CN113248853A - Sealing element and method for producing same - Google Patents
Sealing element and method for producing same Download PDFInfo
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- CN113248853A CN113248853A CN202110798478.3A CN202110798478A CN113248853A CN 113248853 A CN113248853 A CN 113248853A CN 202110798478 A CN202110798478 A CN 202110798478A CN 113248853 A CN113248853 A CN 113248853A
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L27/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers
- C08L27/02—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L27/12—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a halogen; Compositions of derivatives of such polymers not modified by chemical after-treatment containing fluorine atoms
- C08L27/18—Homopolymers or copolymers or tetrafluoroethene
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
- C08L2205/035—Polymer mixtures characterised by other features containing three or more polymers in a blend containing four or more polymers in a blend
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Abstract
The invention relates to a preparation method of a sealing element, which comprises the following steps of pressing and sintering mixed powder to obtain a matrix, wherein the mixed powder comprises the following components in percentage by weight: 54-80% of polytetrafluoroethylene, 8-18% of polyphenyl ester, 5-20% of polyether-ether-ketone, 2-5% of polyamide-imide and 1-5% of polydopamine nano-microspheres; and forming a polydopamine coating on the surface of the substrate. The invention also relates to a sealing element prepared according to the preparation method.
Description
Technical Field
The invention relates to the technical field, in particular to a sealing element and a preparation method thereof.
Background
Polytetrafluoroethylene (PTFE) is widely applied in various fields as a special engineering plastic, has the characteristics of good acid-base resistance, solvent resistance, high-low temperature resistance and weather resistance, and most importantly, compared with other materials, PTFE has low friction coefficient, excellent self-lubricating property and chemical stability, and is a good sealing material, especially an ideal material for manufacturing sealing elements for aeroengines. The sealing element for the aeroengine is mainly applied to a hydraulic system, and mainly plays roles in protection, lubrication and wear resistance in the hydraulic system. The sealing elements play a crucial role in the relevant mechanical equipment of the aircraft engine, the sealing elements applied to the hydraulic system are often required to bear extreme pressure, load and temperature, but PTFE has poor wear resistance, is easy to wear and has short service life, and if the sealing elements fail in any form, the normal operation of the hydraulic system is affected and even seriously damaged, for example, once an oil leakage occurs, the aircraft engine is greatly damaged. Therefore, modification of PTFE materials is desirable.
At present, the tribology modification modes of PTFE in the scientific and engineering communities are mainly three: filling modification, blending modification and surface modification, wherein the most common mode is filling modification, the modification cost is low, and the technology is relatively mature. Through the filling modification of PTFE, the wear resistance of the PTFE can be improved to a certain extent, but the friction coefficient of the material is larger or the friction performance is unstable.
Disclosure of Invention
Based on this, there is a need for a sealing member and a method of making that are excellent in both wear resistance and friction performance.
In one aspect of the present invention, there is provided a method of manufacturing a sealing member, comprising the steps of: pressing and sintering the mixed powder to obtain a matrix, wherein the mixed powder comprises the following components in percentage by weight: 57-85% of polytetrafluoroethylene, 8-18% of polyphenyl ester, 5-20% of polyether-ether-ketone, 2-5% of polyamide-imide and 1-5% of polydopamine nano-microspheres, and a polydopamine coating is formed on the surface of the substrate.
In one embodiment, the mixed powder comprises the following components in percentage by weight: 54-69% of polytetrafluoroethylene, 10-18% of polyphenyl ester, 15-20% of polyether-ether-ketone, 4-5% of polyamide-imide and 2-3% of polydopamine nano-microspheres.
In one embodiment, the thickness of the polydopamine coating is 10-20 μm.
In one embodiment, the thickness of the polydopamine coating is 15-18 μm.
In one embodiment, the polytetrafluoroethylene has an average particle size of 50 to 100 μm, and/or the polyphenyl ester, the polyether ether ketone and the polyamide imide have the same average particle size of 30 to 40 μm, and/or the polydopamine nanospheres have an average particle size of 300 to 400 nm.
In one embodiment, the pressing is cold pressing, the pressing pressure is 27-37 MPa, and the pressing time is 5-15 s.
In one embodiment, the sintering temperature is 380-385 ℃, and the heat preservation time is 1-5 h.
In one embodiment, the preparation method of the mixed powder comprises the following steps:
stirring and mixing polytetrafluoroethylene, polyphenyl ester, polyether-ether-ketone, polyamide-imide and polydopamine nano-microspheres to form a uniform mixture, wherein the stirring speed is 650 r/min-1000 r/min, and the stirring time is 3 min-5 min.
In another aspect of the present invention, there is provided a sealing member obtained by the method for producing a sealing member.
In one embodiment, the sealing element is a seal for an aircraft engine.
Compared with the prior art, the beneficial effect of this application is:
according to the preparation method of the sealing element, three organic fillers of polyphenyl ester, polyether-ether-ketone and polyamide-imide are used for synergistically modifying polytetrafluoroethylene to serve as a matrix, a proper amount of polydopamine nano microspheres are added into the matrix, and a polydopamine coating is formed on the surface of the matrix. The preparation method of the sealing element provided by the invention can effectively improve and balance the wear resistance and the friction performance, so that the sealing element with excellent wear resistance and friction performance can be obtained, particularly the wear resistance at high temperature can be effectively improved (the wear resistance of polytetrafluoroethylene at high temperature is difficult to improve).
Detailed Description
In order that the invention may be more fully understood, a more particular description of the invention will now be rendered by reference to specific embodiments thereof that are illustrated in the appended drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Other than as shown in the operating examples, or where otherwise indicated, all numbers expressing quantities of ingredients, physical and chemical properties, and so forth used in the specification and claims are to be understood as being modified in all instances by the term "about". For example, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can be suitably varied by those skilled in the art in seeking to obtain the desired properties utilizing the teachings disclosed herein. The use of numerical ranges by endpoints includes all numbers within that range and any range within that range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, and 5, and the like.
The embodiment of the invention provides a preparation method of a modified polytetrafluoroethylene composite material, which comprises the following steps of pressing and sintering mixed powder; the mixed powder comprises the following components in percentage by weight: 57-85% of polytetrafluoroethylene, 8-18% of polyphenyl ester, 5-20% of polyether-ether-ketone and 2-5% of polyamide-imide.
The polyphenyl ester can improve the adsorption capacity of the transfer membrane, microfibers are easily formed in a molten state, the wear resistance of the polytetrafluoroethylene can be improved to a certain degree at normal temperature, and the wear resistance of the polytetrafluoroethylene can be obviously improved at high temperature, so that the problem of high-temperature thermal deformation of the composite material in a cross mill can be solved by adding the polyphenyl ester. The "transfer film" refers to that when the modified polytetrafluoroethylene composite material is in a working state, the modified polytetrafluoroethylene composite material and other materials are subjected to counter-grinding, fragments are grinded off and transferred to be adhered to the surface of the counter-grinding material in a transferring way in the friction process to form a layer of thin film, and the thin film is called as the transfer film in tribology. If the transfer film can be stably adsorbed on the surface of the counter-grinding material, the counter-grinding in the later stage is the counter-grinding of the modified polytetrafluoroethylene composite material and the modified polytetrafluoroethylene composite material (namely, the transfer film) on the surface of the counter-grinding material, so that the friction coefficient of a system can be remarkably reduced, and the abrasion of the modified polytetrafluoroethylene composite material can also be remarkably reduced.
The hardness of the polyetheretherketone is higher than that of the polytetrafluoroethylene, the polyetheretherketone can play a role of framework support in the composite material, and most external loads can be borne in the counter-grinding. At normal temperature, the wear modification effect of the polyetheretherketone is the best, but at high temperature, the modification effect is general.
The polyamide-imide has high strength, rigidity, wear resistance and creep resistance at high temperature, and generally shows normal performance at normal temperature, but can obviously play a role in wear resistance after being added in a small amount at high temperature.
The three organic fillers are used for synergistically modifying the polytetrafluoroethylene, so that the wear resistance of the polytetrafluoroethylene at normal temperature and high temperature, particularly the wear resistance at high temperature, can be effectively improved. However, the inventor finds that due to the problem of interface incompatibility among different organic fillers and between the organic fillers and polytetrafluoroethylene matrix, the mixing uniformity among multiple materials is poor, the fillers are unevenly distributed in the matrix, so that the strength of different parts of the matrix is different, and the surface of the sealing element is uneven in the abrasion process, thereby affecting the friction performance of the sealing element. Therefore, only by modifying polytetrafluoroethylene with the three organic fillers, the wear resistance is improved, and simultaneously the friction coefficient of the sealing element is increased and the friction performance is unstable, so that the wear resistance and the friction performance need to be balanced by other means, and the sealing element with excellent wear resistance and friction performance is obtained.
In the preparation method of the sealing element provided by the embodiment of the invention, besides using three organic fillers of polyphenyl ester, polyether ether ketone and polyamide imide to cooperatively modify polytetrafluoroethylene as a substrate, a polydopamine coating is formed on the surface of the substrate, and can reduce the friction coefficient of the surface of the sealing element and balance the wear resistance and the friction performance, but the problem of unevenness of the surface of the sealing element in the abrasion process cannot be solved only by using the polydopamine coating, so that the preparation method of the sealing element provided by the invention adds a proper amount of polydopamine nano microspheres in the substrate, and the polydopamine nano microspheres can effectively improve the interface compatibility between the organic fillers and the polytetrafluoroethylene substrate on one hand, ensure better dispersion uniformity between various organic fillers and the polytetrafluoroethylene on the other hand, and can also play a filling role, therefore, the uniformity of the overall strength of the sealing element is improved, the problem of unevenness on the surface of the sealing element in the abrasion process is avoided, and the friction performance is improved. Furthermore, the polydopamine nano-microspheres can also be used as binding sites, so that the binding force between the substrate and the polydopamine coating is improved, and the wear resistance and the friction performance of the sealing element are further improved.
In the mixed powder, the weight percentage content of the polytetrafluoroethylene can be any value between 54% and 80%, for example, 56%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%. In some preferred embodiments, the mixed powder contains 54% to 69% by weight of polytetrafluoroethylene.
In the mixed powder, the weight percentage content of the polyphenyl ester can be any value between 8% and 18%, for example, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16% and 17%. In some preferred embodiments, the weight percentage of the polyphenyl ester in the mixed powder is 10% to 18%.
In the mixed powder, the weight percentage content of the polyether-ether-ketone can be any value between 5% and 20%, for example, 8%, 10%, 12%, 14%, 16%, 18%. In some preferred embodiments, the mixed powder contains polyetheretherketone in an amount of 15 to 20 wt%.
In the mixed powder, the polyamide imide may be present in an amount of 2 to 5% by weight, for example, 2.5%, 3%, 3.5%, 4%, 4.5%. In some preferred embodiments, the polyamide imide is present in the mixed powder in an amount of 4 to 5 wt%.
In the mixed powder, the weight percentage content of the polydopamine nano-microspheres can be any value between 1% and 5%, for example, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%. In some preferred embodiments, the weight percentage of the polydopamine nano-microspheres in the mixed powder is 2% -3%. The larger the weight percentage of the polydopamine nano-microsphere is, the more the binding sites with the polydopamine coating are, the firmer the binding between the substrate and the coating is, but other problems can be caused, such as the reduction of the ratio of other components, the agglomeration of the polydopamine nano-microsphere and the like, the deterioration of the uniformity of mixed components, the increase of the friction coefficient and the instability of the mixed components can be caused.
The poly-dopamine nano-microsphere can be prepared by a method known by a person skilled in the art by using dopamine hydrochloride as a monomer or by a method purchased commercially. In some embodiments, the method for preparing the polydopamine nanosphere comprises:
s10, mixing ethanol, ammonia water and deionized water according to a volume ratio of 50: (0.5-2) 100 in a proportion of 25% (NH)3The mass content of the component (a), stirring at a stirring speed of 300-500 rpm for 20-60 min at a temperature of 25-30 ℃ to form a uniform mixed solution;
s20, adding 15-25 mL of dopamine hydrochloride solution into the mixed solution, and stirring at a stirring speed of 300-500 rpm for 40-50 h, wherein the concentration of dopamine hydrochloride in the dopamine hydrochloride solution is 30-40 mg/mL.
In some preferred embodiments, the mixed powder comprises the following components in percentage by weight: 54-80% of polytetrafluoroethylene, 8-18% of polyphenyl ester, 5-20% of polyether-ether-ketone, 2-5% of polyamide-imide and 1-5% of polydopamine nano-microspheres.
In some preferred embodiments, the mixed powder comprises the following components in percentage by weight: 54-69% of polytetrafluoroethylene, 10-18% of polyphenyl ester, 15-20% of polyether-ether-ketone, 4-5% of polyamide-imide and 2-3% of polydopamine nano-microspheres.
The average particle diameter of the polytetrafluoroethylene powder may be any value between 50 μm and 100 μm, and may be 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, or 95 μm, for example.
The average particle diameter of the polyphenyl ester powder can be any value between 30 μm and 40 μm, and can be 32 μm, 34 μm, 36 μm and 38 μm.
The mean particle diameter of the polyether-ether-ketone powder may be any value between 30 μm and 40 μm, and may be, for example, 32 μm, 34 μm, 36 μm, or 38 μm.
The average particle diameter of the polyamide imide powder may be any value between 30 μm and 40 μm, and may be, for example, 32 μm, 34 μm, 36 μm, or 38 μm.
In some preferred embodiments, the polyphenyl ester powder, the polyetheretherketone powder and the polyamideimide powder have the same average particle size.
The average particle size of the polydopamine nano-microspheres is any value between 300nm and 400nm, and can be 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm and 390nm, for example.
In some embodiments, the method for preparing the mixed powder comprises:
stirring and mixing polytetrafluoroethylene, polyphenyl ester, polyether-ether-ketone, polyamide-imide and polydopamine nano-microspheres to form a uniform mixture, wherein the stirring speed is 650-1000 r/min, and the stirring time is 3-5 min;
the stirring speed can also be independently selected from 700r/min, 750r/min, 800r/min, 850r/min and 900 r/min;
the stirring time can also be independently selected from 3.5min, 4min and 4.5 min.
The stirring and mixing method within the parameter range can further ensure that the polytetrafluoroethylene, the polyphenyl ester, the polyether-ether-ketone, the polyamide-imide and the polydopamine nano-microspheres are mixed more uniformly.
Further, in some embodiments, before the mixed powder is pressed, a step of standing the mixed powder in a room temperature environment is further included, and the step is also added to facilitate unwinding of the PTFE macromolecule to complete phase transformation.
In some embodiments, the pressing is cold pressing, the pressing pressure is 27-37 Mpa, and the pressing time is 5-15 s;
the pressing pressure can also be independently selected from 28 Mpa, 30 Mpa, 32 Mpa, 34 Mpa and 36 Mpa;
the pressing time may also be independently selected from 6s, 7s, 8s, 9s, 10s, 11s, 12s, 13s, 14 s.
In some embodiments, the sintering temperature is 380-385 ℃, and the holding time is 1-5 h;
the sintering temperature can also be 381 ℃, 382 ℃, 383 ℃ and 384 ℃;
the heat preservation time can also be 1.5h, 2h, 2.5h, 3h, 3.5h, 4h and 4.5 h.
The base body may have any shape, may be used as a seal ring, such as a rectangular ring, a U-shaped seal, or the like, a dust seal, or the like, and is particularly preferable as a seal ring for use in a high-temperature environment.
In some embodiments, the polydopamine coating has a thickness of any value between 10 μm and 20 μm, such as 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm. In some preferred embodiments, the polydopamine coating has a thickness of 15 μm to 18 μm.
The method for preparing the polydopamine coating may comprise the steps of,
s100, placing the substrate in a dopamine deposition solution for deposition reaction, wherein the dopamine deposition solution is a mixed solution containing dopamine hydrochloride and a tris (hydroxymethyl) aminomethane buffer solution, and the pH value of the dopamine deposition solution is 8-9;
s200, carrying out a deposition reaction in a swing type oscillator, wherein the swing speed of the swing type oscillator is 20 r/min-30 r/min, the swing angle is 5-10 degrees, the deposition reaction temperature is 55-65 ℃, and the deposition reaction time is 5-20 min.
In another aspect of the present invention, there is provided a sealing member prepared according to the method for preparing a sealing member.
The sealing member may be used as a sealing ring such as a rectangular ring, a U-shaped seal, etc., a dust seal, etc., and is particularly preferable as a sealing ring for use in a high-temperature environment.
In some preferred embodiments, the sealing element is a sealing element for an aircraft engine.
The following are specific examples. The present invention is intended to be further described in detail to assist those skilled in the art and researchers to further understand the present invention, and the technical conditions and the like do not limit the present invention. Any modification made within the scope of the claims of the present invention is within the scope of the claims of the present invention. The following is an English reference description of the invention:
PTFE: polytetrafluoroethylene, POB: polyphenyl esters, PEEK: polyether ether ketone, PAI: polyamideimide, PDA: polydopamine, PDAPs: polydopamine microspheres.
The average particle size of the polytetrafluoroethylene powder used or prepared in the following examples and comparative examples is about 80 μm, the average particle size of the polybenzoate, polyetheretherketone and polyamideimide powder is about the same, about 35 μm, and the average particle size of the polydopamine nanospheres is about 350 nm.
The polydopamine microspheres used hereinafter were prepared by the following methods:
the stirring temperature was controlled at 25 ℃ and the stirring speed was 500 rpm. Stirring for 20min, adding 25mL of dopamine solution (40 mg/mL) into the solution, then stirring for 40h integrally, and after the reaction is finished, centrifugally cleaning and drying for multiple times to generate poly-dopamine nano microspheres (PDAPs).
Example 1
1. And (2) uniformly mixing 50mL of ethanol, 100mL of deionized water and 2mL of ammonia water by using magnetic stirring, stirring at the temperature of 25 ℃ and the stirring speed of 300rpm for 60min, adding 25mL of dopamine solution (40 mg/mL), continuously stirring for 50h, and after the reaction is finished, centrifugally cleaning and drying for multiple times to generate poly-dopamine nano microspheres (PDAPs).
2. Mixing 8g of polyphenyl ester powder, 5g of polyether-ether-ketone powder, 2g of polyamide imide powder and 5g of polydopamine nano-microspheres in a high-speed mixer, intermittently mixing for 3min, adding 80g of polytetrafluoroethylene powder, mixing, and intermittently mixing for 2 min.
3. Placing the mixed powder in a room temperature (23-25 ℃) environment for 24 hours, then placing the composite powder in a steel mould for powder cold pressing and pressing, wherein the pressing pressure is 27Mpa, obtaining a prefabricated part, then placing the prefabricated part in a sintering furnace for high-temperature sintering, and the sintering temperature is 380 ℃, thus obtaining the sealing element substrate for the aircraft engine.
4. Dissolving 80mg of dopamine hydrochloride by using 60mL of deionized water, adjusting the pH value of the dopamine hydrochloride solution to 8.9 by using a tris (hydroxymethyl) aminomethane buffer solution, then putting the substrate prepared in the step 3 into the prepared dopamine hydrochloride solution for deposition reaction, putting the whole reaction system into a swing type oscillator for carrying out deposition reaction at the swing speed of 30r/min and the swing angle of 5 degrees at the deposition reaction temperature of 55 ℃ for 5min, and obtaining the polydopamine coating with the thickness of 10 mu m.
Example 2
1. And (2) uniformly mixing 50mL of ethanol, 100mL of deionized water and 1.8mL of ammonia water by using magnetic stirring, stirring at the temperature of 25 ℃ and at the stirring speed of 300rpm for 40min, adding 20mL of dopamine solution (40 mg/mL), continuously stirring for 50h, and after the reaction is finished, centrifugally cleaning and drying for multiple times to generate poly-dopamine nano microspheres (PDAPs).
2. 13g of polyphenyl ester powder, 13g of polyether-ether-ketone powder, 3g of polyamide-imide powder and 4g of polydopamine nano-microspheres are mixed in a high-speed mixer, and are intermittently mixed for 3min, then 67g of polytetrafluoroethylene powder is added and mixed, and the intermittent mixing is carried out for 2 min.
3. Placing the mixed composite powder in a room temperature (23-25 ℃) environment for 24 hours, then placing the composite powder in a steel mould for powder cold pressing and pressing, wherein the pressing pressure is 27Mpa, obtaining a prefabricated part, then placing the prefabricated part in a sintering furnace for high-temperature sintering, and the sintering temperature is 380 ℃, thus obtaining the sealing element substrate for the aircraft engine.
4. Dissolving 80mg of dopamine hydrochloride by using 60mL of deionized water, adjusting the pH value of the dopamine hydrochloride solution to 8.6 by using a tris (hydroxymethyl) aminomethane buffer solution, then putting the substrate prepared in the step 3 into the prepared dopamine hydrochloride solution for deposition reaction, putting the whole reaction system into a swing type oscillator for carrying out deposition reaction at the swing speed of 30r/min and the swing angle of 7 degrees at the deposition reaction temperature of 60 ℃ for 10min, and obtaining the polydopamine coating with the thickness of 12 microns.
Example 3
1. And (2) uniformly mixing 50mL of ethanol, 100mL of deionized water and 1.5mL of ammonia water by using magnetic stirring, stirring at the temperature of 30 ℃ and the stirring speed of 400rpm for 40min, adding 25mL of dopamine solution (35 mg/mL), continuously stirring for 45h, and after the reaction is finished, centrifugally cleaning and drying for multiple times to generate poly-dopamine nano microspheres (PDAPs).
2. Mixing 18g of polyphenyl ester powder, 20g of polyether-ether-ketone powder, 5g of polyamide imide powder and 3g of polydopamine nano microspheres in a high-speed mixer, intermittently mixing for 3min, then adding 54g of polytetrafluoroethylene powder, mixing and intermittently mixing for 2 min.
3. Placing the mixed composite powder in a room temperature (23-25 ℃) environment for 24 hours, then placing the composite powder in a steel mould for powder cold pressing and pressing, wherein the pressing pressure is 35Mpa, obtaining a prefabricated part, then placing the prefabricated part in a sintering furnace for high-temperature sintering, and obtaining the sealing element substrate for the aircraft engine, wherein the sintering temperature is 385 ℃.
4. Dissolving 90mg of dopamine hydrochloride by using 55mL of deionized water, adjusting the pH value of the dopamine hydrochloride solution to 8.5 by using a tris (hydroxymethyl) aminomethane buffer solution, then putting the substrate prepared in the step 3 into the prepared dopamine hydrochloride solution for deposition reaction, putting the whole reaction system into a swing type oscillator for carrying out deposition reaction at the swing speed of 25r/min and the swing angle of 10 degrees at the deposition reaction temperature of 60 ℃ for 15min, and obtaining the polydopamine coating with the thickness of 15 microns.
Example 4
1. And (2) uniformly mixing 50mL of ethanol, 100mL of deionized water and 1mL of ammonia water by magnetic stirring, stirring at the temperature of 30 ℃ and the stirring speed of 400rpm for 30min, adding 20mL of dopamine solution (35 mg/mL), continuously stirring for 45h, and after the reaction is finished, centrifugally cleaning and drying for multiple times to generate poly-dopamine nano microspheres (PDAPs).
2. Mixing 10g of polyphenyl ester powder, 15g of polyether-ether-ketone powder, 4g of polyamide imide powder and 2g of polydopamine nano-microspheres in a high-speed mixer, intermittently mixing for 3min, then adding 69g of polytetrafluoroethylene powder, mixing, and intermittently mixing for 2 min.
3. Placing the mixed composite powder in a room temperature (23-25 ℃) environment for 24 hours, then placing the composite powder in a steel mould for powder cold pressing and pressing, wherein the pressing pressure is 37Mpa, obtaining a prefabricated part, then placing the prefabricated part in a sintering furnace for high-temperature sintering, and obtaining the sealing element substrate for the aircraft engine, wherein the sintering temperature is 385 ℃.
4. Dissolving 95mg of dopamine hydrochloride by using 52mL of deionized water, adjusting the pH value of the dopamine hydrochloride solution to 8.5 by using a tris (hydroxymethyl) aminomethane buffer solution, then putting the substrate prepared in the step 3 into the prepared dopamine hydrochloride solution for deposition reaction, putting the whole reaction system into a swing type oscillator for carrying out deposition reaction at the swing speed of 30r/min and the swing angle of 8 degrees at the deposition reaction temperature of 55 ℃ for 20min, and obtaining the polydopamine coating with the thickness of 18 mu m.
Example 5
1. And (2) uniformly mixing 50mL of ethanol, 100mL of deionized water and 0.5mL of ammonia water by using magnetic stirring, stirring at the temperature of 30 ℃ and the stirring speed of 500rpm for 20min, adding 15mL of dopamine solution (30 mg/mL), continuously stirring for 40h, and after the reaction is finished, centrifugally cleaning and drying for multiple times to generate poly-dopamine nano microspheres (PDAPs).
2. Mixing 15g of polyphenyl ester powder, 8g of polyether-ether-ketone powder, 2g of polyamide imide powder and 1g of polydopamine nano-microspheres in a high-speed mixer, intermittently mixing for 3min, adding 74g of polytetrafluoroethylene powder, mixing, and intermittently mixing for 2 min.
3. Placing the mixed composite powder in a room temperature (23-25 ℃) environment for 28 hours, then placing the composite powder in a steel mould for powder cold pressing and pressing, wherein the pressing pressure is 37Mpa, obtaining a prefabricated part, then placing the prefabricated part in a sintering furnace for high-temperature sintering, and obtaining the sealing element substrate for the aircraft engine, wherein the sintering temperature is 385 ℃.
4. Dissolving 100mg of dopamine hydrochloride by using 50mL of deionized water, adjusting the pH value of the dopamine hydrochloride solution to 8.3 by using a tris (hydroxymethyl) aminomethane buffer solution, then putting the substrate prepared in the step 3 into the prepared dopamine hydrochloride solution for deposition reaction, putting the whole reaction system into a swing type oscillator for carrying out deposition reaction at the swing speed of 30r/min and the swing angle of 8 degrees at the deposition reaction temperature of 55 ℃ for 20min, and obtaining the polydopamine coating with the thickness of 20 microns.
Comparative example 1
Placing 100g of polytetrafluoroethylene powder in a room temperature (23-25 ℃) environment for 24 hours, then placing the powder in a steel mould for powder cold pressing and pressing, wherein the pressing pressure is 27Mpa, obtaining a prefabricated part, then placing the prefabricated part in a sintering furnace for high-temperature sintering, and the sintering temperature is 380 ℃, and finally obtaining the polytetrafluoroethylene sealing element for the aeroengine.
Comparative example 2
The preparation method of comparative example 2 and example 1 is substantially the same except that step 4 is omitted.
Comparative example 3
The preparation method of comparative example 3 is substantially the same as that of example 1, except that step 1 is omitted, i.e., the polydopamine nanospheres are not added to the substrate, and the polydopamine coating is formed only on the surface of the substrate.
The raw material compositions of the sealing elements for the aeroengine prepared in the embodiments 1 to 5 and the comparative examples 1 to 3 are listed in table 1, the tribology performance tests at room temperature and high temperature are carried out on the sealing elements prepared in the embodiments 1 to 5 and the comparative examples 1 to 3, the sealing elements prepared in the embodiments 1 to 5 and the comparative examples 1 to 3 are used for the aeroengine, the equivalent simulation experiments are respectively carried out on the working environment of the aeroengine at room temperature and high temperature, the sealing performance is examined by testing the oil leakage amount, and the results are shown in table 1 below, wherein the raw material proportions are calculated by weight percent of the whole composite material:
the test conditions or test standards of each performance test item are as follows:
1. a GCr15 bearing steel ball (phi =4mm, Ra =0.04 μm) and the samples of the workpieces prepared in the examples 1-5 and the comparative examples 1-3 are selected to carry out a counter-grinding experiment, the steel ball is fixed on the sensor and is in close contact with the surface of the sample, the sample is fixed on the test bench and rotates along with the test bench, and the steel ball rotates on the surface of the sample under the principle of relative motion and leaves grinding marks. The test was carried out at a rotational linear speed of 200r/min, a rotational radius of 3mm and a positive pressure (Fz) of 2N applied. And (3) testing the volume wear rate by adopting a NexView three-dimensional white light interferometer, and testing the friction coefficient by adopting a controllable environment friction wear tester UMT.
2. Oil leakage of equivalent simulation experiment:
according to the working mechanism of the sealing position of the aircraft engine and the analysis of the actual working condition of the trial run of the engine pedestal, the main factors influencing the sealing oil leakage, such as load, vibration, working temperature and working spectrum, are obtained. For these factors, test conditions were set up for simulation. And (3) simulating the load borne by the sealing mechanism during the engine bench test, and designing a load simulation device. Axial load is applied through the hydraulic device, radial load is applied through the pneumatic device, and the axial load and the radial load act together to simulate the load borne by a mechanism at the sealing position. The closed circulation temperature control device of the tester controls the temperature of the fuel oil at the inlet of the test piece, so that the temperature of the sealing mechanism is basically consistent with the test-run temperature of the rack.
The actual test load and temperature are obtained through the equivalent simulation conversion, the experiment cycle number is 200 ten thousand, and the equivalent stroke reciprocating experiment is 1 ten thousand hours. The specific experimental operation is carried out according to national standard GB/T32217-. Wherein the diameter of the piston rod is phi 36mm, the surface of the piston rod is plated with hard chromium, the surface roughness Ra = 0.10-0.15, the hardness of the nitrile rubber dust ring is 72-75 IRHD; the amount of oil leakage was measured using a measuring cup.
TABLE 1
Note: when the amount of oil leakage is less than 1 drop, the measurement time is extended to be converted, for example, 0.1 drop/min represents that the 1 st drop of oil actually starts to leak at the 10 th min.
As can be seen from Table 1:
(1) as can be seen from comparative analysis of examples 1-5 and comparative examples 1-3, the proper amount of polydopamine nano-microspheres are added into the substrate, and the polydopamine coating is formed on the surface of the substrate, so that the wear resistance and the friction performance can be effectively balanced, and the sealing element with excellent wear resistance and friction performance can be obtained.
(2) Through comparative analysis of the embodiments 1, 2 and 5 and the embodiments 3 and 4, in the sealing element, the weight percentage of polytetrafluoroethylene is preferably 54-69%, the weight percentage of polyphenyl ester is preferably 10-18%, the weight percentage of polyether-ether-ketone is preferably 15-20%, the weight percentage of polyamide-imide is preferably 4-5%, and the weight percentage of polydopamine nano-microspheres is preferably 2-3%.
(3) Through comparison of the thicknesses of the polydopamine coating layers in the embodiments 1 to 5, it can be seen that the thickness of the polydopamine coating layer mainly influences the retention capacity of the wear resistance of the sealing element at high temperature, and the thicker the polydopamine coating layer is, the closer the polydopamine coating layer is to the wear rate at normal temperature.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A method of making a sealing member, comprising the steps of:
pressing and sintering the mixed powder to obtain a matrix, wherein the mixed powder comprises the following components in percentage by weight:
54% -80% of polytetrafluoroethylene
8-18% of polyphenyl ester
5-20% of polyether-ether-ketone
2-5% of polyamide-imide
1% -5% of polydopamine nano-microspheres;
and forming a polydopamine coating on the surface of the substrate.
2. The preparation method of the sealing element according to claim 1, wherein the mixed powder comprises the following components in percentage by weight:
54% -69% of polytetrafluoroethylene
10-18% of polyphenyl ester
15-20% of polyether-ether-ketone
4-5% of polyamide-imide
2% -3% of polydopamine nano microspheres.
3. The method of producing a sealing member according to claim 1 or 2, wherein the thickness of the polydopamine coating layer is 10 μm to 20 μm.
4. The method of producing a sealing element according to claim 1 or 2, wherein the thickness of the polydopamine coating is 15 μm to 18 μm.
5. The method for preparing a sealing element according to claim 1 or 2, wherein the polytetrafluoroethylene has an average particle size of 50 μm to 100 μm, and/or the polyphenyl ester, the polyether ether ketone and the polyamide imide have the same average particle size of 30 μm to 40 μm, and/or the polydopamine nanospheres have an average particle size of 300nm to 400 nm.
6. The manufacturing method of the sealing element according to claim 1 or 2, wherein the pressing is cold pressing, the pressing pressure is 27Mpa to 37Mpa, and the pressing time is 5s to 15 s.
7. The method for preparing the sealing element according to claim 1 or 2, wherein the sintering temperature is 380 ℃ to 385 ℃, and the holding time is 1h to 5 h.
8. The method for producing a sealing member according to claim 1 or 2, wherein the method for producing the mixed powder comprises:
stirring and mixing polytetrafluoroethylene, polyphenyl ester, polyether-ether-ketone, polyamide-imide and polydopamine nano-microspheres to form a uniform mixture, wherein the stirring speed is 650 r/min-1000 r/min, and the stirring time is 3 min-5 min.
9. The sealing member obtained by the method for producing a sealing member according to any one of claims 1 to 8.
10. The sealing element of claim 9, wherein the sealing element is an aircraft engine sealing element.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114395172A (en) * | 2022-01-20 | 2022-04-26 | 北京石墨烯技术研究院有限公司 | Polytetrafluoroethylene modified filler, modified polytetrafluoroethylene composite material, preparation method and application |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5695197A (en) * | 1996-12-06 | 1997-12-09 | Farley; Michael L. | Seal ring method of sealing and molding composition comprising blend of PTFE copolymer, polyamide and carbon fiber therefor |
| CN103736156A (en) * | 2013-10-10 | 2014-04-23 | 西北大学 | Method for constructing functionalized surface and interface by polydopamine coating layer |
| US20170082202A1 (en) * | 2015-09-17 | 2017-03-23 | Intellectual Property Holdings, Inc. | Seals for natural gas compressor |
| CN109880345A (en) * | 2019-03-04 | 2019-06-14 | 中国工程物理研究院化工材料研究所 | The poly-dopamine microballoon toughening polyurethane elastic composite and preparation method thereof of gamma ray resistant irradiation |
| CN111849099A (en) * | 2020-08-13 | 2020-10-30 | 中国科学院兰州化学物理研究所 | Polyamide-imide-filled polytetrafluoroethylene self-lubricating composite material and preparation method thereof |
-
2021
- 2021-07-15 CN CN202110798478.3A patent/CN113248853B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5695197A (en) * | 1996-12-06 | 1997-12-09 | Farley; Michael L. | Seal ring method of sealing and molding composition comprising blend of PTFE copolymer, polyamide and carbon fiber therefor |
| CN103736156A (en) * | 2013-10-10 | 2014-04-23 | 西北大学 | Method for constructing functionalized surface and interface by polydopamine coating layer |
| US20170082202A1 (en) * | 2015-09-17 | 2017-03-23 | Intellectual Property Holdings, Inc. | Seals for natural gas compressor |
| CN109880345A (en) * | 2019-03-04 | 2019-06-14 | 中国工程物理研究院化工材料研究所 | The poly-dopamine microballoon toughening polyurethane elastic composite and preparation method thereof of gamma ray resistant irradiation |
| CN111849099A (en) * | 2020-08-13 | 2020-10-30 | 中国科学院兰州化学物理研究所 | Polyamide-imide-filled polytetrafluoroethylene self-lubricating composite material and preparation method thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114395172A (en) * | 2022-01-20 | 2022-04-26 | 北京石墨烯技术研究院有限公司 | Polytetrafluoroethylene modified filler, modified polytetrafluoroethylene composite material, preparation method and application |
| CN114395172B (en) * | 2022-01-20 | 2023-12-01 | 北京石墨烯技术研究院有限公司 | Polytetrafluoroethylene modified filler, modified polytetrafluoroethylene composite material, preparation method and application |
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