High-temperature-resistant composite lubricating film in vacuum environment and preparation method of high-temperature-resistant composite lubricating film

Abstract

The invention provides a preparation method of a high-temperature-resistant composite lubricating film in a vacuum environment, and relates to the technical field of functional materials. Through a magnetron sputtering process, a titanium (Ti) transition layer is deposited on the surface of a metal substrate, and silver (Ag) layers and molybdenum disulfide (MoS2) layers are sequentially and alternately deposited on the surface of the transition layer. Through the gradient heterojunction constructed through interface engineering, the bonding strength between the thin film and the metal matrix is remarkably improved, and the scratch critical load is 30 N or above. Under the severe working condition of 300 DEG C in vacuum, the material shows an ultralow friction coefficient (less than 0.15) and a wear-resistant life gt; 5 * 10 < 5 > r. The lubricating oil is particularly suitable for long-life lubrication of a key kinematic pair of a high-temperature transmission mechanism of a spacecraft.

Description

Technical Field

[0001] This invention relates to the field of functional materials technology, specifically to a high-temperature resistant composite lubricating film under vacuum conditions and its preparation method. Background Technology

[0002] In the extreme environments (vacuum, high temperature) of spacecraft propulsion systems, lubrication and wear control of friction pair surfaces remain one of the core technical challenges for ensuring the long-term stable operation of these devices. Traditional liquid lubricants suffer from problems such as leakage risks, high-temperature vaporization, and failure under vacuum conditions (e.g., inability to maintain a stable oil film in space), significantly limiting their applicability. Solid lubricating films have been widely studied as an alternative, but they still face key challenges. At high temperatures, pure MoS2 undergoes pyrolysis, and the evaporation of surface sulfur atoms directly reduces the thickness of the lubricating layer, leading to a sharp increase in the coefficient of friction.

[0003] Therefore, developing a solid lubricating film with a long lifespan under vacuum and high temperature conditions has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To achieve the above objectives, this application provides a high-temperature resistant composite lubricating film for vacuum environments and its preparation method, which has a long service life in vacuum and high-temperature environments and is suitable for moving parts in aerospace vacuum and high-temperature environments.

[0005] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a high-temperature resistant composite lubricating film for use in a vacuum environment, comprising: a transition layer and a lubricating layer, wherein... The transition layer is deposited on the substrate surface, and the lubricating layer is deposited on the surface of the transition layer; The lubrication layer includes a first lubrication layer and a second lubrication layer, which are stacked alternately in sequence. The first lubrication layer is close to the transition layer and the second lubrication layer is far away from the transition layer. An adjacent first lubricating layer and a second lubricating layer constitute a unit, and the lubricating layer comprises 10 to 15 such units.

[0006] Furthermore, the substrate is preferably a metal substrate.

[0007] Furthermore, the transition layer is made of titanium (Ti) and has a thickness of 0.3~0.5 μm.

[0008] Furthermore, the raw material for the first lubricating layer is silver (Ag), and the raw material for the second lubricating layer is molybdenum disulfide (MoS2).

[0009] Furthermore, in the unit, the thickness ratio of the first lubricating layer to the second lubricating layer is (2:1) to (1:2).

[0010] Furthermore, the high-temperature resistant composite lubricating film under vacuum conditions (<5×10⁻⁶) -3 At 300℃, the average friction coefficient is less than 0.15 and the wear life exceeds 500,000 revolutions.

[0011] Furthermore, the hardness of the MoS2-based composite lubricating film is 4~5 GPa (GB / T 25898).

[0012] Secondly, the present invention provides a method for preparing a high-temperature resistant composite lubricating film under vacuum conditions, comprising the following steps: Step 1: Substrate pretreatment; Step 2: Deposit a transition layer on the surface of the substrate using high-power magnetron sputtering technology; Step 3: Using magnetron sputtering technology, the first lubricating layer and the second lubricating layer are deposited alternately on the surface of the transition layer to form an alternating stacked structure, thereby obtaining a high-temperature resistant composite lubricating film under vacuum conditions.

[0013] Further, in step 1, the substrate pretreatment includes: grinding and polishing the surface of the substrate, then cleaning and drying it in acetone solution and alcohol solution in sequence, and finally bombarding the surface of the substrate under vacuum conditions using the anode layer ion source to remove impurities.

[0014] Furthermore, the bombardment of the substrate surface using the anode layer ion source under vacuum conditions includes: placing the dried substrate into the vacuum furnace chamber and evacuating it to a vacuum level of 5 × 10⁻⁶. -3 Below Pa, the vacuum furnace cavity is heated to 70~90℃, the anode layer ion source is turned on to bombard the substrate surface, the anode layer ion beam source voltage is 1000~1200 V, argon gas is introduced into the vacuum furnace cavity to make the vacuum degree 0.3~1 Pa, the substrate bias voltage is -300~-500 V, and the bombardment time is 20~30 min.

[0015] Further, in step 2, the conditions for high-power magnetron sputtering are: sputtering target purity ≥ 99.9%, sputtering target voltage 600~650 V, working environment argon atmosphere (pressure 0.5~1 Pa), sputtering power 5~8 kW, substrate bias voltage -70~-100 V, and deposition time 10~12 min.

[0016] Further, in step 3, the magnetron sputtering conditions for the first lubricating layer are as follows: the working environment is an argon atmosphere (pressure 0.5~1 Pa), the sputtering target voltage for the first lubricating layer is 500~600V, the sputtering power is 3~6 kW, the substrate bias voltage is -70~-100 V, and the deposition time is 2~5 min.

[0017] Further, in step 3, the magnetron sputtering conditions for the second lubricating layer are as follows: the working environment is an argon atmosphere (pressure 0.5~1 Pa), the sputtering target voltage for the second lubricating layer is 900~1100 V, the sputtering power is 2~4 kW, the substrate bias voltage is -50~-70 V, and the deposition time is 2~5 min.

[0018] Furthermore, the preparation is carried out in a vacuum furnace chamber, which is equipped with a workpiece stage. The sides of the vacuum furnace chamber are respectively equipped with a high-power magnetron sputtering target, a first lubricating layer magnetron sputtering target, a second lubricating layer magnetron sputtering target, and an anode layer ion source.

[0019] The technical solution of this invention has the following advantages: This invention utilizes magnetron sputtering technology to construct a gradient heterojunction through interface engineering, thereby preparing a titanium (Ti) transition layer on the substrate surface. This significantly improves the bonding strength between the thin film and the metal substrate, increasing the critical scratch load by over 30 N. Simultaneously, by combining molybdenum disulfide (MoS2), which exhibits excellent vacuum lubrication properties, with silver (Ag), a soft metal with excellent high-temperature resistance, and employing magnetron sputtering technology with an alternating deposition method, an Ag / MoS2 alternating stack structure is formed on the transition layer surface, achieving high-temperature resistance under vacuum.

[0020] The vacuum high-temperature resistant composite lubricating film of this invention has a hardness of 4~5 GPa (GB / T 25898), and can withstand temperatures of <5×10⁻⁶ GPa in a vacuum environment. -3 At a temperature of 300℃, the average coefficient of friction is less than 0.15, and the wear life exceeds 500,000 revolutions. It is suitable for moving parts in the high-temperature vacuum environment of aerospace, and is especially suitable for long-life lubrication of key moving pairs in the high-temperature transmission mechanism of spacecraft. Attached Figure Description

[0021] 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.

[0022] Figure 1This is a schematic diagram of the structure of the high-temperature resistant composite lubricating film prepared in a vacuum environment according to an embodiment of the present invention; Figure 2 This is the friction coefficient curve of the high-temperature resistant composite lubricating film prepared in Example 1 of the present invention under vacuum conditions of 300°C.

[0023] In the picture: 1-Base 2-Transition Layer 3-First Lubricating Layer 4-Second Lubricating Layer Detailed Implementation

[0024] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0025] Where specific experimental steps or conditions are not specified in the embodiments, they can be performed according to the conventional experimental steps or conditions described in the literature in this field. All raw materials or instruments used are commercially available conventional products, including but not limited to those used in the embodiments of this application.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The following will describe the embodiments in conjunction with the appendix. Figure 1 and attached Figure 2 This application provides a detailed description of a high-temperature resistant composite lubricating film for vacuum environments and its preparation method, as provided in the embodiments of this application.

[0027] The technical problem this invention aims to solve is that solid lubricating films of moving parts in spacecraft undergo pyrolysis under vacuum and high-temperature conditions, resulting in the evaporation of sulfur atoms on the surface, leading to a reduction in the thickness of the lubricating layer and a sharp increase in the coefficient of friction. Therefore, this invention proposes a high-temperature resistant composite lubricating film for vacuum conditions and its preparation method. The basic principle is as follows: using magnetron sputtering technology, a titanium (Ti) transition layer is prepared on the substrate surface through a gradient heterojunction constructed by interface engineering, significantly improving the film-substrate adhesion. Simultaneously, by combining molybdenum disulfide (MoS2), a material with excellent vacuum lubrication properties, with silver (Ag), a soft metal with excellent high-temperature resistance, an alternating Ag / MoS2 stacked structure is formed on the transition layer surface using magnetron sputtering technology and a sequential deposition method, achieving high-temperature resistance under vacuum.

[0028] Please see Figure 1The high-temperature resistant composite lubricating film prepared in this embodiment of the application includes a transition layer 2 and a lubricating layer, wherein the lubricating layer includes a first lubricating layer 3 and a second lubricating layer 4. The transition layer 2 is deposited on the surface of a substrate 1, preferably a metal substrate, and the thickness of the transition layer 2 is 0.3-0.5 μm. The first lubricating layer 3 and the second lubricating layer 4 are alternately deposited on the surface of the transition layer 2, with the first lubricating layer 3 closer to the transition layer 2 and the second lubricating layer 4 farther away from the transition layer 2. An adjacent first lubricating layer 3 and a second lubricating layer 4 constitute a unit, wherein the thickness ratio of the first lubricating layer 3 to the second lubricating layer 4 is (2:1) to (1:2). The composite lubricating film includes 10 to 15 units.

[0029] The transition layer 2 is made of titanium (Ti), which can significantly improve the film-substrate adhesion. The first lubricating layer 3 is made of soft silver (Ag), which has excellent vacuum lubrication performance. The second lubricating layer 4 is made of molybdenum disulfide (MoS2), which has excellent high-temperature resistance. Using magnetron sputtering technology, an alternating Ag / MoS2 stacked structure is formed on the surface of the transition layer through sequential deposition, achieving high-temperature resistance under vacuum.

[0030] The method for preparing a high-temperature resistant composite lubricating film under vacuum environment according to the embodiments of this application includes the following steps: Step 1: Pretreatment of substrate 1; Step 2: Deposit a transition layer 2 on the surface of substrate 1 using high-power magnetron sputtering technology; Step 3: Using magnetron sputtering technology, the first lubricating layer 3 and the second lubricating layer 4 are sequentially and alternately deposited on the surface of the transition layer 2 to form an alternating stacked structure, thereby obtaining a high-temperature resistant composite lubricating film under vacuum conditions.

[0031] In step 1, the pretreatment of substrate 1 includes: grinding and polishing the surface of substrate 1, then cleaning and drying it in acetone solution and alcohol solution in sequence, and finally bombarding the surface of substrate 1 with an anode layer ion source under vacuum conditions to remove impurities.

[0032] Specifically, the surface of substrate 1 is bombarded under vacuum conditions using an anode layer ion source, including: placing the dried substrate 1 into a vacuum furnace chamber and evacuating it to a vacuum level of 5 × 10⁻⁶. -3 Below Pa, the vacuum furnace cavity is heated to 70~90℃, and the anode layer ion source is turned on to bombard the surface of substrate 1. The voltage of the anode layer ion beam source is 1000~1200 V. Argon gas is introduced into the vacuum furnace cavity to make the vacuum degree 0.3~1 Pa. The substrate bias voltage is -300~-500V, and the bombardment time is 20~30 min.

[0033] In step 2, the conditions for high-power magnetron sputtering are as follows: target purity ≥ 99.9%, target voltage 600~650 V, working environment argon atmosphere (pressure 0.5~1 Pa), sputtering power 5~8 kW, substrate bias voltage -70~-100 V, and deposition time 10~12 min.

[0034] In step 3, the magnetron sputtering conditions for the first lubricating layer 3 are as follows: the working environment is an argon atmosphere (pressure 0.5~1 Pa), the sputtering target voltage for the first lubricating layer is 500~600 V, the sputtering power is 3~6 kW, the substrate bias voltage is -70~-100 V, and the deposition time is 2~5 min; the magnetron sputtering conditions for the second lubricating layer 4 are as follows: the working environment is an argon atmosphere (pressure 0.5~1 Pa), the sputtering target voltage for the second lubricating layer is 900~1100 V, the sputtering power is 2~4 kW, the substrate bias voltage is -50~-70 V, and the deposition time is 2~5 min.

[0035] The preparation in this embodiment is carried out in a vacuum furnace chamber, which is equipped with a workpiece stage. A high-power magnetron sputtering target, a first lubricating layer magnetron sputtering target, a second lubricating layer magnetron sputtering target, and an anode layer ion source are respectively arranged on the side of the vacuum furnace chamber.

[0036] Example 1 This embodiment provides a method for preparing a high-temperature resistant composite lubricating film under vacuum conditions, including the following steps: (1) Select 9Cr18 stainless steel substrate and pretreat it: First, the 9Cr18 stainless steel substrate is ground and polished to achieve a surface roughness less than Ra0.8. Then, it is ultrasonically cleaned in acetone solution for 10 minutes, followed by cleaning in alcohol solution for 10 minutes. Next, it is dried in a drying oven at 70℃ for 20 minutes. After cleaning and drying, the substrate is placed in a vacuum furnace chamber, fixed on a workpiece holder, and then a vacuum is created in the furnace chamber to achieve a vacuum level better than 1×10⁻⁶. -3 Pa, and the vacuum furnace cavity is heated to 80°C. The anode layer ion source is turned on to bombard the substrate surface to remove impurities. The anode layer ion beam source voltage is 1000 V. Argon gas is introduced into the vacuum furnace cavity to make the chamber vacuum degree 0.5 Pa. The substrate bias voltage is -500 V. The bombardment time is 30 min.

[0037] (2) A titanium (Ti) transition layer was deposited on the surface of a 9Cr18 stainless steel substrate using high-power magnetron sputtering technology: Argon gas was introduced into the vacuum furnace chamber at a pressure of 0.8 Pa. High-power pulsed magnetron sputtering was performed on the Ti target with an average power of 6 kW, a substrate bias of -80 V, and a deposition time of 10 min.

[0038] (3) Using magnetron sputtering technology, silver (Ag) lubricating layer and molybdenum disulfide (MoS2) lubricating layer are sequentially and alternately deposited on the surface of Ti transition layer to form an alternating stacked structure: First, perform Ag magnetron sputtering: keep the argon flow rate constant, turn on the Ag target, set the Ag target power to 4 kW, set the substrate bias to -50V, and set the deposition time to 3 min. Then, turn off the Ag target. Then, MoS2 magnetron sputtering was performed: the argon flow rate was kept constant, the MoS2 target was turned on, the MoS2 target power was 3 kW, the substrate bias voltage was -50 V, the deposition time was 3 min, and the MoS2 target was turned off. Repeat the Ag magnetron sputtering and MoS2 magnetron sputtering processes sequentially, 10 times in total.

[0039] Stop the coating process until the temperature in the vacuum furnace chamber is below 50°C, then remove the substrate to obtain the composite lubricating film.

[0040] The composite lubricating film prepared in this embodiment was characterized by testing. The total thickness was 1.42 μm. The hardness in the nanoindentation test was 4.2 GPa, the film-substrate adhesion in the nanoscratching test was 35 N, the average coefficient of friction was 0.12 at 300℃, and the wear life was >5 × 10⁻⁶. 5 r.

[0041] Example 2 This embodiment provides a method for preparing a high-temperature resistant composite lubricating film under vacuum conditions, including the following steps: (1) Select 9Cr18 stainless steel substrate and pretreat it: First, the 9Cr18 stainless steel substrate is ground and polished to achieve a surface roughness less than Ra0.8. Then, it is ultrasonically cleaned in acetone solution for 10 minutes, followed by cleaning in alcohol solution for 10 minutes. Afterward, it is dried in a drying oven at 70℃ for 20 minutes. The cleaned and dried substrate is then placed in a vacuum furnace chamber, fixed on a workpiece holder, and a vacuum is created in the furnace chamber to achieve a vacuum level better than 1×10⁻⁶. -3 Pa, and the vacuum furnace cavity is heated to 80°C. The anode layer ion source is turned on to bombard the substrate surface to remove impurities. The anode layer ion beam source voltage is 1000 V. Argon gas is introduced into the vacuum furnace cavity to make the chamber vacuum degree 0.5 Pa. The substrate bias voltage is -500 V. The bombardment time is 30 min.

[0042] (2) A titanium (Ti) transition layer was deposited on the surface of a 9Cr18 stainless steel substrate using high-power magnetron sputtering technology: Argon gas was introduced into the vacuum furnace chamber at a pressure of 0.8 Pa. High-power pulsed magnetron sputtering was performed on the Ti target with an average power of 6 kW, a substrate bias of -80 V, and a deposition time of 10 min.

[0043] (3) Using magnetron sputtering technology, silver (Ag) lubricating layer and molybdenum disulfide (MoS2) lubricating layer are sequentially and alternately deposited on the surface of Ti transition layer to form an alternating stacked structure: First, perform Ag magnetron sputtering: keep the argon flow rate constant, turn on the Ag target, set the Ag target power to 4 kW, set the substrate bias to -50V, and set the deposition time to 4 min. Then, turn off the Ag target. Then, MoS2 magnetron sputtering was performed: the argon flow rate was kept constant, the MoS2 target was turned on, the MoS2 target power was 3 kW, the substrate bias voltage was -50 V, the deposition time was 2 min, and the MoS2 target was turned off. Repeat the Ag magnetron sputtering and MoS2 magnetron sputtering processes described above, 10 times in total.

[0044] Stop the coating process until the temperature of the vacuum furnace chamber is below 50°C, then remove the substrate to obtain a MoS2-based composite lubricating film.

[0045] The composite lubricating film prepared in this embodiment was characterized by testing. The total thickness was 1.38 μm. The hardness in the nanoindentation test was 4.5 GPa, the film-substrate adhesion in the nanoscratching test was 36 N, the average coefficient of friction was 0.14 at 300℃, and the wear life was >5 × 10⁻⁶. 5 r.

[0046] Example 3 This embodiment provides a method for preparing a high-temperature resistant composite lubricating film under vacuum conditions, including the following steps: (1) Select 9Cr18 stainless steel substrate and pretreat it: First, the 9Cr18 stainless steel substrate is ground and polished to achieve a surface roughness less than Ra0.8. Then, it is ultrasonically cleaned in acetone solution for 10 minutes, followed by cleaning in alcohol solution for 10 minutes. Afterward, it is dried in a drying oven at 70℃ for 20 minutes. The cleaned and dried substrate is then placed in a vacuum furnace chamber, fixed on a workpiece holder, and a vacuum is created in the furnace chamber to achieve a vacuum level better than 1×10⁻⁶. -3 Pa, and the vacuum furnace cavity is heated to 80°C. The anode layer ion source is turned on to bombard the substrate surface to remove impurities. The anode layer ion beam source voltage is 1000 V. Argon gas is introduced into the vacuum furnace cavity to make the chamber vacuum degree 0.5 Pa. The substrate bias voltage is -500 V. The bombardment time is 30 min.

[0047] (2) A titanium (Ti) transition layer was deposited on the surface of a 9Cr18 stainless steel substrate using high-power magnetron sputtering technology: Argon gas was introduced into the vacuum furnace chamber at a pressure of 0.8 Pa. High-power pulsed magnetron sputtering was performed on the Ti target with an average power of 6 kW, a substrate bias of -80 V, and a deposition time of 10 min.

[0048] (3) Using magnetron sputtering technology, silver (Ag) lubricating layer and molybdenum disulfide (MoS2) lubricating layer are sequentially and alternately deposited on the surface of Ti transition layer to form an alternating stacked structure: First, perform Ag magnetron sputtering: keep the argon flow rate constant, turn on the Ag target, set the Ag target power to 4 kW, set the substrate bias to -50 V, and set the deposition time to 2 min. Then, turn off the Ag target. Then, MoS2 magnetron sputtering was performed: the argon flow rate was kept constant, the MoS2 target was turned on, the MoS2 target power was 3 kW, the substrate bias voltage was -50 V, the deposition time was 2 min, and the MoS2 target was turned off. Repeat the Ag magnetron sputtering and MoS2 magnetron sputtering processes described above, 15 times in total.

[0049] Stop the coating process until the temperature of the vacuum furnace chamber is below 50°C, then remove the substrate to obtain a MoS2-based composite lubricating film.

[0050] The composite lubricating film prepared in this embodiment was characterized by testing. The total thickness was 1.41 μm. The hardness in the nanoindentation test was 4.4 GPa, the film-substrate adhesion in the nanoscratching test was 31 N, the average coefficient of friction was 0.13 at 300℃, and the wear life was >5 × 10⁻⁶. 5 r.

[0051] Test case The wear resistance of the composite lubricating film prepared in Example 1 of this invention was tested, and the test results are as follows: Figure 2 As shown.

[0052] Test method: The tribological properties of the composite lubricating film were determined using a ball-and-disc friction tester. The test environment was a vacuum, with a vacuum degree less than 5 × 10⁻⁶. -3 Pa, temperature 300℃, Si3N4 ceramic balls with a diameter of 8 mm are selected as the friction pair, the load is 5 N, the friction radius is 10 mm, and the rotation speed is 500 r / min.

[0053] Please see Figure 2 The figure shows the friction coefficient curve of the composite lubricating film prepared in an embodiment of the present invention under vacuum conditions of 300°C. Figure 2 As shown, in a vacuum environment (vacuum degree < 5 × 10⁻⁶), -3At a temperature of 300℃, the average coefficient of friction is less than 0.15, and the wear life exceeds 500,000 revolutions.

[0054] In summary, this invention utilizes a gradient heterostructure constructed through interface engineering and magnetron sputtering to prepare a titanium (Ti) transition layer on a metal substrate, significantly improving film-substrate adhesion and increasing the critical scratch load by over 30 N. By combining molybdenum disulfide (MoS2), a material with excellent vacuum lubrication properties, with silver (Ag), a soft metal with excellent high-temperature resistance, and employing magnetron sputtering with an alternating deposition method, an alternating Ag / MoS2 stacked structure is formed on the transition layer surface, achieving high-temperature resistance under vacuum. The vacuum high-temperature resistant composite lubricating film prepared by this invention achieves a hardness of 4~5 GPa (GB / T 25898) under vacuum conditions (<5×10⁻⁶). -3 At a temperature of 300℃, the average coefficient of friction is less than 0.15, and the wear life exceeds 500,000 revolutions. It is suitable for moving parts in the high-temperature vacuum environment of aerospace, and is especially suitable for long-life lubrication of key moving pairs in the high-temperature transmission mechanism of spacecraft.

[0055] 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 high-temperature resistant composite lubricating film for vacuum environments, characterized in that, include: Transition layer and lubrication layer, wherein, The transition layer is deposited on the substrate surface, and the lubricating layer is deposited on the surface of the transition layer; The lubrication layer includes a first lubrication layer and a second lubrication layer, which are stacked alternately in sequence. The first lubrication layer is close to the transition layer and the second lubrication layer is far away from the transition layer. An adjacent first lubricating layer and a second lubricating layer constitute a unit, and the lubricating layer comprises 10 to 15 such units.

2. The high-temperature resistant composite lubricating film under vacuum environment according to claim 1, characterized in that, The substrate is a metal substrate.

3. The high-temperature resistant composite lubricating film under vacuum environment according to claim 1, characterized in that, The transition layer is made of titanium (Ti) and has a thickness of 0.3~0.5 μm.

4. The high-temperature resistant composite lubricating film under vacuum environment according to claim 1, characterized in that, The raw material of the first lubricating layer is silver (Ag), and the raw material of the second lubricating layer is molybdenum disulfide (MoS2). In the unit, the thickness ratio of the first lubricating layer to the second lubricating layer is (2:1) to (1:2).

5. The high-temperature resistant composite lubricating film under vacuum environment according to claim 1, characterized in that, In a vacuum environment (<5×10) -3 At 300℃, the average friction coefficient is less than 0.15, and the wear life exceeds 500,000 revolutions.

6. The method for preparing a high-temperature resistant composite lubricating film under vacuum environment according to claims 1 to 4, characterized in that, Includes the following steps: Step 1: Substrate pretreatment; Step 2: Deposit a transition layer on the surface of the substrate using high-power magnetron sputtering technology; Step 3: Using magnetron sputtering technology, the first lubricating layer and the second lubricating layer are deposited alternately on the surface of the transition layer to form an alternating stacked structure, thereby obtaining a high-temperature resistant composite lubricating film under vacuum conditions.

7. The preparation method according to claim 6, characterized in that, In step 1, the substrate pretreatment includes: grinding and polishing the surface of the substrate, then cleaning and drying it in acetone solution and alcohol solution in sequence, and finally bombarding the surface of the substrate under vacuum conditions using the anode layer ion source to remove impurities.

8. The preparation method according to claim 6 or 7, characterized in that, The bombardment of the substrate surface using the anode layer ion source under vacuum conditions includes: placing the dried substrate into the vacuum furnace chamber and evacuating it to a vacuum level of 5 × 10⁻⁶. -3 Below Pa, the vacuum furnace cavity is heated to 70~90℃, the anode layer ion source is turned on to bombard the substrate surface, the anode layer ion beam source voltage is 1000~1200 V, argon gas is introduced into the vacuum furnace cavity to make the vacuum degree 0.3~1 Pa, the substrate bias voltage is -300~-500 V, and the bombardment time is 20~30 min.

9. The preparation method according to claim 6, characterized in that, In step 2, the conditions for high-power magnetron sputtering are as follows: target purity ≥ 99.9%, target voltage 600~650 V, working environment argon atmosphere (pressure 0.5~1 Pa), sputtering power 5~8 kW, substrate bias voltage -70~-100 V, and deposition time 10~12 min.

10. The preparation method according to claim 6, characterized in that, In step 3, the magnetron sputtering conditions for the first lubricating layer are as follows: the working environment is an argon atmosphere (pressure 0.5~1 Pa), the sputtering target voltage for the first lubricating layer is 500~600 V, the sputtering power is 3~6 kW, the substrate bias voltage is -70~-100 V, and the deposition time is 2~5 min; the magnetron sputtering conditions for the second lubricating layer are as follows: the working environment is an argon atmosphere (pressure 0.5~1 Pa), the sputtering target voltage for the second lubricating layer is 900~1100 V, the sputtering power is 2~4 kW, the substrate bias voltage is -50~-70 V, and the deposition time is 2~5 min.

11. The preparation method according to claim 6, characterized in that, The preparation is carried out in a vacuum furnace chamber, which is equipped with a workpiece stage. A high-power magnetron sputtering target, a first lubricating layer magnetron sputtering target, a second lubricating layer magnetron sputtering target, and an anode layer ion source are respectively arranged on the side of the vacuum furnace chamber.

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