A self-lubricating composite coating material and methods of making and using the same

Abstract

The present application relates to the technical field of high polymer coating, especially to the field of IPC C08L79, and more particularly to a self-lubricating composite coating material and a preparation method and use method thereof. The components include, by weight parts, modified cyanate resin 70-130 parts, low-friction short-cut fiber 80-150 parts, wear-resistant short-cut fiber 5-30 parts, and solvent 20-50 parts. The weight ratio of the low-friction short-cut fiber to the wear-resistant short-cut fiber is (3-7) : 1. When the wear-resistant short-cut fiber includes glass fiber, the wear resistance of the coating can be improved. The length of the low-friction short-cut fiber is 500-1000 μm, and the length of the wear-resistant short-cut fiber is 200-400 μm. The coating can be matched with a wear-resistant friction pair, so that the high-temperature resistance of the coating can be further improved, and the service life of the friction pair can be prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high polymer coating technology, in particular to the field of IPC C08L79, and more particularly to a self-lubricating composite coating material and a preparation method and use method thereof. BACKGROUND

[0002] Self-lubricating sliding bearing refers to a type of sliding bearing that can ensure normal operation of the shaft in a stable low-friction state under the working condition without adding self-lubricating agents such as lubricating oil and lubricating grease. The self-lubricating bearing is usually formed by directly bonding, sintering or hot rolling an outer base alloy and an inner self-lubricating layer to form a whole. At present, the polymer-based wear-resistant composite material is a kind of material that uses thermoplastic or thermosetting resin as the matrix, and adds organic or inorganic friction-reducing components and wear-resistant reinforcing components to exhibit good wear resistance. The wear-resistant composite material using polymer as the matrix has a series of excellent characteristics such as self-lubricating, wear resistance, corrosion resistance, shock absorption, noise reduction, small relative density, high specific strength and easy processing. However, in more complex working conditions, the most typical of which is the use method requirement of 250℃ high temperature working condition, such as aero-engine, main rotor and tail rotor of helicopter, China has not yet broken through the corresponding key technology, and the high temperature wear resistance life of the sliding bearing cannot meet the requirements.

[0003] CN106084773A discloses a preparation method of a modified PA46 high-temperature-resistant self-lubricating sliding bearing material, which comprises the following steps: S1, pretreating inorganic fillers and glass fibers with a silane coupling agent, wherein the inorganic fillers are used to improve the friction and wear properties of the composite material; S2, mixing PA46, a blended polymer, a compatibilizer, and the pretreated glass fibers and inorganic fillers, wherein the content of PA46 is 50-70wt%, the content of the blended polymer is 0-10wt%, the content of the compatibilizer is 0-10wt%, the content of the glass fibers is 10-40wt%, and the content of the inorganic fillers is 0-10wt%; and S3, extruding and granulating the product obtained in step S2 at 280-320℃. However, the compatibility between the resin and the fillers in the improved application is not high enough, and a certain amount of compatibilizer needs to be added, which reduces the high-temperature resistance of the material to a certain extent.

[0004] CN110206822 A discloses a molded self-lubricating bushing and a preparation method thereof. The liner of the invention has a uniform structure, has the characteristics of being machinable and stable friction and wear performance, and is easy to control the thickness size precision, is not sensitive to the humid heat environment, and does not have the risk of peeling failure in complex environment, etc. The stability of the friction and wear performance of the self-lubricating liner material is improved, the equipment operating performance is better, the stability is higher, and the performance is excellent at 163℃, but the high temperature resistance is poor at 250℃. SUMMARY

[0005] To overcome the deficiencies in the background art, the present application provides a self-lubricating composite coating material and its preparation method and use method. By adjusting the ratio of components, the composite coating prepared has low friction and high wear resistance characteristics during friction and wear process in high temperature environment, greatly prolonging the service life of the friction pair, and can well adapt to high temperature, low speed and heavy load working conditions.

[0006] To achieve the purpose of the present application, the first aspect of the present application provides a self-lubricating composite coating material, which comprises, by weight: modified cyanate resin 70-130 parts, low-friction short-cut fiber 80-150 parts, wear-resistant short-cut fiber 5-30 parts, and solvent 20-50 parts.

[0007] The modified cyanate resin comprises cyanate ester monomer and bismaleimide resin.

[0008] The cyanate ester monomer comprises one or more of bisphenol A cyanate ester monomer, bisphenol E cyanate ester monomer, bisphenol F cyanate ester monomer, and tetramethyl bisphenol F cyanate ester monomer.

[0009] Preferably, the cyanate ester monomer comprises bisphenol A cyanate ester monomer (CAS: 1156-51-0).

[0010] Preferably, the weight ratio of the cyanate ester monomer to the bismaleimide resin is 92:(5-13).

[0011] Further preferably, the weight ratio of the cyanate ester monomer to the bismaleimide resin is 92:8.

[0012] Preferably, the bismaleimide resin comprises 4,4'-bismaleimidyl diphenyl methane (CAS: 13676-54-5).

[0013] The low-friction short-cut fiber comprises one of polytetrafluoroethylene fiber, polyimide fiber, and aramid fiber.

[0014] Preferably, the low-friction short-cut fiber comprises one of polytetrafluoroethylene fiber and polyimide fiber.

[0015] Further preferably, the low-friction short-cut fiber comprises polytetrafluoroethylene fiber.

[0016] Preferably, the low-friction short-cut fiber has a length of 500-1000 μm.

[0017] Further preferably, the low-friction short-cut fiber has a length of 600-1000 μm.

[0018] Still further preferably, the low-friction short-cut fiber has a length of 1000 μm.

[0019] Preferably, the wear-resistant short-cut fiber comprises one of glass fiber and carbon fiber.

[0020] Further preferably, the wear-resistant short-cut fiber comprises glass fiber.

[0021] Preferably, the glass fiber has a length of 200-400 μm.

[0022] Further preferably, the glass fiber has a length of 200 μm and is available from Lianyungang Ruichuang New Material Technology Co., Ltd.

[0023] The applicant found that the low-friction short-cut fiber and wear-resistant short-cut fiber weight ratio is (3-7):1, the wear-resistant short-cut fiber includes glass fiber, the wear-resistant short-cut fiber has high strength and rigidity, and can preferentially bear part of the friction force when being subjected to friction, so that the actual friction of the resin matrix is reduced, and the wear-resistant performance is improved, but too much glass fiber addition will affect the wear-resistant performance of the coating, and the glass fiber interface layer may have incompatible components, and voids and defects are easily formed on the interface during compounding, so that the reinforced phase and the matrix material are difficult to form effective bonding, and the interface bonding strength is low. In addition, the glass fiber is wear-resistant, but the friction coefficient is large, and too much glass fiber addition will exacerbate the generation of friction heat, and damage the wear surface. This also limits the addition amount of glass fiber to a certain extent, and the glass fiber is compounded with the low-friction short-cut fiber, especially when the low-friction short-cut fiber includes polytetrafluoroethylene fiber and polyimide fiber, the friction coefficient of the coating can be further reduced, and the wear-resistant performance of the coating can be further improved. It may be that a large number of physical crosslinking points are formed between the high molecular fiber and the resin matrix, which reduces the voids and defects of the glass fiber interface layer to a certain extent. Further research found that the length of the low-friction short-cut fiber is 500-1000 μm, and the length of the wear-resistant short-cut fiber is 200-400 μm, which can further improve the high-temperature-resistant performance of the coating. It may be that the length of the fiber is improved, the bonding strength in the resin matrix is improved, the length is too low, the continuity of the coating is easily broken, and the length is too high, the physical crosslinking points between the fiber and the resin are reduced, and the interface bonding strength is reduced at high temperature. The relatively longer low-friction short-cut fiber end and the relatively shorter wear-resistant short-cut fiber form length complementation, and the formation of voids and defects between the coatings is reduced.

[0024] Preferably, the low-friction short-cut fiber and wear-resistant short-cut fiber weight ratio is (3-7):1.

[0025] Further preferably, the low-friction short-cut fiber and wear-resistant short-cut fiber weight ratio is (4-6):1.

[0026] More preferably, the low-friction short-cut fiber and wear-resistant short-cut fiber weight ratio is 4:1.

[0027] The modified cyanate resin and low-friction short-cut fiber weight ratio is 1:(0.7-1.3).

[0028] Preferably, the modified cyanate resin and low-friction short-cut fiber weight ratio is 1:0.8.

[0029] The solvent includes one of acetone, butanone, methanol, ethanol, and n-propanol.

[0030] Preferably, the solvent includes acetone.

[0031] The second aspect of the present application provides a preparation method of the self-lubricating composite coating material, comprising the following steps: adding modified cyanate resin, low-friction short fibers and wear-resistant short fibers into a solvent in sequence, mixing uniformly by ball milling and stirring, and obtaining the self-lubricating composite coating material after vacuumizing.

[0032] Preferably, the rotating speed of the ball mill is 250-350 rpm.

[0033] Further preferably, the rotating speed of the ball mill is 300 rpm.

[0034] The self-lubricating composite coating material is applied to the surface of a bearing sleeve.

[0035] The third aspect of the present application provides a use method of the self-lubricating composite coating material, comprising the following steps:

[0036] S1, spraying the composite coating material on the self-lubricating bearing sleeve;

[0037] S2, performing machining after pre-curing to obtain a coating 2;

[0038] S3, performing post-curing on the coating 2;

[0039] S4, performing surface treatment on a counter-abrasion friction pair;

[0040] S5, combining the self-lubricating bearing sleeve with the counter-abrasion friction pair.

[0041] The thickness sprayed in the step S1 is 1-2 mm.

[0042] Preferably, the thickness sprayed in the step S1 is 1.5 mm.

[0043] Preferably, the pre-curing temperature is 140-220℃, the time is 3-6h, and the thickness of the coating 2 is 0.2-0.5 mm.

[0044] Further preferably, the pre-curing temperature is 180℃, the time is 4h, and the thickness of the coating 2 is 0.4 mm.

[0045] Preferably, the post-curing temperature is 250℃, and the time is 4h.

[0046] Preferably, the surface treatment comprises one of tungsten carbide treatment and diamond-like carbon treatment.

[0047] Preferably, the material of the counter-abrasion friction pair comprises stainless steel.

[0048] Preferably, the stainless steel comprises one of American precipitation hardening stainless steel (PH13-8Mo) and high-carbon chromium stainless steel (G102Cr18Mo).

[0049] Preferably, the stainless steel comprises high-carbon chromium stainless steel (G102Cr18Mo).

[0050] The surface treatment has a tempering temperature of 250-350℃, a surface hardness of 800-1300HV, and a surface roughness of 0.05-0.2.

[0051] Preferably, the surface treatment has a tempering temperature of 320℃, a surface hardness of 1100HV, and a surface roughness of 0.15.

[0052] Beneficial effects

[0053] 1. The modified cyanate resin comprises cyanate ester monomers and bismaleimide resin, and the weight ratio of the cyanate ester monomers and bismaleimide resin is 92:(5-13), which can reduce the deformation degree of the coating at high temperature and improve the service life.

[0054] 2. The weight ratio of the low-friction short-cut fiber and the wear-resistant short-cut fiber is (3-7):1, and when the wear-resistant short-cut fiber comprises glass fiber, the wear resistance of the coating can be improved.

[0055] 3. The length of the low-friction short-cut fiber is 500-1000μm, and the length of the wear-resistant short-cut fiber is 200-400μm, which can further improve the high-temperature resistance of the coating and prolong the service life of the friction pair.

[0056] 4. The weight ratio of the modified cyanate resin and the low-friction short-cut fiber is 1:0.8, so that the coating can maintain low friction and high wear resistance during friction and wear at a high temperature of 250℃, meeting the use method requirements of aerospace products under high-temperature working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0057] Figure 1 DMA test curve of the modified cyanate resin component of Example 1.

[0058] Figure 2 Test curve of the coating material of Example 1.

[0059] Figure 3 Test curve of the coating material of Example 1.

[0060] Figure 4 Test curve of the coating material of Example 2.

[0061] Figure 5 Test curve of the coating material of Example 2.

[0062] Figure 6 Test curve of the coating material of Example 3.

[0063] Figure 7 Test curve of the coating material of Example 3.

[0064] wherein Figures 2-7 The abscissa is the number of friction times, and the ordinate of the three curves from top to bottom is the friction temperature, the ambient temperature and the deformation peak value. DETAILED DESCRIPTION

[0065] Example 1

[0066] A self-lubricating composite coating material, the components are as follows in parts by weight: modified cyanate resin 100 parts, low-friction short-cut fiber 120 parts, wear-resistant short-cut fiber 20 parts, solvent 30 parts.

[0067] The weight ratio of the bisphenol A cyanate ester monomer to the bismaleimide resin is 92:8.

[0068] The bisphenol A cyanate ester monomer and the bismaleimide resin are copolymerized, the copolymerization temperature is 140°C, and the copolymerization time is 4h.

[0069] The cyanate ester monomer is bisphenol A cyanate ester monomer (CAS: 1156-51-0).

[0070] The bismaleimide resin is 4,4'-bismaleimide diphenyl methane (CAS: 13676-54-5).

[0071] The low-friction short-cut fiber is a polytetrafluoroethylene fiber with a length of 1000μm, which is purchased from Changzhou Xingcheng High Polymer Co., Ltd.

[0072] The wear-resistant short-cut fiber is a glass fiber with a length of 200μm, which is purchased from Lianyungang Ruichuang New Material Technology Co., Ltd.

[0073] The solvent is acetone.

[0074] A preparation method of a self-lubricating composite coating material, which comprises the following steps: sequentially adding modified cyanate resin, low-friction short-cut fiber, and wear-resistant short-cut fiber into a solvent, mixing uniformly by using a planetary ball mill (300rpm), and vacuumizing (10Pa) to obtain the self-lubricating composite coating material.

[0075] A use method of a self-lubricating composite coating material, which comprises the following steps:

[0076] S1, spraying the composite coating material on a self-lubricating shaft sleeve ZT24282442N;

[0077] S2, pre-curing and then machining;

[0078] S3, post-curing;

[0079] S4, surface treatment of the counter friction pair;

[0080] S5, compounding the self-lubricating bush with the counter friction pair.

[0081] The thickness of the spraying in step S1 is 1.5mm.

[0082] The pre-curing temperature is 180℃, the time is 4 hours, and the thickness of the coating 2 is 0.4mm.

[0083] The material of the counter friction pair is stainless steel, and the stainless steel is high-carbon chromium stainless steel (G102Cr18Mo).

[0084] The post-curing temperature is 250℃, and the time is 4 hours.

[0085] The surface treatment is surface supersonic spraying tungsten carbide treatment.

[0086] The specific parameters of the surface treatment are: tempering temperature is 320℃, surface hardness is 1100HV, and surface roughness is 0.15.

[0087] Example 2

[0088] The specific implementation is the same as that of Example 1; the difference is that in Example 2, the low-friction short-cut fiber is 80 parts, and the solvent is 40 parts. The low-friction short-cut fiber is polyimide fiber with a length of 800μm, which is purchased from Jiangsu Xinnuo New Material Technology Co., Ltd.

[0089] Example 3

[0090] The specific implementation is the same as that of Example 1; the difference is that in Example 3, the surface treatment is diamond-like treatment.

[0091] Comparative Example 1

[0092] The specific implementation is the same as that of Example 1; the difference is that in Comparative Example 1, the low-friction short-cut fiber is 100 parts, and the wear-resistant short-cut fiber is 40 parts.

[0093] Comparative Example 2

[0094] The specific implementation is the same as that of Example 1; the difference is that in Comparative Example 2, the low-friction short-cut fiber is 130 parts, and the wear-resistant short-cut fiber is 10 parts.

[0095] Comparative Example 3

[0096] The specific implementation is the same as that of Example 1; the difference is that in Comparative Example 3, the length of the glass fiber is 3mm, which is purchased from Shandong Yuhang Engineering Material Co., Ltd.

[0097] Performance test method

[0098] The tangent value-temperature curve obtained by DMA test was used to characterize the glass transition temperature of the modified cyanate ester resin. As shown in Figure 1 It can be seen from the curve that the modified cyanate ester resin has only one peak, and the temperature corresponding to the peak is 297.4°C, indicating that there is only one glass transition temperature, and the copolymerization reaction between cyanate ester and bismaleimide has occurred.

[0099] The coating materials after use in Examples 1-3 and Comparative Examples 1-3 were tested for performance.

[0100] Test parameters: ambient temperature 250°C, load 245MPa, swing angle ±25°, frequency 0.2Hz (linear speed 4mm / s, PV value 985MPa*mm / s).

[0101] The wear amount (mm) and average life (times) at 25000 times were recorded, the average life was the number of times reached when worn out, the test curve was as shown in Figures 2-7 and the test data was summarized and listed in Table 1.

[0102] Performance test data

[0103] Table 1

[0104] Wear (mm) Average life (cycles) Example 1 0.14 40000 Example 2 0.12 52000 Example 3 0.09 58000 Comparative Example 1 0.25 30000 Comparative Example 2 0.20 35000 Comparative Example 3 - 17000

Claims

1. A self-lubricating composite coating material, characterized in that, By weight, the components include: 70-130 parts modified cyanate resin, 80-150 parts low-friction chopped fiber, 5-30 parts abrasion-resistant chopped fiber, and 20-50 parts solvent. The modified cyanate resin comprises cyanate ester monomer and bismaleimide resin, wherein the weight ratio of cyanate ester monomer to bismaleimide resin is 92:(5-13). The weight ratio of the low-friction chopped fiber to the wear-resistant chopped fiber is (3-7):1, and the length of the low-friction chopped fiber is 500-1000μm; the wear-resistant chopped fiber includes glass fiber, and the length of the glass fiber is 200-400μm. The method of using the self-lubricating composite coating material is characterized by the following steps: S1, spraying the composite coating material onto the self-lubricating bushing; S2, pre-curing and then machining to obtain coating 2; S3, post-curing coating 2; S4, surface treating the friction pair; S5, combining the self-lubricating bushing with the friction pair; the pre-curing temperature is 140-220℃, and the thickness of coating 2 is 0.2-0.5mm.

2. The self-lubricating composite coating material according to claim 1, characterized in that, The cyanate monomer includes one or more of bisphenol A cyanate monomer, bisphenol E cyanate monomer, bisphenol F cyanate monomer, and tetramethylbisphenol F cyanate monomer.

3. The self-lubricating composite coating material according to claim 1, characterized in that, The weight ratio of the modified cyanate resin to the low-friction chopped fiber is 1:(0.7-1.3).

4. The self-lubricating composite coating material according to claim 1, characterized in that, The surface treatment includes one of tungsten carbide treatment and diamond-like carbon treatment.

5. A method for preparing a self-lubricating composite coating material according to claim 1, characterized in that, The process includes the following steps: adding modified cyanate resin, low-friction chopped fiber, and wear-resistant chopped fiber sequentially to a solvent, ball milling and stirring until uniformly mixed, and then vacuuming to obtain the final product.

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