CN116334644A - A large-scale plasma rust removal system and method for metal surfaces - Google Patents

Abstract

The application provides a metal surface rust removal method. The traditional plasma rust removal method uses hydrogen and hydrogen gas mixture as the plasma gas source, which is harmful and pollutes seriously, which is not conducive to industrial production. At the same time, the existing rust removal plasma system is mainly based on arc discharge plasma, which has poor stability, small rust removal area, and low uniformity, making it difficult to use on a large scale. This application adopts the water vapor glow discharge plasma system, the plasma source is water vapor, the cost is low, and the harm is small. The system can efficiently remove the surface rust layer of 3d orbital transition metals, especially metal copper, metal cobalt, and stainless steel surface rust layer. The metal surface after rust removal has high gloss, good uniformity and large rust removal area, which can provide important technical support for industrial production.

Description

A large-scale plasma rust removal system and method for metal surfaces

technical field

The present application relates to the field of metal derusting, in particular to a large-scale plasma derusting system and method for metal surfaces.

Background technique

Copper, pig iron, stainless steel, cobalt and other metals are metal parts widely used in chip processing and automobile engine manufacturing. Lively 3D transitional light metal materials are more likely to produce a rust layer on the surface, so in order to improve the reuse rate of metal parts, it is very necessary to derust the metal parts with rust stains on the surface.

Traditional chemical rust removal methods usually use strong acid to chemically react with metal oxides/hydroxides, the main components in rust stains, to generate soluble salts, so as to achieve the purpose of rust removal. However, during the treatment process, the strong acid will also react with the metal substrate to generate hydrogen gas, which will cause defects, grooves, and even cracks on the metal surface, seriously affecting its performance. At the same time, strong acid is extremely harmful and dangerous, which is not conducive to the needs of industrial production. Although based on strong acid, adding corrosion inhibitors, penetrants, accelerators and other rust removers can reduce the hazards of strong acids. For example, CN103789775A discloses a medical device rust remover, which is a colorless and transparent Mild and weakly acidic liquid, it will not irritate the human respiratory system and is relatively less harmful. CN106191878 discloses a rust remover for medical equipment and a preparation method thereof, which can reduce corrosion to metal equipment while maintaining the original rust removal efficiency. However, the main components of rust removers are still acid chemicals, and their preparation and use costs are still high, making it difficult to achieve the green and environmental protection indicators required by the current industry.

As a new technology in the field of rust removal, plasma surface rust removal technology has attracted extensive attention from research teams at home and abroad. This technology stimulates the active gas under high voltage to promote the chemical reaction between the active gas particles and the rust stains on the surface of the metal material to achieve the rust removal effect. CN107794548A discloses an atmospheric pressure plasma derusting strategy, adopts arc discharge technology, uses alcohol as a reaction source, excites it to generate arc plasma, and sprays it on the surface of metal materials for treatment. In addition, CN110860772A discloses a method of atmospheric pressure plasma surface rust removal, which uses compressed air as a plasma source, and blows the surface of metal materials by the plasma flow generated by breaking down the air, and removes rust stains through physical collisions. Remove cleanly.

Although the above methods have lower application cost and reuse value than acid corrosion and rust removal, they all face the problems of low single-treatment efficiency, slow processing speed, and poor uniformity. For large-area metal parts, such as the field of circuit board manufacturing Widely used large-area metal substrates such as copper brackets, the above strategies are difficult to meet their industrial needs. In addition, traditional plasma usually uses argon, nitrogen, air, etc. as the discharge gas. The active particles produced by the above gases in the plasma are extremely limited, and the rust removal effect is not good.

Contents of the invention

In view of the problems existing in the prior art, this application provides a method for large-area, fast and efficient treatment of rust stains on metal surfaces, especially copper, iron, cobalt, nickel, stainless steel and other materials widely used in chip processing and engine manufacturing fields . The method is carried out in a completely dry state without adding any chemical agent, and realizes effective removal of rust stains, and is especially suitable for material surfaces with complex structures.

In order to achieve the above object, the present application provides a method for derusting a metal surface by using low-temperature and low-pressure steam plasma, which is characterized in that the method uses low-temperature and low-pressure plasma to derust the metal surface.

Using low-temperature and low-pressure plasma to derust the metal surface specifically includes: passing water vapor as a reaction source into the glow plasma cavity, and exciting the water vapor through a glow discharge system to generate glow plasma, and then treating the metal surface Carry out rust removal treatment.

The principle is that water vapor dissociates in the glow discharge to form highly active hydrogen-containing particles, including hydrogen particles and hydroxide particles. Since the speed of electrons in the cavity is much higher than that of hydrogen-containing particles, the electrons will concentrate on the surface of the metal substrate. Make the metal surface form a negative electric sheath, and the hydrogen particles are positively charged, and under the influence of the negative electric sheath, they will preferentially contact the metal substrate, react with the oxide or hydroxide in the surface rust, and generate hydroxide or water molecules It leaves the metal surface in the form of a free state to achieve the effect of removing rust stains on the metal surface.

The plasma generated in the rust removal process of this application is glow plasma. The principle of generation is: the pressure of the cavity is low pressure discharge, and the water molecules exist in gaseous form in the cavity. The mean free path between the molecules is large, and the water molecules The molecules are evenly dispersed, thus generating a glow discharge. During the glow discharge process, the particle distribution follows the Maxwell-Boltzmann distribution, the particles are uniformly distributed in the cavity, and the stability is high, so it can achieve efficient rust removal on large-area metal surfaces.

In terms of metal substrates applicable to this application, metal copper, iron, nickel, and cobalt are metals that are easier to treat with water vapor plasma, because the metal iron, copper, nickel, and cobalt all belong to transition metals with 3d orbitals. In the process of forming rust stains, oxygen atoms in the air contact with metals to form metal oxides, and the chemical bonds come from the molecular orbitals where the 3d orbitals of transition metals combine with the 2p orbitals of oxygen atoms. Since the 3d orbital is far away from the nucleus of the transition metal, the attraction of the nucleus to the electrons on this orbital is weak. During the rust removal process, the highly active hydrogen particles are easy to combine with the 2p orbital of the oxygen atom to form a covalent bond, making it The formation of hydroxide ions detached from the metal surface. For alkali metals or alkaline earth metals that do not contain electrons in the 3d orbital, highly active hydrogen particles are difficult to remove rust stains on their surfaces.

Preferably, the water in the steam is selected from pure water or ultrapure water.

Preferably, the glow discharge system includes any one of microwave discharge, radio frequency discharge, and microsecond pulse discharge.

Preferably, the metal includes any one of copper, iron, pig iron, stainless steel, cobalt and nickel.

Preferably, the metal is any 3d transition metal device used in industry.

Preferably, the single treatment area of the metal is 1-500 cm ² , and the treatment thickness is 1-100 mm.

Preferably, the time for the low-temperature and low-pressure plasma derusting treatment is 1-200s, preferably 10-60s.

Preferably, the steam flow rate of the low-temperature and low-pressure plasma derusting treatment is 5-200 sccm, preferably 20-70 sccm.

Preferably, the chamber pressure of the low-temperature and low-pressure plasma derusting treatment is 5-200Pa, preferably 30-80Pa.

Preferably, the discharge power of the low-temperature glow plasma rust removal treatment is 10-1000W, preferably 100-600W.

Preferably, the electrode distance of the low-temperature glow plasma rust removal treatment is 50-1000 mm, preferably 200-500 mm.

Preferably, when the low-temperature and low-pressure plasma is derusting, the temperature of the glow plasma chamber is always kept at room temperature.

The application provides a system for derusting metal surfaces using low-temperature and low-pressure water vapor plasma. The system includes a glow plasma discharge system, a glow plasma chamber, and a control unit;

The control unit feeds water vapor into the glow plasma chamber as a reaction source, excites water vapor through the glow discharge system to generate glow plasma, and performs rust removal treatment on the metal surface;

The principle is that water vapor dissociates in the glow discharge to form highly active hydrogen-containing particles, including hydrogen particles and hydroxide particles. Since the speed of electrons in the cavity is much higher than that of hydrogen-containing particles, the electrons will concentrate on the surface of the metal substrate. Make the metal surface form a negative electric sheath, and the hydrogen particles are positively charged, and under the influence of the negative electric sheath, they will preferentially contact the metal substrate, react with the oxide or hydroxide in the surface rust, and generate hydroxide or water molecules It leaves the metal surface in the form of a free state to achieve the effect of removing rust stains on the metal surface.

Compared with the prior art solutions, the present application has at least the following beneficial effects:

1) This application is based on the low-temperature and low-pressure glow plasma technology, and provides an environmentally friendly method for removing rust on the surface of metal materials. It utilizes the physical and chemical interaction between highly active hydrogen particles in the plasma and the rust stains on the metal surface to achieve rust removal at room temperature. Efficient rust removal;

2) This application uses water vapor as raw material, does not use chemical reagents such as rust removers, and is environmentally friendly;

3) Compared with the existing arc plasma rust removal technology project, during the glow discharge process, the particle distribution follows the Maxwell-Boltzmann distribution, the particles are uniformly distributed in the cavity, and the stability is high, so large-area metal surfaces can be realized High-efficiency rust removal; the single treatment area of metal is 1-500cm ² , and the treatment thickness is 1-100mm. This method can be widely used in the surface rust removal of various industrial metal materials, and is of great significance to the innovation of rust removal methods;

Description of drawings

Fig. 1 is the water vapor glow plasma derusting system of the present application.

Figure 2 shows the unused copper support in chip processing.

Figure 3 is a copper bracket used many times in chip processing.

Fig. 4 is the copper stent after the water vapor plasma treatment.

Reference signs: 1. Glow discharge system, 2. Glow plasma cavity, 3. Metal sample, 4. Water vapor.

Detailed ways

The application will be further described in detail below. However, the following examples are only simple examples of the present application, and do not represent or limit the protection scope of the present application, and the protection scope of the present application shall be determined by the claims.

The method for removing rust on the surface of metal materials provided by the application, its rust removal effect is based on the hydrogen particles and hydroxide particles cracked by water vapor in glow discharge, through the chemical reaction between the above highly active particles and the rust stains on the surface of metal materials, Restore rust stains to simple metal, so as to achieve the effect of rust removal.

The principle of rust removal in this application mainly includes: water vapor dissociates in glow discharge to form highly active hydrogen-containing particles, including hydrogen particles and hydroxide particles. Since the speed of electrons in the cavity is much higher than that of hydrogen-containing particles, It will concentrate on the surface of the metal substrate, forming a negative electric sheath on the metal surface. The hydrogen particles are positively charged, and will preferentially contact the metal substrate under the influence of the negative electric sheath, and react with the oxide or hydroxide in the surface rust to form Hydroxide or water molecules leave the metal surface in a free state to achieve the effect of removing rust stains on the metal surface. At the same time, because of the negative charge, the free hydroxide particles are difficult to enter the negatively charged sheath region and cannot participate in the reaction. The effective derusting ingredient is hydrogen particles in water vapor plasma.

The plasma source used in this application is water vapor, without introducing any non-reactive gas, with low cost and little harm. The reaction chamber is in a low-pressure environment, and water vapor will exist stably in the chamber in the form of gas instead of liquid, which ensures the uniformity of the reaction source in the reaction chamber, thereby promoting high uniformity and stability during the discharge process. It has good performance and can realize large-scale rust removal on the surface of metal materials.

Since the highly active hydrogen particles generated in the plasma are independent of the metal substrate, this application can treat any industrial light metal, such as copper, iron, stainless steel, etc.

According to a method for derusting the surface of metal materials of the present application, especially copper metal and stainless steel widely used in industry, the treatment includes low-pressure plasma surface derusting, and the surface rust layer includes metal oxidation produced during the use of metal-based devices. substances or hydroxide rust layer, including polymer impurities contaminated on the surface. The method specifically includes the following steps: the low-temperature plasma surface derusting treatment is to pass water vapor into the cavity as a reaction source, excite the water vapor through a discharge system to generate glow plasma, and perform derusting treatment on the surface of the metal material .

The technical solution of the present application will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

Embodiment 1: In this embodiment, a radio frequency capacitive discharge system is used, and a metal copper sheet with rust stains on the surface is put into the cavity, and the size of the copper sheet is 100 cm ² . The formation process of the glow plasma is that electrodes are connected to both sides of the cavity, the reaction cavity is evacuated, water vapor is introduced, the steam flow rate is adjusted, the pressure of the cavity is controlled at 40Pa, and the reaction power is adjusted to 500W, The electrode spacing is 300mm. The plasma treatment time on the copper surface is 10s. After the treatment, by visual inspection, it is detected that the rust spots on the surface of the metal copper are all removed, and the surface of the metal copper presents the original luster.

Embodiment 2: In this embodiment, a radio frequency inductive discharge system is used, and stainless steel with rust stains on the surface is put into the cavity, and the size of the stainless steel is 50 cm ² . The formation process of the glow plasma is that electrodes are connected to both sides of the cavity, the reaction cavity is evacuated, water vapor is introduced, the steam flow rate is adjusted, the pressure of the cavity is controlled at 20Pa, and the reaction power is adjusted to 100W, The electrode spacing is 200mm. The plasma treatment time of the stainless steel surface is 30s. After treatment, by visual inspection, it is detected that all the rust spots on the surface of the stainless steel are removed, and the surface of the stainless steel presents the original luster.

Embodiment 3: In this embodiment, a microwave discharge system is used to put a metal copper sheet with rust stains on the surface into the cavity, and the size of the stainless steel is 200 cm ² . The formation process of the glow plasma is that electrodes are connected to both sides of the cavity, the reaction cavity is evacuated, water vapor is introduced, the steam flow rate is adjusted, the pressure of the cavity is controlled at 40Pa, and the reaction power is adjusted to 300W, The electrode spacing is 500mm. The plasma treatment time of stainless steel surface is 5s. After treatment, by visual inspection, it is detected that the rust spots on the surface of the copper sheet are all removed, and the surface of the copper sheet presents the original luster.

Embodiment 4: In this embodiment, a nanosecond pulse discharge system is used, and pig iron with rust stains on the surface is put into the cavity, and the size of the pig iron is 30 cm ² . The formation process of the glow plasma is that the electrodes are connected to both sides of the cavity, the reaction cavity is evacuated, water vapor is introduced, the steam flow rate is adjusted, the cavity pressure is controlled at 10Pa, and the reaction power is adjusted to 200W, The electrode spacing is 700mm. The plasma treatment time of stainless steel surface is 10s. After the treatment, the rust spots on the surface of the pig iron are all removed by visual inspection, and the surface of the pig iron presents the original luster.

Embodiment 5: In this embodiment, a nanosecond pulse discharge system is used to put a cobalt sheet with rust stains on the surface into the cavity, and the size of the cobalt sheet is 80 cm ² . The formation process of the glow plasma is that electrodes are connected to both sides of the cavity, the reaction cavity is evacuated, water vapor is introduced, the steam flow rate is adjusted, the pressure of the cavity is controlled at 30Pa, and the reaction power is adjusted to 400W, The electrode spacing is 400mm. The plasma treatment time for the surface of the cobalt sheet is 60s. After the treatment, the rust spots on the surface of the cobalt flakes are all removed by visual inspection, and the cobalt

Embodiment 6: In this embodiment, a nanosecond pulse discharge system is used to put a nickel sheet with rust stains on the surface into the cavity, and the size of the cobalt sheet is 50 cm ² . The formation process of the glow plasma is that electrodes are connected to both sides of the cavity, the reaction cavity is evacuated, water vapor is introduced, the steam flow rate is adjusted, the pressure of the cavity is controlled at 40Pa, and the reaction power is adjusted to 150W, The electrode spacing is 300mm. The time for the plasma treatment on the surface of the nickel sheet is 30s. After the treatment, by visual inspection, it is detected that the rust spots on the surface of the nickel sheet are all removed, and the surface of the nickel sheet presents the original luster.

Embodiment 7: In this embodiment, a nanosecond pulse discharge system is used, and an iron sheet with rust stains on the surface is put into the cavity, and the size of the iron sheet is 20 cm ² . The formation process of the glow plasma is that electrodes are connected to both sides of the cavity, the reaction cavity is evacuated, water vapor is introduced, the steam flow rate is adjusted, the pressure of the cavity is controlled at 25Pa, and the reaction power is adjusted to 250W, The electrode spacing is 200mm. The plasma treatment time on the surface of the iron sheet is 15s. After treatment, by visual inspection, it is detected that the rust spots on the surface of the iron sheet are completely removed, and the surface of the nickel sheet presents the original luster.

As shown in Figure 1, it is the water vapor glow plasma rust removal system of the present application. The rust removal system uses water vapor 4 as a reaction source into the glow plasma cavity 2, and the water vapor 4 is excited by the glow discharge system 1. Glow plasma is generated to derust the surface of the metal sample 3 .

As shown in Figure 2, it is an unused copper bracket in chip processing, and its surface is smooth; as shown in Figure 3, it is a copper bracket that has been used many times in chip processing, and its surface has obvious rust stains; as shown in Figure 4 , the surface of the copper bracket is smooth and clean after using the derusting method provided by the application for derusting.

The above is only the preferred embodiment of the application, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the application, some improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of this application.

In addition, it should be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way if there is no contradiction. The combination method will not be described separately.

In addition, any combination of various implementations of the present application can also be made, as long as they do not violate the idea of the present application, they should also be regarded as the content disclosed in the present application.

Claims (10)

1. A metal surface derusting method utilizing low-temperature and low-pressure water vapor plasma, characterized in that, the method is to utilize low-temperature and low-pressure plasma to derust the metal surface; Use low-temperature and low-pressure plasma to derust the metal surface, specifically: water vapor is introduced into the glow plasma chamber as a reaction source, and the water vapor is excited by a glow discharge system to generate glow plasma, and the metal surface is derusted. Rust removal treatment on the surface; The principle is that water vapor dissociates in the glow discharge to form highly active hydrogen-containing particles, including hydrogen particles and hydroxide particles. Since the speed of electrons in the cavity is much higher than that of hydrogen-containing particles, the electrons will concentrate on the surface of the metal substrate. A negative electric sheath is formed on the metal surface, and hydrogen particles are positively charged. Under the influence of the negative electric sheath, they will preferentially contact the metal substrate, react with oxides or hydroxides in the surface rust, and generate hydroxide or water. Molecules leave the metal surface in a free state to remove rust stains on the metal surface. 2. metal surface derusting method according to claim 1, is characterized in that, the water of described steam is selected from pure water or ultrapure water. 3. The metal surface rust removal method according to claim 1, wherein the glow discharge system includes any one of microwave discharge, radio frequency discharge, and microsecond pulse discharge. 4. The metal surface derusting method according to claim 1, wherein the metal comprises any one of copper, iron, pig iron, stainless steel, cobalt, and nickel. 5. The metal surface derusting method according to claim 1, characterized in that, the metal is any 3d transition metal device used in industry. 6 . The method for derusting metal surfaces according to claim 1 , characterized in that, the single treatment area of the metal is 1-500 cm ² , and the treatment thickness is 1-100 mm. 7 . 7. The method for derusting metal surfaces according to claim 1, characterized in that, the time for the low-temperature and low-pressure plasma derusting treatment is 1-200s. 8 . The surface derusting method according to claim 1 , characterized in that, when the low-temperature and low-pressure plasma is derusting, the temperature of the glow plasma chamber is always kept at room temperature. 9. A metal surface derusting system utilizing low-temperature and low-pressure water vapor plasma, characterized in that the system includes a glow plasma discharge system, a glow plasma cavity, and a control unit; The control unit feeds water vapor into the glow plasma chamber as a reaction source, excites water vapor through the glow discharge system to generate glow plasma, and performs rust removal treatment on the metal surface; The principle is that water vapor dissociates in the glow discharge to form highly active hydrogen-containing particles, including hydrogen particles and hydroxide particles. Since the movement speed of electrons in the cavity is much faster than that of hydrogen-containing particles, the electrons will concentrate on the surface of the metal substrate , so that the metal surface forms a negative electric sheath, and the hydrogen particles are positively charged, and under the influence of the negative electric sheath, they will preferentially contact the metal substrate, react with the oxide or hydroxide in the surface rust, and generate hydroxide or water Molecules leave the metal surface in a free state to remove rust stains on the metal surface. 10. A surface derusting system according to claim 1, characterized in that, during derusting, the temperature of the glow discharge plasma cavity is always kept at room temperature.

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