Hollow cathode auxiliary active screen vacuum diffusion coating integrated equipment and application method thereof

Abstract

The invention discloses hollow cathode auxiliary active screen vacuum diffusion coating integrated equipment and an application method thereof. The equipment comprises a vacuum diffusion coating chamber, a vacuum system, a gas control system, an active screen, a hollow cathode system, a workpiece objective table and a power supply control system, the vacuum diffusion coating chamber obtains high vacuum degree and required working atmosphere through a vacuum system and a gas control system; and the power supply control system independently controls the potentials of the active screen, the workpiece objective table and the hollow cathode system. The hollow cathode system not only provides diffusion coating layer sputtering atoms, but also improves the ionization rate of diffusion gas; due to the design of the active screen, elements on the metal surface can be uniformly diffused and permeated, and the utilization rate of sputtering particles is increased; through cooperation of the active screen and the hollow cathode system, the enhanced diffusion coating integrated function is achieved. The method is wide in application range, provides a firm technical support and a reliable solution for the vacuum surface treatment industry, and has huge economic benefits.

Description

Technical Field

[0001] The invention belongs to the field of metal surface infiltration and plating equipment, and in particular relates to a hollow cathode auxiliary active screen vacuum infiltration and plating integrated equipment and an application method thereof. Background Art

[0002] With the rapid development of science and technology, metal materials are increasingly used in all walks of life. However, they often face challenges in corrosion resistance, wear resistance and oxidation resistance in actual use environments. In order to overcome these limitations and improve the comprehensive performance of metal materials, the technology of preparing permeation coatings has emerged. The permeation coating forms one or more alloy layers with specific compositions on the surface of metal materials, which can significantly enhance the corrosion resistance, wear resistance and oxidation resistance of the surface, while optimizing its physical properties such as electrical conductivity and thermal conductivity. This technology not only broadens the application field of metal materials, significantly improves the surface properties of materials, prolongs the service life of materials, but also improves the utilization rate of materials and reduces the overall cost of use. Therefore, the research and development of the preparation technology of permeation coatings on the surface of metal materials is of great significance to promote the development of materials science and the upgrading of related industries.

[0003] However, in the field of metal material surface infiltration and plating, a core challenge facing the current technology system is the asynchrony of the infiltration and plating preparation processes and their mechanistic isolation. Infiltration treatment, as a deep method for material surface modification, involves the diffusion behavior of solute atoms or molecules in the matrix, and its kinetic process is complex and difficult to accurately control. The plating technology focuses on constructing one or more layers of thin films with specific composition and structure on the surface of the substrate, and its quality is affected by many factors such as deposition rate, substrate temperature, and plasma state. The existing preparation methods and approaches for infiltration and plating mainly include infiltration and plating combined processes and in-situ continuous synthesis technologies. The former is achieved through pretreatment, infiltration preparation, surface activation, and plating deposition, while the latter is completed continuously in the same process using a multifunctional coating system or ion infiltration and plating combined methods. These methods are all aimed at improving the comprehensive properties of the coating, such as bonding strength, wear resistance, and corrosion resistance, through technological innovation, while simplifying the preparation process and reducing costs.

[0004] It is worth noting that although hollow cathode technology has shown significant advantages in the field of sputtering coating, such as improving sputtering efficiency and optimizing plasma density, it still faces problems such as low target utilization, uneven spatial plasma distribution and low deposition efficiency. In addition, in the fields of carburizing and nitriding, although the activation screen technology has made some progress in promoting plasma uniformity and reducing energy loss, it is still blank in terms of depositing coatings and integrated infiltration and plating. In the existing technical system, the functions of the hollow cathode system and the activation screen are mostly limited to improving the target sputtering rate and plasma spatial uniformity, respectively, and they have not been effectively combined to simultaneously achieve a composite modification that improves the target sputtering rate and deposition efficiency. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide a hollow cathode assisted active screen vacuum infiltration and plating integrated equipment which can integrate a diffusion layer and a plating layer, has a high sputtering rate and a deposition rate, and has a simple structure and a low cost. Another purpose of the present invention is to provide an application method of the above-mentioned hollow cathode assisted active screen vacuum infiltration and plating integrated equipment.

[0006] Technical solution: The hollow cathode assisted active screen vacuum plating integrated equipment described in the present invention includes a vacuum plating chamber, a vacuum system, a gas control system, an active screen, a hollow cathode system, a workpiece stage and a power control system. The vacuum plating chamber is equipped with a vacuum system and a gas control system; the active screen, the hollow cathode system and the workpiece stage are placed in the vacuum plating chamber as cathodes; the stage is provided with a thermocouple for real-time temperature detection; the power control system is connected to the active screen and the hollow cathode system for controlling the cathode potential.

[0007] Furthermore, the periphery of the vacuum plating chamber is composed of a carrier and a metal anode shell, and the interior contains an active screen, a workpiece carrier, and a hollow cathode system; wherein the workpiece carrier is placed inside the active screen, and the hollow cathode system is composed of one or more sets of parallel plates (solid plates on the top and porous plates on the bottom), which are placed above the active screen; the hollow cathode system is used as a target material, which is composed of carbon, titanium, chromium, copper, zinc, tin or silicon materials, the thickness of a single layer of the target material is 5-20mm, the aperture ratio in the porous plate is 0.1-5, and the spacing between the solid plate and the porous plate is 1-20mm. The hollow cathode system adjusts the hole spacing and the target spacing to generate a hollow cathode effect between the targets, thereby strengthening plasma discharge and promoting the generation of high-temperature plasma inside. These plasmas not only serve as active sources in the plating process, but also can achieve precise control and local heating of the plating area through the special structural design of the hollow cathode system, while directional conduction of sputtered ions to improve the sputtering rate and utilization rate of the target material.

[0008] Furthermore, the active screen is a single-layer or multi-layer porous circular screen, the material of which is made of titanium, copper, or stainless steel, with a hole diameter of 5-20 mm and a hole spacing of 5-20 mm. The active screen is used to achieve uniform diffusion of elements on the metal surface, and at the same time plays a role in the aggregation of sputtered ions and uniform distribution in space, so as to achieve the purpose of increasing the deposition rate.

[0009] Furthermore, the vacuum plating chamber obtains a high vacuum degree through a vacuum system and obtains the required working gas through a gas control system; wherein the vacuum system includes a front-stage pump, a back-stage pump, a solenoid valve, a vacuum pipeline, and a control system, and the gas control system includes high-purity gas, a gas pipeline, a flow meter, a solenoid valve, and a control system.

[0010] Furthermore, the power control system is used to control the cathode potential of the active screen, workpiece stage and hollow cathode system in the vacuum plating chamber respectively; the outer wall of the vacuum plating chamber and the anode cover are grounded as the anode, and the metal anode shell is not limited to a hemispherical type.

[0011] Furthermore, the power control system includes an active screen power control system, a hollow cathode control power system and a workpiece stage control power system. The frequency of the active screen power control system is 0-30kHz, the voltage is 300-1000V, and the maximum power is 60kW; the frequency of the hollow cathode control power system is 0-30kHz, the voltage is 300-1500V, and the maximum power is 60kW; the frequency of the workpiece stage control power system is 0-30kHz, the voltage is 100-1000V, and the maximum power is 15kW.

[0012] Furthermore, in the gas control system, the reaction gas is one or more of N2, CH4, C2H2, the working gas is Ar or H2 or a mixture of the two, and the deposition pressure is 30-100 Pa. The gas control system is used to introduce an appropriate amount of plating reaction gas and protective working gas into the vacuum plating chamber. The gas control system can accurately control the type, flow rate and pressure of the gas to ensure the stability and controllability of the plating process.

[0013] Furthermore, the temperature in the vacuum plating chamber is raised by the heat generated by the discharge, or by additional heating with a resistance wire, and the temperature is controlled within a range of 150-1100° C. by adjusting electrical parameters through a power control system.

[0014] The hollow cathode auxiliary active screen vacuum infiltration integrated equipment provided by the present invention can realize infiltration treatment of various metal materials, including but not limited to stainless steel, aluminum alloy, titanium alloy, etc. This method not only simplifies the infiltration process and reduces production costs, but also improves the comprehensive performance of the infiltration layer, such as corrosion resistance, wear resistance, oxidation resistance, etc., and provides an efficient and environmentally friendly solution for material surface modification in the industrial field.

[0015] The present invention provides an application method of the above hollow cathode auxiliary active screen vacuum infiltration and plating integrated equipment, comprising the following steps:

[0016] (1) First, place the pretreated metal substrate on the workpiece stage, then start the vacuum system to evacuate to a set value, then adjust the gas control system to fill the set gas through the air inlet on the anode cover, and adjust the pressure to the set value through the vacuum system.

[0017] (2) Turn on the power supply system, and heat the workpiece stage by controlling the power supplies of the active screen, the workpiece stage, and the hollow cathode system respectively. When the temperature reaches the set value, the temperature is kept warm by the temperature control system. When the temperature reaches the set value of the insulation time, the power supply control system is cut off, and the low pressure in the furnace is maintained by the vacuum system. Then, the workpiece is taken out after the cavity temperature cools down, thereby obtaining a metal substrate having a diffusion layer, a plating layer, or a diffusion-plated layer on the surface.

[0018] Principle of the invention: Aiming at the preparation technology of the infiltration layer, the coating layer or the infiltration and plating layer, the present invention innovatively integrates the hollow cathode system and the activation screen technology. By deeply exploring the interaction between the hollow cathode effect and the activation screen in the infiltration and plating process, the infiltration layer and the plating layer are synchronously constructed in the same process window. The hollow cathode assisted active screen vacuum infiltration and plating integrated equipment proposed by the present invention, the hollow cathode system composed of a porous plate and a solid plate, not only provides the sputtering atoms of the coating layer, but also has the efficiency of enhanced discharge and rapid temperature rise, thereby improving the ionization rate of the infiltration gas. The active screen design can not only realize the uniform infiltration of elements on the metal surface, but also improve the inhomogeneity of the plasma field, thereby enhancing the utilization rate of the sputtered particles, and finally forming a uniform and dense surface layer on the workpiece surface. Through the coordinated cooperation of the active screen and the hollow cathode system, the equipment of the present invention realizes the enhanced infiltration and plating integration function. In addition, the independently controlled hollow cathode system, active screen and workpiece power supply can freely adjust the sputtering reaction rate, realize the flexible control of the infiltration and plating layer and the multifunctional requirements of the surface layer. The equipment of the present invention can focus on optimizing the hollow cathode system to enhance the target sputtering efficiency and plasma ionization rate, and at the same time design a reasonable activation screen configuration to regulate the plasma spatial distribution and reduce energy scattering, thereby achieving efficient and uniform deposition of the infiltration layer, plating layer or infiltration and plating layer. In summary, the present invention not only breaks through the complex post-processing links involved in the preparation of traditional surface layers, but also achieves high-precision customization of the thickness, composition and microstructure of the surface layer. This integrated preparation scheme can be widely used in the surface modification of various materials, has the characteristics of environmental protection and energy saving, and has huge market potential, and is expected to lead the field of material surface modification to a higher level and more refined development stage.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant effects: (1) Simplified process and improved efficiency: By introducing the hollow cathode auxiliary active screen technology, the present invention simplifies the process of the infiltration plating process and reduces the complex pre-treatment and post-treatment steps in the traditional process. At the same time, the hollow cathode system guides the plasma and the active screen gathers and uniformly distributes the plasma, which significantly improves the sputtering rate and utilization rate of the target material; (2) Cost reduction: Due to the simplified process and improved efficiency, the present invention reduces energy consumption and waste of raw materials in the production process, thereby reducing production costs. In addition, by accurately controlling the infiltration plating parameters and reducing the scrap rate, the economic benefits are further improved; (3) Improved quality of the infiltration plating layer: The gathering and homogenization of the active screen ensures the uniform distribution of the plasma, making the surface layer more dense and uniform, and improving the comprehensive properties of the surface layer, such as corrosion resistance, wear resistance and mechanical properties; (4) Enhanced environmental protection: The present invention reduces the emission and waste of harmful gases by accurately controlling parameters such as gas flow and pressure during the infiltration plating process. At the same time, high-temperature plasma technology helps to decompose and remove harmful substances generated during the infiltration and plating process, reducing pollution to the environment: (5) Strong adaptability: The hollow cathode assisted active screen infiltration and plating vacuum equipment of the present invention can be applied to the infiltration and plating treatment of a variety of metal materials, including but not limited to stainless steel, aluminum alloy, titanium alloy, etc. By adjusting the process parameters and replacing different active screen materials, flexible adaptation to different materials and process requirements can be achieved: (6) High degree of intelligence and automation: The control system integrates advanced sensors, actuators and algorithm technologies to achieve intelligent control and real-time monitoring of the infiltration and plating process. This not only improves the stability and reliability of the production process, but also reduces the cost and risk of manual intervention, and improves the overall production efficiency and product quality. In summary, the present invention has significant advantages in terms of process simplification, cost reduction, improved quality of the infiltration and plating layer, enhanced environmental protection, strong adaptability, and high degree of intelligence and automation, providing an efficient, environmentally friendly and flexible solution for material surface modification in the industrial field. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of the hollow cathode auxiliary active screen vacuum infiltration and plating integrated equipment in Example 1;

[0021] Figure 2 3D structural diagram of the vacuum plating chamber in Example 1;

[0022] Figure 3 The simulation results of the electron density distribution in the vacuum chamber in Example 1 are shown in FIG. 1 , wherein (a) is a cathode plate without an active screen, (b) is an active screen without the assistance of a hollow cathode system, and (c) is an active screen system with the assistance of a hollow cathode;

[0023] Figure 4The cross-section and surface SEM images of the coating in Example 2;

[0024] Figure 5 The coating composition in Example 2, wherein (a) is a Raman test result diagram of the coating; (b) is a XRD test result diagram of Ti6Al4V and the coating;

[0025] Figure 6 The macroscopic morphology and surface SEM images of (a) Ti6Al4V and (b) plated workpieces in Example 2 after corrosion in a 50wt% hydrofluoric acid solution;

[0026] Figure 7 (a) polarization curve diagram and (b) AC impedance diagram of the substrate and the plated workpiece in an acidic solution 0.1wt% NaF solution in Example 2;

[0027] Figure 8 (a) friction coefficient diagram and (b) wear rate diagram of the substrate and the plated workpiece in 0.8wt% NaCl solution in Example 2;

[0028] Fig. 9 The morphology and contour diagrams of (ac) substrate and (df) plated workpiece after wear in Example 2;

[0029] Fig.10 The SEM of the cross section of the AISI316L substrate coating and the corrosion metallographic image of the cross section of the infiltration layer in Example 3;

[0030] Fig.11 The coating composition in Example 3 (a) is the coating Raman test result diagram; (b) is the AISI316L coating XRD test result diagram;

[0031] Fig.12 In Example 3, (a) is a microhardness test curve of the workpiece cross section; (b) is a surface hardness result diagram of AISI316L and the coating;

[0032] Fig.13 The friction and wear test diagrams of 316L and workpiece in Example 3, wherein (a) is the friction coefficient diagram; (b) is the wear rate diagram;

[0033] Fig.14 The wear scar morphology and contour diagram of (ac) 316L and (df) workpiece in Example 3. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the embodiments and drawings.

[0035] Example 1: Figure 1-Figure 2As shown, the hollow cathode assisted active screen vacuum plating integrated equipment provided by the present invention includes a vacuum plating chamber, a vacuum system, a gas control system, an active screen, a hollow cathode system, a workpiece stage and a power control system.

[0036] The vacuum plating chamber comprises a carrier platform 1, an active screen 2, a workpiece carrier platform 3, a hollow cathode system 4 and a semicircular anode metal shell 5; a vacuum chamber is formed between the carrier platform 1 and the anode metal shell 5, the workpiece carrier platform 2 is arranged on the carrier platform 1 through an insulating column 6, the active screen 3 is arranged on the carrier platform 1 through an insulating component, the workpiece carrier platform 2 is arranged at the center of the active screen 3, the active screen is a single-layer or multi-layer porous circumferential screen, the hole diameter is 5-20mm, the hole spacing is 5-20mm, the hollow cathode system 4 is arranged on the active screen 3 through a conductive component, the hollow cathode system 4 comprises a solid plate 401 arranged on the top and a porous plate 402 arranged on the bottom, a conductive spacer 403 is arranged between the solid plate 401 and the porous plate 402, and the hollow cathode system is used as a target. , composed of carbon, titanium, chromium, copper, zinc, tin or silicon materials, the thickness of the single-layer target material is 5-20mm, the aperture ratio in the porous plate is 0.1-5, and the spacing between the solid plate and the porous plate is 1-20mm; the anode metal shell 5 is provided with an air inlet 7, and the carrier is provided with an air outlet 8, the air inlet 7 and the air outlet 8 are respectively connected to the vacuum system, and the air inlet 7 is also connected to the gas control system, and the gas control system includes high-purity gas, gas pipeline, flow meter, solenoid valve, and control system; in the gas control system, the reaction gas is one or more of N2, CH4, and C2H2, the working gas is Ar or H2 or a mixture of the two, and the deposition pressure is 30-100Pa, which is used to introduce an appropriate amount of plating reaction gas and protective working gas into the vacuum plating chamber. The vacuum plating chamber obtains a high vacuum degree through the vacuum system, and obtains the required working gas through the gas control system; the vacuum system includes a front pump, a back pump, a solenoid valve, a vacuum pipeline, and a control system.

[0037] The power control system is used to control the cathode potential of the active screen 2, the workpiece stage 3 and the hollow cathode system 4 in the vacuum plating chamber. The outer wall of the vacuum plating chamber and the anode cover are grounded as the anode. The power control system includes the active screen power control system, the hollow cathode control power system and the workpiece stage control power system. The frequency of the active screen power control system is 0-30kHz, the voltage is 300-1000V, and the maximum power is 60kW; the frequency of the hollow cathode control power system is 0-30kHz, the voltage is 300-1500V, and the maximum power is 60kW; the frequency of the workpiece stage control power system is 0-30kHz, the voltage is 100-1000V, and the maximum power is 15kW; the temperature in the vacuum plating chamber is heated by the heat generated by the glow discharge, or with the additional heating of the resistance wire and the control temperature range is achieved by adjusting the electrical parameters through the power control system.

[0038] Equipment principle: The present invention uses multi-layer hollow cathode plates and solid plates as sputtering sources. By designing and adjusting the aperture ratio and target spacing of the hollow cathode system, a hollow cathode effect is formed between the target materials to enhance the sputtering rate. The hollow cathode system, active screen structure and workpiece stage are independently connected to the power supply, and the distance between the workpiece stage and the hollow cathode system can be freely adjusted. Reaction gases such as N2, CH4 or C2H2 are introduced, and the temperature is kept at 150-1100℃ for 2-24 hours at a pressure of 30-100Pa to form a 2-30μm thick coating on the surface of the workpiece, and a 2-50μnm thick infiltration layer is obtained at the junction of the coating and the substrate.

[0039] The electron distribution simulation results of the deposition system composed of a hollow cathode system and an active screen structure are shown in Figure 3 As shown. The electron distribution of the cathode plate without an active screen is uneven, and no effective sputtering area is formed ( Figure 3 (a)); the active screen structure without the assistance of the hollow cathode system although the electrons are gathered inside the screen ( Figure 3 (b) in the figure), but a large number of electrons are scattered outside the screen and no effective deposition area is formed, resulting in low target sputtering utilization; the simulation results of the hollow cathode auxiliary active screen system show that ( Figure 3 In (c)), the electrons are evenly distributed in the cavity and are strengthened at the position of the hollow cathode system, and the sputtering ionization rate and utilization rate of the target are improved.

[0040] Example 2: Using the hollow cathode assisted active screen vacuum infiltration integrated equipment in Example 1 to coat an amorphous carbon film, the preparation method is as follows:

[0041] A hollow cathode-activated screen plasma deposition system was used, and the target material was a carbon target with a purity of 99.9%. The flat mirror-polished Ti6Al4V sample (φ20mm×2mm) was ultrasonically cleaned in ethanol for 10 minutes, then ultrasonically immersed in a hydrofluoric acid-nitric acid system solution for 3 minutes, ultrasonically cleaned with alcohol for 5 minutes, and then dried and fixed on a flat insulating workpiece stage. The cavity was evacuated, and when the background pressure was lower than 0.1Pa, a mixed gas of argon and hydrogen in a ratio of 3:1 was introduced, and the gas pressure was adjusted to 80Pa. The pulse power supply was turned on, and the temperature of the workpiece stage in the furnace was slowly increased to 500℃ by adjusting the voltage and duty cycle, and then the voltage was maintained at 500V, the hydrogen input was cut off, the argon input was retained, and the temperature was kept for 10 hours. Subsequently, the power supply was cut off, and the workpiece temperature was cooled to room temperature with the furnace while maintaining the low pressure in the furnace, and a workpiece with an amorphous carbon film coating with a thickness of 18-20μm was obtained.

[0042] like Figure 4 As shown, the coating thickness on the Ti6Al4V substrate is 18.5 μm and is well bonded to the substrate.

[0043] Coating composition and phase Figure 5 As shown, Raman detected D peak and G peak, indicating that the amorphous carbon film is composed of sp 2 and sp 3 Hybrid composition, XRD test results show that the coating is composed of amorphous phase and TiC phase.

[0044] The corrosion resistance of Ti6Al4V substrate and carbon film workpiece in 50wt% hydrofluoric acid solution is compared. Figure 6 As shown. The results show that Ti6Al4V is strongly corroded the moment it contacts hydrofluoric acid, and a large amount of corrosion products such as fluorides and oxides accumulate on the surface. When the carbon film workpiece is corroded for 30 minutes, only a small amount of bubbles appear on the surface, indicating that the substrate begins to corrode. Furthermore, from the SEM image, it can be seen that corrosion products accumulate in the holes of the coating, indicating that the coating workpiece mainly undergoes pitting corrosion and has good hydrofluoric acid resistance.

[0045] The obtained workpiece was subjected to a fluorine resistance test. Figure 7 The electrochemical test results of the workpiece and the plated workpiece in a 0.1wt% NaF solution with a pH value of 3. The Tafel test shows that the plated workpiece has a higher corrosion potential and a smaller corrosion current than the Ti6Al4V matrix. The EIS test also shows that the plated workpiece has a larger impedance than the Ti6Al4V matrix. The above electrochemical test results all show that the plated workpiece has better fluorine corrosion resistance than the Ti6Al4V matrix.

[0046] Comparing the friction and wear properties of the coated workpiece and Ti6Al4V, such as Figure 8 The wear rate results show that the wear rate of the coated workpiece is reduced to 11% of the substrate. Further analysis of the wear scar morphology and profile is performed, as shown in Fig. 9 As shown, the coated workpiece has smaller wear scar width and depth than the Ti6Al4V substrate, and has a good wear protection effect on the Ti6Al4V substrate.

[0047] Example 3: The hollow cathode auxiliary active screen vacuum infiltration integrated equipment in Example 1 is used to perform infiltration coating on 316L substrate, and the preparation method is as follows:

[0048] A hollow cathode-activated screen plasma deposition system was used, and the target material was a carbon target with a purity of 99.9%. The flat mirror-polished 316L sample (20mm×30mm) was ultrasonically cleaned in ethanol for 10 minutes, then dried and fixed on a flat insulating workpiece stage. The cavity was evacuated, and when the background pressure was lower than 0.1Pa, a mixed gas of argon and hydrogen in a ratio of 1:1 was introduced, and the pressure was adjusted to 80Pa. The pulse power supply was turned on, and the temperature of the workpiece stage in the furnace was slowly increased to 550℃ by adjusting the voltage and duty cycle, and then the voltage was maintained at 500V, the hydrogen input was cut off, the argon input was retained, and the temperature was kept for 10h. Subsequently, the power supply was cut off, and the workpiece temperature was cooled to room temperature with the furnace while maintaining the low pressure in the furnace, and a workpiece with a diffusion-plating composite structure was obtained, in which a coating with a thickness of 18-20μm was formed on the surface of the substrate, and a diffusion layer with a thickness of 40-60μm was formed under the coating.

[0049] like Fig.10 As shown, the coating has a thickness of 19 μm on the 316L substrate and is well bonded to the substrate, and a 40-50 μm thick carburized layer is formed under the coating.

[0050] Coating composition and phase Fig.11 As shown, Raman detected D peak and G peak, indicating that the amorphous carbon film is composed of sp 2 and sp 3 Hybrid composition, XRD test results show that the coating is composed of amorphous phase and Fe7C3 carbide, and carbon expansion austenite formation is observed, indicating the presence of carburized layer.

[0051] Compare the microhardness of the carbonized layer and the 316L substrate. Fig.12 The surface mechanical properties of the workpiece are improved compared to the matrix. From the near surface (2μm) to the inside of the matrix, the workpiece forms a gradient hardening layer with good load-bearing and buffering capacity after treatment, and the maximum hardness can reach 556Hv 0.05 .

[0052] Comparison of friction and wear properties between the carbonized layer and the 316L substrate. Fig.13 and Fig.14 Its friction coefficient is reduced by more than 3 times compared with the substrate, and the wear rate results show that the workpiece after treatment is reduced to 1 / 4 of the substrate. Therefore, the workpiece treated by this process has good friction reduction and wear resistance.

Claims

1. A hollow cathode auxiliary active screen vacuum plating integrated equipment, characterized in that: It includes a vacuum plating chamber, a vacuum system, a gas control system, an active screen, a hollow cathode system, a workpiece stage and a power control system. The vacuum plating chamber is equipped with a vacuum system and a gas control system; the active screen, the hollow cathode system and the workpiece stage are placed in the vacuum plating chamber as cathodes; the stage is provided with a thermocouple for real-time temperature detection; the power control system is connected with the active screen and the hollow cathode system for controlling the cathode potential.

2. The device according to claim 1, characterized in that The periphery of the vacuum plating chamber is composed of a carrying platform and a metal anode shell, and the interior includes an active screen, a hollow cathode system, and a workpiece carrying platform.

3. The device according to claim 2, characterized in that The workpiece stage is placed inside the active screen, and the hollow cathode system is placed above the active screen. The hollow cathode system is composed of one or more groups of parallel plates, including a solid plate arranged at the top and a porous plate arranged at the bottom; the plate material is composed of carbon, titanium, chromium, copper, zinc, tin or silicon material, the thickness of a single-layer target material is 5-20 mm, the aperture ratio of the porous plate is 0.1-5, and the spacing between the solid plate and the porous plate is 1-20 mm.

4. The device according to claim 2, characterized in that The active screen is a single-layer or multi-layer porous circumferential screen made of titanium, copper or stainless steel, with a hole diameter of 5-20 mm and a hole spacing of 5-20 mm.

5. The device according to claim 2, characterized in that The power control system is used to control the cathode potential of the active screen, workpiece stage and hollow cathode system in the vacuum plating chamber respectively. The outer wall of the vacuum chamber and the anode cover are grounded as the anode. The metal anode shell is not limited to a hemispherical type.

6. The device according to claim 5, characterized in that The power control system includes an active screen power control system, a hollow cathode control power system and a workpiece stage control power system. The frequency of the active screen power control system is 0-30kHz, the voltage is 300-1000V, and the maximum power is 60kW; the frequency of the hollow cathode control power system is 0-30kHz, the voltage is 300-1500V, and the maximum power is 60kW; the frequency of the workpiece stage control power system is 0-30kHz, the voltage is 100-1000V, and the maximum power is 15kW.

7. The device according to claim 1, characterized in that The vacuum plating chamber obtains a high vacuum degree through a vacuum system and obtains the required working gas through a gas control system; wherein the vacuum system includes a front-stage pump, a back-stage pump, a solenoid valve, a vacuum pipeline, and a control system, and the gas control system includes high-purity gas, a gas pipeline, a flow meter, a solenoid valve, and a control system.

8. The device according to claim 1, characterized in that In the gas control system, the reaction gas is one or more of N2, CH4, C2H2, the working gas is Ar or H2 or a mixture of the two, and the deposition pressure is controlled to be 30-100Pa.

9. The device according to claim 1, characterized in that The temperature of the vacuum plating chamber is raised by the heat generated by gas discharge, or by additional heating with a resistance wire, and the temperature is controlled within a range of 150-1100° C. by adjusting electrical parameters through a power control system.

10. An application method of the hollow cathode assisted active screen vacuum infiltration plating integrated equipment according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) First, place the pretreated metal substrate on the workpiece stage, then start the vacuum system to evacuate to a set value, then adjust the gas control system to fill the set gas through the air inlet on the anode cover, and adjust the pressure to the set value through the vacuum system; (2) Turn on the power supply system, and heat the workpiece stage by controlling the power supplies of the active screen, the workpiece stage, and the hollow cathode system respectively. When the temperature reaches the set value, the temperature is kept warm by the temperature control system. When the temperature reaches the set value of the insulation time, the power supply control system is cut off, and the low pressure in the furnace is maintained by the vacuum system. Then, the workpiece is taken out after the cavity temperature cools down, thereby obtaining a metal substrate having a diffusion layer, a plating layer, or a diffusion-plated layer on the surface.

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