CN108644233A - A kind of full working scope high abrasion sliding bearing and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of full working scope high abrasion sliding bearing and preparation method thereof, the sliding surface of bearing main body is constituted with PTFE based composites and two phase stainless steel, and PTFE based composites include according to weight percent：The micron order hard ceramic particle of 3 20wt%, the short carbon fiber of 3 20wt%, surplus is polytetrafluoroethylene (PTFE)；Preparation method is to weigh micron order hard ceramic particle, short carbon fiber and PTFE powder to carry out mechanical agitation；Mixture after stirring is uniformly spread in mold, is carried out cold moudling at room temperature and is obtained prefabricated component；Prefabricated component is put into Muffle furnace and is sintered；Gained PTFE based composites are processed and coordinate the sliding surface for constituting bearing main body with two phase stainless steel, finally obtained full working scope high abrasion sliding bearing has high vibration and noise reducing performance, extremely strong wearability, extremely strong corrosion resistance, lower friction coefficient and intensity is good.

Description

A high wear-resistant sliding bearing under all working conditions and its preparation method

technical field

The invention relates to the technical field of bearing materials, in particular to a high wear-resistant sliding bearing under all working conditions and a preparation method thereof.

Background technique

As a bearing material matrix, polytetrafluoroethylene has excellent chemical corrosion resistance and a relatively low friction coefficient, but its wear resistance is relatively poor, and its mechanical properties and creep resistance are poor, especially its wear resistance. Low surface energy and poor adhesion make simple PTFE materials unfavorable for making wear-resistant bearings. These defects limit the wide application of this material to a certain extent. Therefore, in-depth research on the properties of PTFE and development New PTFE-based composite materials have become the main research and development direction of bearing materials.

In order to make full use of the good performance of polytetrafluoroethylene and exert its corrosion resistance, it is chosen to fill with hard ceramic particles or short carbon fibers, so that polytetrafluoroethylene has the unique properties of fillers and compensates for the corrosion resistance of polytetrafluoroethylene. Poor mechanical properties, wear resistance, creep resistance and wear resistance.

Hard ceramic particles include silicon carbide, silicon nitride, silicon dioxide, alumina, boron nitride, etc. Hard ceramic particles have good wear resistance, lubricity and other mechanical properties. The high-hardness material made of silicon carbide has the advantages of thermal shock resistance, small size, light weight and high strength. Silicon carbide has stable chemical properties, good wear resistance, high hardness, and excellent thermal conductivity. It is a semiconductor. It can resist oxidation at high temperature. Silicon nitride is a superhard material, which has lubricity and wear resistance, and is an atomic crystal; it is resistant to oxidation at high temperatures. Moreover, it can also resist cold and heat shocks. It is heated to above 1000°C in the air, and it will not be broken after rapid cooling and then rapid heating. It has high mechanical strength. The chemical properties of silicon dioxide are relatively stable. It is insoluble in water and does not react with water. It does not react with common acids. The nature of silicon oxide is not active. It does not react with halogens other than fluorine and hydrogen fluoride, hydrogen halides, sulfuric acid, nitric acid, Perchloric acid effect. Adding silica to the rubber can improve the wear resistance of the rubber, reduce the rolling resistance of the tire and improve the wear resistance and wet skid resistance of the tire at the same time, the tensile strength and tear strength of the rubber compound using silica , wear resistance, etc. have been improved. Alumina ceramics is a ceramic material with Al2O3 as the main raw material and corundum as the main crystal phase. Because of its high mechanical strength, high hardness, small high-frequency dielectric loss, high-temperature insulation resistance, chemical corrosion resistance and thermal conductivity Excellent comprehensive technical performance and other advantages. Boron nitride has good thermal stability and wear resistance, as well as strong chemical stability, so it is also one of the main raw materials for ceramic materials. The PTFE-based composite material bearing filled with ceramic particles alone adds the wear resistance of ceramic particles and improves the hardness of the bearing at the same time, so that the bearing has the lubricity of hard ceramic particles and improves the mechanical strength, but the single filling is hard The ceramic particles improve the hardness and brittleness of the obtained bearing, making the obtained bearing inconvenient to work in an environment with impact.

Short carbon fiber is a new type of high-strength and high-modulus fiber material with a carbon content of more than 95%. It can also be used as a filler for PTFE composite materials. Its specific gravity is small and it behaves along the fiber axis. Carbon fiber also has good low temperature resistance, such as not being brittle at the temperature of liquid nitrogen, and it shows its superiority as a bearing material for harsh working conditions. In addition, the short carbon fiber is lighter than metal aluminum, but its strength is higher than that of steel, and it has the characteristics of corrosion resistance, high modulus, low density, high specific performance, no creep, ultra-high temperature resistance in non-oxidizing environment, and fatigue resistance. Good, the specific heat and conductivity are between non-metal and metal, the thermal expansion coefficient is small and anisotropic, the corrosion resistance is good, and the X-ray transparency is good. When filled with short carbon fibers alone, the obtained PTFE-based composite bearing has the low temperature resistance of short carbon fibers, and the short carbon fibers will not be brittle even in liquid nitrogen environment, which makes up for the lack of hard ceramic particles. The bearing reflects its superiority, but lacks the superior properties such as wear resistance and lubricity of hard ceramic particles.

Contents of the invention

In order to solve the problems of bearing wear resistance, vibration reduction and noise reduction and strength, etc., the present invention overcomes the characteristics of poor wear resistance, low hardness, poor creep resistance and thermal conductivity of bearings made of single filling PTFE, and uses a specific The proportioned micron-sized hard ceramic particles and short carbon fibers are filled in the highly corrosion-resistant PTFE material, and according to the molding characteristics of the PTFE material, it is combined with the filled micron-sized hard ceramic particles and Combination of short carbon fibers, post-processing into high wear-resistant sliding bearings; this new type of sliding bearings made of hard ceramic particles and short carbon fibers filled with a specific ratio of PTFE matrix, at the same time has the high hardness and wear resistance of hard ceramic particles As well as the characteristics of lubricity and short carbon fiber's small specific gravity and low temperature resistance, the comprehensive performance of the sliding bearing is improved, the friction coefficient and wear rate are effectively reduced, the bearing strength is improved, and the service life of the bearing is extended.

In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

A high wear-resistant sliding bearing under all working conditions, including a bearing main body, the sliding surface of the bearing main body is composed of PTFE-based composite material and duplex stainless steel, and the PTFE-based composite material is made of the following raw materials according to weight percentage: 3 -20wt% of micron-sized hard ceramic particles, 3-20wt% of short carbon fibers, and the balance is polytetrafluoroethylene; the particle size range of the micron-sized hard ceramic particles is 0.1-5 microns, and the short carbon fibers are over 400 Mesh sieve; the polytetrafluoroethylene adopts PTFE powder with an average particle diameter of 10-30 microns.

Preferably, the micron-sized hard ceramic particles are micron-sized silicon carbide particles, micron-sized silicon nitride particles, micron-sized silicon dioxide particles, micron-sized boron nitride particles or micron-sized alumina particles.

Preferably, the weight percentage of the micron-sized hard ceramic particles is 5 wt%, and the weight percentage of the short carbon fibers is 15 wt%.

A method for preparing the high wear-resistant sliding bearing under all working conditions, the method is carried out according to the following steps:

(1) take described micron order hard ceramic particle, described short carbon fiber and described PTFE powder by weight percentage, carry out mechanical stirring after mixing;

(2) Evenly spread the mixture stirred in step (1) into a mold, and perform cold pressing at room temperature to obtain a prefabricated part;

(3) putting the preform into a muffle furnace for sintering to obtain the PTFE-based composite material;

(4) When the sliding bearing is a radial bearing, process the obtained PTFE-based composite material into the required bearing bush, and cooperate with duplex stainless steel to form the sliding surface of the bearing main body;

When the sliding bearing is a thrust bearing, the obtained PTFE-based composite material is processed into the required thrust plate, and is matched with duplex stainless steel to form the sliding surface of the bearing main body.

Preferably, the micron-sized hard ceramic particles in step (1) are micron-sized silicon carbide particles, micron-sized silicon nitride particles, micron-sized silicon dioxide particles, micron-sized boron nitride particles or micron-sized alumina particles .

Preferably, the weight percentage of the micron-sized hard ceramic particles in step (1) is 5 wt%, and the weight percentage of the short carbon fibers is 15 wt%.

Preferably, the pressure of cold pressing in step (2) is 25±5Mpa, the holding time is 40±10min, and the holding temperature is room temperature.

Preferably, the sintering procedure described in step (3) is: heating up from 30°C to 327°C at a heating rate of 100°C/h; holding at 327°C for 30 minutes; heating up from 327°C to 380°C at a heating rate of 60°C/h h; hold at 380°C for 1 hour; cool down from 380°C to 327°C at a heating rate of 60°C/h; hold at 327°C for 30 minutes; cool down from 327°C to 150°C at a cooling rate of 100°C/h; after reaching 150°C Air cool to room temperature.

The beneficial effects of the present invention are:

The all-working-condition high-wear-resistant sliding bearing prepared by the present invention makes full use of the good hardness properties of hard ceramic particles, and uses the hard ceramic particles to support the abrasive debris on the grinding surface to play a role in the formed dense transfer film. At the same time, under the wrapping of polytetrafluoroethylene, the strip-shaped short carbon fiber closely links the microstructure of the entire composite material, making the matrix more stable, which is conducive to retaining hard ceramic particles or restricting the movement of hard ceramic particles . Short carbon fibers have the inherent intrinsic characteristics of carbon materials and have a good lubricating effect, but their impact resistance is poor, so they wear a lot during the friction process, and the hard ceramic particles just increase the strength of the entire polymer. Reduces the wear rate of short carbon fibers that play an important role in bonding in PTFE. The synergistic effect of short carbon fibers and hard ceramic particles is greatly affected by the proportioning factor. When the weight ratio of hard ceramic particles is too large, the hardness and brittleness of the polymer is obviously improved, and the strength of the overall structure is obviously decreased; when the short carbon fiber accounts for When the specific gravity is too large, the overall wear resistance will be seriously reduced. And experiment finds: the proportioning given by the present invention, i.e. 3-20wt% micron-sized hard ceramic particle and 3-20wt% short carbon fiber proportioning filling polytetrafluoroethylene obtained PTFE-based composite material synergistic effect is more Significantly better performance. In addition, the particle size of micron-sized hard ceramic particles also has an important influence on the preparation process of the entire PTFE-based composite material. When the particle size of the hard ceramic particles is too large, its existence will lead to a significant deterioration of the bonding effect between the raw materials; on the contrary, if the particle size of the hard ceramic particles is too small, the effect of its existence is very small, and it cannot play its own role. performance. Experiments have found that when the particle size range of micron-sized hard ceramic particles is 0.1-5 microns, its effect can be maximized. At the same time, the performance of the PTFE-based composite material obtained by mixing the hard ceramic particles in this particle size range with short carbon fibers with a 400-mesh sieve and PTFE powder with an average particle size of 10-30 microns is better. Under such synergy, the all-working-condition high-wear-resistant sliding bearing of the present invention maximizes the advantages of hard ceramic particles and short carbon fibers.

Due to the synergistic effect of hard ceramic particles and short carbon fibers, the prepared all-working-condition high-wear-resistant sliding bearing has extremely high vibration and noise reduction performance and strong wear resistance, thereby effectively prolonging its service life. The PTFE-based composite material is filled with micron-sized hard ceramic particles with a particle size range of 0.1-5 microns and short carbon fibers passing through a 400-mesh sieve. The supporting and bonding effect of short carbon fibers in PTFE is the hard ceramic The particles provide a solid structural foundation in the process of lubricating, effectively reducing the friction coefficient and ensuring the integrity of the overall structure of the polymer. The PTFE-based composite The proportion of material filler is 5wt% by weight of silicon carbide, 15wt% by weight of short carbon fiber, and the balance is polytetrafluoroethylene, which can effectively reduce the friction coefficient and reduce the force between parts. Good lubricating effect and less wear, the reduction of friction coefficient effectively weakens the transmission of sound waves and the generation of wear debris, ensuring that the high wear-resistant sliding bearings prepared under all working conditions have extremely high vibration and noise reduction performance and extreme wear resistance;

Under the mutual promotion of the filler and the polytetrafluoroethylene, the prepared all-working-condition high-wear-resistant sliding bearing has extremely strong corrosion resistance and good strength. The combination of hard ceramic particles with a specific ratio and size and short carbon fibers can be compared to the internal structure of reinforced concrete. Short carbon fibers are like steel bars, while ceramic particles can be compared to large stones, and polytetrafluoroethylene just plays the role of lime. , it can be seen that in the PTFE-based composite materials of high wear-resistant sliding bearings under all working conditions, polytetrafluoroethylene tightly wraps the hard ceramic particles with the bonding effect of short carbon fibers, so that all raw materials are closely connected and become a dense structure. Indivisible overall structure. It is precisely such a compact structure that makes the high wear-resistant sliding bearings under all working conditions have good strength, and it is also because of such a compact structure that PTFE wraps all the fillers tightly and is not easy to detach, which improves its corrosion resistance. , each component coordinates with each other to improve the overall performance.

Description of drawings

Fig. 1 is a schematic structural view of the full working condition high wear-resistant sliding bearing prepared in Example 1;

In Figure 1: 1-thrust plate processed by PTFE-based composite material, 2-revolving plate made of duplex stainless steel;

Fig. 2 is the friction coefficient curve diagram under the seawater condition of the high wear-resisting sliding bearing (5%SiC+15wt%CF) of all working conditions that embodiment 1 makes;

Fig. 3 is the image obtained under the scanning electron microscope after the full working condition high wear-resistant sliding bearing (5wt%BN+15wt%CF) obtained in Example 16 is worn under seawater conditions;

Fig. 4 is a schematic structural view of a full working condition high wear-resistant sliding bearing prepared in Example 26;

In Fig. 4: 3-PTFE-based composite material processing bearing bush, 4-rotary shaft made of duplex stainless steel;

Detailed ways

The present invention will be described in further detail below by specific embodiment:

The following examples can enable those skilled in the art to understand the present invention more comprehensively, but do not limit the present invention in any way.

Example 1:

To prepare a high wear-resistant sliding bearing under all working conditions, the steps are as follows:

Step 1. Weigh micron-sized hard ceramic particle silicon carbide, short carbon fiber and PTFE material, wherein the proportion of filler is 5wt% by weight of silicon carbide, 15wt% by weight of short carbon fiber, and the balance is polytetrafluoroethylene vinyl. The particle size range of micron-sized hard ceramic particles silicon carbide is 0.1-0.4 microns, the short carbon fiber is passed through a 400-mesh sieve, and the polytetrafluoroethylene is PTFE powder with an average particle size of 10-30 microns. When stirring and mixing, weigh 7.5 g of silicon carbide, 22.5 g of short carbon fiber, and 120 g of PTFE.

Step 2: Mix the micron-sized hard ceramic particles, short carbon fibers and PTFE powder weighed in Step 1, and perform mechanical stirring.

Step 3. Evenly spread the mixture stirred in Step 2 into a mold, and perform cold pressing at room temperature to obtain a disc-shaped preform. Wherein, the pressure of cold pressing is 25±5Mpa, the holding time is 40±10min, and the holding temperature is room temperature.

Step 4: Put the preform into a muffle furnace for sintering to obtain a PTFE-based composite material. Sintering procedure: from 30°C to 327°C, the heating rate is 100°C/h; at 327°C for 30 minutes; from 327°C to 380°C, the heating rate is 60°C/h; at 380°C for 1 hour; from 380°C Cool down to 327°C with a heating rate of 60°C/h; hold at 327°C for 30 minutes; cool down from 327°C to 150°C with a cooling rate of 100°C/h; air cool to room temperature after reaching 150°C.

Step 5, the thrust plate 1 processed by the obtained PTFE-based composite material is combined with the rotary plate 2 made of duplex stainless steel to form the sliding surface of the bearing main body, thereby obtaining a new type of thrust bearing.

Example 2: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 1, the only difference is: the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles silicon carbide The percentage by weight of the short carbon fiber is 10 wt%, and the balance is polytetrafluoroethylene. When stirring and mixing, weigh 15 g of silicon carbide, 15 g of short carbon fiber, and 120 g of PTFE.

Example 3: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 1, the only difference is: the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles silicon carbide is 15wt%, the short carbon fiber is 5wt%, and the balance is polytetrafluoroethylene. When stirring and mixing, weigh 22.5 g of silicon carbide, 7.5 g of short carbon fiber, and 120 g of PTFE.

Example 4: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 1, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles silicon carbide The weight percentage of the short carbon fiber is 3 wt%, and the balance is polytetrafluoroethylene. When stirring and mixing, weigh 4.5 g of silicon carbide, 4.5 g of short carbon fiber, and 141 g of PTFE.

Example 5: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 1, the only difference is: the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles silicon carbide The percentage by weight of the short carbon fiber is 20 wt%, and the balance is polytetrafluoroethylene. When stirring and mixing, weigh 30 g of silicon carbide, 30 g of short carbon fiber, and 90 g of PTFE.

Example 6: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 1, the only difference is that the composition of the raw materials in step 1 is different, that is, the micron-sized hard ceramic particles are changed from silicon carbide to nitrogen Silicon nitride, micron-sized hard ceramic particles, the particle size range of silicon nitride is 0.1-0.4 microns, and the weight ratio of the components remains unchanged. The short carbon fiber passes through a 400-mesh sieve, and the polytetrafluoroethylene adopts PTFE powder with an average particle size of 10-30 microns. Stir and mix and weigh 7.5 g of silicon nitride, 22.5 g of short carbon fiber, and 120 g of PTFE.

Example 7: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 6, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silicon nitride The percentage is 10 wt%, the weight percentage of the short carbon fiber is 10 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 15g of silicon nitride, 15g of short carbon fiber, and 120g of PTFE.

Example 8: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 6, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silicon nitride The percentage is 15 wt%, the weight percentage of short carbon fibers is 5 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 22.5 g of silicon nitride, 7.5 g of short carbon fiber, and 120 g of PTFE.

Example 9: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 6, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silicon nitride The percentage is 3 wt%, the weight percentage of the short carbon fiber is 3 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 4.5 g of silicon nitride, 4.5 g of short carbon fiber, and 141 g of PTFE.

Example 10: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 6, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silicon nitride The percentage is 20 wt%, the weight percentage of the short carbon fiber is 20 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 30 g of silicon nitride, 30 g of short carbon fiber, and 90 g of PTFE.

Example 11: Preparation of a high wear-resistant sliding bearing under all working conditions. The preparation steps are basically the same as in Example 1, the only difference is that the composition of the raw materials in step 1 is different, that is, the micron-sized hard ceramic particles are changed from silicon carbide to two Silicon oxide, micron-sized hard ceramic particles The particle size range of silicon dioxide is 0.4-2 microns, and the weight ratio of the components remains unchanged. The short carbon fiber passes through a 400-mesh sieve, and the polytetrafluoroethylene adopts PTFE powder with an average particle size of 10-30 microns. Stir and mix and weigh 7.5 g of silica, 22.5 g of short carbon fiber, and 120 g of PTFE.

Example 12: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 11, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silica The percentage is 10 wt%, the weight percentage of the short carbon fiber is 10 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 15 g of silica, 15 g of short carbon fiber, and 120 g of PTFE.

Example 13: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 11, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silica The percentage is 15 wt%, the weight percentage of short carbon fibers is 5 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 22.5 g of silica, 7.5 g of short carbon fiber, and 120 g of PTFE.

Example 14: Preparation of a high wear-resistant sliding bearing under all working conditions. The preparation steps are basically the same as in Example 11, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silica The percentage is 3 wt%, the weight percentage of the short carbon fiber is 3 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 4.5 g of silica, 4.5 g of short carbon fiber, and 141 g of PTFE.

Example 15: Preparation of a high wear-resistant sliding bearing under all working conditions. The preparation steps are basically the same as in Example 11, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles silica The percentage is 20 wt%, the weight percentage of the short carbon fiber is 20 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 30g of silica, 30g of short carbon fiber and 90g of PTFE.

Example 16: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 1, the only difference is that the composition of the raw materials in step 1 is different, that is, the micron-sized hard ceramic particles are replaced by nitrogen Boron nitride, micron-sized hard ceramic particles The particle size range of boron nitride is 2-5 microns, and the weight ratio of the components remains unchanged. The short carbon fiber passes through a 400-mesh sieve, and the polytetrafluoroethylene adopts PTFE powder with an average particle size of 10-30 microns. Stir and mix and weigh 7.5 g of boron nitride, 22.5 g of short carbon fiber, and 120 g of PTFE.

Example 17: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 16, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles boron nitride The percentage is 10 wt%, the weight percentage of the short carbon fiber is 10 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 15g of boron nitride, 15g of short carbon fiber, and 120g of PTFE.

Example 18: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 16, the only difference is that the proportion of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles boron nitride The percentage is 15 wt%, the weight percentage of short carbon fibers is 5 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 22.5g of boron nitride, 7.5g of short carbon fiber and 120g of PTFE.

Example 19: Preparation of a high wear-resistant sliding bearing under all working conditions, the preparation steps are basically the same as in Example 16, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles boron nitride The percentage is 3 wt%, the weight percentage of the short carbon fiber is 3 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 4.5 g of boron nitride, 4.5 g of short carbon fiber, and 141 g of PTFE.

Example 20: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 16, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight of micron-sized hard ceramic particles boron nitride The percentage is 20 wt%, the weight percentage of the short carbon fiber is 20 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 30g of boron nitride, 30g of short carbon fiber and 90g of PTFE.

Example 21: Preparation of a high wear-resistant sliding bearing under all working conditions. The preparation steps are basically the same as in Example 1, the only difference is that the composition of the raw materials in step 1 is different, that is, the micron-sized hard ceramic particles are replaced by silicon carbide Aluminum, micron-sized hard ceramic particles, the particle size range of alumina is 2-5 microns, and the weight ratio of the components remains unchanged. The short carbon fiber passes through a 400-mesh sieve, and the polytetrafluoroethylene adopts PTFE powder with an average particle size of 10-30 microns. Stir and mix and weigh 7.5 g of alumina, 22.5 g of short carbon fiber, and 120 g of PTFE.

Example 22: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 21, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles alumina The percentage by weight of the short carbon fiber is 10 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 15 g of alumina, 15 g of short carbon fiber, and 120 g of PTFE.

Example 23: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 21, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles alumina is 15wt%, the short carbon fiber is 5wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 22.5 g of alumina, 7.5 g of short carbon fiber, and 120 g of PTFE.

Example 24: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 21, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles alumina The weight percentage of the short carbon fiber is 3 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 4.5 g of alumina, 4.5 g of short carbon fiber, and 141 g of PTFE.

Example 25: Preparation of a full working condition high wear-resistant sliding bearing, the preparation steps are basically the same as in Example 21, the only difference is that the composition ratio of raw materials in step 1 is different, that is, the weight percentage of micron-sized hard ceramic particles alumina The percentage by weight of the short carbon fiber is 20 wt%, and the balance is polytetrafluoroethylene. Stir and mix and weigh 30 g of alumina, 30 g of short carbon fiber, and 90 g of PTFE.

Example 26: Preparation of a high wear-resistant sliding bearing under all working conditions. The preparation steps are basically the same as in Example 1, except that: Step 5 is to process the obtained PTFE-based composite material into the bearing bush 3, and combine it with duplex stainless steel. The formed rotary shaft 4 cooperates to form the sliding surface of the bearing main body, thereby obtaining a new type of radial bearing.

In the experimental process of the present invention, friction experiments were carried out on the obtained high wear-resistant sliding bearings under all working conditions under dry conditions, water lubrication and seawater lubrication respectively. The experimental specific pressure was 2MPa, the speed was 0.25m/s, and the experimental time was 1h . The statistical results of friction data are shown in Table 1:

Table 1

The experimental data of high wear-resistant sliding bearings under all working conditions obtained by the ratio of hard ceramic particles boron nitride to short carbon fibers were analyzed. The details are shown in Table 2:

Table 2

The comparison results of the high wear-resistant sliding bearing obtained under all working conditions and the sliding bearing obtained by filling with single hard ceramic particles are shown in Table 3:

table 3

The experimental data illustrate the wear rate of the high wear-resistant sliding bearing under different PTFE-based composite material ratios and different environmental conditions obtained by the present invention. It can be seen that the full wear rate obtained when the hard ceramic particles are mixed with short carbon fibers The high wear-resistant sliding bearing under working conditions has a smaller wear rate than that filled with single hard ceramic particles, and the synergistic effect is more obvious. And in many proportions, the filling proportion of PTFE-based composite material is that the weight percent of micron-sized hard ceramic particles is 5wt%, and the weight percent of short carbon fiber is 15wt%, and when the balance is polytetrafluoroethylene, the test can be Obtain a high wear-resistant sliding bearing under all working conditions with a very small wear rate. This bearing has extremely strong wear resistance and oxidation resistance. Compared with the PTFE matrix filled with a single hard ceramic particle (short carbon fiber), it will have a better effect .

Fig. 2 is the friction coefficient curve of the high wear-resistant sliding bearing in all working conditions under seawater conditions. The high wear-resistant sliding bearing in all working conditions is derived from the composite material filler in Example 1. The weight percentage of silicon carbide is 5wt%. , the weight percentage of short carbon fiber is 15wt%, and the balance is polytetrafluoroethylene. It can be seen that during the friction experiment process of the full-working-condition high-wear-resistant sliding bearing obtained by the present invention, the hard ceramic particles play a role in the support of the abrasive debris on the grinding surface, and play a lubricating effect in the formed dense transfer film. The supporting bonding of short carbon fibers in PTFE provides a solid structural foundation for the lubrication of the hard ceramic particles. Because of its low and stable friction coefficient in the whole experiment process, the smoothness of the grinding surface is guaranteed, the frictional resistance between parts is reduced, and the generation of mechanical vibration is effectively weakened. Grinding sliding bearings, compared with metal materials, effectively weakens the transmission of noise, and has good performance in shock absorption and noise reduction.

Fig. 3 is the image obtained under the scanning electron microscope of the thrust plate processed by the PTFE-based composite material of the high wear-resistant sliding bearing under seawater conditions obtained in Example 16, and the figure is micron-scale Hard ceramic particles and short carbon fibers are embedded in the PTFE matrix. On the one hand, the mixed raw materials are fully bonded together, reducing the wear rate during the friction process. On the other hand, the PTFE matrix is effectively used in the composite material. Using the special properties of PTFE, the surface of the PTFE-based composite material of the high wear-resistant sliding bearing under all working conditions can effectively reduce the possibility of chemical reaction and corrosion.

The addition of hard ceramic particles and short carbon fiber fillers in high wear-resistant sliding bearings under all working conditions hinders the extraction of PTFE material macromolecules from the matrix in a ribbon structure, weakens the tendency of adhesive wear, and improves the wear resistance of the composite material. At the same time, due to the action of the filler, the strength of the high wear-resistant sliding bearing under all working conditions gradually increases, and the composite material is not easy to undergo plastic deformation during the wear process, thus ensuring the strength of the obtained high wear-resistant sliding bearing under all working conditions.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, without departing from the gist of the invention and the scope of protection of the claims, personnel can also make specific changes in many forms, and these all belong to the protection scope of the present invention.

Claims (8)

1. A high wear-resistant sliding bearing under all working conditions, comprising a bearing main body, characterized in that, the sliding surface of the bearing main body is formed of PTFE-based composite material and duplex stainless steel, and the PTFE-based composite material is composed of Made of the following raw materials: 3-20wt% of micron-sized hard ceramic particles, 3-20wt% of short carbon fibers, and the balance is polytetrafluoroethylene; the particle size range of the micron-sized hard ceramic particles is 0.1-5 microns, The short carbon fibers pass through a 400-mesh sieve; the polytetrafluoroethylene adopts PTFE powder with an average particle diameter of 10-30 microns. 2. A full working condition high wear-resistant sliding bearing according to claim 1, characterized in that the micron-sized hard ceramic particles are micron-sized silicon carbide particles, micron-sized silicon nitride particles, micron-sized silicon dioxide Silicon particles, micron boron nitride particles or micron alumina particles. 3. A high wear-resistant sliding bearing under all working conditions according to claim 1, characterized in that the weight percentage of the micron-sized hard ceramic particles is 5 wt%, and the weight percentage of the short carbon fibers is 15 wt%. 4. A method for preparing a full working condition high wear-resistant sliding bearing as claimed in claim 1, characterized in that, the method is carried out according to the following steps: (1) take described micron order hard ceramic particle, described short carbon fiber and described PTFE powder by weight percentage, carry out mechanical stirring after mixing; (2) Evenly spread the mixture stirred in step (1) into a mold, and perform cold pressing at room temperature to obtain a prefabricated part; (3) putting the preform into a muffle furnace for sintering to obtain the PTFE-based composite material; (4) When the sliding bearing is a radial bearing, process the obtained PTFE-based composite material into the required bearing bush, and cooperate with duplex stainless steel to form the sliding surface of the bearing main body; When the sliding bearing is a thrust bearing, the obtained PTFE-based composite material is processed into the required thrust plate, and is matched with duplex stainless steel to form the sliding surface of the bearing main body. 5. The preparation method of a full working condition high wear-resistant sliding bearing according to claim 4, wherein the micron-sized hard ceramic particles in step (1) are micron-sized silicon carbide particles, micron-sized Silicon nitride particles, micron-sized silicon dioxide particles, micron-sized boron nitride particles or micron-sized alumina particles. 6. The preparation method of a kind of full working condition high wear-resistant sliding bearing according to claim 4, is characterized in that, the weight percent of described micron-sized hard ceramic particle in step (1) is 5wt%, and described The weight percentage of short carbon fibers is 15wt%. 7. The preparation method of a kind of full working condition high wear-resistant sliding bearing according to claim 4, characterized in that, the pressure of cold pressing in step (2) is 25 ± 5Mpa, and the holding time is 40 ± 10min, The holding temperature is room temperature. 8. The preparation method of a full working condition high wear-resistant sliding bearing according to claim 4, characterized in that the sintering procedure in step (3) is as follows: from 30°C to 327°C, with a heating rate of 100°C ℃/h; hold at 327°C for 30 minutes; heat up from 327°C to 380°C with a heating rate of 60°C/h; hold at 380°C for 1 hour; cool down from 380°C to 327°C with a heating rate of 60°C/h; Keep warm at ℃ for 30 minutes; cool down from 327℃ to 150℃ at a cooling rate of 100℃/h; air cool to room temperature after reaching 150℃.