A wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating, and a preparation method and application thereof

Abstract

The application discloses a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating and a preparation method and application thereof, and relates to the technical field of wide-temperature-range lubricating coating. The adhesive coating raw material comprises an aluminum phosphate adhesive and a filler; the filler comprises graphite nanosheets, chromium oxide-doped molybdenum disulfide and mullite whiskers. The aluminum phosphate / oxidized chromium-doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating is prepared by adopting the air spraying method with the aluminum phosphate adhesive as a matrix and the graphite nanosheets, the chromium oxide-doped molybdenum disulfide and the mullite whiskers as fillers, and can be applied to the lubrication and protection of key moving parts in aerospace.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wide-temperature-range lubricating coating, in particular to a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating and a preparation method and application thereof. BACKGROUND

[0002] In the field of aerospace, some key moving parts are long-term under harsh working conditions, and the surface material is subjected to radiation of various cosmic rays such as atomic oxygen, ultraviolet rays, proton flow, electron flow and the like, and complex and extreme environments such as strong corrosion, high vacuum, high and low temperature cycles, microgravity, and the like. Multi-factor coupling damage easily leads to rapid degradation of service performance and even failure. The lubrication and friction reduction of the surface of related equipment parts cannot be achieved by relying on conventional organic lubricating oil. Therefore, the preparation of a surface lubricating wear-resistant coating is an effective way to improve the service performance of the parts.

[0003] In the prior art, aluminum chromium phosphate is used as an adhesive, and colloidal graphite is used as a solid lubricant to prepare an adhesive solid lubricating coating, which has excellent friction reduction and wear resistance. A self-adaptive phosphate composite coating is prepared by using aluminum chromium phosphate as a binder and adding solid lubricants MoS2 and Ag. It is found that the composite coating with an Ag / MoS2 mass ratio of 2:1 has a stable low friction coefficient at room temperature to 700 DEG C, and a low wear rate. A graphite phosphate composite coating is prepared by using aluminum chromium phosphate as a binder, which has good tribological behavior at high temperatures of 400 DEG C to 700 DEG C, but fails to lubricate at 200 DEG C to 300 DEG C. The person skilled in the art improves the adhesion and wear rate by doping titanium dioxide on the inorganic phosphate coating to construct a micro-nano structure. At the same time, phosphate is selected as a film-forming material, and metal powders such as Ni powder and Al powder and high-temperature-resistant powders such as aluminum oxide and silicon oxide are selected as fillers to prepare a phosphate coating for high-temperature protection of titanium-based high-temperature alloys. It can be seen that the existing phosphate-based composite coatings have the problems of low strength, poor toughness, poor wear resistance and the like. The added solid lubricant components are single, and the application in the lubrication field mostly focuses on high temperature, and the lubrication effect is limited at a wide temperature range (especially in a low temperature environment). Moreover, the existing technical methods generally use chromium phosphate or aluminum chromium phosphate as a binder, and the binder contains chromium ions, which has certain toxicity and is not friendly to the environment. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a wide temperature range self-lubricating inorganic phosphate-based bonded coating and a preparation method and application thereof. The coating takes aluminum phosphate binder as the matrix, graphite nanosheet, chromium oxide doped molybdenum disulfide and mullite whisker as the filler, and an aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating is prepared by an air spraying method. Compared with the traditional phosphate-based bonded coating, the coating prepared by the present application has better bonding property, wear resistance and strength, can have good lubricating property in a wide temperature range (-120-500 DEG C), and can be used in high and low temperature cyclic working conditions.

[0005] The first object of the present application is to provide a wide temperature range self-lubricating inorganic phosphate-based bonded coating, wherein the raw material of the bonded coating comprises aluminum phosphate binder and filler; the filler comprises graphite nanosheet, chromium oxide doped molybdenum disulfide and mullite whisker.

[0006] Preferably, the mass ratio of the aluminum phosphate binder and the filler is 7:3.

[0007] The mass ratio of the graphite nanosheet, the chromium oxide doped molybdenum disulfide and the mullite whisker is 1:1:1-3.

[0008] Preferably, the preparation method of the aluminum phosphate binder comprises the following steps:

[0009] A certain amount of deionized water and phosphoric acid are mixed, heated to 80-85 DEG C, then aluminum hydroxide is added, stirred uniformly, the temperature is raised to 95-100 DEG C, and the reaction is continued for 100-120 min, thereby obtaining the aluminum phosphate binder.

[0010] Preferably, the molar ratio of the phosphoric acid and the aluminum hydroxide is 3:1.3-1.5.

[0011] The second object of the present application is to provide a preparation method of a wide temperature range self-lubricating inorganic phosphate-based bonded coating, comprising the following steps:

[0012] Preparation of aluminum phosphate binder;

[0013] The aluminum phosphate binder and the filler are uniformly dispersed in deionized water according to a certain mass ratio, thereby obtaining a mixed coating;

[0014] The mixed coating is sprayed onto the substrate, and after curing treatment, the wide temperature range self-lubricating inorganic phosphate-based bonded coating is prepared on the substrate.

[0015] Preferably, before the mixed coating is sprayed onto the substrate, the substrate is treated, comprising the following steps:

[0016] The substrate is polished to be scratch-free by sandpaper, ultrasonically cleaned with anhydrous ethanol and dried, and then the substrate is subjected to sand blasting treatment.

[0017] Preferably, when the mixed coating is sprayed onto the substrate, the spraying is carried out by using the air spraying method, using a spray gun with a caliber of 1-2 mm, a spray gun air pressure of 0.3-0.5 MPa, and a spray gun distance from the substrate of 15-25 cm;

[0018] And the spray gun is kept at a right angle with the substrate and runs parallel during the spraying process, reciprocating 1-2 times, and the coating thickness is 50-100 mu m.

[0019] Preferably, the solidification process comprises:

[0020] After the mixed coating is sprayed onto the substrate, the solidification is carried out at 120-150 DEG C for 120-150 min, and then the solidification is carried out at 300-320 DEG C for 60-80 min.

[0021] Preferably, the number of layers of the graphite nanosheet is 5-10 layers, the thickness is <100 nm, the carbon content is >95%, the diameter of the mullite whisker is 0.5-1 mu m, and the length is 15-20 mu m.

[0022] The preparation method of the chromium oxide doped molybdenum disulfide comprises:

[0023] According to a molar ratio of 1:1, ammonium molybdate and thiourea are dispersed in a certain amount of deionized water, chromium oxide is added according to a molar ratio of ammonium molybdate to chromium oxide of 1:9, the mixture is uniformly mixed to obtain a mixed solution, the mixed solution is moved to a hydrothermal reaction kettle, and the hydrothermal reaction kettle is placed in a drying box and dried at 200 DEG C for 24 h to obtain chromium oxide doped molybdenum disulfide.

[0024] The third object of the present application is to provide an application of the wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating in lubrication or protection.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] The application provides a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating and a preparation method and application thereof.The wide-temperature-range phosphate-based lubricating coating is prepared by an air spraying method, the preparation is carried out at room temperature, the process is easy to control, the cost is low, the preparation is convenient to realize, the preparation period is short, and the application is environment-friendly.Because the aluminum phosphate adhesive is used as a matrix, the coating has excellent adhesion, heat resistance and oxidation resistance, and has low preparation cost, non-toxicity and environmental protection.Because the graphite nanosheet and the chromium oxide doped molybdenum disulfide are added in the component, the two have a certain synergistic lubricating effect, so that the coating has excellent lubricating performance in a wide temperature range.Because the mullite whisker is added in the component, the mullite whisker has the advantages of small whisker structure, high melting point, good chemical stability and high strength, so that the coating has higher strength, wear resistance and high-temperature resistance.The phosphate-based lubricating coating prepared by the application has good adhesion, wear resistance and high strength, and can realize self-lubricating function in a wide temperature range (-120-500 DEG C).

[0027] In the application, the graphite nanosheet is laid in the form of a sheet layer between layers of the aluminum phosphate adhesive, and is filled in the pores of the aluminum phosphate adhesive together with the MoS2, Cr2O3 and mullite whisker, so that the P-O-Al network crosslinking structure of the aluminum phosphate adhesive is strengthened, the density and strength of the coating are improved, and the toughness and load capacity of the coating are improved.The aluminum phosphate adhesive and the mullite whisker mainly exist in the form of amorphous, the amorphous passivation film reduces the direct contact of the friction pair to a certain extent, and then reduces the friction and wear.The layered graphite nanosheet and the MoS2 contained in the amorphous passivation film further provide an interface easy to shear to reduce the friction and wear.Therefore, the synergistic effect of the aluminum phosphate adhesive and the added phases is beneficial to forming a complete lubricating film in the friction process, reducing the interlayer shear strength, achieving the synergistic lubricating effect, improving the tribological performance of the coating, and enabling the coating to realize the self-lubricating function in a wide temperature range. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is an SEM morphology diagram and an EDS element area scanning diagram of the phosphate-based adhesive coating provided in Example 1;

[0029] Figure 2 is a friction coefficient curve of the lubricating coating in Example 1 at 500 DEG C;

[0030] Figure 3 is a friction coefficient curve of the lubricating coating in Example 2 at 250 DEG C;

[0031] Figure 4 is a friction coefficient curve of the lubricating coating in Example 3 at room temperature (20 DEG C);

[0032] Figure 5 is a friction coefficient curve of the lubricating coating in Example 4 at -120 DEG C. DETAILED DESCRIPTION

[0033] In order to make the technical personnel of the present application better understand the technical solutions of the present application, the present application is further described below in conjunction with specific examples and drawings, but the examples are not as a limitation of the present application.

[0034] The present application uses aluminum phosphate binder as the matrix, graphite nanosheet, chromium oxide doped molybdenum disulfide, and mullite whisker as the filler, and prepares an aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating by an air spraying method, which can be applied to the lubrication and protection of key moving parts in aerospace. Compared with the prior art method, the preparation method of the present application is simpler, easier to implement, has a short preparation period, is environmentally friendly, and has better adhesion, wear resistance, and strength than the traditional phosphate-based adhesive coating. The coating prepared by the present application has good lubricating performance in a wide temperature range (-120-500 ℃) and can be used in high and low temperature cycle conditions.

[0035] The present application provides a wide temperature range self-lubricating inorganic phosphate-based adhesive coating in a first aspect. The raw materials of the adhesive coating include aluminum phosphate binder and filler. The filler includes graphite nanosheet, chromium oxide doped molybdenum disulfide, and mullite whisker. The mass ratio of the aluminum phosphate binder and the filler is 7:3. The mass ratio of the graphite nanosheet, the chromium oxide doped molybdenum disulfide, and the mullite whisker is 1:1:1-3.

[0036] The preparation method of the aluminum phosphate binder includes:

[0037] A certain amount of deionized water and phosphoric acid are mixed, heated to 80-85 ℃, then aluminum hydroxide is added, stirred uniformly, the temperature is raised to 95-100 ℃, and the reaction is continued for 100-120 min to obtain the aluminum phosphate binder.

[0038] The molar ratio of the phosphoric acid and the aluminum hydroxide is 3:1.3-1.5.

[0039] The present application uses aluminum phosphate binder as the matrix, graphite nanosheet, chromium oxide doped molybdenum disulfide, and mullite whisker as the filler, and prepares an aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating by an air spraying method, which can be applied to the lubrication and protection of key moving parts in aerospace. The preparation process of the present application is simple, has low cost, high controllability, and is environmentally friendly. The coating prepared by the present application has good adhesion, wear resistance, and high strength, and can realize self-lubricating function in a wide temperature range (-120-500 ℃).

[0040] The second aspect of the present application provides a preparation method of a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating, comprising the following steps: preparing an aluminum phosphate adhesive; uniformly dispersing the aluminum phosphate adhesive and the filler in deionized water according to a certain mass ratio to obtain a mixed coating; and spraying the mixed coating onto a substrate and performing a curing treatment to obtain the wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating on the substrate.

[0041] Before the mixed coating is sprayed onto the substrate, the substrate is treated, comprising:

[0042] The substrate is polished to be scratch-free, ultrasonically cleaned with anhydrous ethanol and dried, and then the substrate is sandblasted. When the mixed coating is sprayed onto the substrate, the air spraying method is used for spraying, the spray gun caliber is 1-2 mm, the spray gun air pressure is 0.3-0.5 MPa, the spray gun is 15-25 cm away from the substrate; and the spray gun and the substrate are kept at a right angle and run parallel during the spraying process, reciprocate 1-2 times, and the coating thickness is 50-100 μm.

[0043] The curing treatment process comprises: after the mixed coating is sprayed onto the substrate, curing at 120-150 ℃ for 120-150 min, and then curing at 300-320 ℃ for 60-80 min.

[0044] The graphite nanosheet has the following properties: number of layers: 5-10 layers; thickness: <100 nm; carbon content: >95%; and diameter-thickness ratio: average 9500.

[0045] The preparation method of the chromium oxide doped molybdenum disulfide comprises the following steps:

[0046] The one-step hydrothermal method is used for preparation. First, a certain amount of ammonium molybdate ((NH4)6Mo7O 24 ·4H2O) and thiourea (CN2H4S) are weighed according to a molar ratio of 1:1 and dispersed in a certain amount of deionized water, a certain amount of chromium oxide (Cr2O3) is added according to a molar ratio of ammonium molybdate to chromium oxide of 1:9, and magnetic stirring is performed for 30-40 min, and ultrasonic treatment is performed for 50-60 min until the mixture is fully mixed. Then, the mixed solution is transferred to a 100 ml hydrothermal reaction kettle, which is placed in a drying box at 200 ℃ for 24 h. After natural cooling to room temperature, deionized water and anhydrous ethanol are used for washing, and the final precipitate is collected by centrifugation. Finally, the precipitate is placed in a vacuum drying box at 60 ℃ for 12 h to obtain the MoS2-Cr2O3 lubricating material.

[0047] The mullite whisker has the following properties: diameter: 0.5-1 μm; and length: 15-20 μm.

[0048] In the embodiment, the application provides a preparation method of a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating, and particularly relates to a preparation of a wide-temperature-range lubricating coating by using an aluminum phosphate adhesive as a base body and adding multi-component solid lubricants and fillers (graphite nanosheet, chromium oxide doped molybdenum disulfide and mullite whisker), the prepared coating has excellent lubricating effect at -120-500 ℃, the prepared coating can be used in bearings, bushings, bearing pads and other parts of aerospace equipment, and lubrication and protection under high and low temperature alternating conditions are provided. The specific steps are as follows:

[0049] (1) Preparation of aluminum phosphate adhesive:

[0050] The aluminum phosphate adhesive is prepared by using Al(OH)3 and 85% H3PO4 as raw materials by adopting a constant-temperature water bath method. First, a certain amount of deionized water and phosphoric acid are added to a three-necked flask, and after being heated to 80-85 ℃ under stirring, aluminum hydroxide is added according to the molar ratio of phosphoric acid to aluminum hydroxide of 3:1.3-1.5, and after being uniformly stirred, the temperature is increased to 95-100 ℃, and the reaction is continuously carried out for 100-120 min to prepare the aluminum phosphate base body, which is cooled for standby.

[0051] (2) Preparation of mixed coating:

[0052] The aluminum phosphate adhesive and fillers prepared above are dispersed into deionized water according to the mass ratio of 7:3, and the fillers include graphite nanosheet, chromium oxide doped molybdenum disulfide and mullite whisker, and the mass ratio of the three is 1:1:1-3. After being uniformly dispersed, magnetic stirring and ultrasonic treatment are carried out until the solution is fully mixed to obtain a uniformly mixed coating.

[0053] (3) Preparation of aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite coating:

[0054] The mixed coating is used to prepare the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating by adopting an air spraying method, and the specific steps include: surface treatment of the base body, polishing to no scratch by using sandpaper, ultrasonic cleaning with anhydrous ethanol and drying, sand blasting treatment of the base body; the coating is prepared by adopting the air spraying method, the spraying gun caliber is 1-2 mm, the spraying gun gas pressure is 0.3-0.5 MPa, the base sheet is horizontally placed, the spraying gun is 15-25 cm away from the base sheet, the spraying gun is kept at a right angle with the base sheet and parallel running during the spraying process, and the spraying gun is reciprocated 1-2 times, the coating thickness is 50-100 μm. After the solvent on the surface is evaporated, the base sheet is solidified at 120-150 ℃ for 120-150 min and solidified at 300-320 ℃ for 60-80 min to obtain the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating.

[0055] The third aspect of the present application provides a wide temperature range self-lubricating inorganic phosphate-based adhesive coating in the application of lubrication or protection.

[0056] It should be noted that the experimental methods used in the present application are conventional methods unless otherwise specified; the reagents and materials used are commercially available unless otherwise specified.

[0057] Example 1

[0058] Preparation of mixed coating:

[0059] First, the constant temperature water bath method was used to prepare aluminum phosphate binder with Al(OH)3 and 85% H3PO4 as raw materials. 28 g of deionized water and 40 g of phosphoric acid were added to a three-necked flask, and after stirring and heating to 80 ℃, 11.73 g of aluminum hydroxide was added in batches to make n(P):n(Al)=3:1.3. After stirring uniformly, the temperature was raised to 95 ℃, and the reaction was continued for 120 min to prepare the aluminum phosphate matrix, which was cooled for standby. Then, 1 g of graphite nanosheet, 1 g of chromium oxide doped molybdenum disulfide, 1 g of mullite whisker and 7 g of the above prepared aluminum phosphate matrix were weighed in turn and dispersed into a certain amount of deionized water, stirred by a magnetic stirrer for 40 min, and ultrasonically treated for 60 min until the solution was fully mixed, to obtain the mixed coating required for spraying.

[0060] Process of forming aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating using the prepared mixed coating:

[0061] 1) First, the surface of the substrate was treated. The 718 high-temperature alloy substrate was polished to be scratch-free by 400 mesh, 800 mesh and 1000 mesh sandpaper, then the substrate was immersed in anhydrous ethanol and ultrasonically treated to remove grease and other impurities, and dried. Finally, the surface of the substrate was sandblasted with quartz sand to improve the adhesion of the coating to the substrate.

[0062] 2) Secondly, the coating was pretreated. A certain amount of coating was weighed and ultrasonically treated for 60 min to make it uniformly mixed, and then the coating was directly loaded into a spray pot for standby.

[0063] 3) The coating was prepared by air spraying method. The spray gun caliber was 1-2 mm, and the spray gun gas pressure was 0.3-0.5 MPa. The substrate was placed horizontally, the spray gun was 15-25 cm away from the substrate, and the spray gun and the substrate were kept at right angles and parallel during the spraying process, with 1-2 times of reciprocating frequency, and the coating thickness was 70 μm.

[0064] 4) Finally, the coating is cured. After the coating is prepared, the substrate is placed in a vacuum drying oven at 120-150 °C for 120-150 min, and then transferred to a muffle furnace for curing. The curing temperature is 300-320 °C, and the curing time is 60-80 min. After the temperature is naturally reduced to room temperature, the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphene nanosheet / mullite composite lubricating coating is obtained.

[0065] Example 2

[0066] Preparation of the mixed coating:

[0067] The process of preparing the aluminum phosphate binder using Al(OH)3 and 85% H3PO4 as raw materials is the same as that of Example 1 and is not repeated. Then, 0.4 g of graphene nanosheet, 0.4 g of chromium oxide doped molybdenum disulfide, 0.7 g of mullite whisker, and 3.5 g of the above prepared aluminum phosphate matrix are sequentially weighed and dispersed into a certain amount of deionized water. The solution is stirred for 20 min using a magnetic stirrer and ultrasonically treated for 30 min until the solution is fully mixed. The mixed coating required for spraying is obtained.

[0068] The process of forming the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphene nanosheet / mullite composite lubricating coating using the prepared mixed coating is the same as that of Example 1 and is not repeated.

[0069] Example 3

[0070] Preparation of the mixed coating:

[0071] The process of preparing the aluminum phosphate binder using Al(OH)3 and 85% H3PO4 as raw materials is the same as that of Example 1 and is not repeated. Then, 0.6 g of graphene nanosheet, 0.6 g of chromium oxide doped molybdenum disulfide, 1.2 g of mullite whisker, and 5.6 g of the above prepared aluminum phosphate matrix are sequentially weighed and dispersed into a certain amount of deionized water. The solution is stirred for 30 min using a magnetic stirrer and ultrasonically treated for 40 min until the solution is fully mixed. The mixed coating required for spraying is obtained.

[0072] The process of forming the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphene nanosheet / mullite composite lubricating coating using the prepared mixed coating is the same as that of Example 1 and is not repeated.

[0073] Example 4

[0074] Preparation of the mixed coating:

[0075] The process of preparing the aluminum phosphate binder using Al(OH)3 and 85% H3PO4 as raw materials is the same as that in Example 1 and is not repeated. Then, 0.7 g of graphite nanosheets, 0.7 g of chromium oxide doped molybdenum disulfide, 1 g of mullite whiskers and 5.6 g of the aluminum phosphate matrix prepared above are sequentially weighed and dispersed into a certain amount of deionized water, stirred by a magnetic stirrer for 30 min and ultrasonically treated for 40 min until the solution is fully mixed, so that a mixed coating required for spraying can be obtained.

[0076] The process of forming the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite lubricating coating using the prepared mixed coating is the same as that in Example 1 and is not repeated.

[0077] Figure 1 The SEM morphology and EDS element area scanning of the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite coating prepared according to Example 1 is shown, and it can be seen that the binder wraps the filler and presents a skeleton shape, and the filler particles have particle agglomeration phenomenon; all elements are detected, and the filler is uniformly dispersed on the surface of the matrix and well combined with the aluminum phosphate binder. The analysis and characterization results of SEM and EDS show that the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite coating has been successfully prepared.

[0078] Table 1 shows the comparison results of the micro Vickers hardness and average friction coefficient of the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite coatings with different component ratios prepared according to the method of the present application, and the hardness of the composite coating is about 200 MPa, which is much higher than that of the aluminum phosphate matrix. The results show that the prepared phosphate-based binder coating has good wear resistance and strength. The average friction coefficient of the composite coating at each temperature is low, indicating that the prepared phosphate-based binder coating has good lubricating performance in a wide temperature range (-120-500 ℃).

[0079] Table 1 is the comparison results of the micro Vickers hardness and average friction coefficient of the aluminum phosphate / chromium oxide doped molybdenum disulfide / graphite nanosheet / mullite composite coatings with different component ratios

[0080]

[0081] In order to further illustrate the related performance of the coating provided by the present application, the coating provided by the example is subjected to high temperature lubricating performance detection, and is described in combination with the drawings, as follows:

[0082] The high temperature friction and wear performance is evaluated by a GF-1200 type high temperature reciprocating friction and wear tester, the counter ball is a ceramic (Si3N4) ball, the high temperature furnace heating temperature is room temperature-1200 ℃, the loading load range is 5-80 N, and the reciprocating stroke is 1-25 mm.

[0083] Low temperature friction and wear properties were evaluated by reciprocating mode of MFT-5000 Rtec multi-functional friction and wear tester, with ceramic (Si3N4) ball as counter ball, low temperature chamber: -120 ℃ temperature chamber, liquid nitrogen cooling, force sensor range: 0.2-20 N, resolution 0.6 mN, rotation module: speed 0.1-5000 rpm.

[0084] In Example 1, the prepared mixed coating was sprayed on 718 high-temperature alloy substrate to form a lubricating coating with a thickness of about 70 μm, and then the high-temperature lubricating friction and wear properties of the coating were evaluated by using GF-1200 type high-temperature reciprocating friction and wear tester. The counter ball was ceramic (Si3N4) ball, the load was 5 N, the rotation speed was 180 rpm, the reciprocating stroke was 3 mm, the running time was 30 min, and the experimental temperature was 500 ℃.

[0085] The steady-state average friction coefficient of the lubricating coating of Example 1 was small, about 0.17, and the value was stable. Compared with the aluminum phosphate substrate, the phosphate-based multi-component composite coating could reduce the friction coefficient by more than 70%. The friction coefficient curve is shown in Figure 2 .

[0086] In Example 2, the prepared mixed coating was sprayed on 718 high-temperature alloy substrate to form a lubricating coating with a thickness of about 70 μm, and then the high-temperature lubricating friction and wear properties of the coating were evaluated by using GF-1200 type high-temperature reciprocating friction and wear tester. The counter ball was ceramic (Si3N4) ball, the load was 5 N, the rotation speed was 180 rpm, the reciprocating stroke was 3 mm, the running time was 30 min, and the experimental temperature was 250 ℃.

[0087] The steady-state average friction coefficient of the lubricating coating of Example 2 was small, about 0.25, and the value was stable. Compared with the aluminum phosphate substrate, the phosphate-based multi-component composite coating could reduce the friction coefficient by more than 60%. The friction coefficient curve is shown in Figure 3 .

[0088] In Example 3, the prepared mixed coating was sprayed on 718 high-temperature alloy substrate to form a lubricating coating with a thickness of about 70 μm, and then the room temperature lubricating friction and wear properties of the coating were evaluated by using GF-1200 type high-temperature reciprocating friction and wear tester. The counter ball was ceramic (Si3N4) ball, the load was 5 N, the rotation speed was 180 rpm, the reciprocating stroke was 3 mm, the running time was 30 min, and the experimental temperature was 20 ℃.

[0089] The steady state average friction coefficient of the lubricating coating of Example 3 is small, about 0.22, and the value is stable. Compared with the aluminum phosphate substrate, the phosphate-based multi-component composite coating can reduce the friction coefficient by more than 70%. The friction coefficient curve is shown in Figure 4 .

[0090] In Example 4, the prepared high-temperature lubricant is sprayed on the 718 high-temperature alloy substrate to form a lubricating coating with a thickness of about 70 μm, and then the low-temperature lubrication friction and wear performance of the coating is evaluated by using the MFT-5000 Rtec multifunctional friction and wear tester. The counter ball is a ceramic (Si3N4) ball, the load is 5 N, the rotation speed is 120 rpm, the running time is 30 min, and the experimental temperature is -120 ℃.

[0091] The steady state average friction coefficient of the lubricating coating of Example 4 is small, about 0.26, and the value is stable. Compared with the aluminum phosphate substrate, the phosphate-based multi-component composite coating can reduce the friction coefficient by more than 60%. The friction coefficient curve is shown in Figure 5 .

[0092] Although the embodiments of the present application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A wide temperature range self-lubricating inorganic phosphate-based bond coat characterized in that, The adhesive coating raw material comprises an aluminum phosphate adhesive and a filler; the filler comprises graphite nanosheets, chromium oxide doped molybdenum disulfide, and mullite whiskers; The mass ratio of the aluminum phosphate adhesive and the filler is 7:3; The mass ratio of the graphite nanosheets, the chromium oxide doped molybdenum disulfide, and the mullite whiskers is 1:1:1-3; The preparation method of the aluminum phosphate adhesive comprises: A certain amount of deionized water and phosphoric acid are mixed, heated to 80-85℃, then aluminum hydroxide is added, stirred uniformly, and then the temperature is raised to 95-100℃, and the reaction is continued for 100-120 min to obtain the aluminum phosphate adhesive; The molar ratio of the phosphoric acid and the aluminum hydroxide is 3:1.3-1.5; The graphite nanosheets have 5-10 layers, a thickness of <100 nm, and a carbon content of >95%; the mullite whiskers have a diameter of 0.5-1 μm and a length of 15-20 μm; The preparation method of the chromium oxide doped molybdenum disulfide comprises: Ammonium molybdate and thiourea are weighed according to a molar ratio of 1:1, dispersed in a certain amount of deionized water, then chromium oxide is added according to a molar ratio of ammonium molybdate to chromium oxide of 1:9, mixed uniformly to obtain a mixed solution, the mixed solution is moved to a hydrothermal reaction kettle, and dried in a drying oven at 200℃ for 24 h to obtain chromium oxide doped molybdenum disulfide.

2. A method of producing the wide temperature range self-lubricating inorganic phosphate-based bond coat according to claim 1, characterized by, The method comprises the following steps: Preparation of an aluminum phosphate adhesive; The aluminum phosphate adhesive and the filler are uniformly dispersed in deionized water to obtain a mixed coating; The mixed coating is sprayed onto a substrate, and a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating is prepared on the substrate through solidification treatment.

3. The method for preparing a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating according to claim 2, characterized in that, Before the mixed coating is sprayed onto the substrate, the substrate is treated, which comprises: The substrate is polished to be free of scratches by sandpaper, ultrasonically cleaned with anhydrous ethanol, dried, and then sandblasted.

4. The method for preparing a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating according to claim 2, characterized in that, When the mixed coating is sprayed onto the substrate, air spraying is adopted, the spray gun caliber is 1-2 mm, the spray gun gas pressure is 0.3-0.5 MPa, the spray gun is 15-25 cm away from the substrate, the spray gun is kept at a right angle to the substrate and runs in parallel, and the coating thickness is 50-100 μm. The solidification treatment process comprises:

5. The method for preparing a wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating according to claim 2, characterized in that, After the mixed coating is sprayed onto the substrate, the substrate is solidified at 120-150℃ for 120-150 min, and then solidified at 300-320℃ for 60-80 min.

6. Application of the wide-temperature-range self-lubricating inorganic phosphate-based adhesive coating in lubrication or protection. ​

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