Method for depositing GLC film based on surface of plastic workpiece by adopting PVD (Physical Vapor Deposition) technology

Abstract

The invention provides a method for depositing a GLC film on the basis of the surface of a plastic workpiece through a PVD technology and the corresponding plastic workpiece. The method comprises the steps that S1, the plastic workpiece is subjected to ultrasonic cleaning and baking; s2, a chromium target, a tungsten target and a graphite target are washed through multi-arc ion plating magnetron sputtering coating equipment; s3, vacuumizing the placed plastic workpiece, and introducing argon to open a chromium target to form a metal chromium layer; s4, starting a chromium target and a tungsten target for introducing argon to form a metal chromium-tungsten layer; s5, argon and nitrogen are introduced for starting a bias power supply, a chromium target and a tungsten target are started, and a chromium tungsten nitride layer is formed; s6, turning on a bias voltage power supply, turning off nitrogen, turning on a chromium target, a tungsten target and a graphite target, and introducing argon and acetylene to adjust bias voltage, so as to form a multi-element nano multilayer film structure; s7, turning on a bias power supply, turning off the tungsten target, turning on the chromium target and the graphite target, and introducing argon and acetylene to form a GLC film layer; and S8, a target material power supply, acetylene, argon and a bias power supply are turned off, and the plastic workpiece is cooled.

Description

Technical Field

[0001] This invention relates to the field of PVD coating technology, and in particular to a method for depositing GLC thin films on the surface of plastic workpieces using PVD technology, and the corresponding plastic workpieces. Background Technology

[0002] In modern society, plastic parts are widely used in electronic product casings, drone propellers, Bluetooth headset housings, and other fields. However, existing plastic parts lack protective structures on their surfaces, making them prone to scratches. Therefore, existing plastic parts suffer from poor durability.

[0003] Therefore, it is necessary to provide a method for depositing GLC thin films on the surface of plastic workpieces using PVD technology, and a corresponding plastic workpiece, to solve the above-mentioned technical problems. Summary of the Invention

[0004] This invention provides a method for depositing GLC thin films on the surface of plastic workpieces using PVD technology, and the corresponding plastic workpieces, which effectively solves the technical problem of poor durability of existing plastic workpieces.

[0005] This invention provides a method for depositing GLC thin films on the surface of plastic workpieces using PVD technology, comprising the following steps:

[0006] Step S1: Fix the plastic workpiece to be coated on a specific fixture, and then perform ultrasonic cleaning and baking operations on the plastic workpiece.

[0007] Step S2: Perform dust removal on the furnace chamber of the coating machine vacuum furnace, then close the furnace chamber door and perform a vacuuming operation on the furnace chamber. When the vacuum degree of the furnace chamber reaches 40 Pa, heat the furnace chamber. When the vacuum degree reaches 0.06 Pa, turn on the target power supply and turn on the chromium target, tungsten target and graphite target to be coated for target cleaning. After the target cleaning is completed and the temperature of the furnace chamber is below 80°C, perform a gas filling operation on the furnace chamber, and then open the furnace chamber door.

[0008] Step S3: Place the plastic workpiece to be coated into the furnace chamber, perform a vacuum operation on the furnace chamber, and when the vacuum degree reaches 0.008 Pa, introduce an appropriate amount of argon gas. When the vacuum degree of the furnace chamber reaches 0.3 Pa, turn on the chromium target and perform sputtering and deposition operations on the plastic workpiece for a first set time. Turn off the chromium target to deposit a metallic chromium layer on the surface of the plastic workpiece.

[0009] Step S4: Maintain the vacuum level of the furnace cavity at 0.3 Pa, turn on the chromium target and the tungsten target, and perform sputtering and deposition operations on the plastic workpiece for a second set time. Turn off the chromium target and the tungsten target, thereby depositing and forming a chromium-tungsten metal layer on the surface of the chromium metal layer.

[0010] Step S5: Maintain the vacuum level of the furnace cavity at 0.3 Pa, turn on the bias power supply with a bias voltage of 60V and a duty cycle of 50%, introduce an appropriate amount of nitrogen, turn on the chromium target and the tungsten target, and perform sputtering and deposition operations on the plastic workpiece for a third set time. Turn off the chromium target and the tungsten target, thereby depositing and forming a chromium tungsten nitride layer on the surface of the metallic chromium tungsten layer.

[0011] Step S6: Turn on the bias power supply, turn off the nitrogen gas, turn on the chromium target, tungsten target and graphite target, introduce argon and acetylene, adjust the bias voltage of the bias power supply, and perform sputtering and deposition operations on the plastic workpiece for a fourth set time, thereby depositing a multi-element nano multilayer film structure on the surface of the chromium nitride tungsten layer.

[0012] Step S7: Turn on the bias power supply, turn off the tungsten target, turn on the chromium target and graphite target, introduce an appropriate amount of argon and acetylene, and perform sputtering and deposition operations on the plastic workpiece for a fifth set time to form a GLC film layer on the surface of the multi-element nano-multilayer film structure.

[0013] Step S8: Turn off the target power supply, turn off the nitrogen, acetylene and argon gas, and turn off the bias power supply to cool the plastic workpiece.

[0014] In the method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to the present invention, step S1 includes the ultrasonic cleaning and baking operations.

[0015] Step S11: Add a 3% acidic surfactant to the cleaning solution, immerse the plastic workpiece in the cleaning solution, and then perform ultrasonic cleaning on the plastic workpiece. The cleaning time of the plastic workpiece is 3-5 minutes, and the temperature of the cleaning solution is less than 80°C.

[0016] Step S12: Rinse the plastic workpiece with pure water, wherein the conductivity of the pure water is less than or equal to 15 μS / cm.

[0017] Step S13: Bake the plastic workpiece at a temperature of 50℃-70℃ for 30 minutes.

[0018] In the method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to the present invention, in step S2, when the vacuum degree of the furnace cavity reaches 40 Pa, the temperature of the furnace cavity is heated to 80°C, and the heating time of the furnace cavity is 60 min.

[0019] In the method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to the present invention, in step S2, the chromium target, the tungsten target, and the graphite target are washed with a current of 10-25A and a voltage of 300-600V for 10-30 minutes.

[0020] In the method for depositing GLC thin films on the surface of a plastic workpiece using PVD technology according to the present invention, in step S3, the plastic workpiece is subjected to sputtering and deposition operations for a first set time, the first set time being 10-15 minutes, and the thickness of the metallic chromium layer being 0.3μm-0.5μm.

[0021] In the method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to the present invention, in step S4, the vacuum degree of the furnace cavity is maintained at 0.3 Pa, the chromium target and the tungsten target are turned on, the chromium target current is 15-20 A, the tungsten target current is 15-20 A, and the plastic workpiece is sputtered and deposited for a second set time of 10 minutes, and the thickness of the metallic chromium-tungsten layer is 0.5 μm-0.8 μm.

[0022] In the method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to the present invention, in step S5, the vacuum degree of the furnace cavity is maintained at 0.3 Pa, the bias power supply is turned on with a bias voltage of 60V and a duty cycle of 50%, an appropriate amount of nitrogen is introduced, the chromium target and the tungsten target are turned on with a chromium target current of 20A and a tungsten target current of 15A, and the plastic workpiece is sputtered and deposited for a third set time of 20 minutes, and the thickness of the chromium tungsten nitride is 1.0μm-1.2μm.

[0023] In the method for depositing GLC thin films on the surface of a plastic workpiece using PVD technology according to the present invention, in step S6, the chromium target, the tungsten target, and the graphite target are turned on, the chromium target current is 20A, the tungsten target current is 15A, and the graphite target current is 10A, and sputtering and deposition operations are performed on the plastic workpiece for a fourth set time, the fourth set time being 30 minutes, including...

[0024] Step S61: Turn on the chromium target, introduce an appropriate amount of acetylene, and perform sputtering and deposition operations on the plastic workpiece. Turn off the chromium target to deposit a chromium carbide layer on the surface of the chromium nitride tungsten layer.

[0025] Step S62: Turn on the tungsten target, introduce an appropriate amount of acetylene, and perform sputtering and deposition operations on the plastic workpiece. Turn off the tungsten target to deposit and form the tungsten carbide layer on the surface of the chromium carbide layer.

[0026] Step S63: Turn on the graphite target, introduce an appropriate amount of acetylene, and perform sputtering and deposition operations on the plastic workpiece to deposit the graphite carbide layer on the surface of the tungsten carbide layer.

[0027] Step S64: Repeat steps S61, S62 and S63 30-60 times.

[0028] Thus, the chromium carbide layer, the tungsten carbide layer, and the graphite carbide layer form a multi-element nano-multilayer film structure. The multi-element nano-multilayer film structure includes multiple chromium carbide layers, multiple tungsten carbide layers, and multiple graphite carbide layers. The multi-element nano-multilayer film structure is formed by the alternating deposition of multiple chromium carbide layers, tungsten carbide layers, and graphite carbide layers on the surface of the chromium nitride tungsten layer.

[0029] In the method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to the present invention, in step S7, the chromium target and graphite target are turned on, the tungsten target is turned off, 100 sccm of argon gas and 50-80 sccm of acetylene gas are introduced into the furnace chamber, the pressure in the furnace chamber is 0.3 Pa, the bias voltage of the bias power supply is adjusted to 50 V, the duty cycle is 30%, and the plastic workpiece is subjected to sputtering and deposition operations for a fifth set time of 90 minutes, thereby depositing and forming a GLC film layer on the surface of the multi-element nano-multilayer film structure, the thickness of the GLC film layer being 1.0 μm-1.5 μm.

[0030] A plastic workpiece, comprising,

[0031] Workpiece body;

[0032] A chromium layer is deposited on the surface of the plastic workpiece and is connected to the workpiece body;

[0033] A chromium-tungsten metal layer is deposited on the surface of the chromium metal layer and is connected to the chromium metal layer;

[0034] A chromium tungsten nitride layer is deposited on the surface of the metallic chromium tungsten layer and is connected to the metallic chromium tungsten layer; the chromium tungsten nitride layer includes multiple chromium nitride layers and multiple tungsten nitride layers, and the structure of the chromium tungsten nitride layer is formed by the alternating deposition of multiple chromium nitride layers and multiple tungsten nitride layers on the surface of the metallic chromium tungsten layer;

[0035] A multi-element nano-multilayer film structure is deposited on the surface of the chromium nitride tungsten layer and connected to the chromium nitride tungsten layer. The multi-element nano-multilayer film structure includes multiple chromium carbide layers, multiple tungsten carbide layers and multiple graphite carbide layers. The multi-element nano-multilayer film structure is formed by the alternating deposition of multiple chromium carbide layers, tungsten carbide layers and graphite carbide layers on the surface of the chromium nitride tungsten layer.

[0036] A GLC film is deposited on the surface of the multi-element nano-multilayer film structure and connected to the multi-element nano-multilayer film structure. The W target is turned off, while the Cr target and graphite target are retained. C2H2 is introduced for reactive sputtering, and finally a GLC film is formed.

[0037] Compared to existing technologies, the advantages of this invention are as follows: This invention provides a method for depositing a GLC thin film on the surface of a plastic workpiece using PVD technology. This deposition method can deposit a chromium layer, a chromium-tungsten layer, a chromium-tungsten nitride layer, a multi-element nano-multilayer film structure, and a GLC film layer on the surface of the plastic workpiece, thereby giving the surface of the plastic workpiece a composite film structure. This composite film structure can protect the surface of the plastic workpiece, preventing scratches and improving its durability. It effectively solves the technical problem of poor durability of existing plastic workpieces. Furthermore, the composite film structure has dustproof, waterproof, and corrosion-resistant functions. Therefore, the composite film structure can improve the protective performance of the plastic workpiece, making it wear-resistant and effectively extending its service life. Moreover, the composite film structure exhibits a mirror-like gradient gloss, which can increase the metallic texture of the plastic workpiece and enhance its texture and technological feel. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments are briefly introduced below. The drawings described below are only the corresponding drawings of some embodiments of the present invention.

[0039] Figure 1 This is a process flow diagram of the method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to the present invention.

[0040] Figure 2 This is a schematic diagram of the planar structure of the plastic workpiece of the present invention.

[0041] 10. Plastic workpiece; 11. Workpiece body; 12. Chromium layer; 13. Chromium-tungsten layer; 14. Chromium-tungsten nitride layer; 15. Multi-element nano-multilayer film structure; 151. Chromium carbide layer; 152. Tungsten carbide layer; 153. Graphite carbide layer; 16. GLC film layer. Detailed Implementation

[0042] The technical solution of the invention will be described in detail below with reference to specific embodiments. It should be understood that these embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention. After reading the invention, any modifications of the invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

[0043] The terms "first" and "second" used in the terminology of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor as limiting the order of events.

[0044] This invention primarily utilizes a multi-arc ion plating magnetron sputtering coating system. Currently, this equipment is mainly used in the preparation of PVD thin films on the surfaces of metallic materials such as stainless steel, aluminum alloys, and titanium alloys, specifically for coating mobile phone frames, mobile phone interior accessories, watch cases, and watch straps. However, this invention can deposit metal nitride and metal carbide films on the surfaces of non-metallic materials such as polycarbonate, polyethylene, polystyrene, and acrylonitrile-butadiene-styrene copolymers, thereby achieving PVD coating. Metal nitrides include titanium nitride, titanium aluminum nitride, chromium aluminum nitride, chromium nitride, etc., while metal carbides include titanium carbide, chromium carbide, carbon-chromium-tungsten alloy, chromium silicon carbide, chromium-tungsten silicon carbide, etc. This invention overcomes the limitation that magnetron sputtering coating machines cannot be used to coat non-metallic materials such as plastics, polycarbonate, polyethylene, and acrylonitrile-butadiene-styrene copolymers. This invention enables non-metallic material surfaces to have a metallic texture, makes products lighter, and reduces costs.

[0045] Please refer to Figure 1This invention provides a method for depositing GLC thin films on the surface of a plastic workpiece using PVD technology, comprising the following steps. Step S1 involves fixing the plastic workpiece to be coated onto a specific fixture, and then performing ultrasonic cleaning and baking operations on the workpiece. The material of the plastic workpiece can be plastic or polycarbonate. In step S1, the ultrasonic cleaning and baking operations include steps S11, S12, and S13. In step S11, the user adds a 3% concentration of acidic surfactant to the cleaning solution, and then immerses the plastic workpiece in the cleaning solution. The acidic surfactant is a citric acid-based surfactant or an acetate-based surfactant, and the pH value of the acidic surfactant is in the range of 4.5-5.5. Because the pH value of the acidic surfactant is in the range of 4.5-5.5, the plastic workpiece can avoid being corroded by strong acids with excessively low pH. Subsequently, the user can perform an ultrasonic cleaning operation on the plastic workpiece. The cleaning time of the plastic workpiece is 3-5 minutes, and the temperature of the cleaning solution is less than 80°C. Step S12 involves the user rinsing the plastic workpiece with pure water, the conductivity of which is less than or equal to 15 μS / cm. This rinsing ensures that no ions remain on the plastic workpiece. Step S13 involves the user baking the plastic workpiece at a temperature of 50℃-70℃ for 30 minutes.

[0046] Please refer to Figure 1 Step S2 involves the user vacuuming the furnace chamber of the coating machine and then closing the furnace door. Next, the user evacuates the furnace chamber. When the vacuum level reaches 40 Pa, the furnace chamber can be heated. The heating temperature is 80°C, and the heating time is 60 minutes. When the vacuum level reaches 0.06 Pa, the user can turn on the target power. Heating evaporates contaminants inside the furnace chamber, while evacuation prevents the chromium and tungsten targets from reacting with oxygen to form oxides under heating conditions. Subsequently, the user performs a target cleaning process on the chromium, tungsten, and graphite targets to be coated, using a current of 10-25 A and a voltage of 300-600 V for 10-30 minutes. The target cleaning process removes contaminants from the chromium and tungsten targets through electrical discharge evaporation. Performing target cleaning under a vacuum of 0.06 Pa helps reduce the adverse effects of the target oxide layer on the film purity. After target cleaning is completed and the furnace temperature is below 80°C, the user can purge the furnace chamber with gas, and then open the furnace door. This prevents the plastic workpiece from deforming due to high temperatures, and also prevents the subsequent venting operation during coating from affecting the film adhesion. This venting operation refers to the introduction of gas.

[0047] Please refer to Figure 1Step S3 involves the user placing the plastic workpiece to be coated into the furnace chamber and evacuating the chamber. Once the vacuum reaches 0.008 Pa, an appropriate amount of argon gas is introduced. The argon gas ionizes under a high-voltage electric field to form plasma, which, after acceleration in the electric field, bombards the target surface. Through momentum transfer, target atoms or molecules are sputtered out and deposited onto the plastic workpiece to form a thin film. Furthermore, the introduction of argon gas can also be used to adjust the vacuum level of the furnace chamber. Once the vacuum level reaches 0.3 Pa, the user can turn on the chromium target and perform sputtering and deposition operations on the plastic workpiece for a first set time, which is 10-15 minutes. During this process, the user can turn on the ionization arc target power supply and the chromium target intermediate frequency power supply for sputtering and deposition operations. Subsequently, the user can turn off the chromium target, thereby depositing a metallic chromium layer on the surface of the plastic workpiece. The thickness of the metallic chromium layer is 0.3 μm-0.5 μm. This metallic chromium layer serves as the underlayer. The application of a chromium layer can improve the adhesion between the subsequent film layer and the plastic workpiece, and the chromium layer can also be used for electrical conductivity after deposition.

[0048] Please refer to Figure 1 Step S4 involves maintaining the furnace vacuum at 0.3 Pa. The user can then turn on the chromium and tungsten targets. The chromium target current is 15-20 A, and the tungsten target current is 15-20 A. Sputtering and deposition operations are performed on the plastic workpiece for a second set time, which is 10 minutes. Afterward, the user can turn off the chromium and tungsten targets. This deposits a chromium-tungsten metal layer on the surface of the chromium layer, with a thickness of 0.5 μm-0.8 μm. This chromium-tungsten metal layer serves as a transition layer. Chromium metal has high adhesion and corrosion resistance, while tungsten metal has high hardness and high thermal stability. Therefore, this step combines the characteristics of both chromium and tungsten metals to obtain a chromium-tungsten metal layer with high adhesion, high hardness, corrosion resistance, and high-temperature stability.

[0049] Please refer to Figure 1 Step S5 involves maintaining the furnace vacuum at 0.3 Pa by turning on the bias power supply. The bias power supply has a bias voltage of 60V, a duty cycle of 50%, and a frequency of 10kHz. Next, an appropriate amount of nitrogen gas is introduced. The user can then turn on the chromium and tungsten targets, with a chromium target current of 20A and a tungsten target current of 15A, to perform sputtering and deposition operations on the plastic workpiece for a third set time of 20 minutes. Subsequently, the user can turn off the chromium and tungsten targets. This deposits chromium tungsten nitride on the surface of the metallic chromium tungsten layer, with a thickness of 1.0μm-1.2μm. The chromium tungsten nitride layer comprises multiple chromium nitride layers and multiple tungsten nitride layers, the structure of which is formed by the alternating deposition of multiple chromium nitride layers and tungsten nitride layers on the surface of the metallic chromium tungsten layer. In this step, turning on the bias power supply reduces the stress within the film layer, thereby increasing the energy of the target ions during magnetron sputtering, further hardening the film layer.

[0050] Step S6 further includes steps S61, S62, S63, and S64. Step S6 involves turning on the bias power supply and turning off the nitrogen gas. Subsequently, the chromium target, tungsten target, and graphite target are turned on, and argon and acetylene gas are introduced. Next, the user can adjust the bias voltage of the bias power supply to perform sputtering and deposition operations on the plastic workpiece for a fourth set time, thereby depositing a multi-element nanolayered film structure on the surface of the chromium tungsten nitride layer. The fourth set time is 30 minutes.

[0051] Step S61: The user turns on the chromium target, introduces an appropriate amount of acetylene, and performs sputtering and deposition operations on the plastic workpiece. Subsequently, the user can turn off the chromium target, thereby depositing a chromium carbide layer on the surface of the chromium nitride tungsten layer, with a thickness of less than or equal to 50 nm. Step S62: The user can turn on the tungsten target, introduce an appropriate amount of acetylene, and perform sputtering and deposition operations on the plastic workpiece. Subsequently, the user can turn off the tungsten target, thereby depositing a tungsten carbide layer on the surface of the chromium carbide layer, with a thickness of less than or equal to 50 nm. Step S63: The user turns on the graphite target, introduces an appropriate amount of acetylene, and performs sputtering and deposition operations on the plastic workpiece. Subsequently, the user can turn off the tungsten target, thereby depositing a graphite carbide layer on the surface of the tungsten carbide layer. Step S64 involves the user repeating steps S61, S62, and S63 30-60 times, thereby forming a multi-element nano-multilayer film structure consisting of multiple chromium carbide layers, multiple tungsten carbide layers, and multiple graphite carbide layers. This multi-element nano-multilayer film structure is formed by the alternating deposition of multiple chromium carbide layers, tungsten carbide layers, and graphite carbide layers on the surface of a chromium nitride tungsten layer. Furthermore, the hardness of the multi-element nano-multilayer film structure is greater than or equal to 1100 HV, while the hardness of plastic is less than or equal to 120 HV. Therefore, the hardness of the multi-element nano-multilayer film structure is much greater than that of plastic, which is beneficial for improving the hardness of the plastic workpiece of this invention.

[0052] Please refer to Figure 1 Step S7 involves turning on the chromium and graphite targets and turning off the tungsten target, and introducing argon gas at 100 sccm and acetylene gas at 50-80 sccm into the furnace chamber. The pressure inside the furnace chamber is 0.3 Pa, and the bias voltage of the bias power supply is adjusted to 50 V with a duty cycle of 30%. Sputtering and deposition operations are performed on the plastic workpiece for a fifth set time of 90 minutes, thereby depositing a GLC film layer on the surface of the multi-element nano-multilayer film structure. The thickness of the GLC film layer is 1.0 μm-1.5 μm. Due to its composition of metallic chromium and graphite, the GLC film layer has a nano-hardness of 1500 HV. Therefore, the GLC film layer has a relatively high hardness, which is beneficial for further improving the hardness of the plastic workpiece of this invention.

[0053] Please refer to Figure 1In step S8, the user can turn off the target power supply, nitrogen, acetylene, and argon gas, and the bias power supply. Subsequently, the user can perform a cooling operation on the plastic workpiece. In this invention, the method of depositing GLC thin films on the surface of a plastic workpiece using PVD technology can deposit a chromium layer, a chromium-tungsten layer, a chromium-tungsten nitride layer, a multi-element nano-multilayer film structure, and a GLC film layer on the surface of the plastic workpiece, thereby giving the surface of the plastic workpiece a composite film structure.

[0054] In the testing experiment, the composite film structure of Comparative Example 1 included a chromium layer, a chromium-tungsten layer, and a chromium-tungsten nitride layer. After 50 wear tests, this composite film structure showed significant wear and exposed the substrate. Therefore, this product failed the test.

[0055] The composite film structure of Comparative Example 2 includes a chromium layer, a chromium-tungsten layer, a chromium-tungsten nitride layer, and a chromium-tungsten carbide layer. After 80 wear tests, this composite film structure showed significant wear and exposed the substrate. Therefore, this product is substandard.

[0056] The composite film structure of Comparative Example 3 includes a chromium layer, a chromium-tungsten layer, and a multilayer nanofilm. The multilayer nanofilm comprises multiple chromium nitride layers and multiple tungsten nitride layers. The multilayer nanofilm is formed by the alternating deposition of multiple chromium nitride and tungsten nitride layers on the surface of the chromium-tungsten layer. After 50 wear tests, this composite film structure showed significant wear and exposed the substrate. Therefore, this product is substandard.

[0057] The composite film structure of Comparative Example 4 includes a chromium layer, a chromium-tungsten layer, and a multi-element nanolayered film. The multi-element nanolayered film comprises multiple chromium nitride layers, multiple tungsten nitride layers, and multiple nitrided graphite layers. The multi-element nanolayered film is formed by the alternating deposition of multiple chromium nitride layers, tungsten nitride layers, and nitrided graphite layers on the surface of the chromium-tungsten layer. After 120 wear tests, this composite film structure showed slight wear and slight exposure of the substrate. Therefore, this product is substandard.

[0058] The composite film structure of Comparative Example 5 includes a chromium layer, a chromium-tungsten layer, a chromium-tungsten nitride layer, and a multi-element nanolayered film. The multi-element nanolayered film comprises multiple chromium carbide layers, multiple tungsten carbide layers, and multiple graphite carbide layers. The multi-element nanolayered film is formed by the alternating deposition of multiple chromium carbide, tungsten carbide, and graphite carbide layers on the surface of the chromium-tungsten nitride layer. After 150 wear tests, this composite film structure showed slight wear and slight exposure of the substrate. Therefore, this product is substandard.

[0059] The composite film structure fabricated by the method of this invention includes a chromium layer, a chromium-tungsten layer, a chromium-tungsten nitride layer, a multi-element nano-multilayer film structure, and a GLC film. The multi-element nano-multilayer film structure comprises multiple chromium carbide layers, multiple tungsten carbide layers, and multiple graphite carbide layers. The multi-element nano-multilayer film structure is formed by the alternating deposition of multiple chromium carbide layers, tungsten carbide layers, and graphite carbide layers on the surface of the chromium-tungsten nitride layer. After 200 wear tests, only slight wear occurred, without exposing the substrate. Therefore, the composite film structure fabricated by this invention is a qualified product. Compared to the composite film structure in the comparative example above, the composite film structure exhibits better wear resistance. Specific test results are shown in Table 1.

[0060] Table 1. Test of wear resistance of GLC film layer

[0061]

[0062] Compared to traditionally coated plastics, the plastic parts of this invention offer several advantages. The film adhesion strength of the plastic parts of this invention is greater than or equal to 50 MPa, while that of traditionally coated plastics is less than or equal to 30 MPa. Higher film adhesion strength provides better resistance to external stress, thus extending product lifespan. Products with high film adhesion strength exhibit wear and scratch resistance, fatigue resistance, and other characteristics. Therefore, compared to traditionally coated plastics, the film adhesion strength of the plastic parts of this invention can be increased by 67%. Consequently, the service life of the plastic parts of this invention is longer.

[0063] The wear rate of the plastic workpiece of this invention is less than or equal to 0.5 mg / 1000 cy, while the wear rate of traditional coated plastics is less than or equal to 2 mg / 1000 cy. A lower wear rate indicates less material loss and better wear resistance. A higher wear rate indicates greater material loss and worse wear resistance. Therefore, compared to traditional coated plastics, the wear resistance of the plastic workpiece of this invention can be improved by 75%. Thus, the plastic workpiece of this invention has better wear resistance.

[0064] The plastic workpiece of this invention showed no corrosion after 240 hours of salt spray testing, while traditional coated plastics showed pitting corrosion after only 72 hours. Therefore, compared to traditional coated plastics, the salt spray resistance of the plastic workpiece of this invention is improved by 233%. Furthermore, the plastic workpiece of this invention exhibits stronger corrosion resistance.

[0065] The surface resistivity of the plastic workpiece of this invention is less than or equal to 5 ohms per square meter, while conventionally coated plastics are insulating. Therefore, compared to conventionally coated plastics, the plastic workpiece of this invention is conductive. Consequently, the user can electroplate the plastic workpiece of this invention.

[0066] Please refer to Figure 2The present invention also provides a plastic workpiece 10. This plastic workpiece 10 is manufactured using a method based on PVD technology to deposit a GLC thin film on the surface of the plastic workpiece. The plastic workpiece 10 includes a workpiece body 11, a chromium layer 12, a chromium-tungsten layer 13, a chromium-tungsten nitride layer 14, a multi-element nano-multilayer film structure 15, and a GLC film layer 16. The chromium layer 12 is deposited on the surface of the plastic workpiece 11 and is connected to the workpiece body 11. The thickness of the chromium layer 12 is 0.3 μm-0.5 μm. The chromium-tungsten layer 13 is deposited on the surface of the chromium layer 12 and is connected to the chromium layer 12. The thickness of the chromium-tungsten layer 13 is 0.5 μm-0.8 μm. The chromium-tungsten nitride layer 14 is deposited on the surface of the chromium-tungsten layer 13 and is connected to the chromium-tungsten layer 13. The thickness of the chromium-tungsten nitride layer 14 is 1.0 μm-1.2 μm. A multi-element nanolayered film structure 15 is deposited on the surface of a chromium nitride (ChN) tungsten nitride (TNT) layer 14, and is connected to the TNT layer 14. The multi-element nanolayered film structure 15 includes multiple chromium carbide (ChN) layers 151, multiple tungsten carbide (TCarbide) layers 152, and multiple graphite carbide (Graphite) layers 153, which are formed by alternating deposition of these layers on the surface of the ChN tungsten nitride (ChN) nitride (TNT) layer 14. The thickness of each of the chromium carbide (ChN) layer 151, tungsten carbide (TCarbide) layer 152, and graphite carbide (Graphite) layer 153 is less than or equal to 50 nm. A gas chromium carbide (GLC) film layer 16 is deposited on the surface of the multi-element nanolayered film structure 15, and is connected to the multi-element nanolayered film structure 15. The thickness of the GLC film layer 16 is 1.0 μm–1.5 μm.

[0067] This invention provides a method for depositing a GLC thin film on the surface of a plastic workpiece using PVD technology. This deposition method deposits a chromium layer, a chromium-tungsten layer, a chromium-tungsten nitride layer, a multi-element nanolayered film structure, and a GLC film onto the surface of the plastic workpiece, resulting in a composite film structure. This composite film structure protects the surface of the plastic workpiece, preventing scratches and improving its durability. It effectively solves the technical problem of poor durability in existing plastic workpieces. Furthermore, the composite film structure has dustproof, waterproof, and corrosion-resistant functions. Therefore, this composite film structure enhances the protective performance of the plastic workpiece, making it wear-resistant and effectively extending its service life. Moreover, the composite film structure exhibits a mirror-like gradient gloss, increasing the metallic texture of the plastic workpiece and enhancing its overall quality and technological appeal.

[0068] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A method for depositing GLC thin films on the surface of plastic workpieces using PVD technology, characterized in that, It includes the following methods and steps: Step S1: Fix the plastic workpiece to be coated on a specific fixture, and then perform ultrasonic cleaning and baking operations on the plastic workpiece. Step S2: Perform dust removal on the furnace chamber of the coating machine vacuum furnace, then close the furnace chamber door and perform a vacuuming operation on the furnace chamber. When the vacuum degree of the furnace chamber reaches 40 Pa, heat the furnace chamber. When the vacuum degree reaches 0.06 Pa, turn on the target power supply and turn on the chromium target, tungsten target and graphite target to be coated for target cleaning. After the target cleaning is completed and the temperature of the furnace chamber is below 80°C, perform a gas filling operation on the furnace chamber, and then open the furnace chamber door. Step S3: Place the plastic workpiece to be coated into the furnace chamber, perform a vacuum operation on the furnace chamber, and when the vacuum degree reaches 0.008 Pa, introduce an appropriate amount of argon gas. When the vacuum degree of the furnace chamber reaches 0.3 Pa, turn on the chromium target and perform sputtering and deposition operations on the plastic workpiece for a first set time. Turn off the chromium target to deposit a metallic chromium layer on the surface of the plastic workpiece. Step S4: Maintain the vacuum level of the furnace cavity at 0.3 Pa, turn on the chromium target and the tungsten target, and perform sputtering and deposition operations on the plastic workpiece for a second set time. Turn off the chromium target and the tungsten target, thereby depositing and forming a chromium-tungsten metal layer on the surface of the chromium metal layer. Step S5: Maintain the vacuum level of the furnace cavity at 0.3 Pa, turn on the bias power supply with a bias voltage of 60V and a duty cycle of 50%, introduce an appropriate amount of nitrogen, turn on the chromium target and the tungsten target, and perform sputtering and deposition operations on the plastic workpiece for a third set time. Turn off the chromium target and the tungsten target, thereby depositing and forming a chromium tungsten nitride layer on the surface of the metallic chromium tungsten layer. Step S6: Turn on the bias power supply, turn off the nitrogen gas, turn on the chromium target, tungsten target and graphite target, introduce argon and acetylene, adjust the bias voltage of the bias power supply, and perform sputtering and deposition operations on the plastic workpiece for a fourth set time, thereby depositing a multi-element nano multilayer film structure on the surface of the chromium nitride tungsten layer. Step S7: Turn on the bias power supply, turn off the tungsten target, turn on the chromium target and graphite target, introduce an appropriate amount of argon and acetylene, and perform sputtering and deposition operations on the plastic workpiece for a fifth set time to form a GLC film layer on the surface of the multi-element nano-multilayer film structure. Step S8: Turn off the target power supply, turn off the nitrogen, acetylene and argon gas, and turn off the bias power supply to cool the plastic workpiece.

2. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S1, the ultrasonic cleaning and baking operations include, Step S11: Add a 3% acidic surfactant to the cleaning solution, immerse the plastic workpiece in the cleaning solution, and then perform ultrasonic cleaning on the plastic workpiece. The cleaning time of the plastic workpiece is 3-5 minutes, and the temperature of the cleaning solution is less than 80°C. Step S12: Rinse the plastic workpiece with pure water, wherein the conductivity of the pure water is less than or equal to 15 μS / cm. Step S13: Bake the plastic workpiece at a temperature of 50℃-70℃ for 30 minutes.

3. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S2, when the vacuum degree of the furnace cavity reaches 40 Pa, the temperature of the furnace cavity is heated to 80 °C, and the heating time of the furnace cavity is 60 min.

4. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S2, the chromium target, the tungsten target, and the graphite target are washed with a current of 10-25A and a voltage of 300-600V for 10-30 minutes.

5. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S3, the plastic workpiece is subjected to sputtering and deposition operations for a first set time, which is 10-15 minutes, and the thickness of the chromium layer is 0.3μm-0.5μm.

6. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S4, the vacuum level of the furnace cavity is maintained at 0.3 Pa, the chromium target and the tungsten target are turned on, the chromium target current is 15-20 A, the tungsten target current is 15-20 A, and the plastic workpiece is sputtered and deposited for a second set time of 10 minutes. The thickness of the metallic chromium-tungsten layer is 0.5 μm-0.8 μm.

7. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S5, the vacuum level of the furnace cavity is maintained at 0.3 Pa, the bias power supply is turned on with a bias voltage of 60V and a duty cycle of 50%, an appropriate amount of nitrogen is introduced, the chromium target and the tungsten target are turned on with a current of 20A for the chromium target and 15A for the tungsten target, and the plastic workpiece is sputtered and deposited for a third set time of 20 minutes. The thickness of the chromium tungsten nitride is 1.0μm-1.2μm.

8. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S6, the chromium target, the tungsten target, and the graphite target are turned on. The chromium target current is 20A, the tungsten target current is 15A, and the graphite target current is 10A. A sputtering and deposition operation is performed on the plastic workpiece for a fourth set time, which is 30 minutes. Step S61: Turn on the chromium target, introduce an appropriate amount of acetylene, and perform sputtering and deposition operations on the plastic workpiece. Turn off the chromium target to deposit a chromium carbide layer on the surface of the chromium nitride tungsten layer. Step S62: Turn on the tungsten target, introduce an appropriate amount of acetylene, and perform sputtering and deposition operations on the plastic workpiece. Turn off the tungsten target to deposit and form the tungsten carbide layer on the surface of the chromium carbide layer. Step S63: Turn on the graphite target, introduce an appropriate amount of acetylene, and perform sputtering and deposition operations on the plastic workpiece to deposit the graphite carbide layer on the surface of the tungsten carbide layer. Step S64: Repeat steps S61, S62 and S63 30-60 times. The chromium carbide layer, the tungsten carbide layer, and the graphite carbide layer form a multi-element nano-multilayer film structure. The multi-element nano-multilayer film structure includes multiple chromium carbide layers, multiple tungsten carbide layers, and multiple graphite carbide layers. The multi-element nano-multilayer film structure is formed by the alternating deposition of multiple chromium carbide layers, tungsten carbide layers, and graphite carbide layers on the surface of the chromium nitride tungsten layer.

9. The method for depositing GLC thin films on the surface of plastic workpieces using PVD technology according to claim 1, characterized in that, In step S7, the chromium target and graphite target are turned on, the tungsten target is turned off, and 100 sccm of argon and 50-80 sccm of acetylene are introduced into the furnace chamber. The pressure inside the furnace chamber is 0.3 Pa. The bias voltage of the bias power supply is adjusted to 50 V and the duty cycle is 30%. The plastic workpiece is sputtered and deposited for a fifth set time of 90 minutes, thereby depositing a GLC film layer on the surface of the multi-element nano-multilayer film structure. The thickness of the GLC film layer is 1.0 μm-1.5 μm.

10. A plastic workpiece, characterized in that, It includes, Workpiece body; A chromium layer is deposited on the surface of the plastic workpiece and is connected to the workpiece body; A chromium-tungsten metal layer is deposited on the surface of the chromium metal layer and is connected to the chromium metal layer; A chromium tungsten nitride layer is deposited on the surface of the metallic chromium tungsten layer and is connected to the metallic chromium tungsten layer; The chromium tungsten nitride layer includes multiple chromium nitride layers and multiple tungsten nitride layers, and the chromium tungsten nitride layer structure is formed by the alternating deposition of multiple chromium nitride layers and multiple tungsten nitride layers on the surface of the metallic chromium tungsten layer; A multi-element nano-multilayer film structure is deposited on the surface of the chromium nitride tungsten layer and connected to the chromium nitride tungsten layer. The multi-element nano-multilayer film structure includes multiple chromium carbide layers, multiple tungsten carbide layers and multiple graphite carbide layers. The multi-element nano-multilayer film structure is formed by the alternating deposition of multiple chromium carbide layers, tungsten carbide layers and graphite carbide layers on the surface of the chromium nitride tungsten layer. A GLC film is deposited on the surface of the multi-element nano-multilayer film structure and connected to the multi-element nano-multilayer film structure. The W target is turned off, while the Cr target and graphite target are retained. C2H2 is introduced for reactive sputtering, and finally a GLC film is formed.

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