High-hardness metal tungsten nanocrystalline film and preparation method thereof

Abstract

The invention provides a high-hardness metal tungsten nanocrystalline film and a preparation method thereof. The preparation method comprises the following steps: cleaning a substrate; the dried substrate is fixed to the center position of a sample table capable of rotating in a two-dimensional mode and conveyed into a cavity through a sample conveying rod; high-purity argon is introduced into the chamber; meanwhile, applying negative bias voltage to the substrate so as to perform ion cleaning and etching on the surface of the substrate; heating the substrate on the sample table; continuously introducing high-purity argon into the chamber, and keeping the temperature of the substrate constant by adopting a high-purity metal tungsten target; then, applying negative bias voltage to the substrate, and coating the substrate by adopting a high-voltage magnetron sputtering technology to obtain a sample; and after coating is finished, vacuumizing the chamber to high vacuum, turning off a heating power supply in a high vacuum state, and taking out the sample through a sample transfer rod after the sample is cooled to room temperature. The method has the technical effects that the film layer quality is high, the uniformity is good, the film forming speed is high, the damage to the film layer is small, the coating thickness is controllable, and the grain size can be controlled.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of material surface modification and processing technology, and particularly relates to a high-hardness metal tungsten nanocrystalline thin film and a preparation method thereof. BACKGROUND

[0002] Metal tungsten belongs to refractory metal, and has the advantages of high melting point, high strength, low expansion coefficient, good corrosion resistance and high-temperature structural stability, but its expensive price and difficult processing characteristics limit its application. However, as a coating material, it can be widely used as a wear-resistant, corrosion-resistant and high-temperature-resistant material to improve the performance of the base material, and has attracted the attention of many researchers.

[0003] Nanocrystalline thin film is a new type of protective coating, which solves the problem of mutual diffusion between the coating and the substrate interface, and the problem that the traditional protective coating will reduce the mechanical properties of the original substrate in high-temperature service environment. Nanocrystalline coating is a new type of protective coating that gradually develops, and can be continuously updated and improved with the development of high-temperature alloys, and will not cause problems such as poor bonding due to mismatch of new alloys and traditional coatings in some aspects.

[0004] At present, the more mature technologies for preparing metal tungsten coating include plasma spraying, vapor deposition, molten salt electroplating, etc. Among them, the magnetic control sputtering technology has obvious advantages, is not limited by the substrate material, has good uniformity of the prepared thin film, and has strong repeatability and controllability. Moreover, magnetic control sputtering is a common method for preparing nanometer metal materials. Due to grain refinement and nanometer size effect, the density, hardness and bonding strength of the coating are significantly improved, and this is particularly true for tungsten materials. Grain refinement can significantly improve the toughness and thermal shock resistance of the material.

[0005] Therefore, how to avoid the grain growth of metal tungsten nanometer metal during the deposition process and loss its size effect has become a key problem to be solved. SUMMARY

[0006] The present application aims to at least solve one of the technical problems existing in the prior art, and provides a new technical solution of high-hardness metal tungsten nanocrystalline thin film and a preparation method thereof.

[0007] According to a first aspect of the present application, a preparation method of a high-hardness metal tungsten nanocrystalline thin film is provided, comprising:

[0008] Step S1, cleaning the substrate and drying the cleaned substrate in a drying box;

[0009] Step S2, fixing the dried substrate at the center position of a two-dimensionally rotatable sample table, and conveying into the chamber through a sample conveying rod;

[0010] Step S3: Evacuate the chamber to remove volatile impurities from the chamber and substrate surface;

[0011] Step S4: High-purity argon gas is introduced into the chamber to maintain a constant gas pressure inside the chamber; at the same time, a negative bias voltage is applied to the substrate to perform ion cleaning and etching on the substrate surface.

[0012] Step S5: Heat the substrate on the sample stage; wherein the heating temperature is 300℃-500℃.

[0013] Step S6: High-purity argon gas is continuously introduced into the chamber, and a high-purity tungsten metal target is used to maintain a constant substrate temperature; then, a negative bias is applied to the substrate, and a high-voltage magnetron sputtering technique is used to deposit a film on the substrate to obtain a sample; wherein, the sample has a tungsten nanocrystalline thin film.

[0014] Step S7: After the coating is completed, the vacuum in the chamber is evacuated to a high vacuum. The heating power is turned off under the high vacuum state. After the sample cools to room temperature, the sample is taken out through the sample transfer rod.

[0015] Optionally, in step S1, the substrate is cleaned, including:

[0016] The substrate was ultrasonically cleaned with anhydrous ethanol for 15-20 minutes.

[0017] Optionally, in step S2, the rotation speed of the sample stage is 0.5-5 RPM / min, and the distance between the sample stage and the target is 50-100 mm.

[0018] Optionally, in step S3, the vacuum level of the chamber after evacuation is less than 6.

[0019] ×10 -5 Pa.

[0020] Optionally, in step S4, an arc-enhanced glow discharge technique is used to allow a high-density electron stream to collide with the introduced argon gas, thereby performing ion cleaning and etching on the substrate surface; wherein the ion cleaning and etching time on the substrate surface is 120 s.

[0021] 150s.

[0022] Optionally, in step S5, heating the substrate on the sample stage includes:

[0023] The sample stage is heated by an infrared electric heating tube, and the heat is transferred to the substrate by the sample stage; the temperature of the sample stage is measured by a thermocouple above the sample stage.

[0024] Optionally, in step S6, when the substrate is coated, the sputtering power is 180-250W, the air pressure is 25-45Pa, and the bias voltage is 5-8kV.

[0025] Optionally, in step S6, the sputtering target is a circular tungsten metal target with a purity of 99.9%.

[0026] Optionally, in step S6, the coating time is 120-150min.

[0027] According to a second aspect of the present application, a high-hardness tungsten nanocrystalline thin film is provided, which is prepared by the preparation method according to the first aspect.

[0028] One technical effect of the present application is that:

[0029] In the embodiments of the present application, the high-pressure magnetron sputtering technology is used to prepare the tungsten nanocrystalline thin film. Compared with the traditional coating process, the film layer has high quality, good uniformity, fast film formation rate, small damage to the film layer, and controllable coating thickness. Moreover, the grain size of the tungsten nanocrystalline thin film in the deposition process can be controlled by changing the parameter conditions of the high-pressure magnetron sputtering technology.

[0030] In addition, the tungsten nanocrystalline thin film prepared by the preparation method of the high-hardness tungsten nanocrystalline thin film can greatly improve the mechanical properties of the substrate (i.e., the substrate), so that the hardness can reach more than 21GPa, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 FIG. 1 is a flowchart of a preparation method of a high-hardness tungsten nanocrystalline thin film according to an embodiment of the present application;

[0032] Figure 2 FIG. 2 is an SEM test diagram of a sample prepared by the preparation method of the high-hardness tungsten nanocrystalline thin film according to an embodiment of the present application;

[0033] Figure 3 FIG. 3 is a nanohardness diagram of a sample prepared by the preparation method of the high-hardness tungsten nanocrystalline thin film according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. Note that the relative arrangement, numerical expressions, and numerical values of the components and steps set forth in these embodiments are not limiting to the scope of the present application unless otherwise specifically stated.

[0035] Embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only, and are for the purpose of explanation only, and are not to be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the scope of protection of the present application.

[0036] The terms "first", "second" in the description and claims of the present application can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / ", generally represents that the front and rear associated objects are in an "or" relationship.

[0037] According to the first aspect of the present application, referring to Figure 1 , a preparation method of a high-hardness metal tungsten nanocrystalline thin film is provided, comprising:

[0038] Step S1, cleaning the substrate and placing the cleaned substrate in a drying box for drying.

[0039] Step S2, fixing the dried substrate at the center position of the two-dimensionally rotatable sample table, and conveying it into the chamber through the sample conveying rod; for example, the dried substrate can be fixed at the center position of the sample table by using a high-temperature adhesive tape.

[0040] Step S3, vacuumizing the chamber to remove volatile impurities on the surface of the chamber and the substrate.

[0041] Step S4, continuously inputting high-purity argon gas into the chamber to keep the air pressure in the chamber constant; at the same time, applying a negative bias to the substrate to perform ion cleaning and etching on the surface of the substrate to remove impurities or contaminants on the surface of the substrate.

[0042] Step S5, heating the substrate on the sample table; wherein the heating temperature is 300-500°C.

[0043] Step S6, continuously inputting high-purity argon gas into the chamber, using a high-purity metal tungsten target to keep the temperature of the substrate constant; then, applying a negative bias to the substrate to perform film plating on the substrate by using high-pressure magnetron sputtering technology to obtain a sample; wherein the sample has a metal tungsten nanocrystalline thin film.

[0044] It should be noted that the equipment parameters need to be set before the sample is prepared.

[0045] Step S7, after the coating is finished, the vacuum of the chamber is extracted to high vacuum, the heating power is turned off under the high vacuum state, and the sample is taken out through the sample transfer rod after the sample is cooled to room temperature.

[0046] In the embodiments of the present application, the metal tungsten nanocrystalline film is prepared by the high-pressure magnetron sputtering technology. Compared with the traditional coating process, the film layer has high quality, good uniformity, fast film formation rate, small damage to the film layer, and controllable coating thickness. Moreover, the grain size of the metal tungsten nanocrystalline film during the deposition process can be controlled by changing the parameter conditions of the high-pressure magnetron sputtering technology.

[0047] In addition, the metal tungsten nanocrystalline film prepared by the preparation method of the high-hardness metal tungsten nanocrystalline film can greatly improve the mechanical properties of the substrate (i.e. the substrate), and the hardness can reach more than 21 GPa, which has a wide application prospect.

[0048] Optionally, in step S1, the substrate is cleaned, including:

[0049] The substrate is ultrasonically cleaned with anhydrous ethanol for 15-20 minutes.

[0050] In the above embodiments, the cleanliness and safety of the cleaning of the substrate can be better ensured.

[0051] Optionally, in step S2, the rotation speed of the sample table is 0.5-5 RPM / min, and the distance between the sample table and the target material is 50-100 mm.

[0052] In the above embodiments, the uniformity of the coating of the substrate by the high-pressure magnetron sputtering technology can be effectively ensured, and the film layer has high quality, good uniformity, fast film formation rate, small damage to the film layer, and controllable coating thickness.

[0053] Optionally, in step S3, the vacuum degree of the chamber after being pumped is less than 6x10 -5 Pa. This can remove volatile impurities on the surface of the chamber and the substrate, thereby helping to ensure the cleanliness of the substrate surface.

[0054] Optionally, in step S4, an arc-enhanced glow discharge technology is used to make a high-density electron stream collide with the argon gas introduced to perform ion cleaning and etching on the surface of the substrate. The ion cleaning and etching time of the substrate surface is 120-150 seconds.

[0055] In the above embodiments, the cleanliness of the substrate surface is better ensured.

[0056] Optionally, in step S5, the substrate on the sample table is heated, including:

[0057] The sample stage is heated by an infrared electric heating tube, and the heat is transferred to the substrate from the sample stage; the temperature of the sample stage is measured by thermocouples above the sample stage. For example, four thermocouples are evenly arranged at four positions on the edge of the sample stage surface.

[0058] In the above embodiments, it is helpful to heat the substrate stably and to keep the substrate temperature constant.

[0059] Optionally, in step S6, when depositing the substrate, the sputtering power is 180–250 W, the gas pressure is 25–45 Pa, and the bias voltage is 5–8 kV. This helps to effectively control the equipment parameters for deposition, thereby better controlling the grain size of tungsten nanoparticles during the deposition process.

[0060] Optionally, in step S6, the sputtering target is a circular tungsten metal target with a purity of 99.9%.

[0061] In the above embodiments, the circular design helps to achieve a more uniform magnetic field distribution, which can lead to a more uniform sputtering rate and better film thickness consistency. Moreover, by optimizing the magnetic field configuration of the magnetron sputtering system, the plasma distribution on the target surface can be made more uniform, thereby improving the consistency and repeatability of thin film deposition.

[0062] Optionally, in step S6, the coating time is 120–150 min. This helps to ensure the uniformity of the film and the coating quality.

[0063] According to a second aspect of the present invention, a high-hardness tungsten nanocrystalline thin film is provided, which is prepared by the preparation method described in the first aspect.

[0064] In this embodiment, the performance of the high-hardness tungsten nanocrystalline thin film prepared by the above method was tested, and the specific test results are as follows:

[0065] (1) Morphological characteristics

[0066] like Figure 2 As shown, Figure 2 The surface SEM morphology of a high-hardness tungsten nanocrystalline thin film is shown. Figure 2 It can be seen that the nanocrystalline film deposited by high-pressure magnetron sputtering technology exhibits a "cauliflower-like" morphology on its surface, with no obvious defects such as droplets or voids, and the tungsten nanocrystalline film is uniform and dense.

[0067] (2) Hardness characterization

[0068] See Figure 3 Nanoindentation instruments were used to characterize the nanohardness and elastic modulus of thin film samples. Figure 3It can be seen that the hardness of the high-hardness tungsten nanocrystalline thin film is 21.833 GPa, and the elastic modulus is 252.3 GPa.

[0069] In the above embodiment, the tungsten nanocrystalline thin film prepared by the preparation method of the high-hardness tungsten nanocrystalline thin film can greatly improve the mechanical properties of the substrate (i.e. the substrate), so that the hardness can reach more than 21 GPa, and has a wide application prospect.

[0070] It can be understood that the above embodiments are only exemplary embodiments for illustrating the principles of the present application, but the present application is not limited thereto. Various modifications and improvements can be made by those skilled in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered as the protection scope of the present application.

Claims

1. A method for preparing a high-hardness metal tungsten nanocrystalline thin film, characterized in that, The preparation method comprises the following steps: S1, cleaning the substrate and drying the cleaned substrate in a drying box; S2, fixing the dried substrate at the center position of a two-dimensionally rotatable sample table and conveying the substrate into a chamber through a sample conveying rod; S3, vacuumizing the chamber to remove volatile impurities on the surface of the chamber and the substrate; S4, introducing high-purity argon into the chamber to keep the air pressure in the chamber constant, and applying a negative bias to the substrate to perform ion cleaning and etching on the surface of the substrate; S5, heating the substrate on the sample table, wherein the heating temperature is 300-500℃; S6, continuously introducing high-purity argon into the chamber, keeping the temperature of the substrate constant by using a high-purity tungsten target, and then applying a negative bias to the substrate to perform film plating on the substrate by using high-voltage magnetron sputtering technology to obtain a sample, wherein the sample has a tungsten nanocrystalline thin film; S7, after the film plating is completed, vacuumizing the chamber to high vacuum, turning off the heating power in the high-vacuum state, and taking out the sample through the sample conveying rod after the sample is cooled to room temperature.

2. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S1, the substrate is cleaned, comprising: cleaning the substrate by ultrasonic cleaning with anhydrous ethanol for 15-20 minutes.

3. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S2, the rotation speed of the sample table is 0.5-5 RPM / min, and the distance between the sample table and the target material is 50-100 mm.

4. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S3, the vacuum degree of the chamber after the vacuumizing is less than 6x10 -5 Pa.

5. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S4, the high-density electron stream collides with the introduced argon by using the arc-enhanced glow discharge technology to perform ion cleaning and etching on the surface of the substrate, wherein the ion cleaning and etching time on the surface of the substrate is 120-150 seconds.

6. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S5, the substrate on the sample table is heated, comprising: heating the sample table by using an infrared electric heating tube, and transferring heat from the sample table to the substrate, wherein the temperature of the sample table is measured by a thermocouple above the sample table.

7. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S6, when the substrate is plated, the sputtering power is 180-250 W, the air pressure is 25-45 Pa, and the bias voltage is 5-8 kV.

8. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S6, the sputtering target is a circular tungsten target with a purity of 99.9%.

9. The method for preparing high-hardness tungsten nanocrystalline thin films according to claim 1, characterized in that, In step S6, the film plating time is 120-150 minutes.

10. A high hardness metal tungsten nanocrystalline thin film, characterized in that, The sample is prepared by using the preparation method in any one of claims 1-9.

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