Nitriding coating integrated equipment, method and application

Abstract

The application discloses a nitriding and coating integrated equipment and method and application. The equipment comprises a nitriding and coating integrated equipment body, a baffle, a cathode cylinder and a workpiece rack, and a target material is connected to the inner side wall of the nitriding and coating integrated equipment body in an insulation mode; the baffle is rotatably arranged around the inner wall of the nitriding and coating integrated equipment body, the baffle is spaced from the inner wall of the nitriding and coating integrated equipment body, the baffle is provided with a first opening, and the first opening can be rotated to a position corresponding to the target material; the cathode cylinder comprises a first cathode cylinder and a second cathode cylinder, the baffle and the cathode cylinder are connected to the bottom of the nitriding and coating integrated equipment body in an insulation mode, and a second opening and a third opening provided on the first cathode cylinder and the second cathode cylinder are arranged in correspondence with the target material; and the workpiece rack is located in the second cathode cylinder. The equipment completes the nitriding and coating of a workpiece in the same equipment, and realizes the nitriding and coating integration of the workpiece.

Description

Technical Field

[0001] This invention belongs to the field of metal surface treatment technology, specifically relating to an integrated nitriding coating equipment, method, and application. Background Technology

[0002] With the continuous development of industrial technology, higher requirements are being placed on the surface strength, corrosion resistance, and wear resistance of workpieces. Therefore, single metal surface strengthening methods are increasingly unable to meet the needs of modern industry, making composite surface treatments an inevitable trend. Currently, commonly used metal surface strengthening methods include ion nitriding and ion plating. However, in 1983, Finnish scientist Korhonen proposed the PN-PVD composite technology, which combines the advantages of both nitriding and plating. Nitriding treatment forms a compound layer and a diffusion layer on the surface of the metal workpiece, increasing its surface hardness. The nitrided substrate has higher load-bearing capacity, providing excellent substrate conditions for subsequent plating treatments and significantly improving film-substrate adhesion. The combination of the advantages of these two metal surface modification technologies is of great significance for industrial advancement.

[0003] The performance of metal surfaces after composite treatment is much better than that of single process treatment. The existing method is to first nitrid the workpiece in the nitriding equipment, then take out the workpiece and put it into the coating equipment for coating. Although the nitriding and coating workpiece can be completed by using two equipment, the transfer of the workpiece between the two equipment is cumbersome and time-consuming, and may also cause contamination to the surface of the workpiece. In addition, the process conditions of the two equipment are different, and the intermediate process of converting between the two processes will consume a lot of time and cost. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to provide an integrated nitriding and coating equipment, method, and application. This integrated nitriding and coating equipment performs nitriding and coating on the workpiece in the same device, achieving integrated nitriding and coating of the workpiece. This avoids workpiece contamination caused by transferring the workpiece between two devices, and the process parameters from nitriding to coating are easily adjustable, thereby saving energy and time costs and improving production efficiency.

[0005] In one aspect of the invention, an integrated nitriding coating apparatus is provided. According to an embodiment of the invention, it includes:

[0006] The nitriding coating integrated equipment body has an insulating connecting target material on the inner side wall of the nitriding coating integrated equipment body;

[0007] A baffle is rotatably arranged around the inner wall of the nitriding coating integrated equipment body. The baffle is spaced apart from the inner wall of the nitriding coating integrated equipment body. The baffle is insulated from the bottom of the nitriding coating integrated equipment body. The baffle is provided with a first opening, which can be rotated to the corresponding position of the target material.

[0008] The cathode cylinder includes a first cathode cylinder and a second cathode cylinder. The first cathode cylinder is arranged around the inner wall of the baffle at intervals, and the second cathode cylinder is arranged around the inner wall of the first cathode cylinder at intervals. Both the first cathode cylinder and the second cathode cylinder are insulatedly connected to the bottom of the nitriding coating integrated equipment body. Both the first cathode cylinder and the second cathode cylinder have multiple through holes. The first cathode cylinder and the second cathode cylinder are respectively provided with a second opening and a third opening, which are corresponding to the target material.

[0009] A workpiece holder is located inside the second cathode cylinder and is spaced apart from the inner wall of the second cathode cylinder.

[0010] According to the above embodiments of the present invention, the integrated nitriding coating equipment includes a nitriding coating equipment body, a baffle, a cathode cylinder, and a workpiece holder. When the workpiece is nitrided, it is placed on the workpiece holder. The target material is insulatedly connected to the inner wall of the integrated nitriding coating equipment body. The baffle is rotatably arranged around the inner wall of the integrated nitriding coating equipment body, spaced apart from the inner wall of the integrated nitriding coating equipment body, and insulatedly connected to the bottom of the integrated nitriding coating equipment body. The baffle has a first opening, which can be rotated to the corresponding position of the target material. At this time, in order to avoid the influence of nitriding ionized ions on the target material, the baffle is rotated so that the position of the first opening is misaligned with the target material, that is, the target material is shielded and protected by the baffle, thereby avoiding the influence of gas ions on the target material during the nitriding process. The cathode cylinder includes a first cathode cylinder and a second cathode cylinder. The inner wall of the baffle is arranged with a second cathode cylinder spaced around the inner wall of the first cathode cylinder. Both the first and second cathode cylinders are insulated from the bottom of the nitriding coating integrated equipment body. Both the first and second cathode cylinders have multiple through holes. The workpiece holder is located inside the second cathode cylinder and spaced from its inner wall. At this time, a bias voltage is applied to the workpiece holder, making the workpiece holder and workpiece in a cathode state. At the same time, a bias voltage is applied to the cathode cylinder, making it also in a cathode state. Ammonia gas is introduced into the nitriding coating integrated equipment. When the gas is ionized, the ions generated will bombard the cathode cylinder and the workpiece surface under the action of the electric field. The metal atoms sputtered from the workpiece surface will combine with the active gas atoms and deposit on the workpiece surface. The gas atoms will continue to diffuse into the workpiece to form a nitrogen-reinforced layer.

[0011] After nitriding is complete, the ammonia gas supply is stopped, and the bias power supply to the workpiece holder and cathode cylinder is turned off. When the workpiece is ready for coating after nitriding, the baffle is rotated so that the first opening of the baffle corresponds to the position of the target material. The first and second cathode cylinders are respectively provided with a second and a third opening, which are also positioned to correspond to the target material, thus ensuring no obstruction between the target material and the workpiece. The process parameters such as temperature and pressure within the integrated nitriding and coating equipment are adjusted to meet the coating requirements. A bias voltage is applied to the workpiece holder, placing both the workpiece holder and the workpiece in a cathode state. A bias voltage is also applied to the target material, placing it in a cathode state. Through arc discharge between the target material and the anode, the target material evaporates, forming plasma that is deposited on the workpiece surface. Therefore, this integrated nitriding and coating equipment performs nitriding and coating on the workpiece in the same device, achieving integrated nitriding and coating of the workpiece. This avoids workpiece contamination caused by transferring the workpiece between two devices, and the process parameters from nitriding to coating are easily adjustable, thus saving energy and time costs and improving production efficiency.

[0012] In addition, the integrated nitriding coating equipment according to the above embodiments of the present invention may also have the following technical features:

[0013] In some embodiments of the present invention, an anode column is provided inside the second cathode cylinder, and the anode column is insulated and disposed at the bottom of the integrated nitriding coating equipment body, with the anode column close to the workpiece holder. This is beneficial for improving the coating quality on the workpiece surface.

[0014] In some embodiments of the present invention, an insulating platform is provided on the bottom wall of the integrated nitriding coating equipment body, and the baffle, the cathode cylinder, the workpiece rack and the anode column are arranged on the insulating platform.

[0015] In some embodiments of the present invention, a turntable is provided on the insulating platform, and the workpiece is mounted on the turntable. As a result, the nitriding coating on the workpiece is more uniform.

[0016] In some embodiments of the present invention, a thermocouple is provided inside the integrated nitriding coating equipment. This allows for temperature regulation within the integrated nitriding coating equipment.

[0017] In a second aspect, the present invention provides a method for preparing a nitrided coated workpiece using the aforementioned equipment. According to an embodiment of the present invention, the method includes:

[0018] (1) Place the workpiece on the workpiece holder, rotate the baffle to make the first opening misalign with the target material, and then perform hollow cathode nitriding treatment on the workpiece to obtain a surface nitrided workpiece.

[0019] (2) Rotate the baffle to align the first opening with the target material position, adjust the process gas, temperature and workpiece bias of the equipment, and clean the target material and the surface nitriding workpiece.

[0020] (3) The surface nitrided workpiece after cleaning is further coated to obtain a nitrided coated workpiece.

[0021] Therefore, this method allows for nitriding and coating of workpieces in the aforementioned integrated nitriding and coating equipment, thereby saving energy and time costs and avoiding contamination during workpiece transfer.

[0022] In addition, the method for preparing a nitrided coated workpiece according to the above embodiments of the present invention may also have the following technical features:

[0023] In some embodiments of the present invention, step (2) specifically includes: (2-1) introducing argon gas into the body of the integrated nitriding coating equipment and evacuating the pressure to 0 Pa - 9 × 10⁻⁶ Pa. -3 Pa; (2-2) Align the first opening of the baffle with the target material position, change the temperature inside the integrated nitriding coating equipment to 480℃-500℃, introduce argon and ammonia into the integrated nitriding coating equipment, and evacuate to a pressure of 3×10⁻⁶. -2 Pa-5×10 0 Pa, adjust the workpiece bias voltage to 600V-700V, and clean the target material and the surface nitriding workpiece; (2-3) adjust the temperature inside the nitriding coating integrated equipment to 400℃-450℃, stop the ammonia gas supply, adjust the bias voltage to 400V-500V, turn on the target material arc source power supply, set the current to 70A-100A, and clean the workpiece by target sputtering; (2-4) adjust the workpiece bias voltage to 100V-300V, adjust the duty cycle to 50%-70%, and introduce argon and nitrogen into the nitriding coating integrated equipment to make the gas pressure 5×10 -1 Pa-1×10 1 Pa. Therefore, a better transition occurs between the nitriding treatment and the coating treatment, improving the quality of the nitriding coating on the workpiece.

[0024] In some embodiments of the present invention, in step (2-2), the volume ratio of argon to ammonia is (6:4 to 9:1).

[0025] In some embodiments of the present invention, in steps (2-4), the volume ratio of the argon gas to the nitrogen gas is (0:10 to 3:7).

[0026] In a third aspect, the present invention provides a workpiece. According to an embodiment of the invention, the workpiece is obtained by nitriding coating treatment using the above-described equipment or method. As a result, the workpiece possesses excellent strength and corrosion resistance.

[0027] In a fourth aspect, the present invention provides a mechanical device. According to an embodiment of the invention, the mechanical device includes the aforementioned workpiece. Therefore, the mechanical device has a long service life and high safety performance.

[0028] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0030] Figure 1 This is a cross-sectional view of the integrated nitriding coating equipment according to an embodiment of the present invention;

[0031] Figure 2 This is a partial disassembly diagram of the integrated nitriding coating equipment according to an embodiment of the present invention;

[0032] Figure 3 This is a partial disassembled top view of the integrated nitriding coating equipment according to an embodiment of the present invention;

[0033] Figure 4 This is a diagram of the integrated nitriding coating equipment according to an embodiment of the present invention;

[0034] Figure 5 This is a cross-sectional microstructure diagram of the workpiece according to Embodiment 1 of the present invention;

[0035] Figure 6 These are images of the workpiece surface hardness and indentation morphology from Embodiment 1 of the present invention.

[0036] Figure 7 This is a workpiece scratch morphology diagram of Embodiment 1 of the present invention;

[0037] Figure 8 This is the XRD pattern of the workpiece in Embodiment 2 of the present invention;

[0038] Figure 9 This is a cross-sectional microstructure diagram of the workpiece according to Embodiment 2 of the present invention;

[0039] Figure 10 These are images of the workpiece surface hardness and indentation morphology from Embodiment 2 of the present invention.

[0040] Figure 11 This is the workpiece hardness gradient diagram of Embodiment 2 of the present invention. Detailed Implementation

[0041] The embodiments of the present invention are described in detail below, and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0042] In one aspect of the invention, an integrated nitriding coating apparatus is provided. According to an embodiment of the invention, reference is made to... Figure 1 The equipment includes: a nitriding coating integrated equipment body 100, a baffle 200, a cathode cylinder 300, and a workpiece rack 400.

[0043] According to an embodiment of the present invention, reference Figure 1 , Figure 2 and Figure 3 The inner wall of the nitriding coating integrated equipment body 100 is insulated and connected to the target material 500; a baffle 200 is rotatably arranged around the inner wall of the nitriding coating integrated equipment body 100, the baffle 200 is spaced apart from the inner wall of the nitriding coating integrated equipment body 100, the baffle 200 is insulated and connected to the bottom of the nitriding coating integrated equipment body 100, and the baffle 200 is provided with a first opening 210, which can be rotated to the corresponding position of the target material 500; the cathode cylinder 300 includes a first cathode cylinder 310 and a second cathode cylinder 320, the first cathode cylinder 310 is spaced around the inner wall of the baffle 200. The second cathode cylinder 320 is arranged around the inner wall of the first cathode cylinder 310 at intervals. Both the first cathode cylinder 310 and the second cathode cylinder 320 are insulatedly connected to the bottom of the nitriding coating integrated equipment body 100. Both the first cathode cylinder 310 and the second cathode cylinder 320 have multiple through holes 330. The first cathode cylinder 310 and the second cathode cylinder 320 are respectively provided with a second opening 311 and a third opening 321, which are correspondingly arranged with the target material 500. The workpiece holder 400 is located inside the second cathode cylinder 320 and is spaced apart from the inner wall of the second cathode cylinder 320.

[0044] When nitriding workpiece 410 is performed, workpiece 410 is placed on workpiece holder 400. The target material 500 is insulated and connected to the inner wall of the nitriding coating integrated equipment body 100. To prevent the influence of nitriding ionized ions on the target material 500, the baffle 200 is rotated, causing the position of the first opening 210 to be misaligned with the target material 500. That is, the target material 500 is shielded and protected by the baffle 200, thus avoiding the influence of gas ions on the target material 500 during the nitriding process. At this time, a bias voltage is applied to the workpiece holder 400, causing the workpiece holder 400 and workpiece 410 to... When the cathode is in a cathode state, a bias voltage is applied to the cathode cylinder 300, making the cathode cylinder 300 also in a cathode state. Ammonia gas is introduced into the body 100 of the nitriding coating integrated equipment. At this time, the ions generated after the gas is ionized will bombard the cathode cylinder 300 and the workpiece 410 surface under the action of the electric field. The metal atoms sputtered from the workpiece 410 surface will combine with the active gas atoms and be deposited on the workpiece 410 surface. The gas atoms will continue to diffuse into the workpiece 410 interior to form a nitrogen-reinforced layer.

[0045] After nitriding is completed, the ammonia gas supply is stopped, and the bias power supply to the workpiece holder 400 and cathode cylinder 300 is turned off. When the workpiece 410 is ready for coating after nitriding, the baffle 200 is rotated so that the first opening 210 of the baffle 200 corresponds to the position of the target material 500, and the second opening 311 and the third opening 321 are also set to correspond to the target material 500, so that there is no obstruction between the target material 500 and the workpiece 410, and the sputtering of ions will not be hindered during coating. The temperature, pressure and other process parameters in the body 100 of the integrated nitriding and coating equipment are adjusted to meet the coating requirements. A bias voltage is applied to the workpiece holder 400 so that the workpiece holder 400 and the workpiece 410 are in a cathode state. A bias voltage is applied to the target material 500 so that the target material 500 is in a cathode state. Through the arc discharge between the target material 500 and the anode, the target material 500 evaporates, thereby forming plasma and depositing it on the surface of the workpiece 410. Therefore, this integrated nitriding and coating equipment performs nitriding and coating on the same equipment, realizing the integration of nitriding and coating of the workpiece. It avoids workpiece contamination caused by the transfer of workpieces between two equipment, and the process parameters from nitriding to coating are easy to adjust, thereby saving energy and time costs and improving production efficiency.

[0046] It should be noted that the reference Figure 4For the integrated nitriding coating equipment to operate, it needs to be connected to a gas supply device 10, a power control device 20, and a vacuum device 30. The gas supply device 10, power control device 20, and vacuum device 30 are conventional devices in the art, and those skilled in the art can select them according to actual needs. For example, the power control device includes a cathode cylinder power supply for providing bias voltage to the cathode cylinder, an arc source power supply for providing power and voltage to the target material, and a bias voltage power supply for providing bias voltage to the workpiece. Simultaneously, those skilled in the art can select other devices according to actual needs. For example, it may also include a control panel 40 for convenient integrated control of the equipment, and a water cooling device 50 for cooling the equipment. Furthermore, the number of target materials installed can be selected according to actual needs. For example, if the number of target materials is 3, the corresponding number of the first, second, and third openings will also be adjusted accordingly, i.e., the number of the first, second, and third openings will also be 3.

[0047] According to an embodiment of the present invention, reference Figure 1 An anode column 600 is installed inside the second cathode cylinder 320. The anode column 600 is insulated and located at the bottom of the nitriding coating integrated equipment body 100, close to the workpiece holder 400. The anode column 600 is always in an anode state, which can attract ions to splash towards the workpiece surface and make the plasma distribution more uniform, which is beneficial to improving the coating quality of the workpiece surface.

[0048] According to an embodiment of the present invention, reference Figure 1 An insulating platform (not shown) is provided on the bottom wall of the integrated nitriding coating equipment body 100. A baffle 200, cathode cylinder 300, workpiece holder 400, and anode column 600 are mounted on the insulating platform. Furthermore, a turntable 700 is provided on the insulating platform, and the workpiece holder 400 is mounted on the turntable 700. The turntable 700 can rotate, thereby driving the workpiece holder 400 to rotate, and consequently, the workpiece 410 will also rotate, thus making the nitriding coating on the workpiece 410 more uniform. According to an embodiment of the present invention, a thermocouple 800 is provided inside the integrated nitriding coating equipment body 100, thereby allowing for temperature regulation within the integrated nitriding coating equipment body 100.

[0049] In a second aspect, the present invention provides a method for preparing a nitrided coated workpiece using the aforementioned equipment. According to an embodiment of the present invention, the method includes:

[0050] S100: Place the workpiece on the workpiece holder, rotate the baffle to misalign the first opening with the target material, and then perform hollow cathode nitriding treatment on the workpiece.

[0051] In this step, low-alloy steel bars are cut to obtain pretreated samples. These samples are then subjected to alkaline washing, electrochemical acid washing and polishing, ultrasonic cleaning with alcohol, and finally drying. The dried workpiece is placed into the vacuum chamber of the integrated nitriding coating equipment. A rotating baffle is used to misalign the first opening with the target material. The mechanical pump is then activated to evacuate the air pressure of the integrated nitriding coating equipment to the first-stage air pressure (0-1×10⁻⁶). 1 After maintaining the pressure at 10-20 min (Pa), argon gas is introduced, and the grating angle is adjusted (0°-90°) to keep the gas pressure of the integrated nitriding coating equipment stable. In the second stage, the gas pressure is 1×10⁻⁶ Pa. 0 -2×10 1 (Pa); Turn on the thermocouple and begin heating. Set the first-stage bias voltage (500V-600V) for the equipment, adjust the duty cycle (25%-40%), turn on the cathode cylinder power supply, set the cathode cylinder bias voltage to 500V-800V, adjust the cathode cylinder duty cycle (73%-75%), ensure stable glow discharge inside the equipment for 10-20 minutes, and begin heating; wait for the temperature inside the equipment to reach the first-stage temperature (200-350℃), and ensure the equipment reaches the third-stage pressure (1×10⁻⁶ Pa); 2 -2×10 2 Stop supplying argon gas to the equipment under the condition of (Pa), and introduce ammonia gas instead. Set the second-stage bias voltage (600V-650V), adjust the duty cycle (40%-60%), and continue heating. When the temperature inside the equipment reaches the second-stage temperature (350℃-450℃), continue supplying ammonia gas to the equipment and adjust the equipment to reach the fourth-stage gas pressure (2×10 Pa). 2 -3×10 2 Set the third-stage bias voltage (650V-800V) and adjust the duty cycle (60%-70%). Once the equipment temperature reaches the third-stage temperature (450℃-550℃), begin timing and maintain the temperature. During this maintenance phase, continue introducing ammonia gas into the equipment. It should be noted that the first-stage bias voltage, second-stage bias voltage, and third-stage bias voltage all refer to the workpiece bias voltage.

[0052] S200: Rotate the baffle to align the first opening with the target material, adjust the process gas, temperature, and bias voltage to clean the target material and the surface nitriding workpiece.

[0053] In this step, after the S100 heat treatment time is reached, stop supplying ammonia to the equipment, turn off the cathode cylinder power supply and bias power supply, stop heating, and introduce argon into the nitriding coating integrated equipment body. Start the molecular pump to pump the pre-stage gas pressure to the fifth stage gas pressure (1×10⁻⁶). -2 -1×10 1Wait until the molecular pump power frequency reaches 300Hz-400Hz and the ionization gauge lights up. Open the high-pressure valve, connect the preamplifier and the chamber, and continue evacuating to the sixth stage pressure (0-9×10⁻⁶ Pa). -3 With the first opening of the baffle rotated towards the target material, the thermocouple power is increased, bringing the temperature inside the equipment to the fourth stage temperature (480℃-500℃). Argon and ammonia are continuously introduced into the equipment in a ratio (6:4~9:1) to ensure the vacuum chamber reaches the seventh stage pressure (3×10⁻⁶ Pa). -2 -5×10 0 Turn on the bias power supply and adjust the bias equipment to the fourth stage bias voltage (600V-700V). Clean the surface of the nitrided workpiece and the target surface for 10-20 minutes. After cleaning, reduce the thermocouple power to allow the temperature inside the equipment to reach the fifth stage temperature (400℃-450℃). Stop the supply of ammonia, adjust the bias voltage to the fifth stage bias voltage (400V-500V), turn on the arc source power supply of target 3, set the current (70A-100A), and use target 3 for sputter cleaning for 2-5 minutes. Reduce the thermocouple power and adjust the equipment to the sixth stage bias voltage (100V-300V). Adjust the duty cycle (50%-70%) and continuously supply argon and nitrogen into the equipment in a ratio (0:10~3:7) to maintain the seventh stage gas pressure (5×10⁻⁶). -1 -1×10 1 (Pa). It should be noted that the fourth stage bias, the fifth stage bias, and the sixth stage bias all refer to the workpiece bias.

[0054] S300: Further coating treatment is applied to the cleaned nitrided surface workpiece.

[0055] In this step, wait for the temperature inside the equipment to reach the sixth stage temperature (40℃-300℃), turn on the arc source power supply of target 1, set the current (70A-100A), start the turntable to make the workpiece holder rotate at a certain frequency (25Hz-35Hz), set the first stage deposition time (5min-15min), after the deposition time is reached, turn off the arc source power supply of target 1, stop the nitrogen gas, and continuously introduce argon gas for cleaning for 10min-15min. Stop the argon gas supply, adjust the equipment to the seventh stage bias voltage (100V-200V), turn on the arc source power supply of target 2, set the current (70A-100A), and introduce nitrogen gas to maintain the eighth stage gas pressure (5×10) in the vacuum chamber. -1 -1×10 1Deposition (50-100 min) was carried out, with the arc source power supply to target 2 turned off and the nitrogen supply stopped every 30 min of deposition. Argon gas was then introduced for cleaning for 10-20 min. After deposition, the arc source power supply and bias power supply were turned off, heating was stopped, and argon gas was continuously introduced and adjusted to the ninth stage pressure (2×10 Pa). -3 -3×10 -1 The vacuum pump stops cooling when the internal temperature reaches the seventh stage (25℃-80℃), the vent valve is opened, and the internal pressure is allowed to reach the tenth stage (9.8×10⁻⁶ Pa). 4 -1×10 5 At atmospheric pressure (Pa), open the vacuum chamber door and remove the workpiece. It should be noted that the seventh-stage bias refers to the workpiece bias.

[0056] Therefore, this method allows for nitriding and coating of workpieces within the aforementioned integrated nitriding and coating equipment, achieving integrated nitriding and coating processes, thus saving energy and time costs, and avoiding contamination caused by workpiece transfer. It should be noted that the features and advantages described above for the integrated nitriding and coating equipment also apply to this method, and will not be repeated here.

[0057] In a third aspect, the present invention provides a workpiece. According to an embodiment of the invention, the workpiece is obtained by nitriding coating treatment using the aforementioned equipment or method. Therefore, the workpiece possesses excellent strength and corrosion resistance. It should be noted that the features and advantages described above for the integrated nitriding coating equipment and method also apply to this workpiece, and will not be repeated here.

[0058] In a fourth aspect, the present invention provides a mechanical device. According to an embodiment of the invention, the mechanical device includes the aforementioned workpiece. Therefore, the mechanical device has a long service life and high safety performance. It should be noted that the features and advantages described above for the workpiece also apply to the mechanical device, and will not be repeated here.

[0059] The present invention will now be described with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0060] Example 1

[0061] The 42CrMo bar was cut by wire electrical discharge machining, cleaned with sodium hydroxide-sodium nitrate alkaline solution at 520℃ for 80s, electrochemically polished with nitric acid-hydrofluoric acid solution at 50℃ for 40s, ultrasonically cleaned with alcohol for 2min, and dried at 120℃ to obtain pre-nitrided 42CrMo alloy steel.

[0062] The pre-nitrided 42CrMo alloy steel is suspended on the workpiece rack of the integrated nitriding coating equipment. The first opening of the baffle is misaligned with the target material. The mechanical pump is turned on to evacuate the air pressure in the chamber to the first stage air pressure (6×10). -1 After maintaining the pressure at 1.5 × 10⁻⁶ Pa for 15 minutes, argon gas is introduced, and the grating angle is adjusted to 50° to stabilize the chamber pressure in the second stage. 1 (Pa); Turn on the thermocouple and start heating. Set the first-stage bias voltage (550V) to the equipment and adjust the duty cycle (30%). Turn on the DC power supply to the cathode cylinder and set the cathode cylinder bias voltage (560V). Adjust the cathode duty cycle (73%) to ensure stable glow discharge inside the equipment for 20 minutes. Wait for the temperature inside the equipment to reach the first-stage temperature (300℃), and then ensure that the pressure inside the equipment reaches the third-stage pressure (1.5×10). 2 Under the condition of argon gas pressure (Pa), stop supplying argon gas to the equipment and introduce ammonia gas. Set the second-stage bias voltage to 600V, adjust the duty cycle to 40%, and continue heating. When the temperature inside the equipment reaches the second-stage temperature (400℃), continue supplying ammonia gas to the equipment and adjust the pressure inside the equipment to reach the fourth-stage pressure (3×10⁻⁶ Pa). 2 Set the third-stage bias voltage to 650V and adjust the duty cycle to 70%. Once the internal temperature reaches the third-stage temperature (530℃), begin timing and maintain the temperature for 3 hours, continuing to introduce ammonia gas during this period. After the maintenance time is reached, stop introducing ammonia gas, turn off the cathode cylinder power supply and bias voltage power supply, stop heating, introduce argon gas, and start the molecular pump to evacuate the pre-stage pressure to the fifth-stage pressure (1×10⁻⁶ Pa). - 1 Wait until the molecular pump power frequency reaches 400Hz and the ionization gauge lights up. Open the high-pressure valve, connect the preamplifier and the chamber, and continue evacuating to the sixth stage pressure (5×10⁻⁶ Pa). -3 Pa).

[0063] Rotate the first opening of the baffle to the target material, increase the thermocouple power, and raise the temperature inside the equipment to the fourth stage temperature of 500℃. Continuously introduce argon and ammonia gas into the equipment in a ratio of 3:1 to ensure that the vacuum chamber reaches the seventh stage pressure (5×10⁻⁶). -1Turn on the bias power supply and adjust the bias equipment to the fourth stage bias (700V). Clean the surface of the nitrided workpiece and the target material for 20 minutes. After cleaning, reduce the thermocouple power to bring the temperature inside the equipment to the fifth stage temperature of 400℃. Stop the supply of ammonia and adjust the bias equipment to the fifth stage bias of 500V. Turn on the arc source power supply of target 3 and set the current to 85A. Use target 3 for sputter cleaning for 5 minutes. Reduce the thermocouple power and adjust the equipment to the sixth stage bias of 150V. Adjust the duty cycle (60%) and continuously supply argon and nitrogen into the equipment in a ratio (1:10) to maintain the eighth stage gas pressure (1×10⁻⁶) in the vacuum chamber. 1 Wait for the temperature inside the equipment to reach the sixth stage temperature (280℃), turn on the target 1 arc source power supply, set the current (85A), start the turntable, and rotate the workpiece holder at a certain frequency (25Hz). Set the first stage deposition time (6min). After the deposition time is reached, turn off the target 1 arc source power supply, stop the nitrogen gas supply, and continuously supply argon gas for cleaning for 15min. Stop the argon gas supply, adjust the equipment to the seventh stage bias voltage (150V), turn on the target 2 arc source power supply, set the current (70A), and supply nitrogen gas to maintain the ninth stage gas pressure (1×10⁻⁶ Pa) in the vacuum chamber. 1 Pa), deposit for 90 min, every 30 min, turn off the power supply of the target 2 arc source, stop the nitrogen gas supply, and introduce argon gas for cleaning for 15 min.

[0064] After deposition is complete, turn off the arc source power supply and bias power supply, stop heating, and continuously introduce argon gas, adjusting it to the tenth stage gas pressure (3×10). -2 The vacuum pump is turned off, the vent valve is opened, and the internal pressure is allowed to reach the eleventh stage pressure (1×10⁻⁶ Pa). The cooling phase begins. Once the internal temperature reaches the seventh stage temperature (45℃), the vacuum pump is turned off, the vent valve is opened, and the internal pressure is allowed to reach the eleventh stage pressure (1×10⁻⁶ Pa). 5 When the pressure is at 1000 Pa (atmospheric pressure), open the vacuum chamber door and remove the workpiece.

[0065] The workpiece in Example 1 was cut and the cross-section was polished. The cross-section morphology was observed by etching with 4% nitric acid alcohol. The results are as follows: Figure 5 As shown, the thickness of the nitrided layer is approximately 304.868 μm, the thickness of the compound layer is approximately 16.812 μm, and a WCrN coating of approximately 2.147 μm is deposited on the nitrided surface. Surface hardness and indentation morphology were measured using a microhardness tester, as shown below. Figure 6 As shown, comparison revealed that the surface hardness of sample 1, which only underwent coating treatment, was only 469.562 μm, and the coating near the indentation had collapsed. In contrast, the surface hardness of the workpiece in Example 1 reached 1241.748 μm, three times that of the sample with only coating treatment, and the indentation was very clear and complete, with no collapse of the surrounding coating. Scratch morphology images were obtained using a scratch tester, as shown below. Figure 7 As shown, comparison revealed that in Sample 1, which only underwent coating, the amplitude of the acoustic emission signal suddenly increased at a load of approximately 34N, and the coating began to peel off. Subsequently, a series of continuous acoustic emission peaks appeared. As the applied load further increased, the scratches continued to expand, and the peeling of the coating became correspondingly more severe. At the maximum load of 42N, the substrate underwent severe deformation. In contrast, the workpiece in Example 1 exhibited an acoustic emission signal and the coating began to peel off when a load of 39N was applied. At the maximum load of 60N, most of the coating peeled off.

[0066] Example 2

[0067] The 38CrMoAl rod was cut by wire electrical discharge machining, cleaned with sodium hydroxide-sodium nitrate alkaline solution at 520℃ for 80s, electrochemically polished with nitric acid-hydrofluoric acid solution at 50℃ for 40s, ultrasonically cleaned with alcohol for 2min, and dried at 120℃ to obtain a pre-nitrided 38CrMoAl sample.

[0068] The pre-nitrided 38CrMoAl sample was placed on a rotating rack inside the vacuum chamber of the integrated nitriding and coating composite preparation equipment. The hollow cathode barrel was rotated with the holes facing outwards until there was no target material. The mechanical pump was turned on, and the chamber pressure was evacuated to the first stage pressure (3×10⁻⁶). 1 After maintaining the pressure at 1 Pa for 15 minutes, argon gas is introduced. The grating angle is adjusted (50°) to stabilize the chamber pressure. In the second stage, the pressure is 1 × 10⁻⁶ Pa. 1 (Pa); Turn on the thermocouple and start heating. Set the first-stage bias voltage (550V) to the equipment, adjust the duty cycle (30%), turn on the DC power supply to the cathode cylinder, set the cathode cylinder bias voltage (560V), and adjust the cathode duty cycle (73%) to ensure stable glow discharge inside the equipment for 20 minutes; wait for the temperature inside the equipment to reach the first-stage temperature (300℃), and ensure that the pressure inside the equipment reaches the third-stage pressure (1.5×10). 2 Under the condition of argon gas pressure (Pa), stop supplying argon gas to the equipment and introduce ammonia gas. Set the second-stage bias voltage to 600V, adjust the duty cycle to 40%, and continue heating. When the temperature inside the equipment reaches the second-stage temperature (400℃), continue supplying ammonia gas to the equipment and adjust the pressure inside the equipment to reach the fourth-stage pressure (3×10⁻⁶ Pa). 2 Set the third-stage bias voltage to 650V and adjust the duty cycle to 70%. Once the internal temperature reaches the third-stage temperature (530℃), begin timing and maintain the temperature for 3 hours. During this period, continue introducing ammonia gas into the equipment. After the maintenance time is reached, stop introducing ammonia gas, turn off the DC power supply and bias power supply to the cathode cylinder, stop heating, introduce argon gas into the equipment, and start the molecular pump to evacuate the pre-stage pressure to the fifth-stage pressure (1×10⁻⁶ Pa). -1Wait until the molecular pump power frequency reaches 400Hz and the ionization gauge lights up. Open the high-pressure valve, connect the preamplifier and the chamber, and continue evacuating to the sixth stage pressure (5×10⁻⁶ Pa). -3 Pa).

[0069] Rotate the baffle orifice toward the target material, increase the thermocouple power, and raise the temperature inside the equipment to the fourth stage temperature of 500℃. Continuously introduce argon and ammonia gas into the equipment in a ratio of 3:1 to ensure that the vacuum chamber reaches the seventh stage pressure (5×10⁻⁶). -1 Turn on the bias power supply and adjust the bias equipment to the fourth stage bias voltage (700V). Clean the surface of the nitrided workpiece and the target surface for 20 minutes. After cleaning, reduce the thermocouple power to bring the temperature inside the equipment to the fifth stage temperature of 400℃. Stop the supply of ammonia gas, adjust the bias equipment to the fifth stage bias voltage of 500V, turn on the arc source power supply of target 3, set the current to 85A, and use target 3 for sputter cleaning for 5 minutes. Reduce the thermocouple power, adjust the equipment to the sixth stage bias voltage (200V), adjust the duty cycle (70%), and continuously supply argon and nitrogen gas into the equipment in a ratio (1:10) to maintain the eighth stage gas pressure (1×10⁻⁶) in the vacuum chamber of the equipment. 1 Pa). Wait for the temperature inside the equipment to reach the sixth stage temperature (280℃), turn on the target 1 arc source power supply, set the current (85A), start the turntable, and make the workpiece holder rotate at a certain frequency (25Hz). Set the first stage deposition time (6min). After the deposition time is reached, turn off the target 1 arc source power supply, stop the nitrogen gas supply, and continuously supply argon gas for cleaning for 15min. Stop the argon gas supply, adjust the equipment to the seventh stage bias voltage (150V), turn on the target 2 arc source power supply, set the current (70A), and supply nitrogen gas to maintain the ninth stage gas pressure (1×10⁻⁶ Pa) in the vacuum chamber. 1 Pa), deposition for 90 min, every 30 min, turn off the arc source power supply of target 2, stop the nitrogen gas supply, and introduce argon gas for cleaning for 15 min, and the bias voltage drops by 20V.

[0070] After deposition is complete, turn off the arc source power supply and bias power supply, stop heating, and continuously introduce argon gas, adjusting it to the tenth stage gas pressure (3×10). -2 The vacuum pump is turned off, the vent valve is opened, and the internal pressure is allowed to reach the eleventh stage pressure (1×10⁻⁶ Pa). The cooling phase begins. Once the internal temperature reaches the seventh stage temperature (45℃), the vacuum pump is turned off, the vent valve is opened, and the internal pressure is allowed to reach the eleventh stage pressure (1×10⁻⁶ Pa). 5 When the pressure is at 1000 Pa (atmospheric pressure), open the vacuum chamber door and remove the workpiece.

[0071] XRD patterns of Sample 2 (which only underwent coating) and the workpiece prepared in Example 2 were obtained by X-ray diffraction analysis. Figure 8As shown, the results revealed that both sample surfaces contained CrN, WN, and Cr. The workpiece from Example 2 exhibited more diffraction peaks for Cr, CrN, and WN than the single-coated sample 2. Furthermore, the workpiece from Example 2 showed a W diffraction peak compared to the single-coated sample 2. The workpiece prepared in Example 2 was cut, and the cross-section was polished. The cross-sectional morphology was observed using 4% nitric acid alcohol etching. The results are as follows: Figure 9 As shown, the thickness of the nitrided layer is approximately 334.472 μm, the thickness of the compound layer is approximately 17.430 μm, and a WCrN coating of approximately 2.474 μm is deposited on the nitrided surface. Surface hardness, indentation morphology, and hardness gradient were measured using a microhardness tester. Figure 10 and Figure 11 As shown in the figure. After comparison, it was found that the surface hardness of sample 2, which only underwent coating treatment, was only 462.36 μm, and the coating near the indentation had collapsed. In contrast, the surface hardness of the workpiece in Example 2 reached 1748.371 μm, nearly four times that of sample 2, which only underwent coating treatment. Furthermore, the indentation was very clear and complete, and the coating near it did not collapse. In the hardness gradient graph, it can be observed that the overall hardness of the workpiece in Example 2 increased significantly, and the decreasing trend was relatively slow.

[0072] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0073] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a nitrided coated workpiece, characterized in that, The nitriding coating integrated equipment is adopted, and the nitriding coating integrated equipment includes: The nitriding coating integrated equipment body has an insulating connecting target material on the inner side wall of the nitriding coating integrated equipment body; A baffle is rotatably arranged around the inner wall of the nitriding coating integrated equipment body. The baffle is spaced apart from the inner wall of the nitriding coating integrated equipment body. The baffle is insulated from the bottom of the nitriding coating integrated equipment body. The baffle is provided with a first opening, which can be rotated to the corresponding position of the target material. The cathode cylinder includes a first cathode cylinder and a second cathode cylinder. The first cathode cylinder is arranged around the inner wall of the baffle at intervals, and the second cathode cylinder is arranged around the inner wall of the first cathode cylinder at intervals. Both the first cathode cylinder and the second cathode cylinder are insulatedly connected to the bottom of the nitriding coating integrated equipment body. Both the first cathode cylinder and the second cathode cylinder have multiple through holes. The first cathode cylinder and the second cathode cylinder are respectively provided with a second opening and a third opening, which are corresponding to the target material. A workpiece holder, wherein the workpiece holder is located inside the second cathode cylinder and is spaced apart from the inner wall of the second cathode cylinder; The second cathode cylinder is provided with an anode column, which is insulated at the bottom of the integrated nitriding coating equipment body and is close to the workpiece holder; The method includes: (1) Place the workpiece on the workpiece holder, rotate the baffle to make the first opening misalign with the target material, and then perform hollow cathode nitriding treatment on the workpiece to obtain a surface nitrided workpiece. (2) Rotate the baffle so that the first opening corresponds to the target material position, adjust the process gas, temperature and workpiece bias of the equipment, and clean the target material and the surface nitriding workpiece. (3) The surface nitrided workpiece after cleaning is further coated to obtain a nitrided coated workpiece.

2. The method for preparing a nitrided coated workpiece according to claim 1, characterized in that, An insulating platform is provided on the bottom wall of the integrated nitriding coating equipment body, and the baffle, the cathode cylinder, the workpiece rack and the anode column are arranged on the insulating platform.

3. The method for preparing a nitrided coated workpiece according to claim 2, characterized in that, The insulating platform is equipped with a turntable, and the workpiece is mounted on the turntable.

4. The method for preparing a nitrided coated workpiece according to claim 1, characterized in that, The integrated nitriding coating equipment is equipped with thermocouples.

5. The method for preparing a nitrided coated workpiece according to claim 1, characterized in that, Step (2) specifically includes: (2-1) Argon gas is introduced into the body of the integrated nitriding coating equipment, and a vacuum is drawn until the gas pressure is 0 Pa - 9 × 10⁻⁹. -3 Pa; (2-2) Align the first opening of the baffle with the target material position, change the temperature inside the integrated nitriding coating equipment to 480℃-500℃, introduce argon and ammonia into the integrated nitriding coating equipment, and evacuate to a pressure of 3×10⁻⁶. - 2 Pa-5×10 0 Pa, adjust the workpiece bias voltage to 600V-700V, and clean the target material and the surface nitrided workpiece; (2-3) Adjust the temperature inside the nitriding coating integrated equipment to 400℃-450℃, stop the ammonia gas supply, adjust the workpiece bias voltage to 400V-500V, turn on the target material arc source power supply, set the current to 70A-100A, and clean the workpiece by target material sputtering. (2-4) Adjust the workpiece bias voltage to 100V-300V, adjust the duty cycle to 50%-70%, and introduce argon and nitrogen into the body of the integrated nitriding coating equipment to make the gas pressure 5×10 -1 Pa-1×10 1 Pa.

6. The method for preparing a nitrided coated workpiece according to claim 5, characterized in that, In step (2-2), the volume ratio of argon to ammonia is (6:4-9:1). Optionally, in steps (2-4), the volume ratio of argon to nitrogen is (0:10-3:7).

Images