阅读说明：本技术 一种基于光固化的织构内固体润滑剂的填充方法 (Filling method of photocuring-based solid lubricant in texture ) 是由 严志军 姜渊源 张盛为 申子玉 王剑豪 于 2020-11-27 设计创作，主要内容包括：本发明公开了一种基于光固化的织构内固体润滑剂的填充方法,包括以下步骤：S1、取二硫化钼和/或石墨作为固体润滑材料,其中二硫化钼的粒径为200～325目、莫氏硬度为1～1.5、摩擦系数为0.05～0.1,石墨的粒径为400～550目；S2、按照(1～1.5)：(1～1.5)：1的比例取光固化剂、稀释剂和固体润滑材料,将光固化剂和稀释剂混合搅拌3～5min后,加入固体润滑材料搅拌均匀,得到液态润滑材料；S3、将液态填充材料放入摩擦副表面的微织构中,用波长为320～400nm的紫外光照射固化,固化时间为30～90min。本发明实现固体润滑剂在摩擦副表面的缓释,实现微织构对摩擦副表面润滑的改善,更环保,固化速度快。(The invention discloses a filling method of a photocuring-based solid lubricant in a texture, which comprises the following steps: s1, taking molybdenum disulfide and/or graphite as a solid lubricating material, wherein the particle size of the molybdenum disulfide is 200-325 meshes, the Mohs hardness is 1-1.5, the friction coefficient is 0.05-0.1, and the particle size of the graphite is 400-550 meshes; s2, according to the formula (1-1.5): (1-1.5): 1, taking a light curing agent, a diluent and a solid lubricating material, mixing and stirring the light curing agent and the diluent for 3-5 min, adding the solid lubricating material, and uniformly stirring to obtain a liquid lubricating material; s3, putting the liquid filling material into the micro texture on the surface of the friction pair, and irradiating and curing the liquid filling material by using ultraviolet light with the wavelength of 320-400 nm for 30-90 min. The invention realizes the slow release of the solid lubricant on the surface of the friction pair, realizes the improvement of the micro-texture on the surface lubrication of the friction pair, and has the advantages of more environmental protection and high curing speed.)

1. A filling method of a texture internal solid lubricant based on photocuring is characterized by comprising the following steps: the method comprises the following steps:

s1, preparation of a solid lubricating material: taking molybdenum disulfide and/or graphite as a solid lubricating material, wherein the particle size of the molybdenum disulfide is 200-325 meshes, the Mohs hardness is 1-1.5, the friction coefficient is 0.05-0.1, and the particle size of the graphite is 400-550 meshes;

s2, preparation of the liquid filling material: according to the formula (1-1.5): (1-1.5): 1, mixing and stirring the light curing agent, the diluent and the solid lubricating material for 3-5 min, adding the solid lubricating material, and uniformly stirring to obtain a liquid lubricating material;

s3, solidifying the liquid filling material on the surface of the friction pair: and (3) putting the liquid filling material into the micro-texture on the surface of the friction pair, and irradiating and curing by using ultraviolet light with the wavelength of 320-400 nm.

2. The filling method of the light-curing-based textured internal solid lubricant as claimed in claim 1, wherein the filling method comprises the following steps: in step S1, when molybdenum disulfide and graphite are taken as solid lubricating materials, the mass ratio of molybdenum disulfide to graphite is 1: (1-1.5) mixing.

3. The filling method of the light-curing-based textured internal solid lubricant as claimed in claim 1, wherein the filling method comprises the following steps: in step S2, the light curing agent is formed by compounding a methacrylate monomer and an inorganic filler, wherein the methacrylate monomer is 50-66% by volume, and the inorganic filler is 34-50% by volume.

4. The filling method of the light-curing-based textured internal solid lubricant as claimed in claim 1, wherein the filling method comprises the following steps: in step S2, the diluent is one or more of ethyl acetate, chloroform, acetic acid, and acetone.

5. The filling method of the light-curing-based textured internal solid lubricant as claimed in claim 1, wherein the filling method comprises the following steps: in step S3, the processing method of the micro-texture is a mechanical etching processing method, a chemical etching processing method, or a laser etching processing method.

6. The filling method of the light-curing-based textured internal solid lubricant as claimed in claim 1, wherein the filling method comprises the following steps: in step S3, an ultraviolet lamp with a wavelength of 320 nm-400 nm is used for carrying out 180-degree irradiation curing, the power of the ultraviolet lamp is 20-36W, and the irradiation distance of the ultraviolet lamp is 15 cm-10 cm.

7. The filling method of the light-curing-based textured internal solid lubricant as claimed in claim 1, wherein the filling method comprises the following steps: in step S3, the curing time is 30-180 min.

Technical Field

The invention belongs to the technical field of friction reduction and drag reduction, and particularly relates to a filling method of a solid lubricant in a texture based on photocuring.

Background

The surface microtexture technology can play a great role in the field of friction reduction and drag reduction. The function of the surface microtexture in a fluid lubrication state is not only reflected in a dynamic pressure lubrication effect, but also is beneficial to storing a lubricating material and locking abrasive dust generated by the abrasion of the surface of the friction pair. The existing surface microtexture preparation technology comprises a mechanical etching processing method, a chemical etching processing method, a laser etching processing method and the like. In a grease lubrication state, the existence of the surface texture enables the grease to be easier to form a film on a contact surface so as to form 'secondary lubrication', and the lubrication state of a friction pair can be effectively improved; the surface microtexture is beneficial to forming a dynamic pressure effect of the liquid lubricating grease in the micro-pits and forming a lubricating oil film between contact surfaces, so that the surface bearing capacity of the friction pair is improved; the micro texture on the surface of the friction pair can effectively collect abrasive dust, reduce the probability of three-body friction and reduce the occurrence of possible serious friction. In the liquid lubrication state, the surface texture zone can effectively store the lubricating medium. During the sliding friction process, the lubricating medium provides a basic condition for generating a hydrodynamic effect, and can capture abrasive dust generated during the friction process and continuously supply oil to the contact surface.

In the research of the organic solvent type bonded solid lubricating coating, the commonly used solid lubricants include molybdenum disulfide, graphite, nylon and the like. The molybdenum disulfide is used for friction materials and has the main functions of friction reduction at low temperature, friction increase at high temperature, small loss on ignition and easy volatilization in the friction materials. And the curing means is limited due to poor thermal conductivity, insufficient low friction coefficient and insufficient permeability. The graphite can slide along the crystal layers in a friction state and is oriented along the friction direction. Graphite has good adhesion to surfaces of steel, chromium, rubber, etc., and thus, graphite is an excellent lubricant under ordinary conditions. However, when the adsorption film is desorbed, the frictional wear properties of graphite deteriorate. Nylon has good abrasion resistance, and particularly in an environment with a large amount of dust and mud, the abrasion resistance of the nylon is not comparable with that of other plastics. In the presence of silt, dust or other hard materials on the friction surface, nylon has better wear resistance than bearing steel, cast iron and even quenched or surface-plated carbon steel. However, nylon has high moisture absorption, high water absorption, and poor dimensional stability, and is generally used only under conditions where oil lubrication is at least poor and where a special cooling device is provided.

Common curing methods include photo-curing, thermal curing, and microwave curing. The light curing is a light processing technology which enables liquid resin to be polymerized into a solid state at a high speed by ultraviolet light irradiation with a certain wavelength, and the light curing technology is an energy-saving, clean and environment-friendly technology. At present, the study on the surface texture of the friction pair generally uses heat curing because the heat curing condition is better realized, but the heat curing effect is not ideal for different solid lubricating materials.

Disclosure of Invention

Aiming at the problems, the invention researches and designs a filling method of a photocuring-based solid lubricant in texture to overcome the defects of limited application field and curing mode of the traditional solid lubricating material. The technical means adopted by the invention are as follows:

a filling method of a photocuring-based textured internal solid lubricant comprises the following steps:

s1, preparation of a solid lubricating material: taking molybdenum disulfide and/or graphite as a solid lubricating material, wherein the particle size of the molybdenum disulfide is 200-325 meshes, the Mohs hardness is 1-1.5, the friction coefficient is 0.05-0.1, and the particle size of the graphite is 400-550 meshes;

s2, preparation of the liquid filling material: according to the formula (1-1.5): (1-1.5): 1, mixing and stirring the light curing agent, the diluent and the solid lubricating material for 3-5 min, adding the solid lubricating material, and uniformly stirring to obtain a liquid lubricating material;

s3, solidifying the liquid filling material on the surface of the friction pair: and (3) putting the liquid filling material into the micro-texture on the surface of the friction pair, and irradiating and curing by using ultraviolet light with the wavelength of 320-400 nm.

Preferably, in step S1, when molybdenum disulfide and graphite are used as the solid lubricant, the mass ratio of molybdenum disulfide to graphite is 1: (1-1.5) mixing.

Preferably, in step S2, the light curing agent is formed by compounding a methacrylate monomer and an inorganic filler, wherein the methacrylate monomer is 50-66% by volume, and the inorganic filler is 34-50% by volume.

Preferably, in step S2, the diluent is an organic solvent such as ethyl acetate, chloroform, acetic acid, acetone, or the like, in which polymethacrylate is dissolved.

Preferably, in step S3, the processing method of the microtexture is mechanical etching processing method, chemical etching processing method, laser etching processing method, or the like.

Preferably, in the steps S1-S3, molybdenum disulfide with the particle size of 325 meshes, the Mohs hardness of 1-1.5 and the friction coefficient of 0.05-0.1 and graphite with the particle size of 400-550 meshes are mixed according to a certain proportion to form the solid lubricating material. Filling a diluent and a solid lubricating material into a pit on the surface of a friction pair, firstly adding a small amount of a light curing agent at the bottom of the pit, then adding the diluent into a needle cylinder to fill the pit, and then clockwise stirring by using a small needle to dilute the light curing agent, so that the viscosity of the light curing agent is reduced, adding the solid lubricating material after 3-5 min, and uniformly stirring to complete the preparation of the liquid lubricating material.

After the liquid filling material is injected into the micro-pits on the surface of the friction pair, the friction pair is placed under an ultraviolet lamp with the power of 20-36W and the wavelength of 320-400 nm for 180-degree irradiation curing, the irradiation distance of the ultraviolet lamp is 10-15 cm, and the curing time is 30-180 min according to the shape and the depth of the texture.

Compared with the prior art, the filling method of the texture internal solid lubricant based on photocuring has the beneficial effects that:

1. after the solid lubricating powder is added into the curing agent, the hardness after curing is reduced compared with that without the solid lubricating powder, the reduction amplitude is about 55%, the reduction of the curing hardness is beneficial to better slow release of the solid lubricating powder, and the lubricating effect is enhanced.

2. After the solid lubricating material is solidified in the microtexture of the surface of the friction pair, the solid lubricating material is slowly released on the surface of the friction pair due to the existence of the solid lubricating material during friction, so that the effects of reducing friction and reducing drag are achieved.

3. The existence of the micro-texture on the surface of the friction pair changes the original surface property, the pressure is changed during friction, and the lubrication improvement of the micro-texture on the surface of the friction pair is realized.

4. The invention combines the light curing technology with the surface texture, and the solid lubricating material is cured in the micro texture, thereby changing the surface property of the friction pair. Compared with the traditional thermosetting method, the photo-curing technology has the advantages that: more environment-friendly and has no volatile solvent; the curing speed is high; the curing agent is suitable for curing objects which are not high in temperature resistance, and the temperature of photocuring can be controlled to be very low; the photocuring adhesive force is stronger; and photocuring is more suitable for curing the solid lubricant material of the present invention.

Drawings

FIG. 1 is a schematic illustration of the solidification within the microtexture of the surface of a copper sheet in an embodiment of the present invention.

FIG. 2 is a graph of hardness versus time for a photocurable resin mixed with graphite powder and molybdenum disulfide powder in accordance with an embodiment of the present invention.

Detailed Description

The filling method provided by the invention combines the photocuring technology with the micro-texture preparation technology, and the liquid filling material is cured in the micro-texture by ultraviolet rays to finish the storage of the lubricant on the surface of the friction pair. Diluting a light curing agent by using diluents such as ethyl acetate and the like, adding a solid lubricating material, and matching with the liquid filling material to finish curing in the microtexture on the surface of the friction pair so as to observe the change of hardness and shrinkage rate in the curing process.

The invention utilizes the light curing technology to fill the solid lubricating material in the microtexture. The principle is as follows: the liquid curing agent is polymerized at high speed to form solid by ultraviolet irradiation with certain wavelength, and the solid curing agent is essentially photo-initiated polymerization and crosslinking reaction. Meanwhile, the curing agent can shrink to cause certain deformation in the curing process.

The specific embodiment is as follows:

the solidification of the solid lubricating material mixed by the light-cured resin, the molybdenum disulfide and the graphite in the microtexture comprises the following steps:

s1, preparation of a solid lubricating material: according to the following steps of 1: the solid lubricating material is formed by mixing molybdenum disulfide and graphite according to the mass ratio of 1, wherein the particle size of the molybdenum disulfide is 200 meshes, the Mohs hardness is 1.5, the friction coefficient is 0.1, and the particle size of the graphite is 550 meshes.

In the specific operation, the resin, the molybdenum disulfide powder and the graphite powder can be respectively added into a needle tube with the capacity of 20ml, and the raw materials can be conveniently added into the pits on the surface of the copper sheet (namely the microtexture on the surface of the friction pair) by using a needle.

S2, preparation of the liquid filling material: according to the following steps of 1: 1: 1, mixing and stirring the light curing agent, the diluent and the solid lubricating material for 5min, adding the solid lubricating material, and uniformly stirring to obtain the liquid lubricating material.

During specific operation, a small amount of resin is added to the bottom of the pit, then ethyl acetate is added into the needle cylinder to fill the pit, and then the ethyl acetate is stirred by a small needle to dilute the resin, so that the viscosity of the resin is reduced, and convenience is brought to mixing of the solid lubricating material and the adhesive. Then adding the solid lubricating material and stirring uniformly.

S3, solidifying the liquid filling material on the surface of the friction pair: and (3) putting the liquid filling material into the micro-texture on the surface of the friction pair, and carrying out 180-degree all-directional irradiation curing under an ultraviolet lamp with the wavelength of 400nm, wherein the power of the ultraviolet lamp is 36W, and the irradiation distance of the ultraviolet lamp is 15 cm.

FIG. 1 is a photo-cured copper sheet after mixing resin and solid lubricating material diluted by a diluent, and micro-texture pits filled by curing are two pits in the first row on the left side in FIG. 1. The height of the material in the pits before curing is approximately equal to the plane height of the copper plate, and the surface height in the pits after curing is slightly reduced due to the volatility of the diluent ethyl acetate. For specific applications, the height of the solidified material may be slightly higher than the planar height of the copper plate, taking into account the influence of volatility.

The hardness of the resin and solid powder on the surface of the copper plate in the curing process is measured by the following method:

(1) firstly, diluting resin and ethyl acetate on the surfaces of three copper plates respectively, and then adding graphite powder or molybdenum disulfide powder or mixed powder of graphite and molybdenum disulfide on the three copper plates respectively.

(2) Three copper plates with well-mixed surfaces are placed in an ultraviolet lamp for irradiation, and the mixture is more uniform and sufficient in the micro texture when being irradiated by ultraviolet light when the mixture is cured on the surfaces. Removal was done every 30min to determine the effect of curing by measuring the hardness of the cure.

(3) A D-type digital Shore hardness tester is used for measuring hardness, the test sample is placed on a firm plane, the hardness tester is held, the pointer of the hole in the pressure foot is at least 12mm away from the edge of the test block, the pressure foot is stably pressed on the test sample without any vibration, the pressure foot is kept parallel to the surface of the test sample, so that the pressure pin is vertically pressed into the test sample, the force applied is just enough to enable the pressure foot to be in complete contact with the test sample, the reading is carried out within one second after the pressure foot and the test sample are completely pressed, the hardness value is measured at different positions with the distance of at least 6mm between the test points for 5 times, and the average value is obtained. The measurement results are shown in tables 1 to 3, and the results of table 1 are plotted in fig. 2.

TABLE 1 hardness of resin and molybdenum disulfide powder and graphite powder cured simultaneously versus time

TABLE 2 resin and graphite powder hardness on curing versus time

TABLE 3 hardness of resin and molybdenum disulfide powder cured versus time

The hardness of the resin after curing is 6 HD-6.5 HD when no solid lubricating powder is added, and the time for completing curing under the same ultraviolet irradiation is between 1h and 1.5 h. After the solid lubricating powder is added, the hardness after the solidification is reduced, and the influence of the hardness and the time is different when different solid lubricating powders are mixed and solidified. When the graphite powder is singly mixed with the graphite powder, the hardness measured in the 5 th time period and the hardness measured in the 6 th time period are inferred, the curing effect is achieved in about 150min, and the hardness after curing is about 3.6 HD. After the resin is mixed with the molybdenum disulfide powder alone, the hardness cannot be measured in a fluid state at the time of 30min, and the hardness is 2.2HD after 180min of irradiation. The hardness of the resin after the resin is simultaneously mixed with graphite powder and molybdenum disulfide powder and is cured after being irradiated for 180min is also about 3.6 HD. The comparison shows that the time for completing the curing after the resin is mixed with the graphite powder and the molybdenum disulfide powder is short, the curing strength of the resin is higher than that of the resin mixed with the molybdenum disulfide powder, and the curing strength of the resin mixed with the molybdenum disulfide powder is similar to that of the resin mixed with the graphite powder. Therefore, the influence of hardness and time is different when different solid lubricating powder is mixed and solidified, the mass ratio of graphite and molybdenum disulfide in the solid lubricating powder and the mass of the graphite and molybdenum disulfide solidified in the microtexture after the graphite and molybdenum disulfide are mixed can be adjusted according to specific requirements, and the effect of quantitatively and qualitatively changing the lubricating effect is achieved.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.