A space-grade nano-multilayer WS2 lubricating film and its preparation method

Abstract

This invention relates to the field of surface engineering, specifically to a space-grade nano-multilayer WS2 lubricating film and its preparation method. The space-grade nano-multilayer WS2 lubricating film comprises: a Ti transition layer, a nano-Ti-MoS2 / Ti-WS2 composite layer, and an Ag-Ti-WS2 doped layer. The Ti transition layer is deposited on the substrate surface with a thickness of 80–100 nm; the nano-Ti-MoS2 / Ti-WS2 composite layer comprises Ti-MoS2 and Ti-WS2 layers, alternately deposited on the surface of the Ti transition layer, with a composite layer thickness of 200–300 nm; the Ag-Ti-WS2 doped layer is deposited on the surface of the nano-Ti-MoS2 / Ti-WS2 composite layer with a thickness of 500–1000 nm. The overall thickness of the space-grade nano-multilayer WS2 lubricating film is 800–1500 nm, and it is prepared using high-power pulsed magnetron sputtering technology. By combining a nano-multilayer structure with a soft metal-doped WS2 layer, the soft metal doping and WS2 work together to achieve a synergistic lubrication effect, significantly improving the lubrication life of the WS2 film. This gives the WS2 film excellent atmospheric and vacuum tribological properties, making it suitable for use in heavy-duty, long-life moving parts in space, such as harmonic reducers, shafts, and guide rods.

Description

Technical Field

[0001] This invention relates to the field of surface engineering, specifically to a space-grade nano-multilayer WS2 lubricating film and its preparation method. Background Technology

[0002] Harmonic reducers, bearings, gears, and other moving parts are the main supporting moving components of various transmission and drive mechanisms in space. With the in-depth development of space technology, there are application requirements for high load-bearing capacity, long service life, and miniaturization of space moving parts. When there are high requirements for weight and size constraints, surface treatment is an ideal choice.

[0003] Solid lubricants commonly used in space include soft films and hard films. Soft films are made from materials such as silver, gold, lead, and molybdenum disulfide. These materials have low shear strength and good toughness, and easily form a transfer film under load, exhibiting excellent lubrication performance. Hard films are mainly made from diamond-like carbon and some compound films, which have relatively low coefficients of friction and excellent wear resistance. Both soft and hard films play an important role in the lubrication and wear-resistant service conditions of space moving mechanisms based on their own characteristics. However, to meet the demands of future high-load, long-life applications, it is necessary to develop new types of wear-resistant lubricating films. Summary of the Invention

[0004] To address the shortcomings of existing space lubricating films in terms of their inability to withstand long lifespans and harsh operating conditions, the present invention aims to provide a space-grade nano-multilayer WS2 lubricating film and its preparation method. The nano-multilayer structure design enhances the film's hardness and toughness, and the use of soft metal Ag doping not only improves the film's density but also allows Ag and WS2 to achieve a synergistic lubrication effect.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] In a first aspect, the present invention provides a space-grade nano-multilayer WS2 lubricating film, comprising: a Ti transition layer, a nano-Ti-MoS2 / Ti-WS2 composite layer, and an Ag-Ti-WS2 doped layer, wherein...

[0007] The Ti transition layer is deposited on the substrate surface, and the thickness of the Ti transition layer is 80–100 nm.

[0008] The nano-Ti-MoS2 / Ti-WS2 composite layer comprises n Ti-MoS2 layers and n Ti-WS2 layers, wherein the n Ti-MoS2 layers and the n Ti-WS2 layers are sequentially and alternately deposited on the surface of the Ti transition layer, the number of n being 1 to 5, the n Ti-MoS2 layers being relatively close to the Ti transition layer, and the n Ti-WS2 layers being relatively far from the Ti transition layer, and the thickness of the nano-Ti-MoS2 / Ti-WS2 composite layer being 200 to 300 nm;

[0009] The Ag-Ti-WS2 doped layer is deposited on the surface of the nano-Ti-MoS2 / Ti-WS2 composite layer, and the thickness of the Ag-Ti-WS2 doped layer is 500-1000 nm.

[0010] The thickness of the space-use nano-multilayer WS2 lubricating film is 800–1500 nm.

[0011] Furthermore, based on atomic percentage concentration, the Ti content in each Ti-MoS2 layer is 8–10 at%, and the Ti content in each Ti-WS2 layer is 6–12 at%.

[0012] Furthermore, based on atomic percentage concentration, the Ag content in the Ag-Ti-WS2 doped layer is 6–10 at%, and the Ti content is 3–6 at%.

[0013] Furthermore, the substrate is a metal substrate, preferably a 9Cr18, 30CrMnSi, or 40CrNiMo substrate.

[0014] Secondly, the present invention provides a method for preparing a space-grade nano-multilayer WS2 lubricating film, comprising the following steps:

[0015] Step (1) Matrix pretreatment;

[0016] Step (2) uses high-power magnetron sputtering technology to prepare a Ti transition layer on the surface of the substrate;

[0017] Step (3) uses high-power magnetron sputtering technology to prepare a nano-Ti-MoS2 / Ti-WS2 composite layer on the surface of the Ti transition layer;

[0018] Step (4) uses high-power magnetron sputtering technology to prepare an Ag-Ti-WS2 doped layer on the surface of the nano Ti-MoS2 / Ti-WS2 composite layer.

[0019] Furthermore, in step (2), the conditions for high-power magnetron sputtering are: using a Ti target as the cathode, argon as the working gas, a Ti target current of 1.0 to 2.0 kW, a substrate bias of -50 V to (-150 V), and a deposition time of 8 to 5 min.

[0020] Further, in step (3), the conditions for high-power magnetron sputtering are as follows: Ti target, MoS2 target, and WS2 target are used as cathodes, and argon is used as working gas; Ti-MoS2 and Ti-WS2 layers are deposited alternately in sequence; when depositing Ti-MoS2, the Ti target current is 0.8-1.0kW, the MoS2 target current is 1.5-2.0kW, the substrate bias voltage is -50V to (-150V), and the deposition time is 2-3min; when depositing Ti-WS2, the Ti target current is 1.0-1.5kW, the WS2 target current is 1.5-2.0kW, the substrate bias voltage is -50V to (-150V), and the deposition time is 2-3min.

[0021] Further, in step (4), the conditions for high-power magnetron sputtering are as follows: Ti target, WS2 target, and Ag are used as cathodes, argon is used as working gas, Ti target current is 0.3-0.5kW, Ag target current is 0.8-1.2kW, WS2 target current is 1.5-2.0kW, substrate bias voltage is -50V to (-150V), and deposition time is 35-45min.

[0022] Furthermore, in all steps, the purity of all targets is 99.9%.

[0023] The technical solution of this invention has the following advantages:

[0024] This invention provides a space-grade nano-multilayer WS2 lubricating film that combines a nano-multilayer structure with a soft metal-doped WS2 layer. The nano-multilayer structure offers advantages such as crack deflection at the interface, crack tip passivation at the interface, and prevention of microcrack initiation and propagation caused by stress concentration. It significantly improves the film's toughness, hardness, and film-substrate bonding strength. The soft metal doping provides a synergistic lubrication effect with WS2, greatly extending the lubrication life of the WS2 film. The film prepared by this invention has relatively high hardness, a low coefficient of friction, and a long wear life, exhibiting excellent atmospheric and vacuum tribological properties. It can be applied to heavy-duty, long-life moving parts in space, such as harmonic reducers, shafts, and guide rods.

[0025] This invention utilizes high-power pulsed magnetron sputtering technology to prepare multilayer nano-WS2 lubricating films for space applications. This technology features a high ionization rate, which is beneficial for improving the film's density and substrate adhesion. The method is simple and easy to control, enabling mass production on the surfaces of moving space components, and has strong engineering application prospects. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of a space-use nano-multilayer WS2 lubricating film according to an embodiment of the present invention;

[0028] Figure 2 This is a cross-sectional morphology image of the space nano-multilayer WS2 lubricating film prepared in Example 1 of the present invention;

[0029] Figure 3 This is a curve showing the change in atmospheric friction coefficient with gliding time of the space nano-multilayer WS2 lubricating film prepared in Example 1 of the present invention;

[0030] Figure 4 This is a curve showing the change of vacuum friction coefficient with sliding time for the space nano-multilayer WS2 lubricating film prepared in Example 1 of the present invention;

[0031] Figure 5 This is a cross-sectional morphology image of the space nano-multilayer WS2 lubricating film prepared in Example 2 of the present invention;

[0032] Figure 6 This is a curve showing the change in atmospheric friction coefficient with gliding time of the space nano-multilayer WS2 lubricating film prepared in Example 2 of the present invention;

[0033] Figure 7 This is a curve showing the change of vacuum friction coefficient with sliding time for the space nano-multilayer WS2 lubricating film prepared in Example 2 of the present invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0037] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0038] In addition, the term "multiple" should mean two or more.

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] The technical problem this invention aims to solve is overcoming the difficulty of existing space lubricating films in handling demanding conditions with high load-bearing capacity and long service life. To this end, embodiments of this invention provide a space-grade nano-multilayer WS2 lubricating film and its preparation method.

[0041] Please see Figure 1 The space-use nano-multilayer WS2 lubricating film structure provided in the embodiments of the present invention is as follows: Figure 1As shown, the structure includes: a Ti transition layer, a nano-Ti-MoS2 / Ti-WS2 composite layer, and an Ag-Ti-WS2 doped layer. The Ti transition layer is deposited on the substrate surface, with a thickness of 80–100 nm. The nano-Ti-MoS2 / Ti-WS2 composite layer comprises at least one Ti-MoS2 layer and at least one Ti-WS2 layer, which are alternately deposited on the surface of the Ti transition layer. The Ti-MoS2 layer is relatively close to the Ti transition layer, and the Ti-WS2 layer is relatively far from it. The thickness of the nano-Ti-MoS2 / Ti-WS2 composite layer is 200–300 nm. The Ag-Ti-WS2 doped layer is deposited on the surface of the nano-Ti-MoS2 / Ti-WS2 composite layer, with a thickness of 500–1000 nm. The overall thickness of the space-use nano-multilayer WS2 lubricating film is 800–1500 nm.

[0042] Furthermore, based on atomic percentage concentration, the Ti content in each Ti-MoS2 layer is 8–10 at%, and the Ti content in each Ti-WS2 layer is 6–12 at%. Based on atomic percentage concentration, the Ag content in the Ag-Ti-WS2 doped layer is 6–10 at%, and the Ti content is 3–6 at%.

[0043] Furthermore, the matrix is ​​a metallic matrix, preferably a 9Cr18, 30CrMnSi, or 40CrNiMo matrix.

[0044] The space-use nano-multilayer WS2 lubricating film provided in this embodiment of the invention is prepared by high-power pulsed magnetron sputtering technology, and has a high ionization rate, which is beneficial to improving the compactness of the film and the film-substrate adhesion.

[0045] Example 1

[0046] This embodiment provides a method for preparing a space-grade nano-multilayer WS2 lubricating film, comprising the following steps:

[0047] Step (1) Matrix pretreatment

[0048] The 9Cr18 matrix was sequentially immersed in petroleum ether, alcohol, and acetone solutions, and ultrasonically cleaned for 5 minutes each. The 9Cr18 matrix was then placed into a high-power pulsed magnetron sputtering chamber, and a vacuum was evacuated until the chamber vacuum level was better than 3 × 10⁻⁶. -3 After Pa, the 9Cr18 substrate was etched and cleaned using an Ar+ ion beam generated by an anodic layer ion source. The chamber pressure was 0.5 Pa, a -800V pulse bias was applied to the substrate, the anodic layer ion beam source voltage was 1000V, and the cleaning time was 10 min.

[0049] Step (2) uses high-power magnetron sputtering technology to prepare a Ti transition layer on the surface of the substrate;

[0050] The argon gas pressure was adjusted to 0.3 Pa, a DC bias voltage of -50 V was applied to the substrate, and high-power pulsed magnetron sputtering deposition was performed. The Ti target current was 1.0 kW, the deposition time was 8 min, the purity of the Ti target was 99.9%, and the thickness of the Ti transition layer was controlled to 80 nm.

[0051] Step (3) uses high-power magnetron sputtering technology to prepare a nano-Ti-MoS2 / Ti-WS2 composite layer on the surface of the Ti transition layer.

[0052] The argon gas pressure was adjusted to 0.3 Pa, and a -50 V DC bias voltage was applied to the substrate. The MoS2 and Ti targets were turned on, both with a purity of 99.9%. The Ti target current was 0.8 kW, and the MoS2 target current was 1.5 kW. The deposition time was 3 min, resulting in a Ti-MoS2 layer. Then, the MoS2 target was turned off, and the WS2 target was turned on. The WS2 target purity was 99.9%, and the WS2 target current was 1.0 kW. The deposition time was 3 min, resulting in a Ti-WS2 layer. This cycle was repeated ten times until the thickness of the nano-Ti-MoS2 / Ti-WS2 composite layer was approximately 200 nm.

[0053] Step (4) uses high-power magnetron sputtering technology to prepare an Ag-Ti-WS2 doped layer on the surface of the nano-Ti-MoS2 / Ti-WS2 composite layer.

[0054] High-power magnetron sputtering deposition was performed using Ti and WS2 targets, Ag as cathodes, and argon as the working gas. The purity of both Ti and WS2 targets was 99.9%. The current for Ti target was 0.3 kW, for Ag target was 0.8 kW, and for WS2 target was 1.5 kW. The deposition time was 35 min, and the thickness of the Ag-Ti-WS2 doped layer was controlled to be 800 nm.

[0055] The surface morphology of the space-use nano-multilayer WS2 lubricating film prepared in this embodiment was observed using a 200FEG field emission scanning electron microscope, such as... Figure 2 As shown, the space-use nano-multilayer WS2 lubricating film prepared in this embodiment exhibits a multilayer structure.

[0056] The tribological properties of the space-use nano-multilayer WS2 lubricating film prepared in this embodiment were tested using an Anton Paar ball-and-disc friction testing machine. The test conditions were: the grinding media was a 9Cr18 steel ball with a diameter of Φ8mm, the load was 5N, and the rotational speed was 1000 r / min. The test results are as follows: Figure 3As shown in the figure, the vertical axis represents the coefficient of friction, and the horizontal axis represents the friction time. It can be seen from the figure that the average coefficient of friction is <0.05, and the friction time is greater than 400 min. Based on the calculation of wear life by multiplying the rotational speed by the friction time, the wear life is ≥4 × 10⁻⁶. 5 change.

[0057] The tribological properties of the space-use nano-multilayer WS2 lubricating film prepared in this embodiment were tested using a vacuum ball-and-disc friction tester (Anton Paar). The test conditions were: vacuum level better than 5 × 10⁻⁶. -3 The test was conducted on a 9Cr18 steel ball with a diameter of Φ8mm, using a load of 5N and a rotational speed of 1000r / min. The test results are as follows: Figure 4 As shown in the figure, the vertical axis represents the coefficient of friction, and the horizontal axis represents the friction time. It can be seen from the figure that the average coefficient of friction is <0.005, and the friction time is greater than 400 min. Based on the calculation of wear life by multiplying the rotational speed by the friction time, the wear life is ≥4 × 10⁻⁶. 5 change.

[0058] Example 2

[0059] This embodiment provides a method for preparing a space-grade nano-multilayer WS2 lubricating film, comprising the following steps:

[0060] Step (1) Matrix pretreatment

[0061] The 9Cr18 matrix was sequentially immersed in petroleum ether, alcohol, and acetone solutions, and ultrasonically cleaned for 5 minutes each. The 9Cr18 matrix was then placed into a high-power pulsed magnetron sputtering chamber, and a vacuum was evacuated until the chamber vacuum level was better than 3 × 10⁻⁶. -3 After Pa, Ar is generated using an anolyte ion source. + The 9Cr18 substrate was etched and cleaned using an ion beam with a chamber pressure of 0.5 Pa, an 800 V pulse bias applied to the substrate, an ion beam source voltage of 1000 V for the anode layer, and a cleaning time of 10 min.

[0062] Step (2) uses high-power magnetron sputtering technology to prepare a Ti transition layer on the surface of the substrate;

[0063] Argon gas pressure was adjusted to 0.3 Pa, a DC bias of -150 V was applied to the substrate, and high-power pulsed magnetron sputtering deposition was performed. The Ti target current was 2.0 kW, the deposition time was 5 min, the purity of the Ti target was 99.9%, and the thickness of the Ti transition layer was controlled to 100 nm.

[0064] Step (3) uses high-power magnetron sputtering technology to prepare a nano-Ti-MoS2 / Ti-WS2 composite layer on the surface of the Ti transition layer.

[0065] The argon gas pressure was adjusted to 0.3 Pa, and a -50 V DC bias voltage was applied to the substrate. The MoS2 and Ti targets were turned on, both with a purity of 99.9%. The Ti target current was 1.0 kW, and the MoS2 target current was 2.0 kW. The deposition time was 2 min, resulting in a Ti-MoS2 layer. Then, the MoS2 target was turned off, and the WS2 target was turned on. The WS2 target purity was 99.9%, and the WS2 target current was 1.5 kW. The deposition time was 2 min, resulting in a Ti-WS2 layer. This cycle was repeated ten times until the thickness of the nano-Ti-MoS2 / Ti-WS2 composite layer was approximately 300 nm.

[0066] Step (4) uses high-power magnetron sputtering technology to prepare an Ag-Ti-WS2 doped layer on the surface of the nano-Ti-MoS2 / Ti-WS2 composite layer.

[0067] High-power magnetron sputtering deposition was performed using Ti and WS2 targets, Ag as cathodes, and argon as the working gas. The purity of both Ti and WS2 targets was 99.9%. The current for Ti target was 0.5 kW, for Ag target was 1.2 kW, for WS2 target was 2.0 kW, the deposition time was 45 min, and the thickness of the Ag-Ti-WS2 doped layer was controlled to be 1500 nm.

[0068] The surface morphology of the space-use nano-multilayer WS2 lubricating film prepared in this embodiment was observed using a 200FEG field emission scanning electron microscope, such as... Figure 5 As shown, the space-use nano-multilayer WS2 lubricating film prepared in this embodiment exhibits a multilayer structure.

[0069] The tribological properties of the space-use nano-multilayer WS2 lubricating film prepared in this embodiment were tested using an Anton Paar ball-and-disc friction testing machine. The test conditions were: the grinding media was a 9Cr18 steel ball with a diameter of Φ8mm, the load was 5N, and the rotational speed was 1000 r / min. The test results are as follows: Figure 6 As shown in the figure, the vertical axis represents the coefficient of friction, and the horizontal axis represents the friction time. It can be seen from the figure that the average coefficient of friction is <0.05, and the friction time is greater than 400 min. Based on the calculation of wear life by multiplying the rotational speed by the friction time, the wear life is ≥4 × 10⁻⁶. 5 change.

[0070] The tribological properties of the space-use nano-multilayer WS2 lubricating film prepared in this embodiment were tested using a vacuum ball-and-disc friction testing machine (Anton Paar). The test conditions were: vacuum level better than 5 × 10⁻⁶. -3 The test was conducted on a 9Cr18 steel ball with a diameter of Φ8mm, using a load of 5N and a rotational speed of 1000r / min. The test results are as follows: Figure 7As shown in the figure, the vertical axis represents the coefficient of friction, and the horizontal axis represents the friction time. It can be seen from the figure that the average coefficient of friction is <0.005, and the friction time is greater than 400 min. Based on the calculation of wear life by multiplying the rotational speed by the friction time, the wear life is ≥4 × 10⁻⁶. 5 change.

[0071] Test case

[0072] The tribological properties of the space-use nano-multilayer WS2 lubricating films prepared in Examples 1-2 were tested using an Anton Paar ball-disc friction testing machine. The test conditions were: the grinding media were 9Cr18 steel balls with a diameter of Φ8mm, the load was 5N, and the rotational speed was 1000r / min. The test results are as follows: Figure 3 and 6 As shown in the figure, the vertical axis represents the coefficient of friction, and the horizontal axis represents the friction time. It can be seen from the figure that the average coefficient of friction is <0.05, and the friction time is greater than 400 min. Based on the calculation of wear life by multiplying the rotational speed by the friction time, the wear life is ≥4 × 10⁻⁶. 5 change.

[0073] The tribological properties of the space-use nano-multilayer WS2 lubricating films prepared in Examples 1-2 were tested using an Anton Paar vacuum ball-disc friction testing machine. The test conditions were: vacuum level better than 5 × 10⁻⁶. -3 The test was conducted on a 9Cr18 steel ball with a diameter of Φ8mm, using a load of 5N and a rotational speed of 1000r / min. The test results are as follows: Figure 4 and 7 As shown in the figure, the vertical axis represents the coefficient of friction, and the horizontal axis represents the friction time. It can be seen from the figure that the average coefficient of friction is <0.005, and the friction time is greater than 400 min. Based on the calculation of wear life by multiplying the rotational speed by the friction time, the wear life is ≥4 × 10⁻⁶. 5 change.

[0074] In summary, this invention combines a nano-multilayer structure with a soft metal-doped WS2 layer. The nano-multilayer structure offers advantages such as crack deflection at the interface, crack tip passivation at the interface, and prevention of microcrack initiation and propagation caused by stress concentration, resulting in significant advantages in improving film toughness, hardness, and film-substrate bonding strength. Soft metal doping can synergistically lubricate with WS2, significantly extending the lubrication life of the WS2 film. The space-grade nano-multilayer WS2 lubricating film prepared in this invention exhibits relatively high hardness, low friction coefficient, and long wear life. Its average friction coefficient is <0.05 in atmospheric conditions and <0.005 in vacuum conditions, with a wear life ≥4×10⁻⁶. 5It exhibits excellent tribological properties, meeting the requirements of high load-bearing capacity and long-life lubrication in space applications. It can be applied to heavy-duty, long-life moving parts in space, such as harmonic reducers, shafts, and guide rods.

[0075] This invention employs a high-power pulsed magnetron sputtering method, which exhibits high ionization rate, beneficial for improving film density and substrate adhesion. The preparation method is simple and easy to control, enabling mass production and demonstrating strong engineering application prospects.

[0076] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A space-grade nano-multilayer WS2 lubricating film, characterized in that, include: Ti transition layer, nano-Ti-MoS2 / Ti-WS2 composite layer and Ag-Ti-WS2 doped layer, among which, The Ti transition layer is deposited on the surface of the substrate, and the thickness of the Ti transition layer is 80~100 nm. The nano-Ti-MoS2 / Ti-WS2 composite layer comprises n Ti-MoS2 layers and n Ti-WS2 layers, wherein the n Ti-MoS2 layers and the n Ti-WS2 layers are sequentially and alternately deposited on the surface of the Ti transition layer, the number of n being 1 to 5, the n Ti-MoS2 layers being relatively close to the Ti transition layer, and the n Ti-WS2 layers being relatively far from the Ti transition layer, and the thickness of the nano-Ti-MoS2 / Ti-WS2 composite layer being 200 to 300 nm; The Ti content in each Ti-MoS2 layer is 8~10 at%, and the Ti content in each Ti-WS2 layer is 6~12 at%. The Ag-Ti-WS2 doped layer is deposited on the surface of the nano-Ti-MoS2 / Ti-WS2 composite layer, and the thickness of the Ag-Ti-WS2 doped layer is 500~1000 nm; The Ag-Ti-WS2 doped layer contains 6~10 at% Ag and 3~6 at% Ti. The thickness of the space-use nano-multilayer WS2 lubricating film is 800~1500 nm.

2. The space-grade nano-multilayer WS2 lubricating film according to claim 1, characterized in that, The substrate is a metallic substrate.

3. The method for preparing a space-use nano-multilayer WS2 lubricating film according to any one of claims 1 to 2, characterized in that, Includes the following steps: Step (1) Matrix pretreatment; Step (2) uses high-power magnetron sputtering technology to prepare a Ti transition layer on the surface of the substrate; Step (3) A nano-Ti-MoS2 / Ti-WS2 composite layer is prepared on the surface of the Ti transition layer using high-power magnetron sputtering technology; Step (4) employs high-power magnetron sputtering technology to prepare an Ag-Ti-WS2 doped layer on the surface of the nano-Ti-MoS2 / Ti-WS2 composite layer, wherein, In step (2), the conditions for high-power magnetron sputtering are: Ti target as cathode, argon as working gas, Ti target current of 1.0~2.0 kW, substrate bias of -50V~(-150V), and deposition time of 8~5 min; In step (3), the conditions for high-power magnetron sputtering are as follows: Ti target, MoS2 target, and WS2 target are used as cathodes, and argon is used as the working gas; Ti-MoS2 and Ti-WS2 layers are deposited alternately in sequence; when depositing Ti-MoS2, the Ti target current is 0.8~1.0 kW, the MoS2 target current is 1.5~2.0 kW, the substrate bias voltage is -50V~(-150V), and the deposition time is 2~3 min; when depositing Ti-WS2, the Ti target current is 1.0~1.5 kW, the WS2 target current is 1.5~2.0 kW, the substrate bias voltage is -50V~(-150V), and the deposition time is 2~3 min. In step (4), the conditions for high-power magnetron sputtering are as follows: Ti target, WS2 target, and Ag are used as cathodes, argon is used as working gas, Ti target current is 0.3~0.5 kW, Ag target current is 0.8~1.2 kW, WS2 target current is 1.5~2.0 kW, substrate bias voltage is -50V~(-150V), and deposition time is 35~45min.

4. The method for preparing a space-use nano-multilayer WS2 lubricating film according to claim 3, characterized in that, In all steps, the purity of all targets was 99.9%.

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