Method for solving lubrication failure caused by insufficient adhesive force of solid lubricating powder on surface of metal texture

Abstract

The invention discloses a method for solving lubrication failure caused by insufficient adhesive force of solid lubricating powder on the surface of a metal texture, which is characterized in that nano-scale MoS2 with a spherical or sphere-like structure and graphite are used for compatibility, and the obtained composite solid lubricating agent powder is very suitable for lubricating the surface of the metal texture through proportion control. And the friction coefficient can be stabilized at a relatively low level, and an abnormal lubrication failure phenomenon does not occur, so that the problem that the lubrication failure of solid lubricant powder is easy to occur on the texture surface can be solved when the nanoscale MoS2 and the graphite are matched and used according to a certain proportion. The prepared composite solid lubricant powder has excellent powder lubricating performance on the metal texture surface, can delay the lubrication failure time, and has good application prospects in the technical fields of solid lubricants and metal surface textures.

Description

Technical Field

[0001] The invention relates to the technical field of surface engineering and tribology, and in particular to a method for solving the problem of lubrication failure caused by insufficient adhesion of solid lubricating powder on a metal texture surface. Background Art

[0002] Two-dimensional layered compounds have weak van der Waals forces between layers, which makes it easy for the layers to slide, thus having a low friction coefficient. They can be used as lubricant additives, fillers for coatings and polymer materials, and can also be used directly as powder lubricants. Among them, molybdenum disulfide (MoS2) and graphite are the two most representative solid lubricant materials, so finding ways to improve their lubrication properties is of great significance in the field of solid lubricants.

[0003] When solid lubricant powder is used as lubricant, its surface coverage has a significant impact on the lubrication effect. On smooth metal surfaces, solid lubricant powder is difficult to adhere to the friction surface, so the possibility of entering the friction interface is low, and lubrication failure is prone to occur, especially for solid lubricant powders with spherical structures without active edges (Tribology International, 2016, 104: 131-139).

[0004] Metal surface texturing is one of the effective technologies to improve the lubrication state of the friction interface. The pits on the textured surface can be used as a storage place for wear debris, and can also provide storage space for lubricants, which can replenish lubricants to the friction surface in a timely manner, especially suitable for grease lubricated surfaces. For solid lubricant powder lubrication, there are still some problems in simply relying on the storage of lubricants in the pits on the textured surface to improve the lubrication performance. This is mainly because powder lubricants do not have the good fluidity and surface tension of lubricating grease, and it is difficult to replenish them to the friction interface in time. Summary of the invention

[0005] The purpose of the present invention is to propose a method for solving the problem of lubrication failure caused by insufficient adhesion of solid lubricating powder on metal texture surfaces. The obtained composite solid lubricant powder is very suitable for lubrication of metal texture surfaces, and can stabilize the friction coefficient at a low level without abnormal lubrication failure, thereby solving the problem of lubrication failure caused by insufficient adhesion of solid lubricating powder on metal texture surfaces.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for solving the problem of lubrication failure caused by insufficient adhesion of solid lubricating powder on metal texture surfaces, wherein a composite solid lubricant powder obtained by fully mixing spherical or quasi-spherical nano-MoS2 and graphite is directly placed on the metal texture surface to act as a lubricant.

[0008] As a preferred technical solution of the present invention, the nano-scale MoS2 with a spherical or quasi-spherical structure is a MoS2 particle with an average size of less than 100nm, such as 30 to 90nm. The graphite is a micron-sized two-dimensional graphite sheet with an average particle size of more than 1μm, such as 2 to 10μm. The mass ratio of the nano-scale MoS2 with a spherical or quasi-spherical structure to graphite is 1:0.1 to 10.

[0009] The spherical or quasi-spherical nano-scale MoS2 and graphite are mixed in a mixer at a rotation speed of 5 to 360 r / min for 5 to 360 minutes.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0011] 1. The present invention uses nano-scale MoS2 with spherical or quasi-spherical structures and graphite to match, and through proportion control, the obtained composite solid lubricant is very suitable for metal texture surface lubrication, and no lubricating grease is required.

[0012] 2. The present invention utilizes the film-forming ability of graphite on the friction surface and its bonding ability with nano-MoS2, so that nano-MoS2 with a nano-spherical structure can adhere to the friction surface along with the graphite, and then the nano-MoS2 lubricating film is protected by the graphite sheet, thereby extending the adhesion time of the solid lubricating powder on the friction surface, so that the solid lubricating powder stored in the texture pits can be replenished to the friction interface in time, thereby solving the problem of lubrication failure caused by insufficient adhesion of the solid lubricating powder on the metal texture surface.

[0013] 3. The composite solid lubricant powder prepared by the present invention not only has excellent powder lubrication performance on the metal texture surface, but also can delay the lubrication failure time, and has good application prospects in the field of solid lubricants and metal surface texture technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a SEM image of the nano-scale MoS2 / graphite composite solid lubricant powder with a spherical structure prepared by the present invention. It can be seen from the figure that the graphite and nano-scale MoS2 still maintain the original flake and spherical structure, and the two are obviously adhered together.

[0015] Figure 2The friction curves (a) and load-bearing capacity (b) of different solid lubricant powders on the textured surface of GCr15 steel friction pair. As can be seen from the figure, the friction coefficient of graphite fluctuates around 0.5, and the friction coefficient is basically equivalent to the metal dry friction coefficient, indicating that single graphite is not suitable as a solid powder lubricant for metal textured surfaces; the friction coefficient of spherical nano-MoS2 is around 0.1 at the beginning of friction, which is much better than graphite, but after 7 minutes, lubrication failure occurs and the friction coefficient rises sharply, indicating that nano-MoS2 is also not suitable as a solid powder lubricant; after MoS2 micron flakes and graphite are used in a 1:1 ratio, the friction coefficient is around 0.07, but after 15 minutes, the lubrication failure gradually becomes obvious; after spherical nano-MoS2 and graphite are used in a 1:1 ratio, the friction coefficient can be stabilized at around 0.07, no lubrication failure occurs, and the maximum load without lubrication failure is 45N, which is significantly higher than the 8N of pure nano-MoS2 powder lubrication. It shows that the use of spherical nano-MoS2 and graphite in a certain proportion can solve the problem of lubrication failure of solid lubricant powder on textured surfaces, and can also improve lubrication performance and load-bearing capacity. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with embodiments and drawings.

[0017] Example 1

[0018] Nano-MoS2 with a spherical structure and an average particle size of 90 nm and graphite micro-sheets with an average size of 5 μm were mixed in a mass ratio of 1:1, put into a mixer, and mechanically mixed at a speed of 60 r / min for 30 min to obtain a composite solid lubricant powder ( Figure 1 The obtained composite lubricant powder is evenly coated on the textured surface of the GCr15 steel friction pair, and then the friction pair is assembled. The friction test results are shown in Figure 2 It shows that the friction coefficient of the prepared composite lubricant powder fluctuates slightly around 0.07 during the friction process, indicating that the lubrication performance is not only excellent but also stable, and there is no lubrication failure phenomenon.

[0019] Example 2

[0020] Nano-MoS2 with a spherical structure and an average particle size of 80nm and graphite micron sheets with an average size of 5μm were mixed in a mass ratio of 1:2, put into a mixer, and mechanically mixed at a speed of 60r / min for 30min to obtain a composite solid lubricant powder. The obtained composite lubricant powder was evenly covered on the texture surface of the GCr15 steel friction pair, and then the friction pair was assembled. The friction test showed that the friction coefficient of the prepared composite lubricant powder fluctuated slightly around 0.1 during the friction process, indicating that the lubrication performance was not only excellent but also stable, and there was no lubrication failure.

[0021] Example 3

[0022] Nano-MoS2 with a spherical structure and an average particle size of 80nm and graphite micron sheets with an average size of 3μm were mixed in a mass ratio of 1:1, put into a mixer, and mechanically mixed for 30 minutes at a speed of 60r / min to obtain a composite solid lubricant powder. The obtained composite lubricant powder was evenly covered on the textured surface of the aluminum alloy friction pair, and then the friction pair was assembled. The friction test showed that the friction coefficient of the prepared composite lubricant powder fluctuated slightly around 0.1 during the friction process, indicating that the lubrication performance was not only excellent but also stable, and there was no lubrication failure.

[0023] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for solving the problem of lubrication failure caused by insufficient adhesion of solid lubricating powder on metal texture surface, characterized in that: The composite solid lubricant powder obtained by fully mixing spherical or quasi-spherical nano-MoS2 and graphite is directly placed on the metal texture surface to act as a lubricant.

2. The method according to claim 1, characterized in that The nano-scale MoS2 with a spherical or quasi-spherical structure is MoS2 particles with an average size of less than 100 nm.

3. The method according to claim 1, characterized in that The graphite is a micron-sized two-dimensional graphite sheet with an average particle size of more than 1 μm.

4. The method according to claim 1, characterized in that The mass ratio of the spherical or quasi-spherical nano-scale MoS2 to graphite is 1:0.1-10.

5. The method according to claim 1, characterized in that The spherical or quasi-spherical nano-scale MoS2 and graphite are mixed in a mixer at a rotation speed of 5 to 360 r / min for 5 to 360 minutes.

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