CN203498467U - Device for depositing film on internal surface of long pipe by using plasma enhanced chemical vapor deposition - Google Patents

Abstract

The utility model belongs to the field of material surface modification, and relates to a device for depositing thin films on the inner surface of a long tube by using plasma enhanced chemical vapor deposition, which solves the inhomogeneity of the axial plasma discharge in the tube in the existing PECVD method, and directly causes Problems such as poor uniformity of surface axial film deposition. The slender metal tube to be processed is placed in a tubular vacuum chamber, a tungsten wire electrode is placed axially in the center of the metal tubular workpiece, the working gas is introduced into the metal tube, and a DC pulse is applied between the tungsten wire electrode and the wall of the vacuum chamber or radio frequency signal to stimulate the discharge to generate plasma. The enameled wire is wound outside the vacuum chamber to form an electromagnetic coil, and the electromagnetic coil is connected to a DC regulated power supply to generate an electromagnetic field. The magnetic field is used to confine and control the plasma beam, so as to achieve the purpose of uniformly depositing a thin film on the inner wall of the tube by the plasma, and is suitable for coating the inner wall surface of the tubular workpiece as the service surface.

Description

Device for Depositing Thin Films on the Inner Surface of Long Tubes by Plasma-Enhanced Chemical Vapor Deposition

Technical field:

The utility model belongs to the field of material surface modification, and relates to a device for depositing thin films on the inner surface of long tubes by using plasma enhanced chemical vapor deposition.

Background technique:

In industrial applications, the inner surface of a large number of metal workpieces needs to be modified, especially for pipe fittings, such as oil pump barrels on oil fields, oil pipelines, chemical pipelines, automobile cylinder liners, and military fields, especially on naval ships. For naval gun barrels, torpedo tubes, and other tubular parts whose inner walls need to be strengthened in harsh environments, ordinary treatment methods cannot meet the surface strengthening requirements. These workpieces often fail early due to inner wall wear, corrosion, and oxidation. Therefore, the development of surface modification technologies and processes with anti-wear, anti-corrosion, and anti-oxidation is an urgent problem in the field of surface modification.

Compared with the outer surface of the workpiece, the modification of the inner wall of the tubular workpiece mainly has the following technical problems: First, due to the limitation of the shape and size of the inner cavity, some treatment methods are difficult to implement, or even if it can be implemented, it is difficult A good modification effect is obtained, especially for some slender pipes. Second, limited by the shape and size of the lumen, it is difficult for some treatment media to enter the lumen, or even if it enters, it is difficult to ensure the uniformity of the modified layer. Third, limited by the shape and size of the inner cavity, the bonding strength between the modified layer and the pipe wall is not high, which limits the performance of its service performance.

For the modification of the inner wall of metal pipes, it was first proposed to use electroplating and electroless plating for treatment. However, electroless plating is harmful to the environment due to the frequent use of harmful chemicals, and the compactness of the coating is poor; although electroplating reduces the use of harmful chemicals, and the compactness of the coating is better than that of electroless plating, it still has poor bonding during use and is easy to Peeling problem.

The chemical vapor deposition (CVD) method is easier to deposit workpieces with complex shapes due to the use of gas media. As long as the workpiece is immersed in the working gas, the desired film can be deposited on the surface. The coating on the inner surface of the tubular workpiece is just using this characteristic of the CVD method, and some improved methods have been proposed, including various plasma-enhanced CVD (PECVD) methods. Most of the deposited films are diamond-like carbon (DLC) or TiN films. The high hardness, wear resistance and corrosion resistance of these hard films are used to increase the service life of the workpiece.

Uruguay's Elites Co., Ltd. announced a plasma system for plasma-enhanced chemical vapor deposition (plasma system. Invention patent: 200880127994.6). The system uses the tube to be processed as a vacuum chamber and inserts a same Axial electrode, applying high-frequency field, microwave field, pulse energy field, RF field, CC field, AC field, etc. between the electrode and the tube wall, ionizes the gas introduced into the vacuum chamber to generate plasma, so as to achieve in-tube Thin films deposited on the surface. The advantage of this system is that the treated tube is directly used as a vacuum chamber, the outer wall of the tube does not need special treatment, and it does not require a huge plasma reactor and is easy to carry. However, the uniformity of the film on the inner wall of the tube still needs to be improved.

Xiong Yuqing and others from the 510th Research Institute of the Fifth Research Institute of China Aerospace Science and Technology Corporation proposed a method of coating thin films on the inner walls of slender pipes (a method of coating thin films on the inner walls of slender pipes. Invention patent: 201110283626.4), the method is to place the pipe to be coated in the reaction chamber, and alternately pass the gas-phase precursor into the reactor in the form of pulses. After the first precursor reaches the pipe, it will be chemically adsorbed on the inner wall of the pipe to form a single adsorption layer. ; Then feed the second precursor to react with the first precursor to form a monoatomic layer film on the inner wall of the pipeline. Inert gas cleaning is required between each precursor pulse, and the adsorption and reaction process is repeated to form thin films layer by layer. This method can plate various metals, oxides, nitrides and other film materials on the inner wall of the slender pipe, but the film and the substrate are only combined by chemical adsorption, the bonding force is poor, and the film thickness is relatively thin.

Ralph Stein of Germany also announced a plasma-assisted chemical vapor deposition method and device (a method and device for plasma-assisted chemical vapor deposition on the inner wall of a hollow body. Invention patent: 200780026008.3), which is to be processed The hollow main body is placed in the vacuum chamber, and the large-area radio frequency electrode is placed inside the vacuum chamber. The gas-fuel spray gun is placed in the hollow main body. After the gas is introduced, the plasma chamber is ignited by applying a radio-frequency electric field to the RF electrode. The tip forms a plasma cloud to achieve coating on the inner wall of the hollow body. The device can deposit DLC, TiO _x , SiO ₂ and other coatings, but due to the limitation of the outer diameter of the gas-fired spray gun, the coating on the inner wall of the pipe with an inner diameter of less than 20mm cannot be produced.

Wen Xiaoqiong and Wang Dezhen from Dalian University of Technology invented a method of depositing a diamond-like film on the inner wall of a slender metal tube by DC glow discharge (invention patent: 200610200503.9). This method sets a tungsten wire on the axis of the slender metal tube , form a coaxial electrode with the metal tube. The tungsten wire is used as the anode, and the gas is passed into the vacuum chamber, and a constant DC negative bias is applied to the metal tube to form a strong electric field area around the anode tungsten wire, causing gas discharge, thereby producing a stable cylindrical shape in the entire metal tube. DC glow plasma achieves the purpose of uniformly depositing diamond-like film on the inner surface of the metal tube. The method can process the deposition of diamond-like films on the inner surface of metal tubes with a diameter of more than 5 mm and a length of 5-2000 mm. The types of deposited films are limited, and the bonding force of the film base still needs to be improved.

Israel announced a method of depositing coatings on the inner surface of a tube by chemical vapor deposition (US4764398) (Method of depositing coatings on the inner surface of a tube by chemical vapordeposition), and obtained a US patent, but it is mainly used for depositing solar energy absorption coating.

Although PECVD has solved the technical problems of the modification of the inner wall of the tube to a certain extent, and the quality of the modification has been greatly improved, there are still some problems to be solved. Especially as the inner diameter of the tube becomes smaller or the length becomes larger, the glow discharge becomes more and more difficult to maintain inside the tube. At some point, the plasma even jumped outside the tube, even though a center electrode was inserted to promote plasma stability. This not only affects the uniformity of the axial plasma discharge in the tube, but also directly causes the poor uniformity of the axial film deposition on the inner surface of the tube.

Utility model content:

The purpose of this utility model is to provide a method for depositing a film on the inner surface of a long tube by plasma enhanced chemical vapor deposition, which solves the inhomogeneity of the axial plasma discharge in the tube in the existing PECVD method, and directly causes the axial film on the inner surface of the tube Problems such as poor deposition uniformity.

The technical scheme of the utility model is:

A plasma-enhanced chemical vapor deposition device for depositing thin films on the inner surface of a long tube adopts a magnetic field-enhanced plasma-enhanced chemical vapor deposition device.

The device for depositing thin films on the inner surface of a long tube by plasma-enhanced chemical vapor deposition, the device is to place the metal tubular workpiece to be processed in a tubular vacuum chamber, and a tungsten wire electrode is arranged axially in the center of the metal tubular workpiece, and the tungsten wire Both ends of the electrode are led out through the sealing flange of the vacuum chamber, a DC pulse power supply or a radio frequency power supply is connected between the tungsten wire electrode and the vacuum chamber wall, and an enameled wire is wound outside the vacuum chamber to form an electromagnetic coil.

The device for depositing thin films on the inner surface of long tubes by plasma-enhanced chemical vapor deposition includes: DC pulse power supply or radio frequency power supply, tungsten wire electrode, tubular workpiece, vacuum chamber, coil rotating chain transmission device, electromagnetic coil, air intake pipe , the specific structure is as follows:

The tubular workpiece is set in the vacuum chamber, and the tungsten wire electrode is pierced through the tubular workpiece. The positive pole of the DC pulse power supply or the RF power supply is connected to the tungsten wire electrode, and the negative pole of the DC pulse power supply or the RF power supply is connected to the tubular workpiece; a coil rotation chain is set outside the vacuum chamber. Transmission device, the coil rotation chain transmission device is provided with an electromagnetic coil outside; one end of the air intake pipe extends into the tubular workpiece, and the other end of the air intake pipe extends to the outside of the vacuum chamber to connect with the gas cylinder.

The device for depositing a thin film on the inner surface of a long tube by using plasma enhanced chemical vapor deposition, and a heater is arranged inside the vacuum chamber.

In the device for depositing thin films on the inner surface of long tubes by using plasma enhanced chemical vapor deposition, sealing flanges are respectively arranged at both ends of the vacuum chamber.

The device for depositing a thin film on the inner surface of a long tube by plasma-enhanced chemical vapor deposition, and a gas mass flowmeter is arranged on the inlet tube.

The device for depositing thin films on the inner surface of the long tube by plasma-enhanced chemical vapor deposition, the coil rotating chain transmission device is connected to the chain transmission motor, and the chain transmission motor is connected to the chain transmission motor power supply.

In the device for depositing a thin film on the inner surface of a long tube by using plasma enhanced chemical vapor deposition, the tubular workpiece has a through-hole or blind-hole structure.

A method of depositing a film on the inner surface of a long tube by plasma-enhanced chemical vapor deposition. The metal tubular workpiece to be processed is placed in a tube-shaped vacuum chamber, and a tungsten wire electrode is arranged in the central axis of the metal tubular workpiece. Both ends of the electrode pass through the vacuum chamber. The chamber sealing flange is drawn out, and a DC pulse power supply or a radio frequency power supply is connected between the tungsten wire electrode and the vacuum chamber wall, which not only stimulates the discharge to generate plasma, but also establishes a bias electric field inside the tube to accelerate the plasma to improve the film thickness. base binding force; the enameled wire is wound outside the vacuum chamber to form an electromagnetic coil, and the electromagnetic coil is connected to a DC regulated power supply to generate an electromagnetic field; the magnetic field and electric field are used to confine and control the plasma, so as to achieve the purpose of plasma depositing a thin film on the inner wall of a metal tubular workpiece.

In the method of depositing a thin film on the inner surface of a long tube by plasma-enhanced chemical vapor deposition, the electromagnetic coil is fixed on a sprocket system, the sprocket system is connected to a DC motor, and the DC motor is connected to a DC power supply. After the DC power supply is energized, the motor rotates to Drive the sprocket system to rotate around its own axis, and further realize the synchronous rotation of the electromagnetic coil and the sprocket system.

The method for depositing thin films on the inner surface of long tubes by plasma-enhanced chemical vapor deposition uses plasma-enhanced chemical vapor deposition to deposit thin films. The specific process is as follows: the metal tubular workpiece to be processed is cleaned and dried and then placed in a tubular vacuum chamber. Vacuumize until the vacuum degree in the vacuum chamber reaches 5×10 ^-3 Pa～1×10 ^-2 Pa, introduce the working gas, the pressure is 1～100Pa, turn on the DC pulse power supply or RF power supply to stimulate the discharge to generate plasma, which will damage the metal The surface of the tubular workpiece is sputtered and cleaned for 5 to 40 minutes; at the same time, the heater is turned on to heat the vacuum chamber to the required temperature of 300 to 700°C; The flow ratio of the reactive gas to the working gas is 3-5:1, the air pressure is 1-600Pa, and the reactive gas is discharged to generate plasma; at the same time, the electromagnetic coil current is adjusted to 0.5-10A, and the magnetic induction range is 100-3000 Gauss. The DC power supply drives the DC motor and the sprocket to rotate. The rotation rate is 5-20 rpm, and the coating time is 20-120 minutes. In, continue to evacuate until the workpiece cools down to below 100°C with the furnace, the coating process is over, open the vacuum chamber, and take out the workpiece.

In the method for depositing thin films on the inner surface of long tubes by using plasma enhanced chemical vapor deposition, the voltage of the DC pulse power supply is 1-100kV, the frequency is 1-100kHz, and the duty cycle is 5-85%, which is continuously adjustable.

The method for depositing a thin film on the inner surface of a long tube by plasma enhanced chemical vapor deposition is characterized in that the working gas is argon, krypton or gas.

In the method of depositing thin films on the inner surface of long tubes by plasma enhanced chemical vapor deposition, the reaction gases are CH ₄ , C ₂ H ₂ , H ₂ , TiCl ₄ , NH ₃ , SiCl ₄ , AlCl ₃ , O ₂ and H ₂ gases One or more of them are mixed.

In the method for depositing a thin film on the inner surface of a long tube by plasma enhanced chemical vapor deposition, the metal tubular workpiece is a metal mold with a tube hole structure with a length of 20-1000 mm.

In the method for depositing a thin film on the inner surface of a long tube by plasma enhanced chemical vapor deposition, the metal tubular workpiece is a long metal tube with a tube hole structure with a diameter of 10-200 mm, a length of 20-1000 mm, and a wall thickness of 1-20 mm.

In the method for depositing a thin film on the inner surface of a long tube by plasma enhanced chemical vapor deposition, the metal tubular workpiece is a metal part with a tube hole structure and a length of 20-1000 mm.

The core idea of the utility model is: in order to effectively improve the utilization efficiency of the plasma, improve the axial uniformity of the plasma inside the tube and the film deposition efficiency, after the plasma is generated by the discharge in the tube, the magnetic field generated by the electromagnetic coil and the plasma The interaction of the plasma beam is restricted and controlled, and a sprocket system is driven by a motor to control the rotation of the electromagnetic coil around the central axis, thereby ensuring the uniformity of the film deposition on the inner wall of the lumen to a large extent. In addition, in order to strengthen the good combination of ions and the inner wall, a pulsed electric field is set inside the lumen, and a pulsed negative bias is applied to the tube wall to accelerate the positive ions to ensure a good combination of the film and the inner wall of the tube.

The beneficial effects of the utility model are:

1. The utility model uses a magnetic field to focus and restrain the diffusion of the plasma beam in the tube, which largely ensures the utilization efficiency of the plasma beam.

2. The utility model uses the electromagnetic field generated by the electromagnetic coil to constrain the plasma, and adjusts the magnetic induction intensity by adjusting the current of the electromagnetic coil. The parameters are adjustable and convenient, making it easy to control the focusing and restraint of the plasma beam by the electromagnetic field.

3. The utility model applies a DC pulse power supply to the tubular workpiece, forms a pulsed negative bias electric field in the tube, and accelerates the positive ions to ensure a good combination of the film and the inner wall of the tube.

4. The utility model adopts a relative rotation between the tube and the electromagnetic coil, and uses a motor to drive a sprocket system to control the axial rotation of the electromagnetic coil around the center, further improving the axial uniformity of the film in the tube.

5. The utility model solves the technical problem of uneven PECVD coating on the inner wall of long tubes, and uses the interaction of magnetic field and electric field with plasma to effectively improve the uniformity and deposition quality of the coating on the inner wall of tubular workpieces. Compared with the conventional coating process Ratio, the axial uniformity of the film in the tube is increased to more than 80%, especially suitable for the inner surface coating of the tubular workpiece with the inner wall as the service surface, effectively improving its service life.

Description of drawings

FIG. 1 is a schematic diagram of relative positions of a PECVD device using magnetic field enhancement and a tubular workpiece according to the present invention, wherein the tubular workpiece has a through-hole structure.

Fig. 2 is a schematic diagram of relative positions of a PECVD device using magnetic field enhancement and a tubular workpiece according to the present invention, wherein the tubular workpiece has a blind hole structure.

In the figure, 1 DC pulse power supply or radio frequency power supply; 2 tungsten wire electrode; 3 tubular workpiece; 4 vacuum chamber; 5 heater; 6 coil rotating chain transmission device; 7 electromagnetic coil; Mass flow meter; 11 cylinders; 12 chain drive motor; 13 chain drive motor power supply.

Detailed ways:

As shown in Fig. 1-Fig. 2, the PECVD device adopting magnetic field enhancement of the utility model mainly includes: DC pulse power supply or radio frequency power supply 1, tungsten wire electrode 2, tubular workpiece 3, vacuum chamber 4, heater 5, coil rotating chain Transmission device 6, electromagnetic coil 7, sealing flange 8, intake pipe 9, gas mass flow meter 10, gas cylinder 11, chain drive motor 12, chain drive motor power supply 13, etc. The specific structure is as follows:

The tubular workpiece 3 is set in the vacuum chamber 4, the tungsten wire electrode 2 is pierced through the tubular workpiece 3, the positive pole of the DC pulse power supply or the radio frequency power supply 1 is connected to the tungsten wire electrode 2, and the negative pole of the DC pulse power supply or the radio frequency power supply 1 is connected to the tubular workpiece 3; The inner side of the vacuum chamber 4 is provided with a heater 5, the outer side of the vacuum chamber 4 is provided with a coil rotating chain transmission device 6, the outer side of the coil rotating chain transmission device 6 is provided with an electromagnetic coil 7, and the two ends of the vacuum chamber 4 are respectively provided with sealing flanges 8 for further One end of the gas pipe 9 extends into the tubular workpiece 3, the other end of the air inlet pipe 9 extends to the outside of the vacuum chamber 4 to connect to the gas cylinder 11, and the gas mass flow meter 10 is arranged on the air inlet pipe 9; the coil rotation chain transmission device 6 and the chain transmission motor 12 Transmission connection, chain drive motor 12 and chain drive motor power supply 13. In the utility model, the tubular workpiece 3 is a through hole or blind hole structure.

The metal tubular workpiece 3 to be processed is placed in the tubular vacuum chamber 4, and a tungsten wire electrode 2 is arranged axially in the center of the metal tubular workpiece 3. The two ends of the tungsten wire electrode 2 are drawn out through the vacuum chamber sealing flange 8, and the A DC pulse power supply or RF power supply 1 is connected between the wire electrode 2 and the wall of the vacuum chamber 4, which can not only stimulate the discharge to generate plasma, but also establish a bias electric field inside the tube to accelerate the plasma to improve the bonding force of the film base The enameled wire is wound outside the vacuum chamber 4 to form an electromagnetic coil 7, and the electromagnetic coil 7 is connected to a DC stabilized power supply to generate an electromagnetic field; the plasma is restrained and controlled by the magnetic field and the electric field, so as to realize the deposition of a thin film on the inner wall of the metal tubular workpiece 3 by the plasma Purpose. The electromagnetic coil 7 is fixed to a sprocket system (coil rotating chain drive 6), the sprocket system is connected to a DC motor (chain drive motor 12), the DC motor is connected to a DC power supply (chain drive motor power supply 13), and the DC After the power is turned on, the motor rotates to drive the sprocket system to rotate around its own axis, further realizing the synchronous rotation of the electromagnetic coil and the sprocket system.

The utility model utilizes the magnetic field to constrain and control the plasma during the plasma chemical vapor deposition film process, and utilizes the electric field to accelerate the directional flow of the plasma, thereby ensuring the uniformity of the film deposition on the inner wall of the tube cavity to a large extent. The bonding force with the film base, so as to achieve the purpose of uniformly depositing a thin film on the inner surface of the metal tubular workpiece by plasma.

After cleaning and drying the metal tubular workpiece 3 to be processed, place it in the tubular vacuum chamber 4, and pump the vacuum until the vacuum degree in the vacuum chamber 4 reaches 5×10 ^-3 Pa～1×10 ^-2 Pa, and then inject the working gas, The air pressure is 1-100 Pa, the pulse or radio frequency power supply is turned on to stimulate the discharge to generate plasma, and the surface of the metal tubular workpiece 4 is sputtered and cleaned for 5-40 minutes. At the same time, turn on the heater 5 to heat the temperature of the vacuum chamber 4 to the required temperature (300-700°C); after that, the reaction gas or the mixed gas of the reaction gas and the working gas (the reaction gas and the working gas in the mixed gas) are introduced into the vacuum chamber 4 The gas flow ratio is 3-5:1), the pressure is 1-600Pa, and the reactive gas is discharged to generate plasma. At the same time, adjust the electromagnetic coil current to 0.5-10A, and the magnetic induction range is 100-3000 gauss, turn on the DC power supply (chain drive motor power supply 13), and drive the DC motor (chain drive motor 12) and sprocket (coil rotation chain drive device 6) Rotate, the rotation rate is 5-20 rpm, and the coating time is 20-120 minutes; after the coating is completed, quickly turn off the pulse or radio frequency power supply, turn off the DC power switch, stop the gas supply, and continue to vacuum until the workpiece cools down with the furnace. Below 100°C, the coating process is over, open the vacuum chamber, and take out the workpiece.

In the utility model, the magnetic field generating device placed in the tubular vacuum chamber is an electromagnetic coil with a wire diameter of 0.3-2.5 mm and a winding density of 10-100 turns/mm. The electromagnetic coil is supported by a support cylinder whose outer diameter is 200 ~500mm, the length is 200~2000mm, the magnetic field strength can be adjusted by adjusting the current of the electromagnetic coil.

In the utility model, the voltage of the DC pulse power supply is 1-100kV, the frequency is 1-100kHz, and the duty ratio is 5-85%, which is continuously adjustable.

In the utility model, the metal tubular workpiece is a metal mold with a length of 20-1000 mm and a tube hole structure.

In the utility model, the metal tubular workpiece is a long metal tube with a tube hole structure with a diameter of 10-200mm, a length of 20-1000mm, and a wall thickness of 1-20mm.

In the utility model, the metal tubular workpiece is a metal part with a tube hole structure and a length of 20-1000 mm.

Example 1

Clean and dry a long stainless steel tube with an inner diameter of Φ50mm, a wall thickness of 5mm, and a length of 300mm with a through hole, and place it in a tube-shaped vacuum chamber, as shown in Figure 1, and evacuate until the vacuum degree in the vacuum chamber reaches 7×10 At ^-3 Pa, argon gas is introduced, the pressure is 20 Pa, the DC pulse power supply is turned on to stimulate the discharge to generate plasma, and the surface of the metal tubular workpiece is sputtered and cleaned for 20 minutes. At the same time, turn on the heater to heat the temperature of the vacuum chamber to 300°C; after that, introduce acetylene gas into the vacuum chamber, adjust the flow ratio of acetylene gas to argon gas to 5:1, adjust the air pressure to 5.0Pa, and turn on the DC pulse power supply to The reactant gas is excited to discharge to generate a plasma. At the same time, adjust the current of the electromagnetic coil to 2A, the range of magnetic induction intensity to 1200 gauss, turn on the DC power supply, drive the DC motor and the sprocket to rotate, the rotation rate is 5 rpm, and the coating time is 30 minutes; after the coating is completed, quickly turn off the DC pulse power supply , turn off the DC power switch, stop the gas supply, continue vacuuming until the workpiece cools down to below 100°C with the furnace, the coating process is over, open the vacuum chamber, and take out the workpiece. In this embodiment, the voltage of the DC pulse power supply is 50kV, the frequency is 50kHz, and the duty cycle is 40%.

In this embodiment, a diamond-like carbon (DLC) film can be deposited on the inner surface of the stainless steel tube with an inner diameter of Φ50mm. The film is uniform and dense. Grinding performance, thereby improving the service life of stainless steel pipes.

Example 2

Clean and dry a Φ50×80mm stainless steel tube with a Φ25×60mm blind hole, and place it in a tubular vacuum chamber, as shown in Figure 2. Unlike Figure 1, the stainless steel tube to be treated has a blind hole structure. After evacuating until the vacuum degree in the vacuum chamber reaches 6×10 ^-3 Pa, introduce argon gas at a pressure of 10 Pa, turn on the DC pulse power supply to stimulate the discharge to generate plasma, and perform sputter cleaning on the surface of the metal tubular workpiece for 30 minutes. At the same time, turn on the heater to heat the temperature of the vacuum chamber to 350°C; after that, introduce acetylene gas into the vacuum chamber, adjust the flow ratio of acetylene gas to argon gas to 4:1, adjust the air pressure to 4.0Pa, and turn on the DC pulse power supply to The reactant gas is excited to discharge to generate a plasma. At the same time, adjust the current of the electromagnetic coil to 3A, the range of magnetic induction intensity to 1800 Gauss, turn on the DC power supply, drive the DC motor and the sprocket to rotate, the rotation rate is 5 rpm, and the coating time is 120 minutes; after the coating is completed, quickly turn off the DC pulse power supply , turn off the DC power switch, stop the gas supply, continue vacuuming until the workpiece cools down to below 100°C with the furnace, the coating process is over, open the vacuum chamber, and take out the workpiece. In this embodiment, the voltage of the DC pulse power supply is 10kV, the frequency is 60kHz, and the duty cycle is 30%.

In this embodiment, a diamond-like carbon (DLC) film can be deposited on the inner surface of the stainless steel tube with an inner diameter of Φ25mm. The film is uniform and dense. Grinding performance, thereby improving the service life of stainless steel pipes.

Example 3

After cleaning and drying the Φ50×200mm low-carbon steel parts with Φ40×200mm through holes, place them in a tubular vacuum chamber, as shown in Figure 1, and evacuate until the vacuum degree in the vacuum chamber reaches 5×10 ^-3 Pa , into the argon gas, the pressure is 8Pa, turn on the DC pulse power supply to stimulate the discharge to generate plasma, and perform sputter cleaning on the surface of the metal tubular workpiece for 10 minutes. At the same time, turn on the heater to heat the temperature of the vacuum chamber to 400°C; after that, a mixed gas of TiCl ₄ and NH ₃ is introduced into the vacuum chamber, the gas ratio is 1:1, and the air pressure is adjusted to 200Pa, and the DC pulse power supply is turned on to stimulate the reaction The gas is discharged to create a plasma. At the same time, adjust the electromagnetic coil current to 2A, the magnetic induction intensity range to 1200 Gauss, turn on the DC power supply, drive the DC motor and the sprocket to rotate, the rotation rate is 10 rpm, and the coating time is 60 minutes; after the coating is completed, quickly turn off the DC pulse power supply , turn off the DC power switch, stop the gas supply, continue vacuuming until the workpiece cools down to below 100°C with the furnace, the coating process is over, open the vacuum chamber, and take out the workpiece. In this embodiment, the voltage of the DC pulse power supply is 20kV, the frequency is 20kHz, and the duty cycle is 30%.

This embodiment can deposit a titanium nitride (TiN) film on the inner surface of a low-carbon steel part with an inner diameter of Φ40mm. The film is uniform and dense. The wear resistance and corrosion resistance of the inner wall can improve the service life of low carbon steel parts.

Example 4

Clean and dry a Φ50×200mm hard alloy part with a Φ30×150mm through hole, then place it in a tubular vacuum chamber, as shown in Figure 1, and evacuate until the vacuum degree in the vacuum chamber reaches 6×10 ^-3 Pa , into the argon gas, the pressure is 20Pa, turn on the DC pulse power supply to stimulate the discharge to generate plasma, and perform sputter cleaning on the surface of the metal tubular workpiece for 20 minutes. At the same time, turn on the heater to heat the temperature of the vacuum chamber to 300°C; after that, pass the mixed gas of AlCl ₃ , O ₂ and H ₂ into the vacuum chamber, the gas ratio is 2:3:3, the air pressure is 100Pa, and the DC pulse power supply is turned on To excite the reactive gas discharge to generate plasma. At the same time, adjust the current of the electromagnetic coil to 2A, the range of magnetic induction to 1200 gauss, turn on the DC power supply, drive the DC motor and the sprocket to rotate, the rotation rate is 5 rpm, and the coating time is 60 minutes; after the coating is completed, quickly turn off the DC pulse power supply , turn off the DC power switch, stop the gas supply, continue vacuuming until the workpiece cools down to below 100°C with the furnace, the coating process is over, open the vacuum chamber, and take out the workpiece. In this embodiment, the voltage of the DC pulse power supply is 40kV, the frequency is 80kHz, and the duty cycle is 60%.

In this embodiment, the aluminum oxide (Al ₂ O ₃ ) film can be deposited on the inner surface of the hard alloy part with an inner diameter of Φ30mm. The film is uniform and dense. The wear resistance of the inner wall of the cemented carbide parts can improve the service life of the stainless steel pipe.

Claims (7)

1. One kind with plasma enhanced chemical vapor deposition at long tube internal surface thin film deposition device, it is characterized in that, this device is placed in cast vacuum chamber for pending tubular metal workpiece, at the central shaft of tubular metal workpiece to a tungsten filament electrode is set, draw by vacuum chamber tongued and grooved flanges at tungsten filament electrode two ends, between tungsten filament electrode and vacuum-chamber wall, be connected direct current pulse power source or radio-frequency power supply, at vacuum chamber, be wound around enameled wire outward and form solenoid.
2. 2. the plasma enhanced chemical vapor deposition of using according to claim 1 is at long tube internal surface thin film deposition device, it is characterized in that, this device comprises: direct current pulse power source or radio-frequency power supply, tungsten filament electrode, tubular workpiece, vacuum chamber, coil rotating link chain transmission mechanism, solenoid, inlet pipe, and concrete structure is as follows:

   Tubular workpiece is arranged in vacuum chamber, and tungsten filament electrode is arranged in tubular workpiece, and the positive pole of direct current pulse power source or radio-frequency power supply connects tungsten filament electrode, the negative pole connecting tubular workpiece of direct current pulse power source or radio-frequency power supply; The arranged outside coil rotating link chain transmission mechanism of vacuum chamber, the arranged outside solenoid of coil rotating link chain transmission mechanism; One end of inlet pipe extends in tubular workpiece, and the other end of inlet pipe extends vacuum chamber outside and connects gas cylinder.
3. 3. the plasma enhanced chemical vapor deposition of using according to claim 2, at long tube internal surface thin film deposition device, is characterized in that, the inner side of vacuum chamber arranges well heater.
4. 4. the plasma enhanced chemical vapor deposition of using according to claim 2, at long tube internal surface thin film deposition device, is characterized in that, the two ends of vacuum chamber arrange respectively tongued and grooved flanges.
5. 5. the plasma enhanced chemical vapor deposition of using according to claim 2, at long tube internal surface thin film deposition device, is characterized in that, mass-flow gas meter is set in inlet pipe.
6. 6. the plasma enhanced chemical vapor deposition of using according to claim 2, at long tube internal surface thin film deposition device, is characterized in that, coil rotating link chain transmission mechanism is connected with chain gear motor-driven, chain gear motor and chain gear motor power.
7. 7. the plasma enhanced chemical vapor deposition of using according to claim 2, at long tube internal surface thin film deposition device, is characterized in that, tubular workpiece is through hole or blind hole structure.

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