Helicon wave plasma device and method for surface modification of hot-working die

Abstract

The invention discloses a helicon wave plasma device and method for surface modification of a hot-working die, and belongs to the technical field of material treatment. A cavity comprises a coating area, a diffusion area and a plasma source area which are sequentially communicated from front to back, multiple sets of coils are arranged on the outer side of the plasma source area and the outer side of the diffusion area respectively, and a spiral wave plasma discharge antenna is arranged in a through hole of the plasma source area. One end of the helicon wave plasma discharge antenna is electrically connected with the radio frequency power supply through the network matcher, and the other end is grounded; an argon inlet is formed in the side wall of the plasma source area; the diffusion area is provided with a vacuumizing opening and a probe diagnosis system, and the vacuumizing opening is communicated with the vacuum unit; a composite motion supporting mechanism and a magnetron sputtering coating system are installed in the coating area, and an air inlet port is formed in the side wall of the coating area and communicated with an air supply system of the air supply power supply system. Abrasion resistance and corrosion resistance of the surface of the hot-working die can be improved, and the service life of the hot-working die can be prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of material processing, and particularly relates to a helicon wave plasma device and method for surface modification of hot working dies. Background Art

[0002] Hot working dies for commercial vehicle gears are widely used in manufacturing processes such as forging, die casting, extrusion, and hot stamping, and are a key piece of equipment in the automotive manufacturing field. Hot working dies need to withstand high temperatures, high pressures, and complex mechanical stresses, and have a harsh working environment, making them prone to wear and tear, resulting in large expenditures while also reducing the production line efficiency.

[0003] Using surface modification technology to coat a protective film on the surface of processing dies made of steel structural materials such as ordinary steel parts, stainless steel, and hardened steel can enhance their wear resistance and corrosion resistance, and thus extend the service life of the dies. For example, the AlCrN coating has good oxidation resistance, good hot hardness, and strong wear resistance, and is widely used in the general processing field. The AlCrSiN coating formed by adding Si elements to the AlCrN coating can optimize the structure and improve the performance at high temperatures, and has particular advantages in overall hot working dies.

[0004] Common surface modification technologies can generally be divided into two categories: physical vapor deposition (PVD) and chemical vapor deposition (CVD). The PVD technology uses physical means to evaporate or sputter the target material into atoms / molecules and deposit them on the die surface to form a coating, such as evaporation deposition, magnetron sputtering, ion plating, etc. The CVD technology forms a coating on the die surface through chemical reactions of gaseous substances, such as thermal chemical vapor deposition, plasma enhanced chemical vapor deposition, atomic layer deposition, etc. These common surface modification technologies have different disadvantages, such as expensive equipment, high vacuum requirements, complex process conditions, and difficult control of process parameters. At the same time, they are also difficult to meet the requirements in terms of wear resistance and corrosion resistance. Summary of the Invention

[0005] The purpose of the present invention is to provide a helicon wave plasma device and method for surface modification of hot working dies. Using the helicon wave plasma device and method of the present invention, the wear resistance and corrosion resistance of the surface of hot working dies are improved, the service life of hot working dies is extended, and at the same time, there is no pollution and less consumables, providing an efficient, precise, reliable, and environmentally friendly surface modification solution for fields such as commercial vehicle gear dies.

[0006] The present invention utilizes the high-density helicon wave plasma surface modification technology, which is a cutting-edge technology in the field of manufacturing long-life hot working dies. Its basic principle is the same as that of traditional PVD, and it has the advantages of simple traditional PVD process, environmental improvement, no pollution, and less consumables. It is an environmentally friendly and clean surface treatment method, which conforms to the concept of current green manufacturing. Different from traditional technologies, this technology inputs high-density helicon waves remotely, and the density of the plasma is 2-3 orders of magnitude higher than that of traditional PVD, so that the plasma used for coating deposition has higher density and energy. Without affecting the properties of the substrate, the action depth can reach hundreds to thousands of nanometers. The high-density helicon wave plasma surface modification technology combines the advantages of traditional PVD and remote high-current ion sources, and has the characteristics of high deposition rate, high adhesion, and smooth surface. It has significant advantages in customizing coating composition, microstructure, and properties.

[0007] The helicon wave plasma device and method of the present invention are used for surface modification of hot working dies of commercial vehicle gears.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] A helicon wave plasma device for surface modification of hot working dies, comprising a cavity, a composite motion support mechanism, and a magnetron sputtering coating system;

[0010] The cavity includes a coating region, a diffusion region, and a plasma source region that are connected in sequence from front to back. Multiple groups of coils are respectively arranged outside the plasma source region and the diffusion region. The helicon wave plasma discharge antenna is placed in the argon gas inlet provided on the rear side wall of the plasma source region. One end of the helicon wave plasma discharge antenna is electrically connected to the RF power supply through a network matcher, and the other end of the helicon wave plasma discharge antenna is grounded; the diffusion region is provided with a vacuum pumping port and a probe diagnostic system, and the vacuum pumping port is connected to a vacuum unit; the coating region is equipped with a composite motion support mechanism and a magnetron sputtering coating system, and an air inlet port is provided on the side wall of the coating region. The air inlet port is connected to the gas supply system of the gas supply and power supply system through a first gas supply pipeline.

[0011] Further, the plasma source region is a stainless steel chamber.

[0012] Further, the argon gas inlet is connected to the gas supply system of the gas supply and power supply system through a second gas supply pipeline, and a mass flow meter and an inlet shut-off valve are installed on the second gas supply pipeline.

[0013] Further, the diffusion region is a stainless steel vacuum chamber.

[0014] Further, the probe diagnostic system is disposed at one of the plasma diagnostic windows provided at the top of the diffusion region, and a plasma diagnostic window two is provided on the side wall of the diffusion region. The plasma diagnostic window two is a quartz glass window.

[0015] Further, the vacuum pumping port is disposed opposite to the quartz glass window, and the vacuum pumping port is communicated with the inlet of the vacuum unit through a vacuum pumping pipeline. A super high vacuum gate valve and an electromagnetic isolation valve are installed on the vacuum pumping pipeline.

[0016] Further, the magnetron sputtering coating system includes a target, a magnetron sputtering cathode, and multiple magnets; the back of the target is connected to the magnetron sputtering cathode, the back of the magnetron sputtering cathode is connected to multiple magnets, and the N and S poles of adjacent two magnets are alternately arranged; the target serves as the cathode, and the mold to be plated serves as the anode and is disposed opposite to the front of the target. The target is made of CrAl alloy material.

[0017] Further, the helicon wave plasma device further includes a plasma diagnostic system, a remote control system, and a gas supply and power supply system; the plasma diagnostic system is disposed on the diffusion region, the remote control system and the gas supply and power supply system are both disposed outside the cavity, and the remote control system is respectively connected to the plasma diagnostic system, the composite motion support mechanism, the magnetron sputtering coating system, the coil, the helicon wave plasma discharge antenna, the radio frequency power supply, the vacuum unit, and the gas supply and power supply system by signals; the plasma diagnostic system is connected to the probe diagnostic system by signals;

[0018] The gas supply system of the gas supply and power supply system includes a gas supply tank one and a gas supply tank two. The gas supply tank one is communicated with the air inlet through an air inlet pipeline one, and the gas supply tank two is communicated with the argon gas inlet through an air inlet pipeline two; the power supply system of the gas supply and power supply system 7 is electrically connected to all components that require power supply.

[0019] Further, multiple groups of the coils are all water-cooled DC electromagnetic coils.

[0020] A method for surface modification of a hot working die, the method comprising the following steps:

[0021] Step one: After ultrasonic cleaning the mold to be plated, clamp and fix it on the composite motion support mechanism, install the CrAl alloy target on the magnetron sputtering cathode, and adjust the distance between the target and the mold to a preset value;

[0022] Step two: Pump the cavity to the base vacuum, introduce high-purity argon gas from the argon gas inlet into the coating region, in a magnetic field environment with a magnetic field intensity of 1500 - 3000 Gs, turn on the radio frequency power supply, and excite the helicon wave plasma discharge antenna to discharge helicon wave plasma to form a high-density argon plasma; use the argon plasma to clean the surface of the mold;

[0023] Step 3: Maintain the argon plasma discharge state, while introducing high-purity nitrogen gas into the cavity and spraying argon gas onto the mold surface; the argon plasma ionizes the nitrogen gas to form a nitride deposition layer; subsequently, start the magnetic field control system of the magnetron sputtering cathode and the remote control system, and under the synergistic action of the electromagnetic field, argon ions bombard the CrAl alloy target to achieve target sputtering. The sputtered particles combine with the active nitrogen in the plasma to form a CrAlN composite modified layer, i.e., the coating, on the mold surface. The overall deposition time is 10 - 15 min;

[0024] Step 4: After the coating is completed, turn off the RF power supply and all gas sources, evacuate the cavity back to the base vacuum state, and then introduce high-purity argon gas to slowly increase the cavity pressure to atmospheric pressure; then, take out the mold, and thus the surface modification process is all completed.

[0025] The beneficial effects of the present invention compared with the prior art are:

[0026] The present invention applies the high-density helicon wave plasma surface modification technology to the surface modification process of commercial vehicle gear hot working molds, combines the advantages of traditional PVD and remote high-current ion sources, has the characteristics of high deposition rate, high adhesion and smooth surface, and has significant advantages in customizing coating composition, microstructure and properties. This technology improves the wear resistance and corrosion resistance of hot working molds, extends the service life of hot working molds, and at the same time has no pollution and less consumables, providing an efficient, precise, reliable and environmentally friendly surface modification solution for fields such as commercial vehicle gear molds. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of the helicon wave plasma device for surface modification of hot working molds of the present invention. The plasma diagnostic system, remote control system, gas supply and power supply system, and probe diagnostic system are not shown;

[0028] Figure 2 is a schematic structural diagram of the magnetron sputtering coating system;

[0029] Figure 3 is a schematic diagram of the signal connection of the remote control system.

[0030] The component names and reference numerals involved in the above drawings are as follows:

[0031] Cavity 1, coating area 101, diffusion area 102, plasma source area 103, coil 104, helicon wave plasma discharge antenna 105, network matcher 106, RF power supply 107, vacuum unit 108, air inlet port 109, argon gas inlet 110, quartz glass window 111, compound motion support mechanism 2, magnetron sputtering coating system 3, target 301, magnet 302, magnetron sputtering cathode 303, mold 4, plasma diagnostic system 5, remote control system 6, gas supply and power supply system 7, probe diagnostic system 8. Specific embodiments

[0032] The following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings, but it is not limited thereto. Any modification or equivalent replacement of the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention shall be covered by the protection scope of the present invention.

[0033] Specific embodiment 1: As Figures 1 - 3 shown, this embodiment discloses a helicon wave plasma device for surface modification of hot working molds. The helicon wave plasma device includes a cavity 1, a compound motion support mechanism 2, and a magnetron sputtering coating system 3;

[0034] The cavity 1 includes a coating area 101, a diffusion area 102, and a plasma source area 103 that are connected in sequence from front to back. Multiple groups of coils 104 are respectively arranged outside the plasma source area 103 and the diffusion area 102 (the purpose of arranging the coil 104 outside the plasma source area 103 is to generate a high-intensity magnetic field inside the plasma source area 103; the purpose of arranging the coil 104 outside the diffusion area 102 is to maintain the stable diffusion of the plasma). The helicon wave plasma discharge antenna 105 is placed in the argon gas inlet 110 provided on the rear side wall of the plasma source area 103 (argon gas enters the diffusion area 102 and the coating area 101 through the plasma source area 103 to generate helicon wave plasma). One end of the helicon wave plasma discharge antenna 105 is electrically connected to an RF power supply 107 (with a frequency of 13.56 MHz) through a network matcher 106 (an L-type network matcher), and the other end of the helicon wave plasma discharge antenna 105 is grounded;; The diffusion area 102 is provided with a vacuum pumping port and a probe diagnostic system 8 (with RF filtering function), and the vacuum pumping port is connected to the vacuum unit 108;

[0035] The coating area 101 (the main working area) is equipped with a compound motion support mechanism 2 (for clamping the mold 4) and a magnetron sputtering coating system 3. An air inlet port 109 is provided on the side wall of the coating area 101, and the air inlet port 109 is connected to the gas supply system of the gas supply and power supply system 7 through a first air inlet pipeline (for introducing nitrogen gas, or methane gas can also be introduced. Which gas to introduce depends on the coating composition. In this invention, nitrogen gas is taken as an example).

[0036] Further, the plasma source region 103 is a stainless steel chamber (for generating helicon wave plasma).

[0037] Further, the argon gas inlet 110 is communicated with the gas supply system of the gas supply and power supply system 7 through the second gas inlet pipeline, and a mass flow meter (for controlling the gas intake) and a gas inlet stop valve are installed on the second gas inlet pipeline.

[0038] Further, the diffusion region 102 is a stainless steel vacuum chamber (made of 304 stainless steel).

[0039] The vacuum chamber is used to maintain the plasma and diagnose the plasma parameters at the same time.

[0040] Further, the probe diagnostic system 8 is arranged at a plasma diagnostic window 1 provided at the top of the diffusion region 102, and a plasma diagnostic window 2 is provided on the side wall of the diffusion region 102. The plasma diagnostic window 2 is a quartz glass window 111.

[0041] The probe diagnostic system 8 (which is a prior art) is used to diagnose plasma parameters such as electron temperature, density, energy distribution, etc., and monitor the plasma state; the quartz glass window 111 is used for the acquisition of emission spectrum signals.

[0042] Further, the vacuum pumping port is arranged opposite to the quartz glass window 111. The vacuum pumping port is communicated with the inlet of the vacuum pumping unit 108 through a vacuum pumping pipeline, and a super high vacuum gate valve and an electromagnetic isolation valve are installed on the vacuum pumping pipeline (by controlling the super high vacuum gate valve and the electromagnetic isolation valve, the diffusion region 102 (vacuum chamber) is pumped, and the ultimate vacuum degree can reach 1×10 - 5 Pa).

[0043] Further, the magnetron sputtering coating system 3 includes a target 301, a magnetron sputtering cathode 303 and multiple magnets 302 (which are permanent magnets or electromagnets, creating a magnetic field environment);

[0044] The back of the target 301 is connected to the magnetron sputtering cathode 303, the back of the magnetron sputtering cathode 303 is connected to multiple magnets 302, and the N and S poles of adjacent two magnets 302 are arranged alternately; the target 301 serves as the cathode, and the mold to be plated 4 serves as the anode and is arranged opposite to the front of the target 301. The target 301 is made of CrAl alloy material (which is the material source for high-energy ion bombardment).

[0045] Further, the helicon wave plasma device further includes a plasma diagnostic system 5, a remote control system 6, and a gas supply and power supply system 7; the plasma diagnostic system 5 is disposed on the diffusion region 102, and both the remote control system 6 and the gas supply and power supply system 7 are disposed outside the cavity 1. The remote control system 6 is respectively signal-connected to the plasma diagnostic system 5 (for detecting and diagnosing the plasma state, which is prior art), the compound motion support mechanism 2, the magnetron sputtering coating system 3, the coil 104, the helicon wave plasma discharge antenna 105, the RF power supply 107, the vacuum unit 108, and the gas supply and power supply system 7; the plasma diagnostic system 5 is signal-connected to the probe diagnostic system 8 (directly transmitting the results to the remote control system 6).

[0046] The gas supply system of the gas supply and power supply system 7 includes a first gas supply tank and a second gas supply tank. The first gas supply tank is communicated with the air inlet port 109 through a first gas inlet pipeline, and the second gas supply tank is communicated with the argon gas inlet 110 through a second gas inlet pipeline; the power supply system of the gas supply and power supply system 7 is electrically connected to all components that require power supply (for supplying power to these components).

[0047] Further, multiple groups of the coils 104 are all water-cooled DC electromagnetic coils.

[0048] Specific Embodiment 2: As shown in Figures 1 - 3 A method for surface modification of a hot working die based on the helicon wave plasma device described in Specific Embodiment 1 includes the following steps:

[0049] Step 1: After ultrasonic cleaning the die to be plated 4 (a stainless steel automotive gear die), clamp and fix it on the compound motion support mechanism 2, install the CrAl alloy target 301 on the magnetron sputtering cathode 303, and adjust the distance between the target 301 and the die 4 to a preset value (adjust the die 4 to correspond to the target 301).

[0050] Specifically, Step 1 is as follows: The die to be plated 4 is successively ultrasonically cleaned with acetone, absolute ethanol, and deionized water for 5 - 10 minutes to remove surface oil stains and impurities; the cleaned die 4 is clamped and fixed on the compound motion support mechanism 2 (ensuring its stability); subsequently, the CrAl alloy target 301 is installed at the magnetron sputtering cathode position, and the distance between the target 301 and the die 4 is adjusted to a preset value.

[0051] Step 2: Pump the cavity 1 to the base vacuum, introduce high-purity argon gas from the argon gas inlet 110 into the coating region 101, and in a magnetic field environment with a magnetic field intensity of 1500 - 3000 Gs, turn on the RF power supply 107 to excite the helicon wave plasma discharge antenna 105 to discharge helicon waves of plasma, forming a high-density argon plasma; use the argon plasma to clean the surface of the die 4.

[0052] Step 2 is as follows: evacuate the cavity 1 to a background vacuum with a vacuum degree of 1×10-5-1×10-4Pa, introduce high-purity argon gas with a purity of 99.999% from the argon gas inlet 110 of the cavity 1, and set the gas flow rate to 40-60sccm; in a magnetic field environment with a magnetic field strength of 1500-3000Gs, turn on the radio frequency power supply 107 (frequency of 13.56MHz, power of 1500-2000W), excite spiral wave plasma discharge, and form high-density argon plasma; use argon plasma to clean the surface of the mold 4 for 5 minutes to remove residual pollutants;

[0053] Step 3: Keep the argon plasma discharge state, and at the same time, introduce high-purity nitrogen into the cavity 1, and spray argon onto the surface of the mold 4; the argon plasma ionizes the nitrogen to form a nitride deposition layer; then, start the magnetic field control system of the magnetron sputtering cathode and the remote control system 6, and under the synergistic effect of the electromagnetic field, argon ions bombard the CrAl alloy target 301 to achieve sputtering of the target 301, and the sputtered particles combine with the active nitrogen in the plasma to form a CrAlN composite modified layer, i.e., a coating, on the surface of the mold 4; the overall deposition time is 10-15 minutes;

[0054] Step three is specifically as follows: while maintaining the argon plasma discharge state, high-purity nitrogen with a purity of 99.999% is introduced into the cavity 1 at a flow rate of 20-40 sccm, and argon is evenly sprayed onto the surface of the mold 4, and the argon plasma ionizes the nitrogen to form a nitride deposition layer; subsequently, the magnetic field control system of the magnetron sputtering cathode and the remote control system 6 is started, and under the synergistic effect of the electromagnetic field, argon ions bombard the CrAl alloy target 301 to achieve sputtering of the target 301, and the sputtered particles combine with the active nitrogen in the plasma to form a CrAlN composite modified layer, i.e., a coating, on the surface of the mold 4; the overall deposition time is 10-15 minutes.

[0055] Step 4: After the coating is completed, turn off the RF power supply 107 and all gas sources, evacuate the cavity 1 to the background vacuum state again, and then introduce high-purity argon gas to slowly raise the pressure of the cavity 1 to normal pressure; then, take out the mold 4, and the surface modification process is completed.

[0056] In step 4, high-purity argon gas is introduced with a purity of 99.999% and a flow rate of 55 sccm.

[0057] The function of the spiral wave plasma device of the present invention is to generate high-density active ions using plasma. By injecting the ions into a substrate (commercial vehicle gear die), an activation layer with excellent quality can be obtained at room temperature. At the same time, the substrate plasma is generated by discharging in a low-pressure gas under a vacuum background. The gas is relatively pure and easy to precisely control, enabling control of the surface composition, facilitating the formation of a very high-purity ceramic layer, and also suitable for preparing multi-component and high-melting-point compounds, such as the formation of CrAlSiN, etc.

[0058] The composite motion support mechanism 2 of the present invention adopts the structure of the "rotary clamping robotic arm mechanism" with the authorization announcement number CN221583634U and the authorization announcement date of August 23, 2024. Through this rotary clamping robotic arm mechanism, clamping operations can be achieved at different angles, expanding the working range and flexibility of the robotic arm, and being suitable for clamping requirements in various complex environments.

[0059] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, should be covered by the protection scope of the present invention.

Claims

1. A helicon wave plasma device for surface modification of hot working molds, characterized in that: It comprises a cavity (1), a composite motion support mechanism (2) and a magnetron sputtering coating system (3); The cavity (1) comprises a coating region (101), a diffusion region (102) and a plasma source region (103) which are connected in sequence from front to back. Multiple groups of coils (104) are respectively arranged outside the plasma source region (103) and the diffusion region (102). A spiral wave plasma discharge antenna (105) is placed in an argon gas inlet (110) arranged on the rear side wall of the plasma source region (103). One end of the spiral wave plasma discharge antenna (105) is connected to a radio frequency power source through a network matcher (106). (107) is electrically connected, and the other end of the spiral wave plasma discharge antenna (105) is grounded; the diffusion area (102) is provided with a vacuum port and a probe diagnostic system (8), and the vacuum port is connected to the vacuum unit (108); the coating area (101) is installed with a composite motion support mechanism (2) and a magnetron sputtering coating system (3), and the side wall of the coating area (101) is provided with an air intake port (109), and the air intake port (109) is connected to the air supply system of the air supply and power supply system (7) through an air intake pipeline.

2. The helicon wave plasma device for surface modification of hot working molds according to claim 1, characterized in that: The plasma source region (103) is a stainless steel chamber.

3. The helicon wave plasma device for surface modification of hot working molds according to claim 1, characterized in that: The argon gas inlet (110) is connected to the gas supply system of the gas supply and power supply system (7) through a second gas inlet pipeline, and a mass flow meter and a gas inlet stop valve are installed on the second gas inlet pipeline.

4. The helicon wave plasma device for surface modification of hot working molds according to claim 1, characterized in that: The diffusion area (102) is a stainless steel vacuum chamber.

5. The helicon wave plasma device for surface modification of hot working molds according to claim 1, characterized in that: The probe diagnostic system (8) is arranged at a first plasma diagnostic window provided at the top of the diffusion region (102), and a second plasma diagnostic window is provided on the side wall of the diffusion region (102), and the second plasma diagnostic window is a quartz glass window (111).

6. The helicon wave plasma device for surface modification of hot working molds according to claim 5, characterized in that: The vacuum port is arranged opposite to the quartz glass window (111), and is connected to the inlet of the vacuum unit (108) through a vacuum pipeline, and an ultra-high vacuum gate valve and an electromagnetic isolation valve are installed on the vacuum pipeline.

7. The helicon wave plasma device for surface modification of hot working molds according to claim 1, characterized in that: The magnetron sputtering coating system (3) comprises a target material (301), a magnetron sputtering cathode (303) and a plurality of magnets (302); the back of the target material (301) is connected to the magnetron sputtering cathode (303), the back of the magnetron sputtering cathode (303) is connected to the plurality of magnets (302), and the N and S poles of two adjacent magnets (302) are arranged alternately; the target material (301) serves as a cathode, and the mold to be plated (4) serves as an anode and is arranged opposite to the front of the target material (301), and the target material (301) is made of CrAl alloy.

8. The helicon wave plasma device for surface modification of hot working molds according to claim 5, characterized in that: The helicon wave plasma device further comprises a plasma diagnostic system (5), a remote control system (6) and a gas supply and power system (7); the plasma diagnostic system (5) is arranged on the diffusion region (102), the remote control system (6) and the gas supply and power system (7) are both arranged outside the cavity (1), the remote control system (6) is respectively connected to the plasma diagnostic system (5), the composite motion support mechanism (2), the magnetron sputtering coating system (3), the coil (104), the helicon wave plasma discharge antenna (105), the radio frequency power supply (107), the vacuum unit (108) and the gas supply and power system (7) by signals; the plasma diagnostic system (5) is connected to the probe diagnostic system (8) by signals; The gas supply system of the gas supply and power supply system (7) comprises a gas supply tank 1 and a gas supply tank 2, wherein the gas supply tank 1 is connected to the gas inlet port (109) via a gas inlet pipe 1, and the gas supply tank 2 is connected to the argon gas inlet port (110) via a gas inlet pipe 2; the power supply system of the gas supply and power supply system (7) is electrically connected to all components that require power supply.

9. The helicon wave plasma device for surface modification of hot working molds according to claim 1, characterized in that: The multiple groups of coils (104) are all water-cooled DC electromagnetic coils.

10. A method for surface modification of hot working molds based on the helicon wave plasma device according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: Step 1: After ultrasonic cleaning of the mold to be plated (4), the mold is clamped and fixed on the composite motion support mechanism (2), a CrAl alloy target (301) is mounted on the magnetron sputtering cathode (303), and the distance between the target (301) and the mold (4) is adjusted to a preset value; Step 2: evacuate the cavity (1) to a base vacuum, introduce high-purity argon gas from the argon gas inlet (110) into the coating area (101), and in a magnetic field environment with a magnetic field strength of 1500-3000 Gs, turn on the radio frequency power supply (107) to excite the helicon wave plasma discharge antenna (105) to discharge helicon wave plasma to form high-density argon plasma; and use the argon plasma to clean the surface of the mold (4); Step 3: maintaining the argon plasma discharge state, while introducing high-purity nitrogen into the cavity (1), and spraying argon onto the surface of the mold (4); the argon plasma ionizes the nitrogen to form a nitride deposition layer; then, starting the magnetic field control system of the magnetron sputtering cathode and the remote control system (6), under the synergistic effect of the electromagnetic field, argon ions bombard the CrAl alloy target (301), achieving sputtering of the target (301), and the sputtered particles combine with the active nitrogen in the plasma to form a CrAlN composite modified layer, i.e., a coating, on the surface of the mold (4); the overall deposition time is 10-15 minutes; Step 4: After the coating is completed, turn off the RF power supply (107) and all gas sources, evacuate the cavity (1) to the background vacuum state, and then introduce high-purity argon gas to slowly raise the pressure of the cavity (1) to normal pressure; then, take out the mold (4), and the surface modification process is completed.

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