One-way belt pulley of engine and preparation process of one-way belt pulley

Abstract

The invention relates to the technical field of belt pulleys, in particular to an engine one-way belt pulley and a preparation technology thereof.The preparation technology of the engine one-way belt pulley comprises the following steps that first nano particles are prepared; mixing the first nano particles with an adhesive and an auxiliary agent to obtain first mixed powder; a belt pulley is provided, the belt pulley is heated, then the first mixed powder is added into spraying equipment, and the first mixed powder is sprayed to the surface of the belt pulley through the spraying equipment; and then carrying out further hot pressing treatment to obtain the surface-modified belt pulley. Through the preparation process provided by the invention, the belt pulley with relatively good wear resistance, corrosion resistance, hydrophobicity and oleophobicity can be obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of pulleys, and particularly to a one-way pulley for an engine and its preparation process. Background Art

[0002] In modern mechanical transmission systems, pulleys, as key components, undertake the important functions of power transmission and motion conversion. From industrial production equipment to various means of transportation, the performance and lifespan of pulleys play a decisive role in the overall operating efficiency and stability. However, during long-term operation, the surface of the pulley is subject to wear and corrosion by various factors, resulting in a gradual decline in performance and even failures.

[0003] On the one hand, when the pulley surface continuously contacts and undergoes frictional transmission with the belt, mechanical wear inevitably occurs. As the usage time prolongs, this wear intensifies, changing the shape of the pulley groove, and thus affecting the correct meshing and transmission accuracy of the belt. Especially under high-load and high-speed working conditions, the wear rate of the pulley surface is faster, not only reducing the transmission efficiency but also possibly causing problems such as vibration and noise, seriously affecting the normal operation of mechanical equipment. On the other hand, various corrosive factors in the working environment cannot be ignored. For example, in humid, acidic, alkaline, or chemically medium-containing environments, the pulley surface is prone to chemical corrosion, forming defects such as oxide layers and corrosion pits. These corrosion phenomena further weaken the strength and surface quality of the pulley, shortening its service life, and may even cause the pulley to suddenly break during use, leading to safety accidents.

[0004] With the continuous development of materials science and surface engineering technologies, higher requirements have been put forward for pulley surface modification processes. In recent years, the application research of nanotechnology, new coating materials, and advanced spraying processes in the field of pulley surface modification has gradually emerged. For example, nano-particle reinforced coatings can significantly improve the hardness, wear resistance, and corrosion resistance of the coating by adding nano-materials to the coating; advanced spraying processes such as plasma spraying can achieve good bonding between the coating and the substrate, improving the density and uniformity of the coating. These new surface modification technologies provide new ways to improve the performance and lifespan of pulleys. Summary of the Invention

[0005] The purpose of the present invention is to provide a one-way pulley for an engine and its preparation process to solve the problems of improving the wear resistance, corrosion resistance, hydrophobic and oleophobic properties, etc. of the pulley as mentioned in the above background art.

[0006] To achieve the above purpose, the present invention provides the following technical solution: According to the first aspect of the embodiments of the present disclosure, a preparation process for a one-way pulley for an engine is provided, including the following steps: Step 1: Prepare the first nano-particles; Step 2: Mix the first nanoparticles with a binder and additives to obtain a first mixed powder; Step 3: Provide a pulley, heat the pulley to 250°C - 400°C, then add the first mixed powder prepared in Step 1 to a spraying device, and spray the first mixed powder on the surface of the pulley through the spraying device to obtain the pulley of Step 3; Step 4: Perform hot pressing on the pulley prepared in Step 3 to obtain a pulley with surface modification.

[0007] In one aspect of the embodiments of the present disclosure, the first nanoparticles comprise at least one metal-organic framework material.

[0008] In one aspect of the embodiments of the present disclosure, preferably, the first nanoparticles are a metal-organic framework material.

[0009] In one aspect of the embodiments of the present disclosure, in the metal-organic framework material, at least one metal-organic framework material contains rare earth elements; the rare earth elements are selected from La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Yb, Sc or Y.

[0010] In one aspect of the embodiments of the present disclosure, the first nanoparticles are a metal-organic framework material containing rare earth elements; the rare earth elements are selected from La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Yb, Sc or Y.

[0011] In one aspect of the embodiments of the present disclosure, the rare earth elements are selected from La, Ce, Gd, Yb, Sc or Y.

[0012] In one aspect of the embodiments of the present disclosure, the first nanoparticles are a metal-organic framework material, the metal-organic framework material contains rare earth elements, and the rare earth elements are selected from La, Ce, Gd, Yb, Sc or Y.

[0013] In one aspect of the embodiments of the present disclosure, specifically, the rare earth elements are selected from Y.

[0014] In one aspect of the embodiments of the present disclosure, the metal-organic framework material is prepared through the following steps: Step 1-1: Provide a salt of rare earth elements; add the salt of rare earth elements and 3,5-dichlorobenzaldehyde to DMF, then dropwise add glacial acetic acid, stir for 20 - 45 min, and then age for 8 - 20 h to obtain a first mixed solution; Step 1-2: Add bis(trichloromethyl) carbonate to the first mixed solution, then heat it at 150°C - 180°C for 16 - 48 h, and then collect the solid after filtration, washing, and drying; Step 1-3: Heat the solid prepared in Step 1-2 to 500°C - 600°C under a nitrogen atmosphere and hold for 5 - 8 h to obtain the metal-organic framework material.

[0015] In one aspect of the embodiments of the present disclosure, the metal-organic framework material is prepared through the following steps: Step 1-1: Provide a salt of a rare earth element; add the salt of the rare earth element and 3,5-dichlorobenzaldehyde to DMF, then dropwise add glacial acetic acid, stir for 20 - 30 min, and then age for 8 - 12 h to obtain a first mixed solution; wherein, the molar ratio of the salt of the rare earth element to 3,5-dichlorobenzaldehyde is selected from 1:(4 - 7); Step 1-2: Add bis(trichloromethyl) carbonate to the first mixed solution, then heat it at 150°C - 180°C for 20 - 30 h, and then collect the solid after filtration, washing, and drying; wherein, the molar ratio of the salt of the rare earth element to bis(trichloromethyl) carbonate is selected from 1:(0.25 - 0.45); Step 1-3: Heat the solid prepared in Step 1-2 from room temperature to 550°C - 600°C at a heating rate of 3 - 5°C / min under a nitrogen atmosphere, hold for 5 - 8 h, and then naturally cool to room temperature to obtain the metal-organic framework material.

[0016] In one aspect of the embodiments of the present disclosure, in Step 1-1, the mass of glacial acetic acid added is 10% - 25% of the mass of the salt of the rare earth element.

[0017] In one aspect of the embodiments of the present disclosure, specifically, the metal-organic framework material is prepared through the following steps: Step 1-1: Provide a salt of a rare earth element; add the salt of the rare earth element and 3,5-dichlorobenzaldehyde to DMF, then dropwise add glacial acetic acid, stir for 30 min, and then age for 12 h to obtain a first mixed solution; wherein, the molar ratio of the salt of the rare earth element to 3,5-dichlorobenzaldehyde is selected from 1:5.5; the mass of glacial acetic acid added is 20% of the mass of the salt of the rare earth element; the salt of the rare earth element is a nitrate or hydrochloride of the rare earth element; Step 1-2: Add bis(trichloromethyl) carbonate to the first mixed solution, then heat it at 175°C for 24 h, and then collect the solid after filtration, washing, and drying; wherein, the molar ratio of the salt of the rare earth element to bis(trichloromethyl) carbonate is selected from 1:0.35; Step 1-3: Heat the solid prepared in Step 1-2 from room temperature to 580 °C at a heating rate of 5 °C / min under a nitrogen atmosphere, hold for 6 h, and then cool naturally to room temperature to obtain the metal-organic framework material.

[0018] In one aspect of the embodiments of the present disclosure, the binder is selected from inorganic silicate binders or inorganic phosphate binders; preferably an inorganic phosphate binder.

[0019] In one aspect of the embodiments of the present disclosure, specifically, the inorganic phosphate binder is selected from aluminum dihydrogen phosphate.

[0020] In one aspect of the embodiments of the present disclosure, the auxiliary agent is selected from potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium dihydrogen phosphate or calcium dihydrogen phosphate.

[0021] In one aspect of the embodiments of the present disclosure, specifically, the auxiliary agent is selected from ammonium dihydrogen phosphate.

[0022] In one aspect of the embodiments of the present disclosure, Step 2 includes: Step 2-1: Provide a binder and an auxiliary agent, wherein the binder is selected from inorganic silicate binders or inorganic phosphate binders; the auxiliary agent is selected from potassium dihydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium dihydrogen phosphate or calcium dihydrogen phosphate; the mass ratio of the first nanoparticles, the binder and the auxiliary agent is selected from 1:(0.15-0.25):(0.1-0.2); Step 2-2: Ball mill the first nanoparticles, the binder and the auxiliary agent to obtain a first mixed powder.

[0023] In one aspect of the embodiments of the present disclosure, in Step 2-2, the ball milling parameters are: the ball milling speed is selected from 200-300 r / min, the ball-to-material mass ratio is selected from 8:1-10:1, and the ball milling time is selected from 4-8 h.

[0024] In one aspect of the embodiments of the present disclosure, Step 3 includes: Step 3-1: Provide a pulley, wash, sandblast and wash the pulley again to obtain a pretreated pulley; Step 3-2: Heat the pretreated pulley to 250 °C - 300 °C; Step 3-3: Add the first mixed powder to the powder feeder in a cold spraying device, and uniformly spray the first mixed powder on the surface of the pulley by a cold spraying process to obtain the pulley of Step 3-2; wherein the carrier gas pressure is selected from 3-8 MPa; the spraying speed is selected from 200-600 m / s; the carrier gas temperature is selected from 80 °C - 300 °C; the spraying distance is selected from 10-50 mm.

[0025] In one aspect of the embodiments of the present disclosure, specifically, step 3 includes: Step 3-1: Provide a pulley, and subject the pulley to washing, sandblasting, and then washing again to obtain a pretreated pulley; Step 3-2: Heat the pretreated pulley to 280 °C; Step 3-3: Add the first mixed powder to the powder feeder in the cold spraying equipment, and evenly spray the first mixed powder on the surface of the pulley through the cold spraying process to obtain the pulley of step 3-2; wherein, the carrier gas pressure is selected from 5 MPa; the spraying speed is selected from 400 m / s; the carrier gas temperature is selected from 250 °C; the spraying distance is selected from 35 mm.

[0026] In one aspect of the embodiments of the present disclosure, in the cold spraying process, the nozzle used can be a Laval nozzle, a nozzle with a circular cross-section, a nozzle with a rectangular cross-section, or a nozzle with an elliptical cross-section, and the present disclosure is not limited thereto.

[0027] In one aspect of the embodiments of the present disclosure, step 4 includes: Step 4-1: Perform vacuum hot pressing on the pulley obtained in step 3-3; wherein, the hot pressing pressure is selected from 5-8 MPa; the hot pressing time is selected from 60-90 min; the hot pressing temperature is selected from 800 °C - 900 °C; the heating rate is selected from 10-15 °C / min; Step 4-2: After completing the vacuum hot pressing treatment, allow the pulley to cool with the furnace. When the temperature drops to 200 °C, introduce air and continue to cool down to room temperature to obtain the surface-modified pulley.

[0028] In one aspect of the embodiments of the present disclosure, specifically, step 4 includes: Step 4-1: Perform vacuum hot pressing on the pulley obtained in step 3-3; wherein, the hot pressing pressure is selected from 6.5 MPa; the hot pressing time is selected from 90 min; the hot pressing temperature is selected from 900 °C; the heating rate is selected from 10 °C / min; Step 4-2: After completing the vacuum hot pressing treatment, allow the pulley to cool with the furnace. When the temperature drops to 200 °C, introduce air and continue to cool down to room temperature to obtain the surface-modified pulley.

[0029] Compared with the prior art, the beneficial effect of the present disclosure is that: through the preparation process of the engine one-way pulley provided by the present disclosure, a pulley with good wear resistance, corrosion resistance, water repellency, and oil repellency can be obtained. Description of the Drawings

[0030] The drawings here are incorporated into the specification and form a part of this specification, showing the embodiments that conform to the present disclosure, and are used together with the specification to explain the principles of the present disclosure.

[0031] Figure 1 TEM images of the metal-organic framework materials prepared in Example 1 of the present disclosure; Figure 2 TEM images of the metal-organic framework materials prepared in Example 2 of the present disclosure; Figure 3 TEM images of the metal-organic framework materials prepared in Example 3 of the present disclosure. Detailed implementation manners

[0032] The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0033] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments. Apparently, the described embodiments are some but not all of the embodiments of the present application. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of the present application. The embodiments of the present application should not be construed as a limitation of the present application.

[0034] For the sake of brevity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, each individually disclosed point or single numerical value itself can be used as a lower limit or an upper limit and combined with any other point or single numerical value or combined with other lower limits or upper limits to form a range not explicitly recited.

[0035] In this document, the term "comprising", "including" or any other variant thereof is intended to cover a non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0036] In the description herein, unless otherwise specified, "above" and "below" include the corresponding numbers.

[0037] Unless otherwise specified, the terms used in this disclosure have the well-known meanings commonly understood by those skilled in the art. Unless otherwise specified, the numerical values of the various parameters mentioned in this disclosure can be measured by various commonly used measurement methods in the art (for example, they can be tested according to the methods given in the embodiments of this disclosure).

[0038] The term "about" is used to describe and account for small variations. When used in connection with an event or circumstance, the term can refer to instances where the event or circumstance occurs precisely as well as instances where it occurs very nearly. For example, when used in connection with a numerical value, the term can refer to a variation range of ±10% or less than or equal to the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, sometimes quantities, ratios, and other numerical values are presented in a range format in this document. It should be understood that such range formats are for convenience and brevity, and should be understood flexibly to include not only the numerical values explicitly specified as range limits, but also all individual numerical values or sub-ranges subsumed within the said range, as if each numerical value and sub-range were explicitly specified.

[0039] A list of items connected by the terms "at least one of", "at least a", "at least one kind of" or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A can include a single component or multiple components. Item B can include a single component or multiple components. Item C can include a single component or multiple components.

[0040] The present disclosure will be further elaborated below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present disclosure and not to limit the scope of the present disclosure.

[0041] Embodiments Embodiment 1 Embodiment 1 includes the following steps: 1. Prepare a metal-organic framework material: Yttrium nitrate hexahydrate (3.83 g, 10 mmol), 3,5-dichlorobenzaldehyde (9.625 g, 6.875 mL, 55 mmol) were added to 80 mL of DMF, then 0.73 mL of glacial acetic acid (0.766 g) was added dropwise, and the mixture was stirred for 30 min and then aged for 12 h to obtain a first mixed solution; 1 g of bis(trichloromethyl) carbonate (3.5 mmol) was added to the first mixed solution, and then the mixture was heated at 175 °C for 24 h, and then the solid was collected after filtration, washing, and drying; the collected solid was heated from room temperature to 580 °C at a heating rate of 5 °C / min under a nitrogen atmosphere and held for 6 h, and then naturally cooled to room temperature to obtain the metal-organic framework material of Example 1; the TEM image of the metal-organic framework material of Example 1 is as Figure 1 shown.

[0042] The above steps can be repeated multiple times to prepare sufficient metal-organic framework materials.

[0043] 2. Surface modification: Provide 10 parts by weight of the metal-organic framework material prepared above, 2 parts by weight of the binder aluminum dihydrogen phosphate, and 1.5 parts by weight of the auxiliary ammonium dihydrogen phosphate; the metal-organic framework material, the binder, and the auxiliary are ball-milled to obtain a first mixed powder; the ball-milling parameters are: the ball-milling speed is 250 r / min, the ball-to-material mass ratio is selected from 8:1, and the ball-milling time is selected from 6 h.

[0044] Provide a pulley (the size specifications of the pulleys used in the examples and comparative examples are the same, spb150-03 type pulley), wash the pulley, perform sandblasting treatment, and wash it again to obtain a pretreated pulley; heat the pretreated pulley to 280 °C; add the first mixed powder to the powder feeder in the cold spraying equipment, and evenly spray the first mixed powder on the surface of the pulley through the cold spraying process; wherein, the carrier gas pressure is selected from 5 MPa; the spraying speed is selected from 400 m / s; the carrier gas temperature is selected from 250 °C; the spraying distance is selected from 35 mm.

[0045] Perform vacuum hot pressing on the pulley; wherein, the hot pressing pressure is selected from 6.5 MPa; the hot pressing time is selected from 90 min; the hot pressing temperature is selected from 900 °C; the heating rate is selected from 10 °C / min; after the vacuum hot pressing treatment is completed, the pulley is cooled with the furnace, and when the temperature drops to 200 °C, air is introduced and it continues to drop to room temperature to obtain the surface-modified pulley of Example 1.

[0046] Example 2 Example 2 includes the following steps: 1. Preparation of metal-organic framework material: Yttrium nitrate hexahydrate (3.83 g, 10 mmol), 3,5-dichlorobenzaldehyde (9.625 g, 6.875 mL, 55 mmol) were added to 80 mL of DMF, and then 0.73 mL of glacial acetic acid (0.766 g) was added dropwise. After stirring for 30 min, it was aged for 12 h to obtain a first mixed solution; it was heated at 175 °C for 24 h, and then the solid was collected after filtration, washing, and drying; the collected solid was heated from room temperature to 580 °C at a heating rate of 5 °C / min under a nitrogen atmosphere and held for 6 h, and then naturally cooled to room temperature to obtain the metal-organic framework material of Example 2; the TEM image of the metal-organic framework material of Example 2 is as Figure 2 shown.

[0047] The above steps can be repeated multiple times to prepare enough metal-organic framework materials.

[0048] 2. Surface modification: 10 parts by weight of the metal-organic framework material prepared above, 2 parts by weight of binder aluminum dihydrogen phosphate and 1.5 parts by weight of auxiliary ammonium dihydrogen phosphate were provided; the metal-organic framework material, binder, and auxiliary were ball-milled to obtain a first mixed powder; the ball-milling parameters were: the ball-milling speed was 250 r / min, the ball-to-material mass ratio was selected from 8:1, and the ball-milling time was selected from 6 h.

[0049] A pulley was provided (the size specifications of the pulleys used in the examples and comparative examples were the same, spb150-03 type pulley), and the pulley was washed, sandblasted, and washed again to obtain a pretreated pulley; the pretreated pulley was heated to 280 °C; the first mixed powder was added to the powder feeder in the cold spraying equipment, and the first mixed powder was evenly sprayed on the surface of the pulley by the cold spraying process; among them, the carrier gas pressure was selected from 5 MPa; the spraying speed was selected from 400 m / s; the carrier gas temperature was selected from 250 °C; the spraying distance was selected from 35 mm.

[0050] The pulley was subjected to vacuum hot pressing; among them, the hot pressing pressure was selected from 6.5 MPa; the hot pressing time was selected from 90 min; the hot pressing temperature was selected from 900 °C; the heating rate was selected from 10 °C / min; after the vacuum hot pressing treatment was completed, the pulley was cooled with the furnace. When the temperature dropped to 200 °C, air was introduced, and it continued to drop to room temperature to obtain the surface-modified pulley of Example 2.

[0051] The difference between Example 2 and Example 1 is that bis(trichloromethyl) carbonate was not added during the preparation of the metal-organic framework in Example 2.

[0052] Example 3 Example 3 includes the following steps: 1. Preparation of metal-organic framework material: Magnesium nitrate hexahydrate (2.56 g, 10 mmol) and 3,5-dichlorobenzaldehyde (9.625 g, 6.875 mL, 55 mmol) were added to 80 mL of DMF, and then 0.73 mL of glacial acetic acid (0.766 g) was added dropwise. After stirring for 30 min and then aging for 12 h, a first mixed solution was obtained. 1 g of bis(trichloromethyl) carbonate (3.5 mmol) was added to the first mixed solution, and then it was heated at 175 °C for 24 h. Then, the solid was collected after filtration, washing, and drying. The collected solid was heated from room temperature to 580 °C at a heating rate of 5 °C / min under a nitrogen atmosphere and held for 6 h, and then naturally cooled to room temperature to obtain the metal-organic framework material of Example 3. The TEM image of the metal-organic framework material of Example 3 is as Figure 3 shown.

[0053] The above steps can be repeated multiple times to prepare sufficient metal-organic framework materials.

[0054] 2. Surface modification: 10 parts by weight of the metal-organic framework material prepared above, 2 parts by weight of the binder aluminum dihydrogen phosphate, and 1.5 parts by weight of the auxiliary ammonium dihydrogen phosphate were provided. The metal-organic framework material, the binder, and the auxiliary were ball-milled to obtain a first mixed powder. The ball-milling parameters were: the ball-milling speed was 250 r / min, the ball-to-material mass ratio was selected from 8:1, and the ball-milling time was selected from 6 h.

[0055] A pulley was provided (the size specifications of the pulleys used in the examples and comparative examples were the same, spb150-03 type pulley). The pulley was washed, sandblasted, and washed again to obtain a pretreated pulley. The pretreated pulley was heated to 280 °C. The first mixed powder was added to the powder feeder in the cold spraying equipment, and the first mixed powder was evenly sprayed on the surface of the pulley by the cold spraying process. Among them, the carrier gas pressure was selected from 5 MPa; the spraying speed was selected from 400 m / s; the carrier gas temperature was selected from 250 °C; the spraying distance was selected from 35 mm.

[0056] The pulley was subjected to vacuum hot pressing; among them, the hot pressing pressure was selected from 6.5 MPa; the hot pressing time was selected from 90 min; the hot pressing temperature was selected from 900 °C; the heating rate was selected from 10 °C / min. After the vacuum hot pressing treatment was completed, the pulley was cooled with the furnace. When the temperature dropped to 200 °C, air was introduced, and it continued to drop to room temperature to obtain the surface-modified pulley of Example 3.

[0057] The difference between Example 3 and Example 1 is that in the process of preparing the metal-organic framework in Example 3, magnesium nitrate was used and no rare earth element was added.

[0058] Comparative Example 1 Comparative Example 1 is an untreated spb150-03 type pulley.

[0059] Comparative Example 2 Comparative Example 2 includes the following steps: Provide 10 parts by weight of commercially available yttrium oxide powder (average particle size 50 nm), 2 parts by weight of binder aluminum dihydrogen phosphate and 1.5 parts by weight of auxiliary ammonium dihydrogen phosphate; after ball milling the metal-organic framework material, binder and auxiliary, obtain the first mixed powder; the ball milling parameters are: the ball milling speed is 250 r / min, the ball-to-material mass ratio is selected from 8:1, and the ball milling time is selected from 6 h.

[0060] Provide a pulley (the size specifications of the pulleys used in the examples and comparative examples are the same, spb150-03 type pulley), wash, sandblast and wash the pulley again to obtain a pretreated pulley; heat the pretreated pulley to 280 °C; add the first mixed powder to the powder feeder in the cold spraying equipment, and evenly spray the first mixed powder on the surface of the pulley through the cold spraying process; wherein, the carrier gas pressure is selected from 5 MPa; the spraying speed is selected from 400 m / s; the carrier gas temperature is selected from 250 °C; the spraying distance is selected from 35 mm.

[0061] Perform vacuum hot pressing on the pulley; wherein, the hot pressing pressure is selected from 6.5 MPa; the hot pressing time is selected from 90 min; the hot pressing temperature is selected from 900 °C; the heating rate is selected from 10 °C / min; after completing the vacuum hot pressing treatment, let the pulley cool with the furnace, when the temperature drops to 200 °C, introduce air, and continue to drop to room temperature to obtain the surface-modified pulley of Comparative Example 2.

[0062] Abrasion resistance test: According to standard ASTM D1044, use a CS-10 grinding wheel to conduct a wear test on the surface of the pulleys of Examples 1 to 3 under a load of 1000 g and a rotation speed of 1500 r / min for 48 hours; measure the mass loss to test the abrasion resistance of the samples of Examples 1 to 3; the mass loss of Example 2 is 1.15 times that of Example 1, the mass loss of Example 3 is 4.47 times that of Example 1, the mass loss of Comparative Example 1 is 5.25 times that of Example 1, and the mass loss of Comparative Example 2 is 2.76 times that of Example 1.

[0063] Corrosion resistance test: Place the pulleys of Examples 1 to 3 in a salt spray test chamber, spray 5% NaCl solution, control the temperature in the chamber to be about 35 °C, and observe the corrosion situation of the specimens after 72 h. The surfaces of Comparative Example 1 and Comparative Example 2 were severely corroded, moderate corrosion occurred on the surfaces of Example 2 and Example 3, and no corrosion occurred on the surface of Example 1.

[0064] During the hot pressing process, yttrium atoms in the materials of Examples 1 to 2 are more likely to diffuse and interact with iron atoms on the surface of the pulley under the action of high temperature and pressure, forming a dense intermetallic compound or solid solution layer that is tightly bonded to the substrate. This layer structure has high hardness and good wear resistance. Although magnesium atoms in Example 3 can also diffuse and interact with iron atoms, the intermetallic compound or solid solution layer formed by them and iron atoms is not as dense as the former. During the hot pressing process, the diffusion and penetration of yttrium oxide on the surface of the pulley are restricted, and it is difficult to form an intermetallic compound or solid solution layer with iron elements on its surface with the MOF material as the core like the yttrium-containing MOF materials of Examples 1 to 2, resulting in an insignificant improvement in wear resistance. Therefore, the wear resistance of Comparative Examples 1 to 2 is significantly better than that of Comparative Example 2. In addition, bis(trichloromethyl) carbonate contains highly reactive trichloromethyl groups, which can react with the MOF metal center to form more stable chemical bonds, making the material structure more dense. Therefore, the wear resistance and corrosion resistance of Example 1 are further better than those of Example 2.

[0065] Other embodiments of the present disclosure will be readily apparent to those skilled in the art in view of the specification and practice of the disclosure herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include known common knowledge or conventional technical means in the technical field not disclosed herein.

Claims

1. A preparation process for a one-way pulley of an engine, characterized in that, It includes the following steps: Step 1: Prepare the first nanoparticles; Step 2: Mix the first nanoparticles with a binder and an auxiliary agent to obtain a first mixed powder; Step 3: Provide a pulley, heat the pulley to 250°C - 400°C, then add the first mixed powder prepared in Step 1 into a spraying device, and spray the first mixed powder on the surface of the pulley through the spraying device to obtain the pulley of Step 3; Step 4: Perform hot pressing treatment on the pulley prepared in Step 3 to obtain a pulley with surface modification.

2. The preparation process of the engine one-way pulley according to claim 1, characterized in that, The first nanoparticles contain at least one metal-organic framework material.

3. The preparation process of the engine one-way pulley according to claim 2, characterized in that, In the metal-organic framework material, at least one metal-organic framework material contains rare earth elements; the rare earth elements are selected from La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Yb, Sc or Y.

4. The preparation process of the engine one-way pulley according to claim 3, characterized in that, The rare earth elements are selected from La, Ce, Gd, Yb, Sc or Y.

5. The preparation process of the engine one-way pulley according to any one of claims 1-4, characterized in that, The first nanoparticles are a metal-organic framework material, the metal-organic framework material contains rare earth elements, and the rare earth elements are selected from La, Ce, Gd, Yb, Sc or Y.

6. The preparation process of the engine one-way pulley according to claim 5, characterized in that, The metal-organic framework material is prepared through the following steps: Step 1-1: Provide a salt of a rare earth element; add the salt of the rare earth element and 3,5-dichlorobenzaldehyde into DMF, then dropwise add glacial acetic acid, stir for 20 - 45 min, and then age for 8 - 20 h to obtain a first mixed solution; Step 1-2: Add bis(trichloromethyl) carbonate to the first mixed solution, then heat at 150°C - 180°C for 16 - 48 h, and then collect the solid after filtration, washing and drying; Step 1-3: Heat the solid prepared in Step 1-2 to 500°C - 600°C in a nitrogen atmosphere and keep it warm for 5 - 8 h to obtain the metal-organic framework material.

7. The preparation process of the engine one-way pulley according to claim 6, characterized in that The metal-organic framework material is prepared through the following steps: Step 1-1: Provide a salt of a rare earth element; add the salt of the rare earth element and 3,5-dichlorobenzaldehyde into DMF, then dropwise add glacial acetic acid, stir for 20 - 30 min, and then age for 8 - 12 h to obtain a first mixed solution; wherein, the molar ratio of the salt of the rare earth element to 3,5-dichlorobenzaldehyde is selected from 1:(4 - 7); Step 1-2: Add bis(trichloromethyl) carbonate to the first mixed solution, then heat at 150°C - 180°C for 20 - 30 h, and then collect the solid after filtration, washing and drying; wherein, the molar ratio of the salt of the rare earth element to bis(trichloromethyl) carbonate is selected from 1:(0.25 - 0.45); Step 1-3: Heat the solid prepared in Step 1-2 from room temperature to 550°C - 600°C at a heating rate of 3 - 5°C / min in a nitrogen atmosphere, keep it warm for 5 - 8 h, and then naturally cool to room temperature to obtain the metal-organic framework material.

8. The preparation process of the engine one-way pulley according to claim 1, characterized in that, Step 3 includes: Step 3-1: Provide a pulley, wash the pulley, perform sandblasting treatment, and wash it again to obtain a pretreated pulley; Step 3-2: Heat the pre-treated pulley to 250°C - 300°C; Step 3-3: Add the first mixed powder into the powder feeder of the cold spraying equipment, and evenly spray the first mixed powder on the surface of the pulley through the cold spraying process to obtain the pulley of Step 3-2; wherein, the carrier gas pressure is selected from 3 - 8 MPa; the spraying speed is selected from 200 - 600 m / s; the carrier gas temperature is selected from 80°C - 300°C; the spraying distance is selected from 10 - 50 mm.

9. The preparation process of the engine one-way pulley according to claim 1 or 8, characterized in that, Step 4 includes: Step 4-1: Conduct vacuum hot pressing treatment on the pulley obtained in Step 3-3; wherein, the hot pressing pressure is selected from 5 - 8 MPa; the hot pressing time is selected from 60 - 90 min; the hot pressing temperature is selected from 800°C - 900°C; the heating rate is selected from 10 - 15°C / min; Step 4-2: After completing the vacuum hot pressing treatment, let the pulley cool with the furnace. When the temperature drops to 200°C, introduce air and continue to cool down to room temperature to obtain the surface-modified pulley.

10. A one-way pulley for an engine, characterized in that, The engine one-way pulley is prepared by the preparation process of the engine one-way pulley according to any one of claims 1-9.

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