Apparatus for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionization of a hollow cathode tube and method of use

Abstract

The application relates to a device for pre-ionization hollow cathode tube discharge for rapidly and uniformly depositing a thin film on the inner wall of an elongated tube and a use method thereof. The device belongs to the field of surface treatment. The device solves the problems of hollow cathode target deformation failure and difficulty in uniformly and rapidly depositing a large-thickness thin film on the inner wall of an elongated tube. The device comprises a pre-ionization device composed of a pre-ionization power supply, a pre-ionization ion source and an anode ring; the pre-ionization ion source, the anode ring, the hollow cathode target material, the elongated tube and the anode rod are coaxially arranged. The pre-ionization ion source is arranged to reduce the difficulty of hollow cathode target material discharge, improve the hollow cathode target material discharge intensity, reduce the heat input of the hollow cathode target material port, avoid the port overheating deformation failure, and further improve the thin film deposition rate. The reciprocating mechanism drives the relative movement of the elongated tube and the hollow cathode target material discharge area, realizes the plasma discharge in the elongated tube, and solves the problem of uniformly and rapidly depositing a large-thickness thin film.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment, specifically relating to an apparatus and method for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by discharge inside a pre-ionized hollow cathode tube. Background Technology

[0002] With the advancement of industrial society, slender tubular materials are increasingly used in industrial production. In practical applications, slender tubular components often fail due to high temperatures, friction, or corrosion on their inner walls. Inner wall coating is an effective way to address this problem. Common methods for coating the inner walls of slender tubular components include chemical vapor deposition (CVD), electroplating, magnetron sputtering, and cathodic arc ion plating. CVD technology requires heating the metal to be plated above its boiling point, making it unsuitable for temperature-sensitive substrates, and its ionization rate is too low. While electroplating can achieve surface coatings on complex structures, it suffers from brittle coatings, severe environmental pollution, and low current utilization. PVD technology offers advantages such as environmental friendliness and fewer restrictions on the types of coatings that can be plated. However, conventional PVD technologies like arc ion plating or magnetron sputtering require built-in magnetic fields and water-cooling structures, limiting the target volume and size. For slender tubular components, it is impossible to integrate the target while maintaining a large target-substrate distance, making discharge extremely difficult. Similarly, due to space limitations within the tube, the remaining space after the target for arc ion plating or magnetron sputtering is minimal, making it impossible to embed the anode. This necessitates a two-electrode discharge method where the target is connected to the positive electrode and the slender tube is connected to the positive electrode of the power supply, limiting the effective regulation of plasma energy. The hollow cathode discharge method is simple to implement and can simultaneously perform three-stage discharges inside a slender tube. However, during hollow cathode discharge, the plasma concentrates at the tube opening, resulting in extremely high local plasma density and energy. The narrow space within the tube is insufficient for cooling methods such as water cooling within the hollow cathode discharge structure, ultimately leading to localized overheating and deformation failure at the hollow cathode target port. Therefore, how to reduce plasma energy and heat input at the port while maintaining plasma density and ionization rate has become a key issue limiting the further application of this method in coating the inner walls of slender tubes, and urgently needs to be addressed. Summary of the Invention

[0003] The purpose of this invention is to solve the problem that the hollow cathode target deformation and failure caused by excessively high local temperature at the hollow cathode port in the hollow cathode discharge coating method inside the slender tube, and the problem that conventional methods are difficult to achieve uniform and rapid deposition of a thick film on the inner wall of the slender tube. Therefore, this invention provides an apparatus and method for rapidly and uniformly depositing a film on the inner wall of the slender tube by discharge coating with a pre-ionized hollow cathode tube.

[0004] A device for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by discharge in a pre-ionized hollow cathode tube, comprising a pre-ionization ion source, an anode ring, a hollow cathode target, a slender tube, an anode rod, a pre-ionization power supply, a hollow cathode power supply, a bias power supply, and a pre-ionization chamber.

[0005] One end of the pre-ionization ion source is connected to the negative output terminal of the pre-ionization power supply, the positive output terminal of the pre-ionization power supply is connected to the anode ring and one end of the hollow cathode target, the other end of the hollow cathode target is connected to the negative output terminal of the hollow cathode power supply, the positive output terminal of the hollow cathode power supply is connected to one end of the anode rod and grounded, the slender tube is connected to the negative output terminal of the bias power supply, and the positive output terminal of the bias power supply is connected to the anode rod and grounded.

[0006] An opening is provided on one side of the pre-ionization chamber, with one end of the hollow cathode target connected to the opening, and the anode ring on the other side of the opening; the pre-ionization ion source, anode ring, opening, hollow cathode target, slender tube and anode rod are arranged coaxially;

[0007] The other end of the hollow cathode target is fitted inside one end of the slender tube, and the other end of the anode rod is fitted inside the other end of the slender tube.

[0008] The pre-ionization ion source and anode ring are located inside the pre-ionization chamber, and the working gas enters the pre-ionization chamber; the pre-ionization ion source, anode ring, and pre-ionization chamber constitute a pre-ionization device.

[0009] Furthermore, it also includes a base plate, a first insulating support, a second insulating support, and a reciprocating mechanism; the pre-ionization device is fixed on the base plate; the hollow cathode target is fixed on the base plate via the first insulating support; the anode rod is fixed on the base plate via the first insulating support; the slender tube is fixed on the reciprocating mechanism via the second insulating support; the reciprocating mechanism is located on the base plate; the second insulating support is pulled by the reciprocating mechanism to drive the slender tube to reciprocate at a uniform speed along the axial direction.

[0010] Furthermore, the hollow cathode target is made of Cr, Ti, Ta, Cu, Ni, Zn, Nb, Sn, Al, Fe, Mg or Zr.

[0011] Alternatively, it can be a nickel-chromium alloy, a nickel-aluminum alloy, a nickel-iron alloy, a nickel-vanadium alloy, a titanium-aluminum alloy, a titanium-aluminum-silicon alloy, a gold-tin alloy, a gold-palladium alloy, a molybdenum-niobium alloy, a ruthenium-chromium alloy, a boron-iron alloy, or a silicon-iron alloy.

[0012] Furthermore, the pre-ionization ion source is classified into hollow cathode pre-ionization ion source, magnetron sputtering pre-ionization ion source, or arc pre-ionization ion source according to different discharge modes; the material of the pre-ionization ion source is Cr, Ti, Ta, Cu, Ni, Zn, Nb, Sn, Al, Fe, Mg, or Zr.

[0013] Alternatively, it can be a nickel-chromium alloy, a nickel-aluminum alloy, a nickel-iron alloy, a nickel-vanadium alloy, a titanium-aluminum alloy, a titanium-aluminum-silicon alloy, a gold-tin alloy, a gold-palladium alloy, a molybdenum-niobium alloy, a ruthenium-chromium alloy, a boron-iron alloy, or a silicon-iron alloy.

[0014] Furthermore, the pre-ionization power supply, hollow cathode power supply, and bias power supply can all be DC power supplies, pulse power supplies, high-voltage power supplies, radio frequency power supplies, intermediate frequency power supplies, or high-power pulse power supplies.

[0015] The method of using the above-mentioned device for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by internal discharge of a pre-ionized hollow cathode tube is achieved by the following steps:

[0016] I. Self-glow cleaning of the inner wall of slender tubes and cylinders:

[0017] The vacuum chamber is evacuated, and the working gas enters the pre-ionization chamber. The vacuum chamber pressure is maintained at 0.1 to 50 Pa. The positive output terminal of the bias power supply is connected to the anode rod and grounded, and the negative output terminal is connected to the slender tube. The voltage of the bias power supply is controlled at -50 to -2000 V, and the duty cycle is 5% to 100%. The plasma generated by the hollow cathode discharge effect performs self-glow cleaning on the inner surface of the slender tube, resulting in a self-glow cleaned slender tube.

[0018] II. Hollow cathode enhanced glow discharge cleaning of the inner wall of slender tubes:

[0019] Maintain the vacuum chamber pressure at 0.1–50 Pa. Connect the negative output terminal of the pre-ionization power supply to the pre-ionization ion source. Connect the positive output terminal to the anode ring and one end of the hollow cathode target. Connect the other end of the hollow cathode target to the negative output terminal of the hollow cathode power supply. Connect the positive output terminal of the hollow cathode power supply to one end of the anode rod and ground it. Connect the slender tube after glow discharge cleaning to the negative output terminal of the bias power supply. Connect the positive output terminal of the bias power supply to the anode rod and ground it. Control the voltage of the pre-ionization power supply to 400–2000 V and the peak current. The working gas is ionized by a pre-ionization ion source and then transported to the hollow cathode target. The voltage of the hollow cathode power supply is 400-2000V, the peak current is 0.1-100A, and the duty cycle is 0.1%-100%. The bias power supply voltage is -50 to -2000V, and the duty cycle is 5%-100%. The working gas is further ionized by the hollow cathode target to perform hollow cathode enhanced glow discharge cleaning, resulting in a slender tube after hollow cathode enhanced glow discharge cleaning.

[0020] III. Deposits on the inner wall of pipe fittings:

[0021] Connect the negative output terminal of the pre-ionization power supply to the pre-ionization ion source, and connect the positive output terminal to the anode ring and one end of the hollow cathode target. Connect the other end of the hollow cathode target to the negative output terminal of the hollow cathode power supply, and connect the positive output terminal of the hollow cathode power supply to the anode rod. Simultaneously, connect the negative output terminal of the bias power supply to the slender tube after the hollow cathode enhanced glow discharge cleaning, and ground the positive output terminal of the bias power supply to maintain the vacuum chamber pressure at 0.1–50 Pa. Control the voltage of the pre-ionization power supply at 400–2000 V, with a peak voltage of [missing value]. The current is 0.1–100A, the duty cycle is 0.1%–100%, the voltage of the hollow cathode power supply is 400–2000V, the peak current is 0.1–100A, the duty cycle is 0.1%–100%, the voltage of the bias power supply is -0.1–-500V, the duty cycle is 5%–100%, the working gas is ionized by the pre-ionization ion source, and then further ionized by the hollow cathode target material to perform hollow cathode coating, so as to complete the uniform deposition of a thin film on the inner wall of the slender tube, thus completing the method of using the device.

[0022] Furthermore, the working gas mentioned in step one is argon, helium, neon, krypton, xenon, radon, oxygen, nitrogen, hydrogen, methane, hydrogen sulfide, ammonia, Ar+O2, Ar+N2, Ar+H2, O2+N2, O2+CH4, Ar+He, or Ar+Xe; when the working gas is a mixed gas, the two are mixed in any ratio.

[0023] Furthermore, the self-glow cleaning time described in step one is 15 min to 600 min.

[0024] Furthermore, the time for the hollow cathode enhanced glow discharge cleaning in step two is 15 min to 600 min.

[0025] Furthermore, the time for hollow cathode coating in step three is 10 min to 600 min.

[0026] The principle and beneficial effects of this invention:

[0027] 1. In the process of hollow cathode discharge coating, the present invention effectively reduces the difficulty of hollow cathode discharge by using an external pre-ionization ion source. At the same time, the reciprocating mechanism drives the slender tube to move back and forth along the axial direction at a uniform speed, which facilitates the uniform coating layer in all parts of the slender tube.

[0028] 2. This invention, through an external pre-ionization ion source, successfully achieves efficient, controlled, and uniform deposition of plasma discharge and coating in slender tubes, effectively solving the problem of excessive local heat input during hollow cathode discharge leading to overheating, deformation, and failure of the hollow cathode port. The principle is as follows: Hollow cathode technology is a method of achieving efficient ionization discharge by utilizing the reciprocating oscillation of electrons between the cathode walls. An external pre-ionization ion source is used to pre-ionize the gas. The pre-ionized gas travels through the hollow cathode tube to the hollow cathode port. The unrecombined residual plasma (including electrons and ions) in the gas can be used for the hollow cathode discharge process at the port, effectively reducing the difficulty of hollow cathode discharge. This results in a lower excitation voltage at the same current, meaning a lower heat input to the hollow cathode port at the same plasma density. This avoids localized overheating and deformation failure at the port under non-water-cooled conditions, while ensuring high plasma density and high ionization rate during hollow cathode discharge. Since the opening direction of the hollow cathode can be along the axial direction, and its anode can be coaxially placed inside the tube, the plasma generated by both can be controllably deposited on the inner wall of the slender tube under the influence of the bias electric field between the anode and the tube, effectively achieving regulation of plasma energy. Meanwhile, by traction and movement of the slender tube, effective contact can be achieved between the discharge area and different positions on the inner wall of the slender tube, resulting in uniform and effective deposition of coating at all positions inside the slender tube.

[0029] 3. Due to the small inner diameter of the slender tube, traditional columnar magnetron sputtering targets or multi-arc targets have complex structures and are difficult to place inside the slender tube. Therefore, achieving sputtering coating on slender tubes using columnar targets is very difficult. To address this issue, an innovative hollow cathode target, which can be even smaller, is placed inside the slender tube. The hollow cathode target is connected to the negative output terminal of the hollow cathode power supply, the positive output terminal of the hollow cathode power supply is connected to the anode rod and grounded, and the slender tube is connected to the negative output terminal of the bias power supply, while the positive output terminal of the bias power supply is grounded. An insulating support is installed at the bottom of the slender tube, and the height of the insulating support is adjustable to ensure coaxiality of the slender tube, hollow cathode target, and anode rod, while simultaneously maintaining coaxiality with the pre-ionization ion source, anode ring, and opening.

[0030] 4. This invention, through an external pre-ionization ion source, successfully achieves efficient, controlled, and uniform deposition of plasma discharge and coating within a slender tube, effectively solving the problem of excessive local heat input during hollow cathode discharge leading to overheating and deformation failure at the hollow cathode port. This reduces the difficulty of hollow cathode discharge, resulting in a lower excitation voltage at the same current, i.e., a reduced heat input to the hollow cathode port at the same plasma density. It avoids local overheating and deformation failure at the port position under non-water-cooled conditions, while ensuring high plasma density and high ionization rate during hollow cathode discharge.

[0031] 5. By setting a pre-ionized ion source, this invention reduces the difficulty of discharge of hollow cathode target, increases the discharge intensity of hollow cathode target, and reduces the heat input at the port of hollow cathode target, thereby increasing the deposition rate of thin film. By using a reciprocating mechanism to drive the relative movement between the slender tube and the discharge area of ​​hollow cathode target, the problem of uniform and rapid deposition of thick thin films is solved.

[0032] This invention is applicable to the rapid and uniform deposition of thin films on the inner wall of slender tubes by discharge inside a pre-ionized hollow cathode tube. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an apparatus for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by internal discharge of a pre-ionized hollow cathode tube according to the present invention. In the diagram, 1 represents a pre-ionization ion source, 2 represents an anode ring, 3 represents a base plate, 4 represents a first insulating support, 5 represents a hollow cathode target, 6 represents a slender tube, 7 represents a second insulating support, 8 represents an anode rod, 9 represents a pre-ionization power supply, 10 represents a hollow cathode power supply, 11 represents a bias power supply, 12 represents a reciprocating mechanism, 13 represents a pre-ionization chamber, and 14 represents an opening.

[0034] Figure 2 This is a surface electron microscope image of the hollow cathode target deposited with a thin film on the inner wall of a slender tube with an inner diameter of 6 mm, as shown in the embodiment.

[0035] Figure 3 This is a cross-sectional electron microscope image of the thin film deposited on the hollow cathode target in the embodiment;

[0036] Figure 4 The image shows the indentation morphology of the thin film deposited on the hollow cathode target in the embodiment.

[0037] Figure 5 The diagram shows the discharge current and voltage waveforms of the hollow cathode target power supply in the embodiment. Detailed Implementation

[0038] Specific implementation method one: as follows Figure 1 As shown in the figure, this embodiment of the device for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by discharge in a pre-ionized hollow cathode tube includes a pre-ionization ion source 1, an anode ring 2, a hollow cathode target 5, a slender tube 6, an anode rod 8, a pre-ionization power supply 9, a hollow cathode power supply 10, a bias power supply 11, and a pre-ionization box 13.

[0039] The other end of the pre-ionization ion source 1 is connected to the negative output end of the pre-ionization power supply 9. The positive output end of the pre-ionization power supply 9 is connected to the anode ring 2 and one end of the hollow cathode target 5. The other end of the hollow cathode target 5 is connected to the negative output end of the hollow cathode power supply 10. The positive output end of the hollow cathode power supply 10 is connected to one end of the anode rod 8 and grounded. The slender tube 6 is connected to the negative output end of the bias power supply 11. The positive output end of the bias power supply 11 is connected to the anode rod 8 and grounded.

[0040] An opening 14 is provided on one side of the pre-ionization chamber 13. One side of the opening 14 is connected to one end of the hollow cathode target 5, and the other side of the opening 14 is the anode ring 2. The pre-ionization ion source 1, anode ring 2, opening 14, hollow cathode target 5, slender tube 6 and anode rod 8 are arranged coaxially.

[0041] The other end of the hollow cathode target 5 is fitted inside one end of the slender tube 6, and the other end of the anode rod 8 is fitted inside the other end of the slender tube 6.

[0042] The pre-ionization ion source 1 and the anode ring 2 are disposed inside the pre-ionization chamber 13, and the working gas enters the pre-ionization chamber 13; the pre-ionization ion source 1, the anode ring 2 and the pre-ionization chamber 13 constitute a pre-ionization device.

[0043] The slender tube 6 described in this embodiment has an inner diameter of 6-100mm and a length of 10-1000mm, and is made of carbon steel, stainless steel, titanium alloy, copper alloy or aluminum alloy.

[0044] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that it further includes a base plate 3, a first insulating support 4, a second insulating support 7, and a reciprocating mechanism 12; the pre-ionization device is fixed on the base plate 3; the hollow cathode target 5 is fixed on the base plate 3 via the first insulating support 4; the anode rod 8 is fixed on the base plate 3 via the first insulating support 4; the slender tube 6 is fixed on the reciprocating mechanism 12 via the second insulating support 7; the reciprocating mechanism 12 is disposed on the base plate 3; the second insulating support 7, pulled by the reciprocating mechanism 12, can drive the slender tube 6 to reciprocate at a uniform speed along the axial direction. Everything else is the same as in Specific Implementation Method One.

[0045] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 in that the hollow cathode target 5 is made of Cr, Ti, Ta, Cu, Ni, Zn, Nb, Sn, Al, Fe, Mg or Zr.

[0046] Alternatively, it can be a nickel-chromium alloy, nickel-aluminum alloy, nickel-iron alloy, nickel-vanadium alloy, titanium-aluminum alloy, titanium-aluminum-silicon alloy, gold-tin alloy, gold-palladium alloy, molybdenum-niobium alloy, ruthenium-chromium alloy, ferroboron alloy, or ferrosilicon alloy. Other aspects are the same as in Specific Embodiment 1.

[0047] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the pre-ionization ion source 1 is classified into hollow cathode pre-ionization ion source, magnetron sputtering pre-ionization ion source, or arc pre-ionization ion source according to different discharge modes; the material of the pre-ionization ion source 1 is Cr, Ti, Ta, Cu, Ni, Zn, Nb, Sn, Al, Fe, Mg, or Zr.

[0048] Alternatively, it can be a nickel-chromium alloy, nickel-aluminum alloy, nickel-iron alloy, nickel-vanadium alloy, titanium-aluminum alloy, titanium-aluminum-silicon alloy, gold-tin alloy, gold-palladium alloy, molybdenum-niobium alloy, ruthenium-chromium alloy, ferroboron alloy, or ferrosilicon alloy. Other aspects are the same as in Specific Embodiment 1.

[0049] In this embodiment, the material of the pre-ionization ion source 1 can be the same as or different from the material of the hollow cathode target 5.

[0050] In this embodiment, the pre-ionization ion source 1 is a hollow cathode pre-ionization ion source, and the working gas enters the pre-ionization box (13) through one end of the hollow cathode pre-ionization ion source.

[0051] If the pre-ionization ion source 1 is a magnetron sputtering pre-ionization ion source or an arc pre-ionization ion source, then the working gas enters the pre-ionization chamber (13) through the air inlet of the magnetron sputtering pre-ionization ion source or the arc pre-ionization ion source.

[0052] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the pre-ionization power supply 9, the hollow cathode power supply 10, and the bias power supply 11 can all be DC power supplies, pulse power supplies, high-voltage power supplies, radio frequency power supplies, intermediate frequency power supplies, or high-power pulse power supplies. Everything else is the same as in Specific Implementation Method One.

[0053] Specific Implementation Method Six: This implementation method describes a method for using an apparatus for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by discharge within a pre-ionized hollow cathode tube. The method comprises the following steps:

[0054] I. Self-glow cleaning of the inner wall of slender tubes and cylinders:

[0055] The vacuum chamber is evacuated, and the working gas enters the pre-ionization chamber 13 to maintain the vacuum chamber pressure at 0.1 to 50 Pa. The positive output terminal of the bias power supply 11 is connected to the anode rod 8 and grounded, and the negative output terminal is connected to the slender tube 6. The voltage of the bias power supply 11 is controlled to be -50 to -2000 V, and the duty cycle is 5% to 100%. The plasma generated by the hollow cathode discharge effect performs self-glow cleaning on the inner surface of the slender tube 6 to obtain the slender tube after self-glow cleaning.

[0056] II. Hollow cathode enhanced glow discharge cleaning of the inner wall of slender tubes:

[0057] Maintain the vacuum chamber pressure at 0.1–50 Pa. Connect the negative output terminal of the pre-ionization power supply 9 to the pre-ionization ion source 1. Connect the positive output terminal to the anode ring 2 and one end of the hollow cathode target 5. Connect the other end of the hollow cathode target 5 to the negative output terminal of the hollow cathode power supply 10. Connect the positive output terminal of the hollow cathode power supply 10 to one end of the anode rod 8 and ground it. Connect the slender tube after glow discharge cleaning to the negative output terminal of the bias power supply 11. Connect the positive output terminal of the bias power supply 11 to the anode rod 8 and ground it. Control the voltage of the pre-ionization power supply 9 to 400–2000 V. The peak current is 0.1–100A, and the duty cycle is 0.1%–100%. The working gas is ionized by the pre-ionization ion source 1 and then moves and is transmitted to the hollow cathode target 5. The voltage of the hollow cathode power supply 10 is 400–2000V, the peak current is 0.1–100A, and the duty cycle is 0.1%–100%. The voltage of the bias power supply 11 is -50 to -2000V, and the duty cycle is 5%–100%. The working gas is further ionized by the hollow cathode target 5 to perform hollow cathode enhanced glow discharge cleaning, resulting in a slender tube after hollow cathode enhanced glow discharge cleaning.

[0058] III. Deposits on the inner wall of pipe fittings:

[0059] Connect the negative output terminal of the pre-ionization power supply 9 to the pre-ionization ion source 1, and connect the positive output terminal to the anode ring 2 and one end of the hollow cathode target 5. Connect the other end of the hollow cathode target 5 to the negative output terminal of the hollow cathode power supply 10, and connect the positive output terminal of the hollow cathode power supply 10 to the anode rod 8. Simultaneously, connect the negative output terminal of the bias power supply 11 to the slender tube after the hollow cathode enhanced glow discharge cleaning, and ground the positive output terminal of the bias power supply 11 to maintain the vacuum chamber pressure at 0.1–50 Pa. Control the voltage of the pre-ionization power supply 9 to 400–2000 kPa. The voltage of the hollow cathode power supply 10 is 400-2000V, the peak current is 0.1-100A, the duty cycle is 0.1%-100%, the voltage of the bias power supply 11 is -0.1--500V, the duty cycle is 5%-100%, the working gas is ionized by the pre-ionization ion source 1, and then further ionized by the hollow cathode target material 5 to perform hollow cathode coating, thereby completing the uniform deposition of a thin film on the inner wall of the slender tube, thus completing the method of using the device.

[0060] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that the working gas in step one is argon, helium, neon, krypton, xenon, radon, oxygen, nitrogen, hydrogen, methane, hydrogen sulfide, ammonia, Ar+O2, Ar+N2, Ar+H2, O2+N2, O2+CH4, Ar+He, or Ar+Xe; when the working gas is a mixed gas, the two are mixed in any ratio. Other steps and parameters are the same as in Specific Implementation Method Six.

[0061] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Six in that the self-glow cleaning time in step one is 15 min to 600 min. Other steps and parameters are the same as in Specific Implementation Method Six.

[0062] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Six in that the hollow cathode enhanced glow discharge cleaning time in step two is 15 min to 600 min. Other steps and parameters are the same as in Specific Implementation Method Six.

[0063] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method Six in that the hollow cathode coating time in step three is 10 min to 600 min. Other steps and parameters are the same as in Specific Implementation Method Six.

[0064] The beneficial effects of the present invention are verified through the following embodiments:

[0065] Example:

[0066] A method for using an apparatus for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by internal discharge of a pre-ionized hollow cathode tube is described, comprising the following steps:

[0067] I. Self-glow cleaning of the inner wall of slender tubes and cylinders:

[0068] The vacuum chamber is evacuated, and the working gas enters the pre-ionization chamber 13 to maintain the vacuum chamber pressure at 10Pa. The positive output terminal of the bias power supply 11 is connected to the anode rod 8 and grounded, and the negative output terminal is connected to the slender tube 6. The voltage of the bias power supply 11 is controlled to be -900V and the duty cycle is 30%. The plasma generated by the hollow cathode discharge effect performs self-glow cleaning on the inner surface of the slender tube 6 to obtain the slender tube after self-glow cleaning.

[0069] II. Hollow cathode enhanced glow discharge cleaning of the inner wall of slender tubes:

[0070] Maintain the vacuum chamber pressure at 10 Pa. Connect the negative output terminal of the pre-ionization power supply 9 to the pre-ionization ion source 1. Connect the positive output terminal to the anode ring 2 and one end of the hollow cathode target 5. Connect the other end of the hollow cathode target 5 to the negative output terminal of the hollow cathode power supply 10. Connect the positive output terminal of the hollow cathode power supply 10 to one end of the anode rod 8 and ground it. Connect the slender tube after glow discharge cleaning to the negative output terminal of the bias power supply 11. Connect the positive output terminal of the bias power supply 11 to the anode rod 8 and ground it. Control the pre-ionization ion source 1. The voltage of the ionization power supply 9 is 600V, the peak current is 40A, and the duty cycle is 30%. The working gas is ionized by the pre-ionization ion source 1 and then moves and is transported to the hollow cathode target 5. The voltage of the hollow cathode power supply 10 is 650V, the peak current is 50A, and the duty cycle is 40%. The voltage of the bias power supply 11 is -1000V and the duty cycle is 30%. The working gas is further ionized by the hollow cathode target 5 to perform hollow cathode enhanced glow discharge cleaning, and a slender tube is obtained after hollow cathode enhanced glow discharge cleaning.

[0071] III. Deposits on the inner wall of pipe fittings:

[0072] Connect the negative output terminal of the pre-ionization power supply 9 to the pre-ionization ion source 1, and connect the positive output terminal to the anode ring 2 and one end of the hollow cathode target 5. Connect the other end of the hollow cathode target 5 to the negative output terminal of the hollow cathode power supply 10, and connect the positive output terminal of the hollow cathode power supply 10 to the anode rod 8. Simultaneously, connect the negative output terminal of the bias power supply 11 to the slender tube after the hollow cathode enhanced glow discharge cleaning, and ground the positive output terminal of the bias power supply 11 to maintain the vacuum chamber pressure at 10 Pa and control the pre-ionization. The voltage of the ionization power supply 9 is 1000V, the peak current is 36A, and the duty cycle is 1.5%. The voltage of the hollow cathode power supply 10 is 1000V, the peak current is 36A, and the duty cycle is 1.5%. The voltage of the bias power supply 11 is -400V and the duty cycle is 30%. The working gas is ionized by the pre-ionization ion source 1 and then further ionized by the hollow cathode target material 5 to perform hollow cathode coating, thereby completing the uniform deposition of a thin film on the inner wall of the slender tube, thus completing the usage method of the device.

[0073] In this embodiment, the pre-ionization power supply 9 is a pulse power supply; the hollow cathode power supply 10 is a pulse power supply; and the bias power supply 11 is a DC power supply.

[0074] The slender tube 6 mentioned in step one of this embodiment is a martensitic aging steel with an inner diameter of 6mm and a length of 120mm.

[0075] In step two of this embodiment, the hollow cathode target 5 is made of Cu; the pre-ionization ion source is a hollow cathode pre-ionization ion source with an inner diameter of 4mm, made of Cu; and the anode rod 8 is a high-temperature resistant metal Mo rod.

[0076] Figure 2The image shown is a surface electron microscope image of the thin film deposited on the inner wall of a slender tube with an inner diameter of 6 mm by the hollow cathode target in the embodiment. It can be seen that the surface of the film is relatively smooth and there is no accumulation or enrichment of large particles, indicating that the film deposited by the experimental device of rapid and uniform deposition of thin film on the inner wall of the slender tube by pre-ionized hollow cathode tube discharge has good uniformity.

[0077] Figure 3 The image shown is a cross-sectional electron microscope image of the thin film deposited on the hollow cathode target in the embodiment. It can be seen that the film thickness is 279 nm, which is relatively dense. This indicates that the experimental device for rapid and uniform deposition of a thin film on the inner wall of a slender tube by discharge inside the pre-ionized hollow cathode tube is feasible and stable.

[0078] Figure 4 This image shows the indentation morphology of the hollow cathode target deposited thin film in this embodiment. The HRC test method is a commonly used method for evaluating the bonding strength between the film and the substrate material. When measuring the bonding strength, a 120° conical diamond indenter was used, and the load was set to 1470 N (150 kgf) for 10 seconds. The indentation morphology was analyzed using a VHX-1000E ultra-depth-of-field optical microscope (KEYENCE, Japan). Comparing with the VDI3198 standard spectrum, the bonding strength was divided into six levels (HF1-HF6). The results show that the bonding strength between the film and the substrate reached levels HF1-HF2. The HRC indentation morphology was complete, with a perfectly circular indentation, and no radial cracks or large areas of delamination.

[0079] Figure 5 The figure shows the discharge current and voltage waveforms of the hollow cathode target power supply in this embodiment. The figure shows that during the film deposition process in this embodiment, the actual sputtering power supply pulse voltage is 1000V, the pulse peak current is 36A, the corresponding frequency is 1000Hz, and the pulse width is 15μs.

[0080] This embodiment achieves pre-ionization of the gas through an external pre-ionization ion source. The pre-ionized gas travels through the hollow cathode tube to the hollow cathode port. The unrecombined residual plasma (including electrons and ions) in the gas can be used for the hollow cathode discharge process at the port, effectively reducing the difficulty of hollow cathode discharge. This is manifested in a lower excitation voltage at the same current, i.e., a lower heat input to the hollow cathode port at the same plasma density. Local overheating and deformation failure at the port is avoided under non-water-cooled conditions, while ensuring high plasma density and high ionization rate for hollow cathode discharge. Since the opening direction of the hollow cathode can be along the axial direction, and its anode can be coaxially placed inside the tube, the plasma generated by both can be controllably deposited on the inner wall of the slender tube under the action of the bias electric field between the anode and the slender tube. This method effectively reduces the temperature rise on the surface of the slender tube material. While ensuring the mechanical properties of the material, the requirements for film thickness and uniformity are met.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An apparatus for rapidly and uniformly depositing a thin film on the inner wall of a slender tube by discharge within a pre-ionized hollow cathode tube, characterized in that... It comprises a pre-ionization ion source (1), an anode ring (2), a hollow cathode target (5), an elongated tube (6), an anode rod (8), a pre-ionization power supply (9), a hollow cathode power supply (10), a bias power supply (11) and a pre-ionization box (13); One end of the pre-ionization ion source (1) is connected to the negative output end of the pre-ionization power supply (9), the positive output end of the pre-ionization power supply (9) is connected to the anode ring (2) and one end of the hollow cathode target (5), the other end of the hollow cathode target (5) is connected to the negative output end of the hollow cathode power supply (10), the positive output end of the hollow cathode power supply (10) is connected to one end of the anode rod (8) and grounded, the elongated tube (6) is connected to the negative output end of the bias power supply (11), and the positive output end of the bias power supply (11) is connected to the anode rod (8) and grounded; One side of the pre-ionization box (13) is provided with an opening (14), one side of the opening (14) is butted against one end of the hollow cathode target (5), and the other side of the opening (14) is the anode ring (2); the pre-ionization ion source (1), the anode ring (2), the opening (14), the hollow cathode target (5), the elongated tube (6) and the anode rod (8) are coaxially arranged; The other end of the hollow cathode target (5) is sleeved on one end of the elongated tube (6), and the other end of the elongated tube (6) is sleeved on the other end of the anode rod (8); The pre-ionization ion source (1) and the anode ring (2) are arranged inside the pre-ionization box (13), and the working gas enters the pre-ionization box (13); the pre-ionization ion source (1), the anode ring (2) and the pre-ionization box (13) constitute a pre-ionization device.

2. The apparatus for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tube according to claim 1, wherein It further comprises a base plate (3), a first insulating support (4), a second insulating support (7) and a reciprocating mechanism (12); the pre-ionization device is fixed on the base plate (3); the hollow cathode target (5) is fixed on the base plate (3) through the first insulating support (4); the anode rod (8) is fixed on the base plate (3) through the first insulating support (4); the elongated tube (6) is fixed on the reciprocating mechanism (12) through the second insulating support (7); the reciprocating mechanism (12) is arranged on the base plate (3); the second insulating support (7) is driven by the reciprocating mechanism (12) to drive the elongated tube (6) to move uniformly and reciprocally along the axial direction.

3. The apparatus for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tube according to claim 1, wherein The material of the hollow cathode target (5) is Cr, Ti, Ta, Cu, Ni, Zn, Nb, Sn, Al, Fe, Mg or Zr; Or a nickel-chromium alloy, a nickel-aluminum alloy, a nickel-iron alloy, a nickel-vanadium alloy, a titanium-aluminum alloy, a titanium-aluminum-silicon alloy, a gold-tin alloy, a gold-palladium alloy, a molybdenum-niobium alloy, a ruthenium-chromium alloy, a boron-iron alloy or a silicon-iron alloy.

4. The apparatus for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tube according to claim 1, wherein The pre-ionization ion source (1) is divided into a hollow cathode pre-ionization ion source, a magnetron sputtering pre-ionization ion source or an arc pre-ionization ion source according to different discharge modes; the material of the pre-ionization ion source (1) is Cr, Ti, Ta, Cu, Ni, Zn, Nb, Sn, Al, Fe, Mg or Zr; Or nickel-chromium alloy, nickel-aluminum alloy, nickel-iron alloy, nickel-vanadium alloy, titanium-aluminum alloy, titanium-aluminum silicon, gold-tin alloy, gold-palladium alloy, molybdenum-niobium alloy, ruthenium-chromium alloy, boron-iron alloy or silicon-iron alloy.

5. The apparatus for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tube according to claim 1, wherein The pre-ionization power supply (9), the hollow cathode power supply (10) and the bias power supply (11) are all direct current power supplies, pulse power supplies, high voltage power supplies, radio frequency power supplies, intermediate frequency power supplies or high power pulse power supplies.

6. The method of using the device for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionization discharge in a hollow cathode tube as recited in claim 1, wherein, It is realized in the following steps: I. Self-glow cleaning the inner wall of the slender tube: The vacuum chamber is evacuated, the working gas enters the pre-ionization box (13), the pressure of the vacuum chamber is maintained at 0.1~50Pa, the positive output end of the bias power supply (11) is connected with the anode rod (8) and grounded, the negative output end is connected with the slender tube (6), the voltage of the bias power supply (11) is controlled at-50~-2000V, the duty cycle is 5%~100%, the plasma generated by the hollow cathode discharge effect is used to self-glow clean the inner surface of the slender tube (6), and the self-glow cleaned slender tube is obtained; II. Hollow cathode enhanced glow cleaning the inner wall of the slender tube: The pressure of the vacuum chamber is maintained at 0.1~50Pa, the negative output end of the pre-ionization power supply (9) is connected with the pre-ionization ion source (1), the positive output end is connected with the anode ring (2) and one end of the hollow cathode target material (5), the other end of the hollow cathode target material (5) is connected with the negative output end of the hollow cathode power supply (10), the positive output end of the hollow cathode power supply (10) is connected with one end of the anode rod (8) and grounded, the self-glow cleaned slender tube is connected with the negative output end of the bias power supply (11), the positive output end of the bias power supply (11) is connected with the anode rod (8) and grounded, the voltage of the pre-ionization power supply (9) is controlled at 400~2000V, the peak current is 0.1~100A, the duty cycle is 0.1%~100%, the working gas is ionized through the pre-ionization ion source (1) and then moves to the hollow cathode target material (5), the voltage of the hollow cathode power supply (10) is 400~2000V, the peak current is 0.1~100A, the duty cycle is 0.1%~100%, the voltage of the bias power supply (11) is-50~-2000V, the duty cycle is 5%~100%, the working gas is further ionized by the hollow cathode target material (5), and the hollow cathode enhanced glow cleaning is carried out, and the hollow cathode enhanced glow cleaned slender tube is obtained; III. Deposition of the inner wall of the tube: The negative output end of the pre-ionization power supply (9) is connected with the pre-ionization ion source (1), the positive output end is connected with the anode ring (2) and one end of the hollow cathode target material (5), the other end of the hollow cathode target material (5) is connected with the negative output end of the hollow cathode power supply (10), the positive output end of the hollow cathode power supply (10) is connected with the anode rod (8), the negative output end of the bias power supply (11) is connected with the elongated tube after the hollow cathode enhanced glow cleaning, the positive output end of the bias power supply (11) is grounded, the air pressure in the vacuum chamber is maintained at 0.1-50 Pa, the voltage of the pre-ionization power supply (9) is controlled at 400-2000 V, the peak current is 0.1-100 A, and the duty cycle is 0.1%-100%, the voltage of the hollow cathode power supply (10) is 400-2000 V, the peak current is 0.1-100 A, and the duty cycle is 0.1%-100%, the voltage of the bias power supply (11) is-0.1--500 V, and the duty cycle is 5%-100%, the working gas is ionized through the pre-ionization ion source (1), and then further gas ionization is performed through the hollow cathode target material (5), hollow cathode coating is performed, uniform thin film deposition on the inner wall of the elongated tube is completed, and the use method of the device is completed.

7. The method of using the device for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tubular member according to claim 6, characterized in that The working gas in step one is argon, helium, neon, krypton, xenon, radon, oxygen, nitrogen, hydrogen, methane, hydrogen sulfide, ammonia, Ar+O2, Ar+N2, Ar+H2, O2+N2, O2+CH4, Ar+He or Ar+Xe; when the working gas is a mixed gas, the two are mixed in any ratio.

8. The method of using the device for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tubular member according to claim 6, characterized in that The self-glow cleaning time in step one is 15 min-600 min.

9. The method of using the device for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tubular member according to claim 6, characterized in that The hollow cathode enhanced glow cleaning time in step two is 15 min-600 min.

10. The method of using the device for rapid and uniform deposition of thin films on the inner wall of an elongated tubular member by pre-ionized hollow cathode discharge in a tubular member according to claim 6, characterized in that The hollow cathode coating time in step three is 10 min-600 min.

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