A wide-temperature-range tungsten disulfide lubricating coating and a preparation method thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- LUOYANG LYC BEARING
- Filing Date
- 2026-04-28
- Publication Date
- 2026-05-29
Smart Images
Figure CN122105342A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of tungsten disulfide coating preparation, specifically relating to a wide-temperature-range tungsten disulfide lubricating coating and its preparation method. Background Technology
[0002] As the "heart" component of critical equipment, bearings directly determine the reliability and lifespan of the main unit. In cutting-edge fields such as aerospace engines and high-speed precision equipment, bearings often face stringent challenges involving high speeds, heavy loads, and wide temperature ranges (e.g., from room temperature to around 350°C). Under these conditions, relying solely on traditional grease lubrication is insufficient. Developing high-performance solid lubricant coatings on critical friction surfaces has become an irreplaceable technological approach to improving bearing performance. The development of lubricant coatings with low friction, high wear resistance, strong load-bearing capacity, and stable performance across a wide temperature range is an urgent engineering need.
[0003] Molybdenum disulfide (MoS2) is widely used in solid lubricants, but it is easily oxidized in an oxygen-rich environment at around 350°C to form hard abrasive particles MoO3, leading to high-temperature lubrication failure. Tungsten disulfide (WS2) has better potential, with an oxidation resistance temperature of up to about 450°C, and the oxidation product WO3 still has some lubricity, giving it a theoretically wider operating temperature range.
[0004] However, pure WS2 coatings have inherent defects: coatings prepared using conventional physical vapor deposition techniques often have a loose structure, low hardness, and weak adhesion, resulting in insufficient load-bearing capacity; and their tribological properties lack stability over a wide temperature range. To improve these shortcomings, doping modification is a common method. Traditional research has focused on doping with hard metals (Cr, Ti) or compounds (TiB2, LaF3) to improve coating hardness and density, but this often comes at the cost of sacrificing the material's intrinsic lubricity or increasing brittleness, and offers limited improvement in lubrication performance at higher temperatures.
[0005] The applicant's team previously studied a Cu-doped WS2 thin film (Pei Lulu et al., Coatings, 2025, 15, 173), which prepared a WS2-Cu composite coating using magnetron sputtering technology at different sputtering powers. This coating can improve the hardness and density of the WS2 film to a certain extent. Under optimized sputtering power, the hardness of the WS2-Cu composite coating can reach 6.6 GPa, and the resulting coating surface is uniform and smooth with good overall quality.
[0006] The WS2-Cu composite coating exhibits a low coefficient of friction in the range of room temperature to 100℃, but when the temperature rises to higher temperatures, such as 350~400℃, its high-temperature lubrication performance and friction performance will drop sharply, and it cannot well meet the bearing lubrication and friction reduction requirements under high-temperature conditions. Summary of the Invention
[0007] The purpose of this invention is to provide a method for preparing a wide-temperature-range tungsten disulfide lubricating coating to solve the problem of insufficient high-temperature lubrication and friction performance of WS2-Cu composite coatings prepared by existing magnetron sputtering processes.
[0008] The second objective of this invention is to provide a tungsten disulfide lubricating coating obtained by the above-described method for preparing a wide-temperature-range tungsten disulfide lubricating coating, in order to solve the problem that existing WS2 coatings cannot maintain good lubrication and friction performance in a wide temperature range of room temperature to 400°C.
[0009] To achieve the above objectives, the technical solution of the method for preparing the wide-temperature-range tungsten disulfide lubricating coating of the present invention is as follows: A method for preparing a wide-temperature-range tungsten disulfide lubricating coating includes the following steps: using magnetron sputtering technology, firstly sputtering a Cr transition layer on the metal substrate to be treated, then turning on the WS2 target RF power supply and the Cu target DC power supply, adjusting the sputtering power of the WS2 target to 150~190W and the sputtering power of the Cu target to 10~25W, co-sputtering to obtain a WS2-Cu composite layer with WS2-Cu particles dispersed on the coating surface.
[0010] This invention employs unbalanced magnetron sputtering technology to prepare a WS2-Cu composite coating. By adjusting the coating process parameters, a WS2-based composite coating with excellent load-bearing capacity and good lubrication performance over a wide temperature range is obtained. Tribological tests show that the WS2-Cu composite coating obtained by this method exhibits a low coefficient of friction at room temperature, 100℃, and 400℃.
[0011] Magnetron sputtering technology generally aims to obtain a uniform and smooth coating. Using this invention, a WS2-Cu composite coating is obtained, which exhibits a heterogeneous morphology, consisting of a uniformly deposited WS2-Cu layer connected to a Cr transition layer, and a large WS2-Cu particle layer composited on the uniformly deposited WS2-Cu layer. The large WS2-Cu particle layer includes WS2-Cu particles discretely distributed on the uniformly deposited WS2-Cu layer.
[0012] Furthermore, energy-dispersive X-ray spectroscopy (EDS) analysis showed that the WS2-Cu composite coating prepared using this method contained a higher O content (possibly originating from residual O or adsorbed O in the chamber). The differences in the microstructure and elemental composition of the coatings mentioned above may explain why the WS2-Cu composite coating maintains good lubrication and friction properties even at high temperatures.
[0013] The aforementioned metal substrate is preferably bearing steel. A Cr transition layer and a WS2-Cu composite coating are plated on the surface of the bearing steel, which can be well adapted to bearings that operate in a wide temperature range, thereby improving the operational stability and service life of such bearings.
[0014] Preferably, the working gas introduced during co-sputtering is argon, with an argon flow rate of 40-80 sccm; the sputtering pressure is 0.6-1.2 Pa; and the deposition time is 60-80 min. Controlling these working parameters during the co-sputtering of the WS2-Cu composite coating is beneficial for obtaining the aforementioned WS2-Cu composite coating with a heterogeneous morphology.
[0015] More preferably, the sputtering power of the WS2 target is 180~190W, the sputtering power of the Cu target is 10~20W; the argon flow rate is 40~50sccm; the sputtering pressure is 1.0~1.2Pa; and the deposition time is 60~70min. By further controlling the co-sputtering conditions within this operating parameter range, a tungsten disulfide lubricating coating with high hardness and good tribological properties can be obtained.
[0016] Preferably, during the sputtering of the Cr transition layer, the Cr target is powered by a DC power supply, the target sputtering power is 50~100W, the argon flow rate is 40~80sccm, the sputtering pressure is 0.5~1.0Pa, and the deposition time is 5~20min. Controlling the operating parameters of the sputtered Cr transition layer within this range is beneficial for obtaining a uniform and dense Cr transition layer.
[0017] More preferably, the Cr target sputtering power is 60~70W; the argon flow rate is 40~50sccm; the sputtering pressure is 0.5~0.7Pa; and the deposition time is 15~20min. By further controlling the operating parameters of the sputtered Cr transition layer within this range, a transition layer of suitable thickness can be obtained, effectively ensuring the coating adhesion.
[0018] Preferably, the metal substrate to be treated is obtained by plasma cleaning, wherein the plasma cleaning includes: evacuating the gas pressure in the coating chamber to no more than 6.4 × 10⁻⁶. -4 The working gas, argon, is introduced at a flow rate of 50–100 sccm, and the chamber pressure is stabilized at 0.5–2.3 Pa. The substrate temperature is 100–350 °C, and the plasma cleaning time is 10–20 min. This plasma cleaning process optimizes the adhesion of the Cr transition layer to the substrate, creating favorable conditions for subsequent magnetron sputtering coating preparation.
[0019] More preferably, the air pressure in the coating chamber is evacuated to no more than 5.0 × 10⁻⁶. -4 The plasma cleaning process involves the following parameters: argon flow rate of 60-70 sccm; chamber pressure stable at 1.0-2.0 Pa; substrate temperature of 200-300℃; and plasma cleaning time of 10-15 min. Under this optimized plasma cleaning process, consistent treatment results can be achieved quickly and effectively.
[0020] Preferably, the thickness of the Cr transition layer is 0.1~0.3μm, the thickness of the WS2-Cu composite layer is 2~6μm, and the hardness of the WS2-Cu composite layer is 7~9GPa. More preferably, the thickness of the Cr transition layer is 0.1~0.3μm, the thickness of the WS2-Cu composite layer is 3~4μm, and the hardness of the WS2-Cu composite layer is 7~9GPa. Controlling the thickness of each layer within the above range ensures good adhesion between the coating and the substrate, and the thinness of the WS2-Cu coating does not affect product assembly. Simultaneously, the WS2-Cu coating at this thickness can guarantee high-temperature lubrication requirements at 350~400℃.
[0021] Preferably, the wide temperature range is from room temperature to 400°C. Maintaining good lubrication and friction performance within this wide temperature range ensures stable and reliable performance of the bearing even under high-speed, heavy-load, and wide-temperature conditions.
[0022] A tungsten disulfide lubricating coating obtained by the above-described method for preparing a wide-temperature-range tungsten disulfide lubricating coating.
[0023] The tungsten disulfide lubricating coating prepared by the above method has a hardness of 7~9 GPa; the coefficient of friction at room temperature is maintained at 0.085~0.251, the coefficient of friction at 100℃ is maintained at 0.054~0.197, and the coefficient of friction at 400℃ is maintained at 0.043~0.142. It effectively overcomes the problems of poor high-temperature lubrication performance and insufficient hardness of WS2 coating, and exhibits good tribological properties in a wide temperature range.
[0024] Compared with the prior art, the present invention mainly achieves the following beneficial effects: 1. A WS2-Cu composite coating was prepared using unbalanced magnetron sputtering technology, exhibiting excellent load-bearing performance. Tribological tests showed that the WS2-Cu composite coating exhibited a low coefficient of friction at room temperature, 100℃, and 400℃, filling the technical gap in the existing WS2-based composite coatings, which are difficult to achieve good lubrication performance over a wide temperature range.
[0025] 2. Both the Cr transition layer and the WS2-Cu composite layer were prepared using magnetron sputtering technology, which has high process efficiency. The Cu content in the coating is 10~15 at.%, and the O content in the coating is greater than 20 at.%, which breaks through the conventional elemental composition of the coating and obtains a heterogeneous morphology. Attached Figure Description
[0026] Figure 1 The surface cross-sectional morphology of the tungsten disulfide lubricating coating in Comparative Example 1 is shown. Figure 2 The surface cross-sectional morphology of the tungsten disulfide lubricating coating in Comparative Example 2 is shown. Figure 3The surface cross-sectional morphology of the tungsten disulfide lubricating coating in Comparative Example 3 is shown. Figure 4 The cross-sectional morphology and elemental analysis diagram of the tungsten disulfide lubricating coating of Example 1 of the present invention are shown below; Figure 5 The surface cross-sectional morphology of the tungsten disulfide lubricating coating in Example 2 of the present invention is shown. Figure 6 The surface cross-sectional morphology of the tungsten disulfide lubricating coating in Example 3 of the present invention is shown. Figure 7 The friction coefficient curves of the tungsten disulfide lubricating coatings of Examples 1-3 and Comparative Example 1 of the present invention at room temperature are shown. Figure 8 The friction coefficient curves of the tungsten disulfide lubricating coatings of Examples 1-3 and Comparative Example 1 of the present invention at 100°C are shown. Figure 9 The friction coefficient curves of the tungsten disulfide lubricating coatings of Examples 1-3 and Comparative Example 1 of the present invention at 400°C are shown. Detailed Implementation
[0027] (I) Preferred embodiments of the wide-temperature-range tungsten disulfide lubricating coating and its preparation method of the present invention This invention unexpectedly prepared a WS2-based composite coating with a heterogeneous morphology by optimizing the unbalanced magnetron sputtering technology. This coating has higher hardness (up to 7-9 GPa) and excellent tribological properties over a wide temperature range.
[0028] The heterogeneous morphology of this WS2-based composite coating is characterized by a uniform WS2-Cu deposition layer, with large WS2-Cu particles distributed on the surface of this layer. Furthermore, in the WS2-Cu composite coating, when the Cu content is below 20 at.% (10~15 at.%) and the O content is above 20 at.% (20~23 at.%), it exhibits the aforementioned excellent wide-temperature-range tribological performance characteristics. This typical elemental composition also differs from that of conventional magnetron sputtered WS2-Cu composite coatings.
[0029] The above-mentioned method for preparing a wide-temperature-range tungsten disulfide lubricating coating employs unbalanced magnetron sputtering technology, specifically using the following steps: (1) Matrix pretreatment The metal substrate is first ground with sandpaper of different roughness using a precision grinding and polishing machine, and then the substrate surface is polished. During the polishing process, diamond polishing paste needs to be applied to the polished surface multiple times to improve the grinding effect. Then, the metal substrate and single crystal silicon wafer are ultrasonically cleaned with analytical grade ethanol and acetone for 20-30 minutes, dried with nitrogen, and then placed in a vacuum coating chamber.
[0030] The metal substrate here can be steel substrates such as GCr15 bearing steel or 304 stainless steel. The purpose of the single-crystal silicon wafer is to facilitate the characterization of the microstructure of the thin film.
[0031] (2) Plasma cleaning of substrate This step involves plasma cleaning to remove residual impurities and contaminants from the substrate surface, preparing it for a strong bonding between the coating and the substrate.
[0032] Specifically, the air pressure in the coating chamber can be evacuated to no more than 5.0 × 10⁻⁶. -4 ~6.4×10 -4 Pa, then introduce argon working gas and turn on the substrate cleaning power supply. Control the substrate temperature at 100~350 ℃, the Ar gas flow rate at 50~100 sccm, the chamber pressure at 0.5~2.3 Pa, the cleaning power supply is DC power, the sputtering power is 10~30W, and the processing time is 10~20 min.
[0033] The plasma cleaning process is further preferably carried out by: evacuating the gas pressure in the coating chamber to no more than 5.0 × 10⁻⁶. -4 ~5.5×10 -4 Pa, base temperature 200~300 ℃, Ar gas flow rate 60~70 sccm, chamber pressure stable at 1.0~2.0 Pa.
[0034] (3) Sputtering Cr transition layer.
[0035] This step uses argon as the sputtering gas and a Cr target as the sputtering target to prepare a Cr transition layer.
[0036] The Cr target is powered by a DC power supply with a target sputtering power of 50~100W; the argon flow rate is 40~80sccm, the sputtering pressure is 0.5~1.0Pa, and the deposition time is 5~20min.
[0037] The process parameters for sputtering the Cr transition layer were further optimized as follows: target sputtering power of 60~70W; argon flow rate of 40~50sccm; sputtering pressure of 0.5~0.7 Pa; and deposition time of 15~20min.
[0038] (4) Co-sputtered WS2-Cu composite coating This step uses argon as the sputtering gas and WS2 and Cu targets as sputtering targets to co-sputter and prepare the WS2-Cu composite coating.
[0039] The Cu target is powered by a DC power supply, while the WS2 target is powered by an RF power supply. The sputtering power of the Cu target is controlled at 10~25W; the sputtering power of the WS2 target is controlled at 150~190W. The argon flow rate is 40~80sccm; the sputtering pressure is 0.6~1.2Pa; and the deposition time is 60~80min.
[0040] The preferred control parameters are: Cu target sputtering power of 10~20W; WS2 target sputtering power of 180~190W; argon flow rate of 40~60sccm; sputtering pressure of 1.0~1.2Pa; and deposition time of 60~80min.
[0041] More preferably, the sputtering power of the Cu target is 10~12W; the sputtering power of the WS2 target is 190W. The argon flow rate is 40~50sccm; the sputtering pressure is 1.0~1.2Pa; and the deposition time is 60~70min.
[0042] Controlling the sputtering power of the WS2 target to no more than 190W and the sputtering power of the Cu target to 10~20W is the key to forming the non-uniform morphology WS2-Cu composite coating of the present invention. At the same time, the lower the sputtering power of the Cu target, the easier it is to obtain a tungsten disulfide lubricating coating with better performance.
[0043] The wide-temperature-range tungsten disulfide lubricating coating prepared by the above process includes a Cr transition layer and a WS2-Cu composite layer on the composite Cr transition layer. The WS2-Cu composite layer includes a uniformly deposited WS2-Cu layer that is composited with the Cr transition layer, and WS2-Cu particles that are discretely distributed on the uniformly deposited WS2-Cu layer.
[0044] During magnetron sputtering, the thickness of the Cr transition layer is controlled to be 0.1~0.3μm, and the thickness of the WS2-Cu composite layer is controlled to be 2~6μm, more preferably 3~4μm.
[0045] The preferred embodiments described above will be described in detail below with reference to specific examples.
[0046] Example 1 The method for preparing the wide-temperature-range tungsten disulfide lubricating coating in this embodiment uses unbalanced magnetron sputtering technology to prepare the Cr transition layer and the WS2-Cu composite layer, and specifically adopts the following steps: (1) The metal substrate was first polished with sandpaper of different roughness using a precision grinding and polishing machine; then the metal substrate and the single crystal silicon wafer were ultrasonically cleaned with analytical grade ethanol and acetone for 20 min respectively, dried with nitrogen gas and placed in the vacuum coating chamber. In this embodiment, the metal substrate is GCr15 bearing steel.
[0047] (2) Evacuate the air pressure in the coating chamber to 5.0 × 10⁻⁶. -4 Pa, then argon working gas is introduced at a flow rate of 70 sccm, the pressure in the control chamber is stabilized at 1.0 Pa, the substrate heating temperature is adjusted to 300℃, the cleaning power supply is DC power supply, the sputtering power is 20W, and the substrate plasma cleaning is performed for 15 minutes.
[0048] (3) Subsequently, the argon flow rate was adjusted to 40 sccm, the sputtering pressure to 0.6 Pa, the Cr target sputtering power to 70 W, and the deposition time to 15 min, to prepare a Cr transition layer of approximately 150 nm. The Cr target was a circular target with a diameter of 50.8 cm, a thickness of 3 mm, and a purity higher than 99.9%.
[0049] (4) Turn off the Cr target, keep the Ar gas flow rate constant, adjust the gas pressure to 1.0 Pa, increase the Cu target sputtering power to 10 W, and then control the WS2 target sputtering power to 190 W. The total sputtering time is 60 min. The WS2 target is a circular target with a diameter of 50.8 cm, a thickness of 3 mm, and a purity higher than 99.9%. The Cu target is a circular target with a diameter of 50.8 cm, a thickness of 3 mm, and a purity higher than 99.9%.
[0050] The tungsten disulfide lubricating coating of this embodiment is obtained using the method described in this embodiment. It consists of a Cr transition layer and a WS2-Cu composite layer laminated on the Cr transition layer. The thickness of the Cr transition layer is 150 nm, the thickness of the uniform WS2-Cu composite layer is approximately 0.4 μm, and the thickness of the large WS2-Cu particle layer is approximately 3.2 μm.
[0051] Example 2 The preparation method of the wide-temperature-range tungsten disulfide lubricating coating in this embodiment specifically adopts the following steps: (1) The metal substrate (same as in Example 1) was first polished with sandpaper of different roughness using a precision grinding and polishing machine; then the metal substrate and single crystal silicon wafer were ultrasonically cleaned with analytical grade ethanol and acetone for 20 min, dried with nitrogen and placed in the vacuum coating chamber.
[0052] (2) Evacuate the air pressure in the coating chamber to 5.0 × 10⁻⁶. -4 Pa, then argon working gas is introduced at a flow rate of 70 sccm, the pressure in the control chamber is stabilized at 1.0 Pa, the substrate heating temperature is adjusted to 300℃, the cleaning power supply is DC power supply, the sputtering power is 20W, and the substrate plasma cleaning is performed for 15 minutes.
[0053] (3) Then the argon flow rate was adjusted to 40 sccm, the sputtering pressure was 0.6 Pa, the Cr target sputtering power was adjusted to 70 W, and the deposition time was 15 min to prepare a Cr transition layer of about 150 nm.
[0054] (4) Turn off the Cr target, keep the Ar gas flow rate constant, adjust the gas pressure to 1.0 Pa, increase the sputtering power of the Cu target to 15 W, and then control the sputtering power of the WS2 target to 190 W. The total sputtering time is 60 min.
[0055] The tungsten disulfide lubricating coating of this embodiment is obtained by the method of this embodiment, and it consists of a Cr transition layer and a WS2-Cu composite layer laminated on the Cr transition layer.
[0056] Example 3 The preparation method of the wide-temperature-range tungsten disulfide lubricating coating in this embodiment specifically adopts the following steps: (1) The metal substrate (same as in Example 1) was first polished with sandpaper of different roughness using a precision grinding and polishing machine; then the metal substrate and single crystal silicon wafer were ultrasonically cleaned with analytical grade ethanol and acetone for 20 min, dried with nitrogen and placed in the vacuum coating chamber.
[0057] (2) Evacuate the air pressure in the coating chamber to 5.0 × 10⁻⁶. -4 Pa, then introduce working gas argon at a flow rate of 70 sccm, control the chamber pressure to stabilize at 1.0 Pa, adjust the substrate heating temperature to 300℃, and perform substrate plasma cleaning for 15 min.
[0058] (3) Then the argon flow rate was adjusted to 40 sccm, the sputtering pressure was 0.6 Pa, the Cr target sputtering power was adjusted to 70 W, and the deposition time was 15 min to prepare a Cr transition layer of about 150 nm.
[0059] (4) Turn off the Cr target, keep the Ar gas flow rate constant, adjust the gas pressure to 1.0 Pa, increase the sputtering power of the Cu target to 20 W, and then control the sputtering power of the WS2 target to 190 W. The total sputtering time is 60 min.
[0060] The tungsten disulfide lubricating coating of this embodiment is obtained by the method of this embodiment, and it consists of a Cr transition layer and a WS2-Cu composite layer laminated on the Cr transition layer.
[0061] Comparative Example 1: Pure WS2 Coating The preparation method of the tungsten disulfide lubricating coating in this comparative example specifically adopts the following steps: (1) The metal substrate (same as in Example 1) was first polished with sandpaper of different roughness using a precision grinding and polishing machine; then the metal substrate and single crystal silicon wafer were ultrasonically cleaned with analytical grade ethanol and acetone for 20 min, dried with nitrogen and placed in the vacuum coating chamber.
[0062] (2) Evacuate the air pressure in the coating chamber to 5.0 × 10⁻⁶. -4 Pa, then introduce working gas argon at a flow rate of 70 sccm, control the chamber pressure to stabilize at 1.0 Pa, adjust the substrate heating temperature to 300℃, and perform substrate plasma cleaning for 15 min.
[0063] (3) Then the argon flow rate was adjusted to 40 sccm, the sputtering pressure was 0.6 Pa, the Cr target sputtering power was adjusted to 70 W, and the deposition time was 15 min to prepare a Cr transition layer of about 150 nm.
[0064] (4) Turn off the Cr target, keep the Ar gas flow rate constant, adjust the gas pressure to 1.0 Pa, increase the sputtering power of the WS2 target to 190 W, and the total sputtering time is 60 min.
[0065] Comparative Example 2 compares the WS2 target sputtering power of 200W and the Cu target sputtering power of 15W in the background technology. The preparation method of the tungsten disulfide lubricating coating in this comparative example specifically adopts the following steps: (1) The metal substrate (same as in Example 1) was first polished with sandpaper of different roughness using a precision grinding and polishing machine; then the metal substrate and single crystal silicon wafer were ultrasonically cleaned with analytical grade ethanol and acetone for 20 min, dried with nitrogen and placed in the vacuum coating chamber.
[0066] (2) Evacuate the air pressure in the coating chamber to 6.4 × 10⁻⁶. -4 Pa, then introduce working gas argon at a flow rate of 70 sccm, control the chamber pressure to stabilize at 2.3 Pa, adjust the substrate heating temperature to 300℃, and perform substrate plasma cleaning for 10 min.
[0067] (3) Then the argon flow rate was adjusted to 50 sccm, the sputtering pressure to 0.6 Pa, the Cr target sputtering power to 60 W, and the deposition time to 15 min, to prepare a Cr transition layer of about 150 nm.
[0068] (4) Turn off the Cr target, keep the Ar gas flow rate constant, adjust the gas pressure to 1.0 Pa, increase the sputtering power of the WS2 target to 200 W, increase the sputtering power of the Cu target to 15 W, and the total sputtering time is 70 min.
[0069] Comparative Example 3 compares the WS2 target sputtering power of 200W and the Cu target sputtering power of 45W in the background technology. The preparation method of the tungsten disulfide lubricating coating in this comparative example specifically adopts the following steps: (1) The metal substrate (same as in Example 1) was first polished with sandpaper of different roughness using a precision grinding and polishing machine; then the metal substrate and single crystal silicon wafer were ultrasonically cleaned with analytical grade ethanol and acetone for 20 min, dried with nitrogen and placed in the vacuum coating chamber.
[0070] (2) Evacuate the air pressure in the coating chamber to 6.4 × 10⁻⁶. -4Pa, then introduce working gas argon at a flow rate of 70 sccm, control the chamber pressure to stabilize at 2.3 Pa, adjust the substrate heating temperature to 300℃, and perform substrate plasma cleaning for 10 min.
[0071] (3) Then the argon flow rate was adjusted to 50 sccm, the sputtering pressure to 0.6 Pa, the Cr target sputtering power to 60 W, and the deposition time to 15 min, to prepare a Cr transition layer of about 150 nm.
[0072] (4) Turn off the Cr target, keep the Ar gas flow rate constant, adjust the gas pressure to 1.0 Pa, increase the sputtering power of the WS2 target to 200 W, increase the sputtering power of the Cu target to 45 W, and the total sputtering time is 70 min.
[0073] (II) Experimental Examples Experimental Example 1 The coatings prepared in each embodiment and comparative example were tested using scanning electron microscopy to determine the elemental content of the coatings in each embodiment and comparative example. The results are shown in Table 1 below.
[0074] Table 1. Element content (at.%) of each embodiment and comparative example.
[0075] As shown in Table 1, the coatings prepared using Examples 1-3 have an O content of over 20 at.%, reaching 20.7-22.6 at.%, and a Cu content of less than 15 at.%, reaching 10.3-13.8 at.%. In contrast, the coatings prepared using conventional magnetron sputtering processes (Comparative Examples 2 and 3) have an O content of less than 15 at.% and a Cu content of over 20 at.%.
[0076] The surface cross-sectional morphology of the coatings obtained in Comparative Examples 1-3 is as follows: Figures 1-3 As shown. The surface cross-sectional morphology of the coatings obtained in Examples 1-3 is as follows. Figures 4-6 As shown.
[0077] It can be seen that there are significant differences in the coating morphology between the examples and the comparative examples. The coating surface obtained in the comparative examples is more uniform and smooth, while the coating surface of the examples has WS2-Cu particles dispersedly distributed. The method of the examples forms a uniform composite coating at the beginning of co-deposition, but large particles are formed on the surface during the later deposition process. Analysis shows that the main component of the particles is Cu.
[0078] Experiment Example 2 According to the national standard GB / T 25898-2010 "Instrumented Nanoindentation Test Method - Indentation Hardness and Elastic Modulus of Thin Films", the hardness of the coatings prepared in each example was tested using a nanoindenter, and the results are shown in Table 2.
[0079] The friction coefficients of the coatings prepared in each example and comparative example were tested at different temperatures using a ball-and-disc high-temperature friction and wear testing machine (HT-1000). The test conditions were: rotation radius of 5 mm, frequency of 5.5 Hz, load of 5 N, and test time of 30 min. The friction coefficient curves of the coatings prepared in Comparative Example 1, Example 1, Example 2, and Example 3 at different temperatures are shown below. Figures 7-9 As shown in Table 2, the coefficients of friction for each embodiment and comparative example are summarized in Table 2.
[0080] Table 2. Coating hardness and coefficient of friction for each embodiment and comparative example.
[0081] As shown in Table 2, the molybdenum disulfide lubricating coatings of Examples 1-3 exhibited low coefficients of friction at room temperature, 100℃, and 400℃, demonstrating excellent tribological properties over a wide temperature range. Among them, the molybdenum disulfide lubricating coating of Example 1, compared to the comparative examples, exhibited good tribological properties across all temperature ranges, making it the best performing process in terms of overall performance.
[0082] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing a wide-temperature-range tungsten disulfide lubricating coating, characterized in that, Includes the following steps: Using magnetron sputtering technology, a Cr transition layer is first sputtered onto the metal substrate to be treated. Then, the WS2 target RF power supply and the Cu target DC power supply are turned on, and the sputtering power of the WS2 target is adjusted to 150~190W and the sputtering power of the Cu target is adjusted to 10~25W. Co-sputtering is then used to obtain a WS2-Cu composite layer with WS2-Cu particles dispersed on the coating surface.
2. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 1, characterized in that, The working gas introduced during co-sputtering is argon, with an argon flow rate of 40-80 sccm; the sputtering pressure is 0.6-1.2 Pa; and the deposition time is 60-80 min.
3. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 2, characterized in that, The sputtering power of the WS2 target was 180~190W, and the sputtering power of the Cu target was 10~20W; the argon flow rate was 40~50sccm; the sputtering pressure was 1.0~1.2Pa; and the deposition time was 60~70min.
4. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 1 or 2, characterized in that, When sputtering the Cr transition layer, the Cr target is powered by a DC power supply, the target sputtering power is 50~100W; the argon flow rate is 40~80sccm, the sputtering pressure is 0.5~1.0Pa; and the deposition time is 5~20min.
5. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 4, characterized in that, The sputtering power of the Cr target is 60~70W; the argon flow rate is 40~50sccm; and the sputtering pressure is 0.5~0.7Pa. The deposition time is 15-20 minutes.
6. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 1 or 2, characterized in that, The metal substrate to be treated is obtained by plasma cleaning, wherein the plasma cleaning includes: evacuating the gas pressure in the coating chamber to no more than 6.4 × 10⁻⁶. -4 Pa, argon gas is introduced as the working gas, with an argon gas flow rate of 50~100 sccm, and the chamber pressure is stabilized at 0.5~2.3 Pa; the substrate temperature is 100~350℃; the plasma cleaning time is 10~20 min.
7. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 6, characterized in that, The air pressure in the coating chamber was evacuated to no more than 5.0 × 10⁻⁶. -4 The argon flow rate is 60~70 sccm, and the chamber pressure is stabilized at 1.0~2.0 Pa; the substrate temperature is 200~300℃; and the plasma cleaning time is 10~15 min.
8. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 1, characterized in that, The thickness of the Cr transition layer is 0.1~0.3μm, the thickness of the WS2-Cu composite layer is 2~6μm, and the hardness of the WS2-Cu composite layer is 7~9GPa.
9. The method for preparing a wide-temperature-range tungsten disulfide lubricating coating as described in claim 1, 2, or 8, characterized in that, The wide temperature range is from room temperature to 400℃.
10. A tungsten disulfide lubricating coating obtained by the preparation method of the wide temperature range tungsten disulfide lubricating coating according to any one of claims 1 to 9.