surface material and reducing surface roughness by using mechanical, chemical, laser and other energy forms to obtain a smooth surface. As the last process of part processing, polishing can optimize the surface quality of the part to meet specific functional requirements. Metal part polishing plays an important role in many aspects of modern manufacturing, especially in ultra-precision manufacturing. The surface roughness of metal parts has a great influence on the service life, corrosion resistance, fatigue resistance and wear resistance of mechanical products, and polishing process plays an irreplaceable role in modern manufacturing.

[0003] Electrochemical polishing, also known as anodic polishing or electrolytic polishing, is a finishing process based on the principle of anodic dissolution to remove material from metal or alloy. In this process, material is removed from the workpiece surface ion by ion, with ultra-high precision and flexible controllability, and is a non-contact and non-damaging processing process. Electrochemical polishing is widely used in metal finishing industry due to its simplicity of equipment and its ability to polish complex structures. However, traditional electrochemical polishing has high requirements for the initial surface roughness of the part, and the polishing effect is good for metal parts with an initial roughness value Ra of about 1 μm, but when the initial surface roughness value is high (such as Ra>5 μm), the polishing effect is poor, and even cannot achieve the polishing effect. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects of the prior art and provide a solid medium electrochemical polishing method with controllable material removal rate.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] The solid medium electrochemical polishing method with controllable material removal rate of the present application mainly comprises the following steps:

[0007] 1) Using solid particles containing electrolyte as conductive medium, adjusting the content of electrolyte in the solid particles during polishing to produce different current densities between the polished parts and the cathode, so as to control the material removal rate of the polishing process and adapt to the polishing of different roughness surfaces;

[0008] 2) The solid particles in step 1 have pore structure and retain a certain amount of electrolyte, which gives the solid particles the required conductivity when voltage is applied between the parts and the cathode;

[0009] 3) The electrolyte content in the solid particles in step 2 is adjusted by adding electrolyte to the solid particles by the liquid supply pump, the polished part is rotated at a certain speed, so that the added electrolyte is fully and uniformly absorbed by the solid particles, and the added electrolyte makes the solid particles have stronger conductivity, thereby generating greater current density under the same polishing voltage;

[0010] 4) In step 3, the consumption of electrolyte in the polishing process will show a slow downward trend, and the liquid supply pump needs to continuously add appropriate amount of electrolyte to maintain the current density; the polishing voltage is provided by the polishing power supply, the polished part is connected to the positive pole of the polishing power supply, and the negative pole of the polishing power supply is connected to the negative pole of the polishing power supply.

[0011] 5) In step 4, the current density is monitored by the ammeter, when the current density is higher, the material removal rate is higher, which is suitable for rapid polishing of high rough surface, and when the current density is lower, the material removal rate is lower, thereby producing a bright surface.

[0012] As a preferred technical solution of the present application, the solid particles are spherical particles with a diameter ranging from 0.3 to 1.5 mm, having a pore structure inside, and composed of styrene-divinylbenzene copolymer.

[0013] As a preferred technical solution of the present application, the current density ranges from 40 to 600 mA / cm 2 , and the corresponding material removal rate is 0.1-3 μm / min, and for different surface roughness of the polished part, specifically: for high roughness surface with Ra≥5 μm, the current density range is selected to be 400-600 mA / cm 2 , and the material removal rate in this stage is 1.5-3 μm / min; for surface with 5 μm>Ra≥1 μm, the current density range is selected to be 150-300 mA / cm 2 , and the material removal rate in this stage is 0.5-1.2 μm / min; for low roughness surface with Ra<1 μm, the current density range is selected to be 40-80 mA / cm 2 , and the material removal rate in this stage is 0.1-0.2 μm / min.

[0014] As a preferred technical solution of the present application, the current density in the electrolyte consumption, the current density in the polishing process will show a slow downward trend, when it is necessary to maintain a certain material removal rate, the liquid supply pump needs to add electrolyte in time; when it is necessary to increase the material removal rate, the liquid supply pump needs to add a large amount of electrolyte; when it is necessary to reduce the material removal rate, the liquid supply pump stops adding electrolyte, the current density gradually decreases, and then the target area is added with appropriate amount of electrolyte to stabilize the material removal rate.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] 1. The material removal rate of the solid medium electrochemical polishing method of the present application can be controlled and adjusted. The solid particles containing pore structures are used as conductive media, and the current density can be adjusted by adjusting the content of electrolyte in the solid particles, so as to realize the controllable adjustment of the material removal rate in the polishing process.

[0017] 2. The solid medium electrochemical polishing method of the present application not only has good polishing effect on low surface roughness surfaces, but also has good polishing effect on high roughness surfaces. By continuously adjusting the material removal rate, the rough surface can be gradually smoothed and brightened.

[0018] 3. The solid medium electrochemical polishing method of the present application contains electrolyte in the solid particles, which reduces the risk of workers contacting strong acid electrolyte and does not produce waste liquid, which is environmentally friendly.

[0019] 4. The solid medium electrochemical polishing method of the present application can effectively polish parts or curved surfaces with complex shapes, and has good polishing effect on areas prone to edge effect in traditional liquid medium electrochemical polishing. BRIEF DESCRIPTION OF DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present application, and constitute a part of the specification, together with the embodiments of the present application, to explain the present application, and do not constitute a limitation of the present application. In the drawings:

[0021] Fig. 1 It is a process schematic diagram of the solid medium electrochemical polishing method of the present application.

[0022] Fig. 2 It is a scanning electron microscope image of the resin particles used in the solid medium electrochemical polishing method of the present application.

[0023] Fig. 3 It is a comparison diagram of the polishing effect before and after the solid medium electrochemical polishing method of the present application on 316L stainless steel parts.

[0024] In the figure: 1, polishing power supply; 2, ammeter; 3, rotating rod; 4, cathode barrel; 5, air; 6, solid particles; 7, parts to be polished; 8, liquid supply pump; 9, liquid tank. DETAILED DESCRIPTION

[0025] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and do not limit the present application.

[0026] Example 1

[0027] like Figs. 1-3 As shown, this invention provides a solid dielectric electrochemical polishing method with controllable material removal rate. Example 1:

[0028] First, a certain amount of electrolyte is mixed with solid particles 6 so that a certain amount of electrolyte is retained in the pore structure inside the solid particles 6. Then, a certain amount of solid particles 6 containing electrolyte are placed in the cathode bucket 4. Since the solid particles 6 have a certain diameter, the spaces between the particles are filled with air 5.

[0029] Next, the part to be polished 7 is fixed on the rotating rod 3, and the part to be polished 7 and the rotating rod 3 are electrically connected. The part to be polished 7 is completely immersed in the solid particles 6. The rotating rod is connected to the positive terminal of the polishing power supply 1, and the cathode barrel 4 is connected to the negative terminal of the polishing power supply 1 through the ammeter 2. The rotating rod 3 rotates at a certain speed, causing the part to be polished 7 to rotate together. The part to be polished 7 and the solid particles 6 are in full contact. The polishing power supply 1 is turned on, and a voltage difference is generated between the part to be polished 7 and the cathode barrel 4. The solid particles 6 form an "electric bridge" through mutual collision. The solid particles 6 in contact with the part to be polished 7 produce local electro-corrosion on the part to be polished 7, thereby removing the material.

[0030] Then, based on the different roughness of the polished parts 7, the material removal rate is set; for high-roughness surfaces, the liquid supply pump 8 is turned on to add the electrolyte in the liquid tank 9 to the solid particles 6, and the polishing current is monitored by the ammeter 2, with the current density controlled at 400-600 mA / cm². 2 In order to obtain a high material removal rate, the surface roughness of the polished part 7 will decrease rapidly. During this period, the electrolyte in the solid particles is gradually consumed. It is necessary to turn on the supply pump 8 as needed to add electrolyte to the solid particles 6 in order to maintain the electrolyte content in the solid particles, thereby maintaining the current density to ensure a relatively constant material removal rate.

[0031] Finally, at a current density of 400-600 mA / cm² 2 After polishing for a period of time, the surface roughness of the polished part 7 decreased. The liquid supply pump 8 was then turned off, causing the electrolyte content in the solid particles 6 to continue to decrease. At this time, the current density shown by the ammeter 2 also decreased synchronously, dropping to 150-300 mA / cm². 2 During this period, the liquid supply pump 8 is turned on to maintain a relatively constant material removal rate in order to further reduce the surface roughness of the polished part 7; in this way, the polishing current density is continuously reduced to adjust the material removal rate, thereby polishing the high roughness part to a smooth and bright state in one go.

[0032] It should be noted that the present application is a solid medium electrochemical polishing method with controllable material removal rate, each piece is a general standard piece or a component known to those skilled in the art, and its structure and principle can be known by technical personnel through technical manual or through conventional experimental method.

[0033] Working principle: the system of the present application mainly consists of polishing power supply 1, ammeter 2, solid particles 6 and liquid supply pump 8. Before polishing, a certain amount of electrolyte is filled in the solid particles 6, so that it has a certain conductivity, the polished part 7 is connected with the positive electrode of the polishing power supply 1, and the negative electrode barrel 4 is connected with the negative electrode of the polishing power supply 1, the polished part 7 is completely immersed in the solid particles 6, so as to polish the whole part. The polishing power supply 1 provides driving force for the electrochemical reaction of the oxidation and dissolution of the metal element in polishing, the ammeter 2 can monitor the current in the polishing process in real time, as the basis for judging the material removal rate adjustment, the liquid supply pump 8 is used to adjust the content of electrolyte in the solid particles 6, and the electrolyte in the solid particles 6 is supplemented in real time and in proper amount. The system of the present application also includes rotating rod 3, negative electrode barrel 4, polished part 7 and liquid tank 9. The rotating rod 3 drives the polished part 7 to rotate, so that the solid particles 6 can collide with it fully, on the one hand, it can quickly remove the polishing chips, and on the other hand, it can make the electrolyte of the liquid supply pump 8 mix with the solid particles 6 fully, so as to achieve the purpose of uniform electrolyte supplement. The negative electrode barrel 4 is used as a polishing container for containing solid particles 6, and it provides a path for polishing current. The liquid tank 9 is used for containing electrolyte.

[0034] Finally, it should be pointed out that: the above only describes the preferred embodiments of the present application and is not used to limit the present application, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A solid medium electrochemical polishing method for controllable adjustment of material removal rate, mainly comprising the following steps: 1) Using solid particles containing electrolyte as conductive medium, adjusting the content of electrolyte in the solid particles during polishing to produce different current densities between the polished parts and the cathode, so as to control the material removal rate of the polishing process and adapt to the polishing of surfaces with different roughness; 2) The solid particles in step 1 have a pore structure inside, retaining a certain amount of electrolyte, which gives the solid particles the required conductive properties when a voltage is applied between the parts and the cathode; 3) The content of electrolyte in the solid particles in step 2 is adjusted by adding electrolyte to the solid particles with a liquid supply pump, and the polished parts are rotated at a certain speed, so that the added electrolyte is fully and uniformly absorbed by the solid particles. The added electrolyte makes the solid particles have stronger conductive properties, thereby producing greater current density under the same polishing voltage; 4) During the polishing process in step 3, the consumption of electrolyte will show a slow downward trend, and the liquid supply pump needs to continuously add an appropriate amount of electrolyte to maintain the current density; When it is necessary to maintain a certain material removal rate, the liquid supply pump needs to add electrolyte in time; When it is necessary to increase the material removal rate, the liquid supply pump needs to add a large amount of electrolyte; when it is necessary to reduce the material removal rate, the liquid supply pump stops adding electrolyte, and the current density gradually decreases until the target area is added with an appropriate amount of electrolyte to stabilize the material removal rate. By continuously reducing the polishing current density, the material removal rate is adjusted, and the polishing voltage is provided by the polishing power supply. The polished parts are connected to the positive pole of the polishing power supply, and the cathode barrel containing the solid particles is connected to the negative pole of the polishing power supply; 5) The current density in step 4 is monitored by an ammeter. When the current density is high, the material removal rate is high, which is suitable for rapid polishing of high roughness surfaces. When the current density is low, the material removal rate is low, thereby producing a bright surface.

2. The method of claim 1, wherein the material removal rate is controlled by adjusting the concentration of the solid medium in the electrolyte solution. The solid particles are spherical particles with a diameter ranging from 0.3 to 1.5 mm, and have a pore structure inside. The material composition is styrene-divinylbenzene copolymer.

3. The method of claim 1, wherein the material removal rate is controlled by adjusting the concentration of the solid medium in the electrolyte solution. for high roughness surfaces with Ra≥ 5 pm, current density range 400-600 mA / cm 2 with material removal rate of 1.5-3 pm / min; for surfaces with 5 pm > Ra≥ 1 pm, current density range 150-300 mA / cm 2 with material removal rate of 0.5-1.2 pm / min; for low roughness surfaces with Ra< 1 pm, current density range 40-80 mA / cm 2 with material removal rate of 0.1-0.2 pm / min.

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