Colored TAC coating and preparation process thereof

Abstract

The colored TAC coating is characterized in that the colored TAC coating comprises a base coat and a functional layer which are sequentially arranged on the surface of a workpiece from inside to outside, the base coat is prepared through the sputter coating process, a target material used in the sputter coating process is one of chromium, titanium and tungsten carbide, the functional layer is prepared through the pure ion coating process, and the functional layer is prepared through the pure ion coating process. A target material used in the pure ion coating process is a pure carbon target. According to the technical scheme provided by the invention, the TAC coating with high hardness, high durability and excellent decoration can be prepared on the surface of the workpiece, the TAC coating can be used for surface treatment of small cutting tools such as milling cutters and micro drills, and various advantages of the TAC coating are fully exerted.

Description

Technical Field

[0001] This invention relates to the field of vacuum coating, specifically to a colored TAC coating and its preparation process. Background Technology

[0002] Surface coatings are applied to products to enhance their performance, and are widely used in various cutting tools, molds, and automotive parts. Compared to traditional vapor deposition, sputtering, and electroplating processes, TAC films have gained increasing popularity in related fields due to their simple preparation, wide range of controllable hardness and thickness, corrosion resistance, wear resistance, and high-temperature resistance. However, the performance of coatings prepared using current TAC processes on small cutting tools such as milling cutters and micro drills does not meet the standards for coatings on other products, thus necessitating a solution to this problem. Summary of the Invention

[0003] The purpose of this invention is to provide a colored TAC coating and its preparation process, which can be used in small cutting tools such as milling cutters and micro drills to fully utilize the advantages of TAC coating.

[0004] The present invention is implemented according to the technical solution described below.

[0005] A colored TAC coating and its preparation process include an underlayer and a functional layer sequentially disposed from the inside to the outside on the surface of the workpiece. The underlayer is prepared by sputtering deposition, and the target material used in the sputtering deposition process is one of chromium, titanium, and tungsten carbide. The functional layer is prepared by pure ion plating, and the target material used in the pure ion plating process is a pure carbon target.

[0006] The specific solution is as follows: the thickness of the base layer is 0.01 to 0.2 μm, and the thickness of the functional layer is 0.2 to 1.0 μm.

[0007] This invention also provides a process for preparing a colored TAC coating, comprising the following operations: S10: Install the workpiece on the fixture inside the vacuum chamber, and perform vacuuming and baking heating; S20: Turn on the PIC arc power supply to preheat the PIC target material; S30: Ar gas is injected from the ion source inlet to perform ion cleaning and activation on the workpiece; S40: Ar gas is injected from the sputtering target inlet, and the sputtering power supply and bias power supply are turned on to perform sputtering coating on the workpiece. S50: Turn off the Ar gas and turn on the PIC arc power supply to perform pure ion plating on the workpiece.

[0008] Furthermore, in operation S10, after evacuating to 0.05 Pa, the heating system is turned on to bake and degas the vacuum chamber to 100-280°C for 1-2 hours.

[0009] During operation S20, the temperature of the vacuum chamber is maintained at 100–280°C. When the gas pressure inside the vacuum chamber is evacuated to 1×10⁻⁶, the vacuum chamber temperature is reduced to 1×10⁻⁶. -2 When the pressure is below Pa, turn on the PIC arc power supply.

[0010] In operation S20, the arc current is set to 70-150A, the filter current to 10-20A, the anode current to 10-20A, and the preheating time to 500-3000s.

[0011] In operation S30, adjust the temperature of the vacuum chamber to 100-150℃, and when the gas pressure in the vacuum chamber is evacuated to 5×10... -3 When the pressure is below Pa, Ar gas is introduced from the ion source inlet.

[0012] During operation S30, after Ar gas is introduced, the vacuum level in the vacuum chamber is maintained at 9 × 10⁻⁶. -2 Pa~8×10 -1 Pa, set ion source voltage: 800~2200V, ion source current: 0.1~1.5A, workpiece bias voltage: 500~1500V, workpiece bias current: 0.2~1.5A, ion cleaning and activation time: 0.5~2.5h.

[0013] During operation S40, maintain the temperature of the vacuum chamber at 100–150°C and evacuate the vacuum level to 2 × 10⁻⁶. -3 Below Pa, 300–4500 sccm of Ar gas is introduced from the inlet of the sputtering target, and the vacuum level is maintained at 1 × 10⁻⁶. -1 Pa ~ 1.5 × 10 0 Pa, set sputtering power: 2~10KW, workpiece bias voltage: 100~500V, workpiece bias current: 0.2~1.2A, first sputter for 100~400s with the sputtering baffle closed, then open the baffle so that the sputtering target can perform the undercoat coating on the workpiece surface in the vacuum chamber, the undercoat coating time: 100~1500s.

[0014] In operation S50, after the underlayer preparation is completed, turn off the underlayer sputtering power supply, turn off the Ar gas and flow meter switches, turn off the heater, and open the baffle of the magnetic filter bend. When the gas pressure is lower than 5×10 -4When the pressure is 80-120°C, turn on the PIC arc power supply, set the arc current to 70-150A, the filter current to 10-20A, the anode current to 10-20A, the workpiece bias voltage to 100-2000V, and the workpiece bias current to 0.2-1.2A. Every 1000-2000 seconds during the coating process, reduce the workpiece bias voltage by 300-600V until the target bias voltage is reached.

[0015] The bias voltage can be adjusted according to the table below: The technical solution provided by this invention can prepare a TAC coating with high hardness, high durability and excellent decorative properties on the surface of a workpiece. It can be used for surface treatment of small cutting tools such as milling cutters and micro drills, giving full play to the various advantages of TAC coating. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0017] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0018] As used herein, the terms “parallel,” “perpendicular,” etc., are not limited to their strict geometric definitions, but include tolerances for reasonable and inconsistent machining or human errors.

[0019] like Figure 1 As shown, the colored TAC coating provided by the present invention includes a base layer and a functional layer being prepared sequentially on the surface of the workpiece. The base layer is prepared by (magnetron) sputtering, and the target material used for sputtering is a target material that matches the substrate. Common materials include chromium, titanium, tungsten carbide, etc. The functional layer is prepared by pure ion plating technology, and the target material used is a pure carbon target.

[0020] The specific preparation method includes the following steps: Step 1: Fix the workpiece on the fixture, load it into the vacuum chamber, start the vacuum system to begin operation, and after evacuating to 0.05 Pa, turn on the heating system to bake and degas the workpiece, rotating frame, and inner wall of the chamber. Subsequently, heat the vacuum chamber to 100-280℃ for 1-2 hours. This step involves evacuating the chamber while simultaneously baking at high temperature to maintain the chamber in a dry vacuum environment.

[0021] Step 2: Maintain heating at 100-280℃, when the air pressure is below 1×10 -2At Pa, turn on the PIC arc power supply, set the arc current to 70-150A, the filter current to 10-20A, and the anode current to 10-20A, and begin the preheating program of the pure ion plating source for 500-3000s. This step of preheating the PIC target is to bake and clean the arc power supply system (anode, bend, target) to ensure the adhesion between subsequent coatings.

[0022] Step 3: Adjust the heating temperature range of the vacuum chamber to 100-150℃, and evacuate the base vacuum to 5×10 -3 Below Pa, 50-200 sccm Ar is introduced from the ion source inlet, and the vacuum degree is maintained at 9 × 10⁻⁶. -2 Pa-8×10 -1 At Pa, turn on the ion source power supply and bias power supply. Ion source voltage: 800-2200V, ion source current: 0.1-1.5A, workpiece bias voltage: 500-1500V, workpiece bias current: 0.2-1.5A, ion cleaning and activation time: 0.5-2.5h. This step cleans the substrate surface, removing dirt and foreign matter at the microscopic level to ensure the adhesion between the subsequent coating and the substrate.

[0023] Step 4: Maintain the temperature of the coating chamber at 100-150℃, and evacuate the base vacuum to 2×10⁻⁶. -3 Below Pa, 300-4500 sccm Ar is introduced from the inlet of the sputtering target, and the vacuum level is maintained at 1×10⁻⁶. -1 Pa-1.5×10 0 At step 1, turn on the sputtering power supply and bias power supply. Sputtering power: 2-10KW; workpiece bias voltage: 100-500V; workpiece bias current: 0.2-1.2A. With the sputtering baffle closed, perform coating for 100-400s to clean the sputtering target surface. Then, open the baffle to allow the sputtering target to deposit a base film on the workpiece surface in the coating chamber. The base film deposition time is 100-1500s, and the base film thickness is 0.01-0.2μm. This step prepares the base film by sputtering on the substrate surface, ensuring the adhesion between the entire coating and the substrate.

[0024] Step 5: After the base film preparation is complete, turn off the base film sputtering power supply, turn off the Ar gas charging valve and flow meter switch, turn off the heater, and open the baffle of the magnetic filter bend. When the gas pressure is lower than 5×10 -4When the pressure is 80-120℃ and the temperature is 80-120℃, turn on the PIC arc power supply, set the arc current to 70-150A, filter current to 10-20A, anode current to 10-20A, workpiece bias voltage to 100-2000V, and workpiece bias current to 0.2-1.2A (using a low-frequency, low-duty-cycle bias power supply); the plasma beam passes through the magnetic filter bend, where uncharged large particles and droplets are not constrained by the filter magnetic field and directly impact the inner wall of the bend. Only charged particles can pass through the bend and, under the action of the scanning coil, uniformly deposit a Ta-C layer on the workpiece surface, starting the pure ion plating source for preparation. Then, every 1000-2000 seconds, reduce the workpiece bias voltage by 300-600V until the target bias voltage is reached (determined according to the target hardness). The thickness of this TAC layer is 0.2-1.0μm. This step can prepare a dark-colored TAC film layer with high hardness and high durability.

[0025] Example 1 (300nm Ta-C color filter) The preparation steps for preparing Ta-C coatings using the PIS-622 pure ion vacuum coating equipment are as follows.

[0026] (1) Baking to remove gas.

[0027] After the product is loaded, the vacuum system starts working. After the pressure is reduced to 0.05 Pa, the remaining gas is mainly water vapor. The heating system is then turned on to bake and degas the product, the rotating frame, and the inner wall of the chamber.

[0028] (2) Preheating of pure ion plating source (PIC).

[0029] Maintain heating at 100℃, when the air pressure is below 1×10 -2 At Pa, close the baffle of the magnetic filter bend to prevent the PIC plasma beam from entering the chamber and contaminating the product. Turn on the PIC arc power supply, set the arc current to 110A, the filter current to 12A, and the anode current to 13A, and start the preheating program of the pure ion plating source (PIC) for 2400s.

[0030] (3) Ion cleaning and surface activation of workpieces by high-energy ion beam.

[0031] The heating temperature of the vacuum chamber is maintained at 100℃, and the background vacuum is evacuated to 5×10⁻⁶. -3 Below Pa, 150 sccm Ar is introduced from the ion source inlet, and the vacuum degree is maintained at 3.5 × 10⁻⁶ Pa. -1 Pa, turn on the ion source power supply and bias power supply, ion source voltage: 1500V, ion source current: 1.0A, workpiece bias voltage: 800V, workpiece bias current: 1.5A, ion cleaning and activation time: 2h.

[0032] (4) Preparation of Cr base film by magnetron sputtering.

[0033] The specific parameters are as follows: Turn off heating, and evacuate to a base vacuum of 2×10⁻⁶. -3 Below Pa, 500 sccm Ar is introduced from the inlet of the WC sputtering target, and the vacuum level is maintained at 3 × 10⁻⁶ Pa. -1 Pa, turn on the sputtering power supply and bias power supply, sputtering power: 5KW, workpiece bias voltage: 800V, workpiece bias current: 0.4A, coating for 400s with the baffle closed, then open the baffle, base film coating time: 700s, coating thickness 0.05μm.

[0034] (5) The first Ta-C layer was prepared using a pure ion plating source.

[0035] Close the Ar inflation valve and flow meter switch, open the baffle of the magnetic filter bend, and when the air pressure is lower than 5×10 -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 1600V, workpiece bias current to 0.4A, start the pure ion plating source (PIC) to prepare the first Ta-C layer, time 1000s, coating thickness 0.05μm.

[0036] (6) The second Ta-C layer is prepared using a pure ion plating source.

[0037] Open the baffle of the magnetic filter bend when the air pressure is below 5×10. -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 1200V, and workpiece bias current to 0.4A (using a high-frequency, low-duty-cycle bias power supply), start preparing the second Ta-C layer, time 1000s, coating thickness 0.05μm.

[0038] (7) The third Ta-C layer was prepared using a pure ion plating source.

[0039] Open the baffle of the magnetic filter bend when the air pressure is below 5×10. -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 900V, and workpiece bias current to 0.4A (using a high-frequency, low-duty-cycle bias power supply), start preparing the third Ta-C layer, time 1000s, coating thickness 0.05μm.

[0040] (8) The fourth Ta-C layer was prepared using a pure ion plating source.

[0041] Open the baffle of the magnetic filter bend when the air pressure is below 5×10. -4Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 500V, and workpiece bias current to 0.4A (using a high-frequency, low-duty-cycle bias power supply), start preparing the third Ta-C layer, time 2000s, coating thickness 0.1μm.

[0042] Example 2 (350nm Ta-C color filter) The preparation steps for preparing Ta-C coatings using the PIS-622 pure ion vacuum coating equipment are as follows.

[0043] (1) Baking to remove gas.

[0044] After the product is loaded, the vacuum system starts working. After the pressure is reduced to 0.05 Pa, the remaining gas is mainly water vapor. The heating system is then turned on to bake and degas the product, the rotating frame, and the inner wall of the chamber.

[0045] (2) Preheating of pure ion plating source (PIC).

[0046] Maintain heating at 100℃, when the air pressure is below 1×10 -2 At Pa, close the baffle of the magnetic filter bend to prevent the PIC plasma beam from entering the chamber and contaminating the product. Turn on the PIC arc power supply, set the arc current to 110A, the filter current to 12A, and the anode current to 13A, and start the preheating program of the pure ion plating source (PIC) for 2400s.

[0047] (3) Ion cleaning and surface activation of workpieces by high-energy ion beam.

[0048] The heating temperature of the vacuum chamber is maintained at 100℃, and the background vacuum is evacuated to 5×10⁻⁶. -3 Below Pa, 150 sccm Ar is introduced from the ion source inlet, and the vacuum degree is maintained at 3.5 × 10⁻⁶ Pa. -1 Pa, turn on the ion source power supply and bias power supply, ion source voltage: 1500V, ion source current: 1.0A, workpiece bias voltage: 800V, workpiece bias current: 1.5A, ion cleaning and activation time: 2h.

[0049] (4) Preparation of Cr base film by magnetron sputtering.

[0050] The specific parameters are as follows: Turn off heating, and evacuate to a base vacuum of 2×10⁻⁶. -3 Below Pa, 500 sccm Ar is introduced from the inlet of the WC sputtering target, and the vacuum level is maintained at 3 × 10⁻⁶ Pa. -1Pa, turn on the sputtering power supply and bias power supply, sputtering power: 5KW, workpiece bias voltage: 800V, workpiece bias current: 0.4A, coating for 400s with the baffle closed, then open the baffle, base film coating time: 700s, coating thickness 0.05μm.

[0051] (5) The first Ta-C layer was prepared using a pure ion plating source.

[0052] Close the Ar inflation valve and flow meter switch, open the baffle of the magnetic filter bend, and when the air pressure is lower than 5×10 -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 1600V, workpiece bias current to 0.4A, start the pure ion plating source (PIC) to prepare the first Ta-C layer, time 1000s, coating thickness 0.05μm.

[0053] (6) The second Ta-C layer is prepared using a pure ion plating source.

[0054] Open the baffle of the magnetic filter bend when the air pressure is below 5×10. -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 1200V, and workpiece bias current to 0.4A (using a high-frequency, low-duty-cycle bias power supply), start preparing the second Ta-C layer, time 1000s, coating thickness 0.05μm.

[0055] (7) The third Ta-C layer was prepared using a pure ion plating source.

[0056] Open the baffle of the magnetic filter bend when the air pressure is below 5×10. -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 900V, and workpiece bias current to 0.4A (using a high-frequency, low-duty-cycle bias power supply), start preparing the third Ta-C layer, time 1000s, coating thickness 0.05μm.

[0057] (8) The fourth Ta-C layer was prepared using a pure ion plating source.

[0058] Open the baffle of the magnetic filter bend when the air pressure is below 5×10. -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 500V, and workpiece bias current to 0.4A (using a high-frequency, low-duty-cycle bias power supply), start preparing the third Ta-C layer, time 1000s, coating thickness 0.05μm.

[0059] (9) The fifth Ta-C layer was prepared using a pure ion plating source.

[0060] Open the baffle of the magnetic filter bend when the air pressure is below 5×10. -4 Pa, turn on the PIC arc power supply, set the arc current to 110A, filter current to 13A, anode current to 12A, workpiece bias voltage to 100V, and workpiece bias current to 0.4A (using a high-frequency, low-duty-cycle bias power supply), start preparing the third Ta-C layer, time 2000s, coating thickness 0.1μm.

[0061] The coatings prepared in Examples 1 and 2 were subjected to performance testing, and the results are as follows.

[0062] Testing items Product A prepared in Example 1 Product B prepared in Example 2 Testing standards Instruments used Detection steps Membrane-based bonding strength HF1 HF1 CYQC-2005 Rockwell hardness tester 1. Cut a stainless steel test block of appropriate size and place it on the working platform of the hardness tester; 2. Apply a loading force of 150N to the test block for indentation testing; 3. Place the indented test block under a microscope and observe the indentation condition using a 10x objective lens; 4. Determine the indentation grade by comparing it with the standard. Thickness (nm) 312 368 CYQC-2005 D-300 Step Instrument 1. Clean the Si wafers coated in the same furnace with alcohol and place them on the working platform of the step profiler; 2. Slowly lower the probe until a clear product surface is observed on the screen; 3. Select an interface with and without a film layer, and move the working platform so that the probe can scan this interface; 4. Click "scan", the probe starts scanning, forming a step profile. Drag the two lines with the mouse so that one is in the area without a film layer and the other is in the area with a film layer to obtain the film thickness data. Nanohardness (HV) 2896 3733 CYQC-2005 <![CDATA[NHT 3 Nanoindenter 1. Select a representative coated product or high-speed steel sheet with no visible defects and clean its surface with alcohol; 2. Fix the sample to be tested onto the fixture on the stage; 3. Open the testing software and select 5x, 20x, and 100x magnification lenses in sequence, adjusting until the image is clear; 4. Select the "visual advanced" testing method, filter out a clean, impurity-free area in the interface and set it as the ADO area, setting the indentation force to 10mN; 5. After selecting the ADO area, select 5-8 test points around the origin; 6. Click OK, and the equipment will start automatic testing to obtain hardness data. The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A colored TAC coating and a process for its preparation, characterized in that: The workpiece surface is sequentially provided with a base layer and a functional layer from inside to outside, the base layer is prepared by sputtering coating process, the target material used in the sputtering coating process is one of chromium, titanium and tungsten carbide, and the functional layer is prepared by pure ion coating process, the target material used in the pure ion coating process is pure carbon target.

2. The colored TAC coating layer and process for producing the same according to claim 1, characterized in that: The thickness of the base layer is 0.01-0.2 μm, and the thickness of the functional layer is 0.2-1.0 μm.

3. A process for the preparation of a color TAC coating characterized in that, The method comprises the following operations: S10: mounting the workpiece on a clamp in a vacuum chamber, vacuumizing and baking heating; S20: starting a PIC arc power supply to preheat the PIC target material; S30: injecting Ar gas from an ion source gas inlet to ion-clean and activate the workpiece; S40: injecting Ar gas from a sputtering target gas inlet, starting a sputtering power supply and a bias power supply to sputter coat the workpiece; S50: closing the Ar gas, starting the PIC arc power supply to perform pure ion coating treatment on the workpiece.

4. The process for the preparation of a color TAC coating according to claim 3, characterized in that, In operation S10, after vacuumizing to 0.05 Pa, the heating system is started to bake and degas, the vacuum chamber is heated to 100-280 ℃, and the baking time is 1-2 h.

5. The process for the preparation of a color TAC coating according to claim 3, characterized in that, In operation S20, the vacuum chamber temperature is maintained at 100-280℃, and when the air pressure in the vacuum chamber is reduced to 1x10 -2 Pa or below, the PIC arc power source is turned on.

6. The process for the preparation of a color TAC coating according to claim 3, characterized in that, In operation S20, the arc current is set to 70-150 A, the filter current is set to 10-20 A, the anode current is set to 10-20 A, and the preheating time is set to 500-3000 s.

7. The process for the preparation of a color TAC coating according to claim 3, characterized in that, In operation S30, the temperature of the vacuum chamber is adjusted to 100-150°C, and when the air pressure in the vacuum chamber is reduced to 5x10 -3 Pa or below, Ar gas is filled from the gas inlet of the ion source.

8. The process for the preparation of a color TAC coating according to claim 3, characterized in that, In operation S30, after the Ar gas is filled, the vacuum degree in the vacuum chamber is maintained at 9x10 -2 Pa~8x10 -1 Pa, the ion source voltage is set to 800~2200V, the ion source current is set to 0.1~1.5A, the workpiece bias voltage is set to 500~1500V, the workpiece bias current is set to 0.2~1.5A, and the ion cleaning and activation time is set to 0.5~2.5h.

9. The process for the preparation of a color TAC coating according to claim 8, characterized in that, In operation S40, the temperature of the vacuum chamber is kept at 100-150℃, and the vacuum degree is extracted to 2x10 -3 Pa. Then, 300-4500sccm Ar gas is filled into the gas inlet of the sputtering target, and the vacuum degree is kept at 1x10 -1 Pa-1.5x10 0 Pa. The sputtering power is set at 2-10KW, the workpiece bias is set at 100-500V, and the workpiece bias current is set at 0.2-1.2A. First, the shutter is closed during sputtering for 100-400s. Then, the shutter is opened, so that the sputtering target performs bottom layer coating on the surface of the workpiece in the vacuum chamber. The coating time of the bottom layer is 100-1500s.

10. The process for the preparation of a color TAC coating according to claim 8, characterized in that, In operation S50, after the preparation of the primer layer is completed, the sputtering power of the primer film layer is turned off, the Ar gas and the flowmeter switch are turned off, the heater is turned off, the baffle of the magnetic filter elbow is opened, and when the air pressure is lower than 5*10 -4 When the air pressure is lower than 5*10 Pa and the temperature is 80-120℃, the PIC arc power is turned on, the arc current is set to 70-150A, the filter current is set to 10-20A, the anode current is set to 10-20A, the workpiece bias voltage is set to 100-2000V, the workpiece bias current is set to 0.2-1.2A, and the film plating time is 1000-2000s, the workpiece bias voltage is reduced by 300-600V every 1000-2000s until the target bias voltage is reached.

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