High-temperature anti-friction lubricating composite coating for space as well as preparation method and application of high-temperature anti-friction lubricating composite coating

Abstract

The invention relates to a high-temperature antifriction lubricating composite coating for space as well as a preparation method and application thereof, and belongs to the technical field of material surface modification and application. The coating is prepared from the following raw materials in percentage by mass: 65%-90% of aluminum bronze powder, 5%-15% of Ag powder and 5%-20.0% of MoS < 2 >-Ni powder, wherein the raw materials for preparing the coating are 100%; according to the coating, aluminum bronze powder, Ag powder and MoS2atNi powder which are evenly mixed are prepared on the surface of a metal matrix through the plasma spraying technology. The coating has excellent antifriction and lubricating effects in a space at 200-600 DEG C.

Description

TECHNICAL FIELD

[0001] The application relates to a high-temperature friction-reducing lubricating composite coating for space use and a preparation method and application thereof, and belongs to the technical field of material surface modification and application. BACKGROUND

[0002] When space moving mechanisms such as high-speed rotating planetary reducers in lunar robots and reciprocating pistons in Stirling generators move for a long time under extreme service conditions such as high vacuum, high temperature, high speed and heavy load, the surfaces of the moving mechanisms are seriously worn, the moving mechanisms are inoperable, and even major engineering tasks such as deep space exploration are failed. As a material with high-temperature stability and excellent friction-reducing lubricating performance, the high-temperature solid lubricating coating is one of the most effective ways to improve and enhance the service life and reliable operation of the space moving mechanisms.

[0003] The high-temperature solid lubricating coating is obtained by compounding a metal or ceramic binder with a high-temperature lubricant to improve the friction and wear performance of the base body. As a metal-based lubricating material with good heat conduction, electrical conductivity and corrosion resistance, the copper-based lubricating material has an atmospheric dry friction factor of about 0.1-0.2, is the first choice for sliding friction parts, and has excellent friction-reducing performance especially under high load. However, the problem of lubrication at room temperature to 600 DEG C high temperature cannot be effectively solved by relying on the aluminum bronze material only. Meanwhile, there is no lubricant that can realize continuous lubrication in a wide temperature range from room temperature to 600 DEG C. SUMMARY

[0004] Therefore, the application aims to provide a high-temperature friction-reducing lubricating composite coating for space use and a preparation method and application thereof. The aluminum bronze is used as the base body or binder, the solid lubricant is selected, the design idea of compounding the soft metal Ag and the lamellar vacuum high-temperature lubricant MoS2 is adopted, the component ratio of the metal binder and the lubricant is optimized, and the performance of the composite lubricating coating is excellent through the optimization of the thermal spraying process parameters, so that the friction and wear problems of the space moving mechanisms under the special working conditions of the high-temperature environment of 200 DEG C-600 DEG C are solved.

[0005] To achieve the above-mentioned purpose, the technical scheme of the application is as follows.

[0006] A high-temperature friction-reducing lubricating composite coating for space use, wherein the raw material composition of the coating is 100%, and the component and mass percentage are as follows: aluminum bronze powder 65%-90%, Ag powder 5%-15%, and MoS2@Ni powder 5%-20.0%; the MoS2@Ni powder is a Ni-coated MoS2 composite powder.

[0007] Preferably, the mass percentage of each component and its mass percentage is as follows, based on 100% of the raw material of the coating: the mass percentage of the aluminum bronze powder is 80% to 85%, the mass percentage of Ag powder is 10% to 15%, and the mass percentage of MoS2@Ni powder is 10% to 20.0%.

[0008] Preferably, the particle size of the aluminum bronze powder is 5 to 50 microns, the particle size of the Ag powder is 20 to 30 microns, and the particle size of the MoS2@Ni powder is 20 to 75 microns.

[0009] Preferably, the mass percentage of MoS2 in the MoS2@Ni powder is 20% to 40%, based on the total mass of the MoS2@Ni powder.

[0010] A preparation method of a high-temperature friction-reducing lubricating composite coating for space, the raw materials of the coating are mixed to obtain the coating.

[0011] The application of a high-temperature friction-reducing lubricating composite coating for space, the mixed and uniform raw materials are sprayed on the surface of a metal substrate by using plasma spraying technology.

[0012] In the plasma spraying technology, the main spraying process is as follows: the voltage is 40 to 60 V, the current is 550 to 620 A, the argon flow rate is 45 to 55 L / min, the hydrogen flow rate is 1.50 to 3.50 L / min, the powder feeding rate is 2.5 to 4.5 L / min, and the spraying distance is 70 to 100 mm, so as to obtain a high-temperature friction-reducing lubricating composite coating on the surface of the metal substrate.

[0013] Advantages

[0014] The application provides a high-temperature friction-reducing lubricating composite coating for space, which is composed of aluminum bronze, Ag and MoS2@Ni in a set content.

[0015] The application provides a high-temperature friction-reducing lubricating composite coating for space, which is composed of aluminum bronze, Ag and MoS2@Ni in a set content.

[0016] The application provides a preparation method of a high-temperature friction-reducing and lubricating composite coating for space, and the plasma spraying technology is adopted, compared with the conventional thermal spraying technology, the spraying distance is short, and problems such as oxidation and decomposition of the powder during long-time movement in the spraying process are avoided. DETAILED DESCRIPTION

[0017] The application will be further described in detail below in combination with specific embodiments.

[0018] The high-temperature friction-reducing and lubricating composite coating for space is prepared from the following raw materials: 65-90% of aluminum bronze powder, 5-15% of Ag powder and 5-20.0% of MoS2@Ni powder, and the total amount of the raw materials is 100%.

[0019] The particle size of the aluminum bronze powder is 5-50 microns, the particle size of the Ag powder is 20-30 microns, and the particle size of the MoS2@Ni powder is 20-75 microns.

[0020] The mass percentage of MoS2 in the MoS2@Ni powder is 20-40%.

[0021] The plasma spraying technology is adopted, and the main spraying process is as follows: the voltage is 40-60V, the current is 550-620A, the argon flow rate is 45-55L / min, the hydrogen flow rate is 1.50-3.50L / min, the powder feeding rate is 2.5-4.5L / min, and the spraying distance is 70-100mm, so that a high-temperature friction-reducing and lubricating composite coating is obtained on the surface of the metal substrate.

[0022] The application relates to a high-temperature friction-reducing and lubricating composite coating for space, a preparation method and application thereof, and belongs to the technical field of material surface modification and application.

[0023] The following examples are provided in combination with the technical scheme of the application.

[0024] Example 1

[0025] The particle size of the aluminum bronze powder is 5 μm-50 μm, the particle size of the Ag powder is 20 μm-30 μm, and the particle size of the Ni-coated 20% MoS2 powder is 20 μm-75 μm. The TC4 titanium alloy is used as the base body, and the sample size is Φ25.4 mm×8 mm.

[0026] The surface of the TC4 titanium alloy is subjected to sand blasting treatment before spraying, and the surface roughness Ra after sand blasting is 3.2 μm.

[0027] The particle size of the aluminum bronze powder is 5 μm-50 μm, the particle size of the Ag powder is 20 μm-30 μm, and the particle size of the Ni-coated 20% MoS2 powder is 20 μm-75 μm. The TC4 titanium alloy is used as the base body, and the sample size is Φ25.4 mm×8 mm.

[0028] The thickness of the coating is tested by using a digital caliper, and the coating thickness is 193 μm. The bonding force of the coating is tested according to GB / T 8642-2002 "Determination of Tensile Bonding Strength of Thermal Spraying", and the bonding force is 38.5 MPa. The friction coefficient of the coating is tested by using a vacuum-high temperature friction tester, the vacuum degree is ≤10 -3 Pa, the friction pair is an Al2O3 ceramic ball with a diameter of 8 mm, the loading load is 5 N, the rotation speed is 500 r / min, and the friction coefficient of the coating is 0.21.

[0029] Example 2

[0030] The particle size of the aluminum bronze powder is 5 μm-50 μm, the particle size of the Ag powder is 20 μm-30 μm, and the particle size of the Ni-coated 20% MoS2 powder is 20 μm-75 μm. The TC4 titanium alloy is used as the base body, and the sample size is Φ25.4 mm×8 mm.

[0031] The surface of the TC4 titanium alloy is subjected to sand blasting treatment before spraying, and the surface roughness Ra after sand blasting is 3.2 μm.

[0032] The particle size of the aluminum bronze powder is 5-50 μm, the particle size of the Ag powder is 20-30 μm, and the Ni-coated 20% MoS2 powder is mechanically mixed uniformly at a mass ratio of 70:15:15, and then is kept in a drying box at 60°C for 1 h, and then is placed in a powder feeder of a spraying device. The spraying process parameters are as follows: voltage is 52 V, current is 600 A, argon flow rate is 52 L / min, hydrogen flow rate is 2.2 L / min, powder feeding rate is 3.5 L / min, and spraying distance is 90 mm, so that a high-temperature friction-reducing lubricating composite coating is obtained on the surface of the 9Cr18.

[0033] The thickness of the coating is tested by using a digital caliper, and the coating thickness is 261 μm. The bonding force of the coating is tested according to GB / T 8642-2002 Determination of Tensile Bond Strength of Thermal Sprayed Coatings, and the bonding force is 48.3 MPa. The friction coefficient of the coating is tested by using a vacuum-high-temperature friction tester, the vacuum degree is ≤10 Pa, the friction pair is an Al2O3 ceramic ball with a diameter of 8 mm, the loading load is 5 N, the rotation speed is 500 r / min, and the friction coefficient of the coating is 0.17. -3

[0034] In summary, the application includes but is not limited to the above embodiments, and any equivalent replacement or partial improvement made under the spirit and principles of the application shall be considered within the protection scope of the application.

[0035] In summary, the above is only a preferred embodiment of the application, and is not used to limit the protection scope of the application. Any modification, equivalent replacement, improvement, etc. made under the spirit and principles of the application shall be included in the protection scope of the application.​

Claims

1.A high-temperature friction-reducing lubricating composite coating for space, characterized in that: each component and its mass percentage, based on 100% of the raw material composition of the coating, are as follows: aluminum bronze powder 65%-90%, Ag powder 5%-15%, and MoS2@Ni powder 5%-20.0%; the MoS2@Ni powder is a Ni-coated MoS2 composite powder. 2.The high-temperature friction-reducing lubricating composite coating for space according to claim 1, characterized in that: each component and its mass percentage, based on 100% of the raw material composition of the coating, are as follows: aluminum bronze powder 80%-85%, Ag powder 10%-15%, and MoS2@Ni powder 10%-20.0%. 3.The high-temperature friction-reducing lubricating composite coating for space according to claim 1 or 2, characterized in that: the particle size of the aluminum bronze powder is 5 μm-50 μm, the particle size of the Ag powder is 20 μm-30 μm, and the particle size of the MoS2@Ni powder is 20 μm-75 μm. 4.The high-temperature friction-reducing lubricating composite coating for space according to claim 1, characterized in that: based on 100% of the total mass of the MoS2@Ni powder, the mass percentage of MoS2 in the MoS2@Ni powder is 20%-40%. 5.A method for preparing a high-temperature friction-reducing lubricating composite coating for space, characterized in that: the raw materials of the coating are mixed to obtain the coating. 6.An application of a high-temperature friction-reducing lubricating composite coating for space, characterized in that: the mixed raw materials are sprayed on the surface of a metal substrate using plasma spraying technology. 7.An application of a high-temperature friction-reducing lubricating composite coating for space, characterized in that: in the plasma spraying technology, the main spraying process is as follows: voltage 40 V-60 V, current 550 A-620 A, argon flow rate 45 L / min-55 L / min, hydrogen flow rate 1.50 L / min-3.50 L / min, powder feeding rate 2.5 L / min-4.5 L / min, and spraying distance 70 mm-100 mm, so as to obtain a high-temperature friction-reducing lubricating composite coating on the surface of the metal substrate. 8.The application of a high-temperature friction-reducing lubricating composite coating for space according to claim 7, characterized in that: the surface of the metal substrate is sandblasted before spraying. ​ ​ ​ ​ ​ ​ ​ ​