One-way pulley of engine and its manufacturing process

Abstract

The present invention relates to the field of pulley technology, specifically to a one-way engine pulley and a preparation process thereof. The preparation process for the one-way engine pulley comprises the following steps: preparing first nanoparticles; mixing the first nanoparticles with a binder and an additive to obtain a first mixed powder; providing a pulley, heating the pulley, and then adding the first mixed powder to a spraying device, spraying the first mixed powder onto the surface of the pulley via the spraying device; and then further performing a hot pressing treatment to obtain a surface-modified pulley. The preparation process provided by the present disclosure can produce a pulley with good wear resistance, corrosion resistance, and hydrophobicity and oleophobicity.

Description

Technical Field

[0001] The invention relates to the technical field of pulleys, in particular to a one-way pulley of an engine and a preparation process thereof. Background Art

[0002] In modern mechanical transmission systems, pulleys are key components, carrying out the crucial functions of power transmission and motion conversion. From industrial production equipment to various forms of transportation, pulley performance and lifespan play a decisive role in overall operational efficiency and stability. However, over long-term operation, pulley surfaces are subject to wear and corrosion from various factors, leading to a gradual decline in performance and even failure.

[0003] On the one hand, the pulley surface inevitably experiences mechanical wear due to continuous contact with the belt and frictional transmission. This wear intensifies with extended use, causing the pulley groove shape to change, which in turn affects the correct engagement of the belt and transmission accuracy. Especially under high-load and high-speed conditions, the pulley surface wears more rapidly, not only reducing transmission efficiency but also potentially causing problems such as vibration and noise, seriously impacting the normal operation of the machinery. On the other hand, various corrosive factors in the working environment should not be ignored. For example, in humid, acidic, alkaline environments, or in the presence of chemical media, the pulley surface is prone to chemical corrosion, forming defects such as oxide layers and corrosion pits. These corrosion phenomena further weaken the pulley's strength and surface quality, shortening its service life, and may even cause the pulley to suddenly fail during use, leading to safety accidents.

[0004] With the continuous advancement of materials science and surface engineering technologies, higher requirements are being placed on pulley surface modification processes. In recent years, research on the application of nanotechnology, new coating materials, and advanced spraying processes in pulley surface modification has gradually emerged. For example, nanoparticle-enhanced coatings significantly improve the hardness, wear resistance, and corrosion resistance of coatings by adding nanomaterials. Advanced spraying processes such as plasma spraying can achieve a good bond between the coating and the substrate, improving the density and uniformity of the coating. These new surface modification technologies provide new avenues for improving pulley performance and lifespan. Summary of the Invention

[0005] The object of the present invention is to provide an engine one-way pulley and a preparation process thereof, so as to solve the problem of improving the wear resistance, corrosion resistance, hydrophobicity and oleophobicity of the pulley proposed in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] According to a first aspect of an embodiment of the present disclosure, a process for preparing a one-way pulley of an engine is provided, comprising the following steps:

[0008] Step 1: preparing the first nanoparticles;

[0009] Step 2: mixing the first nanoparticles with a binder and an additive to obtain a first mixed powder;

[0010] Step 3: providing a pulley, heating the pulley to 250° C.-400° C., then adding the first mixed powder prepared in step 1 to a spraying device, and spraying the first mixed powder on the surface of the pulley through the spraying device to obtain the pulley of step 3;

[0011] Step 4: The pulley prepared in step 3 is subjected to hot pressing treatment to obtain a surface-modified pulley.

[0012] In one aspect of the embodiments of the present disclosure, the first nanoparticles comprise at least one metal-organic framework material.

[0013] In one aspect of the embodiments of the present disclosure, preferably, the first nanoparticles are a metal organic framework material.

[0014] In one aspect of the embodiments of the present disclosure, among the metal-organic framework materials, at least one metal-organic framework material contains a rare earth element; the rare earth element is selected from La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Yb, Sc or Y.

[0015] In one aspect of the embodiments of the present disclosure, the first nanoparticle is a metal organic framework material containing a rare earth element; the rare earth element is selected from La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Ho, Er, Yb, Sc or Y.

[0016] In one aspect of the embodiments of the present disclosure, the rare earth element is selected from La, Ce, Gd, Yb, Sc or Y.

[0017] In one aspect of the embodiments of the present disclosure, the first nanoparticles are metal-organic framework materials, and the metal-organic framework materials contain rare earth elements, and the rare earth elements are selected from La, Ce, Gd, Yb, Sc or Y.

[0018] In one aspect of the embodiments of the present disclosure, specifically, the rare earth element is selected from Y.

[0019] In one aspect of the embodiments of the present disclosure, the metal organic framework material is prepared by the following steps:

[0020] Step 1-1: providing a salt of a rare earth element; adding the salt of the rare earth element and 3,5-dichlorobenzaldehyde to DMF, then dropwise adding glacial acetic acid, stirring for 20-45 minutes, and then aging for 8-20 hours to obtain a first mixed solution;

[0021] Step 1-2: adding bis(trichloromethyl) carbonate to the first mixed solution, followed by heating at 150° C.-180° C. for 16-48 hours, and then collecting the solid by filtration, washing, and drying;

[0022] Step 1-3: The solid prepared in step 1-2 is heated to 500° C.-600° C. under a nitrogen atmosphere and kept warm for 5-8 hours to obtain the metal organic framework material.

[0023] In one aspect of the embodiments of the present disclosure, the metal organic framework material is prepared by the following steps:

[0024] Step 1-1: Providing a rare earth element salt; adding the rare earth element salt and 3,5-dichlorobenzaldehyde to DMF, then dropwise adding glacial acetic acid, stirring for 20-30 minutes, and then aging for 8-12 hours to obtain a first mixed solution; wherein the molar ratio of the rare earth element salt to 3,5-dichlorobenzaldehyde is selected from 1:(4-7);

[0025] Step 1-2: adding bis(trichloromethyl) carbonate to the first mixed solution, followed by heating at 150° C.-180° C. for 20-30 hours, filtering, washing, and drying to collect the solid; wherein the molar ratio of the rare earth element salt to the bis(trichloromethyl) carbonate is selected from 1:(0.25-0.45);

[0026] Step 1-3: The solid prepared in step 1-2 is heated from room temperature to 550°C-600°C at a heating rate of 3-5°C / min under a nitrogen atmosphere, and kept warm for 5-8 hours, and then naturally cooled to room temperature to obtain the metal organic framework material.

[0027] In one aspect of the embodiments of the present disclosure, in step 1-1, the mass of the added glacial acetic acid is 10%-25% of the mass of the salt of the rare earth element.

[0028] In one aspect of the embodiments of the present disclosure, specifically, the metal organic framework material is prepared by the following steps:

[0029] Step 1-1: Providing a rare earth element salt; adding the rare earth element salt and 3,5-dichlorobenzaldehyde to DMF, then dropwise adding glacial acetic acid, stirring for 30 minutes, and then aging for 12 hours to obtain a first mixed solution; wherein the molar ratio of the rare earth element salt to 3,5-dichlorobenzaldehyde is selected from 1:5.5; the mass of the added glacial acetic acid is 20% of the mass of the rare earth element salt; the rare earth element salt is a nitrate or hydrochloride of the rare earth element;

[0030] Step 1-2: adding bis(trichloromethyl) carbonate to the first mixed solution, followed by heating at 175° C. for 24 hours, and then filtering, washing, and drying to collect the solid; wherein the molar ratio of the rare earth element salt to the bis(trichloromethyl) carbonate is selected from 1:0.35;

[0031] Step 1-3: The solid prepared in step 1-2 is heated from room temperature to 580° C. at a heating rate of 5° C. / min under a nitrogen atmosphere, and kept warm for 6 hours, and then naturally cooled to room temperature to obtain the metal organic framework material.

[0032] In one aspect of the embodiments of the present disclosure, the binder is selected from an inorganic silicate binder or an inorganic phosphate binder, preferably an inorganic phosphate binder.

[0033] In one aspect of the embodiments of the present disclosure, specifically, the inorganic phosphate binder is selected from aluminum dihydrogen phosphate.

[0034] In one aspect of the embodiments of the present disclosure, the auxiliary agent is selected from potassium dihydrogen phosphate, potassium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium dihydrogen phosphate or calcium dihydrogen phosphate.

[0035] In one aspect of the embodiments of the present disclosure, specifically, the auxiliary agent is selected from ammonium dihydrogen phosphate.

[0036] In one aspect of the embodiments of the present disclosure, step 2 includes:

[0037] Step 2-1: Providing a binder and an auxiliary agent, wherein the binder is selected from an inorganic silicate binder or an inorganic phosphate binder; the auxiliary agent is selected from potassium dihydrogen phosphate, potassium hydrogen phosphate, sodium dihydrogen phosphate, disodium hydrogen phosphate, ammonium dihydrogen phosphate, or calcium dihydrogen phosphate; and 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);

[0038] Step 2-2: ball-milling the first nanoparticles, binder and additive to obtain a first mixed powder.

[0039] In one aspect of the disclosed embodiments, 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.

[0040] In one aspect of the embodiments of the present disclosure, step 3 includes:

[0041] Step 3-1: providing a pulley, washing the pulley, sandblasting the pulley, and washing the pulley again to obtain a pre-treated pulley;

[0042] Step 3-2: heating the pretreated pulley to 250° C.-300° C.;

[0043] 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 3-8 MPa; the spraying speed is selected from 200-600 m / s; the carrier gas temperature is selected from 80℃-300℃; and the spraying distance is selected from 10-50 mm.

[0044] In one aspect of the embodiment of the present disclosure, specifically, step 3 includes:

[0045] Step 3-1: providing a pulley, washing the pulley, sandblasting the pulley, and washing the pulley again to obtain a pre-treated pulley;

[0046] Step 3-2: heating the pretreated pulley to 280° C.;

[0047] 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; and the spraying distance is selected from 35 mm.

[0048] In one aspect of an embodiment of the present disclosure, in the cold spray process, the nozzle used may be a Laval nozzle, a circular cross-section nozzle, a rectangular cross-section nozzle, or an elliptical cross-section nozzle, but the present disclosure is not limited thereto.

[0049] In one aspect of the embodiments of the present disclosure, step 4 includes:

[0050] Step 4-1: subjecting the pulley obtained in step 3-3 to vacuum hot pressing; 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. to 900° C.; and the heating rate is selected from 10-15° C. / min;

[0051] Step 4-2: After completing the vacuum hot pressing treatment, the pulley is allowed to cool in the furnace. When the temperature drops to 200° C., air is introduced and the temperature is further lowered to room temperature to obtain the surface-modified pulley.

[0052] In one aspect of the embodiment of the present disclosure, specifically, step 4 includes:

[0053] Step 4-1: subjecting the pulley obtained in step 3-3 to vacuum hot pressing; 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.; and the heating rate is selected from 10° C. / min;

[0054] Step 4-2: After completing the vacuum hot pressing treatment, the pulley is allowed to cool in the furnace. When the temperature drops to 200° C., air is introduced and the temperature is further lowered to room temperature to obtain the surface-modified pulley.

[0055] 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, hydrophobicity and oleophobicity can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0057] Figure 1 This is a TEM image of the metal-organic framework material prepared in Example 1 of the present disclosure;

[0058] Figure 2 This is a TEM image of the metal-organic framework material prepared in Example 2 of the present disclosure;

[0059] Figure 3 This is a TEM image of the metal-organic framework material prepared in Example 3 of the present disclosure. DETAILED DESCRIPTION

[0060] The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0061] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of this application, rather than all the embodiments. The relevant embodiments described herein are illustrative and are used to provide a basic understanding of this application. The embodiments of this application should not be interpreted as limiting this application.

[0062] For the sake of clarity, only some numerical ranges are specifically disclosed herein. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, each individually disclosed point or single value may itself serve as a lower limit or upper limit and be combined with any other point or single value, or with other lower limits or upper limits, to form an unspecified range.

[0063] As used herein, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0064] In the description herein, unless otherwise specified, “above” and “below” include the number itself.

[0065] Unless otherwise specified, the terms used in this disclosure have the commonly understood 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 using various measurement methods commonly used in the art (for example, they can be tested according to the methods given in the examples of this disclosure).

[0066] The term "about" is used to describe and illustrate small changes. When used in conjunction with an event or situation, the term may refer to an example in which the event or situation occurs precisely and an example in which the event or situation occurs very approximately. For example, when used in conjunction with a numerical value, the term may refer to a variation range of less than or equal to ±10% of 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%. In addition, amounts, ratios, and other numerical values ​​are sometimes presented in this article in a range format. It should be understood that such range formats are for convenience and brevity, and should be flexibly understood to include not only numerical values ​​explicitly designated as range limits, but also all individual numerical values ​​or subranges encompassed within the range, as if each numerical value and subrange were explicitly designated.

[0067] A list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, 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, 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 contain a single component or multiple components. Item B can contain a single component or multiple components. Item C can contain a single component or multiple components.

[0068] The present disclosure is further described below with reference to the following examples. It should be understood that these examples are only used to illustrate the present disclosure and are not intended to limit the scope of the present disclosure.

[0069] Example

[0070] Example 1

[0071] The first embodiment includes the following steps:

[0072] 1. Preparation of metal-organic framework materials:

[0073] Yttrium nitrate hexahydrate (3.83 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, 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 heated at 175 ° C for 24 h, and then filtered, washed, and dried to collect the solid; the collected solid was heated from room temperature to 580 ° C under a nitrogen atmosphere at a heating rate of 5 ° C / min, and kept warm 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 shown as follows: Figure 1 shown.

[0074] The above steps can be repeated multiple times to prepare enough metal-organic framework materials.

[0075] 2. Surface modification:

[0076] 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 additive ammonium dihydrogen phosphate; ball-mill the metal-organic framework material, the binder, and the additive to obtain a first mixed powder; the ball-milling parameters are: a ball-milling speed of 250 r / min, a ball-to-material mass ratio selected from 8:1, and a ball-milling time selected from 6 hours.

[0077] A pulley is provided (the pulleys used in the embodiment and the comparative example have the same size specifications, namely, a spb150-03 pulley), the pulley is washed, sandblasted, and washed again to obtain a pretreated pulley; the pretreated pulley is heated to 280°C; a first mixed powder is added to a powder feeder in a cold spraying device, and the first mixed powder is uniformly sprayed on the surface of the pulley through a 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; and the spraying distance is selected from 35 mm.

[0078] The pulley is subjected to vacuum hot pressing treatment; 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; and the heating rate is selected from 10°C / min; after completing the vacuum hot pressing treatment, the pulley is allowed to cool with the furnace, and when the temperature drops to 200°C, air is introduced and the temperature is continued to drop to room temperature to obtain the surface-modified pulley of Example 1.

[0079] Example 2

[0080] The second embodiment includes the following steps:

[0081] 1. Preparation of metal-organic framework materials:

[0082] Yttrium nitrate hexahydrate (3.83 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, stirred for 30 min, and then aged for 12 h to obtain a first mixed solution; heated at 175 ° C for 24 h, and then filtered, washed, and dried to collect the solid; the collected solid was heated from room temperature to 580 ° C under a nitrogen atmosphere at a heating rate of 5 ° C / min, and kept warm 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 shown as follows: Figure 2 shown.

[0083] The above steps can be repeated multiple times to prepare enough metal-organic framework materials.

[0084] 2. Surface modification:

[0085] 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 additive ammonium dihydrogen phosphate; ball-mill the metal-organic framework material, the binder, and the additive to obtain a first mixed powder; the ball-milling parameters are: a ball-milling speed of 250 r / min, a ball-to-material mass ratio selected from 8:1, and a ball-milling time selected from 6 hours.

[0086] A pulley is provided (the pulleys used in the embodiment and the comparative example have the same size specifications, namely, a spb150-03 pulley), the pulley is washed, sandblasted, and washed again to obtain a pretreated pulley; the pretreated pulley is heated to 280°C; a first mixed powder is added to a powder feeder in a cold spraying device, and the first mixed powder is uniformly sprayed on the surface of the pulley through a 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; and the spraying distance is selected from 35 mm.

[0087] The pulley is subjected to vacuum hot pressing treatment; 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; and the heating rate is selected from 10°C / min; after completing the vacuum hot pressing treatment, the pulley is allowed to cool with the furnace, and when the temperature drops to 200°C, air is introduced and the temperature is continued to drop to room temperature to obtain the surface-modified pulley of Example 2.

[0088] The difference between Example 2 and Example 1 is that in Example 2, no bis(trichloromethyl) carbonate is added during the preparation of the metal organic framework.

[0089] Example 3

[0090] The third embodiment includes the following steps:

[0091] 1. Preparation of metal-organic framework materials:

[0092] 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, stirred for 30 min, and then aged for 12 h to obtain a first mixed solution; 1 g of di(trichloromethyl) carbonate (3.5 mmol) was added to the first mixed solution, and then heated at 175 ° C for 24 h, and then filtered, washed, and dried to collect the solid; the collected solid was heated from room temperature to 580 ° C under a nitrogen atmosphere at a heating rate of 5 ° C / min, and kept warm 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 shown as follows: Figure 3 shown.

[0093] The above steps can be repeated multiple times to prepare enough metal-organic framework materials.

[0094] 2. Surface modification:

[0095] 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 additive ammonium dihydrogen phosphate; ball-mill the metal-organic framework material, the binder, and the additive to obtain a first mixed powder; the ball-milling parameters are: a ball-milling speed of 250 r / min, a ball-to-material mass ratio selected from 8:1, and a ball-milling time selected from 6 hours.

[0096] A pulley is provided (the pulleys used in the embodiment and the comparative example have the same size specifications, namely, a spb150-03 pulley), the pulley is washed, sandblasted, and washed again to obtain a pretreated pulley; the pretreated pulley is heated to 280°C; a first mixed powder is added to a powder feeder in a cold spraying device, and the first mixed powder is uniformly sprayed on the surface of the pulley through a 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; and the spraying distance is selected from 35 mm.

[0097] The pulley is subjected to vacuum hot pressing treatment; 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; and the heating rate is selected from 10°C / min; after completing the vacuum hot pressing treatment, the pulley is allowed to cool with the furnace, and when the temperature drops to 200°C, air is introduced and the temperature is continued to drop to room temperature to obtain the surface-modified pulley of Example 3.

[0098] The difference between Example 3 and Example 1 is that in Example 3, magnesium nitrate is used in the process of preparing the metal organic framework without adding rare earth elements.

[0099] Comparative Example 1

[0100] Comparative Example 1 is an untreated SPB150-03 pulley.

[0101] Comparative Example 2

[0102] Comparative Example 2 comprises the following steps:

[0103] 10 parts by weight of commercially available yttrium oxide powder (average particle size 50 nm), 2 parts by weight of aluminum dihydrogen phosphate (a binder), and 1.5 parts by weight of ammonium dihydrogen phosphate (an additive) are provided; the yttrium oxide powder, the binder, and the additive are ball-milled to obtain a first mixed powder; the ball-milling parameters are as follows: a ball-milling speed of 250 r / min, a ball-to-material mass ratio of 8:1, and a ball-milling time of 6 hours.

[0104] A pulley is provided (the pulleys used in the embodiment and the comparative example have the same size specifications, namely, a spb150-03 pulley), the pulley is washed, sandblasted, and washed again to obtain a pretreated pulley; the pretreated pulley is heated to 280°C; a first mixed powder is added to a powder feeder in a cold spraying device, and the first mixed powder is uniformly sprayed on the surface of the pulley through a 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; and the spraying distance is selected from 35 mm.

[0105] The pulley is subjected to vacuum hot pressing treatment; 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; and the heating rate is selected from 10°C / min; after completing the vacuum hot pressing treatment, the pulley is allowed to cool with the furnace, and when the temperature drops to 200°C, air is introduced and the temperature continues to drop to room temperature to obtain the surface-modified pulley of Comparative Example 2.

[0106] Wear resistance test:

[0107] According to the standard ASTM D1044, the pulley surfaces of Examples 1 to 3 were subjected to a wear test using a CS-10 grinding wheel at a load of 1000 g and a speed of 1500 rpm, and the test time was 48 hours; the wear resistance of the samples of Examples 1 to 3 was tested by measuring the mass loss; the mass loss of Example 2 was 1.15 times that of Example 1, the mass loss of Example 3 was 4.47 times that of Example 1, the mass loss of Comparative Example 1 was 5.25 times that of Example 1, and the mass loss of Comparative Example 2 was 2.76 times that of Example 1.

[0108] Corrosion resistance test:

[0109] The pulleys of Examples 1 to 3 were placed in a salt spray test chamber, sprayed with a 5% NaCl solution, and the temperature in the chamber was controlled at approximately 35°C. The corrosion of the samples was observed after 72 hours. The surfaces of Comparative Examples 1 and 2 showed severe corrosion, while the surfaces of Examples 2 and 3 showed moderate corrosion. The surface of Example 1 showed no corrosion.

[0110] During the hot pressing process, the yttrium atoms in the materials of Examples 1 and 2 are more likely to diffuse and interact with the iron atoms on the pulley surface 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 has high hardness and good wear resistance. Although the magnesium atoms in Example 3 can also diffuse and interact with the iron atoms, the intermetallic compound or solid solution layer formed by them and the iron atoms is not as dense as the former. During the hot pressing process, the diffusion and penetration of yttrium oxide on the pulley surface are restricted. 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, as in Examples 1 and 2, as the yttrium-containing MOF materials, resulting in an insignificant wear resistance improvement effect. Therefore, the wear resistance of Examples 1 and 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 metal center of MOF to form more stable chemical bonds, making the material structure more compact. Therefore, the wear resistance and corrosion resistance of Example 1 are further superior to those of Example 2.

[0111] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the disclosure disclosed herein. This 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 common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A process for preparing a one-way pulley of an engine, characterized in that: The following steps are involved: Step 1: preparing the first nanoparticles; Step 2: mixing the first nanoparticles with a binder and an additive to obtain a first mixed powder; Step 3: providing a pulley, heating the pulley to 250° C.-400° C., then adding the first mixed powder prepared in step 2 to a spraying device, and spraying the first mixed powder on the surface of the pulley through the spraying device to obtain the pulley of step 3; Step 4: hot pressing the pulley prepared in step 3 to obtain a surface-modified pulley; Wherein, the first nanoparticle is a metal organic framework material, the metal organic framework material contains a rare earth element, and the rare earth element is selected from La, Ce, Gd, Yb, Sc or Y; The metal organic framework material is prepared by the following steps: Step 1-1: providing a salt of a rare earth element; adding the salt of the rare earth element and 3,5-dichlorobenzaldehyde to DMF, then dropwise adding glacial acetic acid, stirring for 20-45 minutes, and then aging for 8-20 hours to obtain a first mixed solution; Step 1-2: adding bis(trichloromethyl) carbonate to the first mixed solution, followed by heating at 150° C.-180° C. for 16-48 hours, and then collecting the solid by filtration, washing, and drying; Step 1-3: The solid prepared in step 1-2 is heated to 500° C.-600° C. under a nitrogen atmosphere and kept warm for 5-8 hours to obtain the metal organic framework material.

2. The process for preparing the one-way pulley of the engine according to claim 1, characterized in that: The metal organic framework material is prepared by the following steps: Step 1-1: Providing a rare earth element salt; adding the rare earth element salt and 3,5-dichlorobenzaldehyde to DMF, then dropwise adding glacial acetic acid, stirring for 20-30 minutes, and then aging for 8-12 hours to obtain a first mixed solution; wherein the molar ratio of the rare earth element salt to 3,5-dichlorobenzaldehyde is selected from 1:(4-7); Step 1-2: adding bis(trichloromethyl) carbonate to the first mixed solution, followed by heating at 150° C.-180° C. for 20-30 hours, filtering, washing, and drying to collect the solid; wherein the molar ratio of the rare earth element salt to the bis(trichloromethyl) carbonate is selected from 1:(0.25-0.45); Step 1-3: The solid prepared in step 1-2 is heated from room temperature to 550°C-600°C at a heating rate of 3-5°C / min under a nitrogen atmosphere, and kept warm for 5-8 hours, and then naturally cooled to room temperature to obtain the metal organic framework material.

3. The process for preparing the one-way pulley of the engine according to claim 1, characterized in that: Step 3 includes: Step 3-1: providing a pulley, washing the pulley, sandblasting the pulley, and washing the pulley again to obtain a pre-treated pulley; Step 3-2: heating the pretreated pulley to 250° C.-300° 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 3-8 MPa; the spraying speed is selected from 200-600 m / s; the carrier gas temperature is selected from 80℃-300℃; and the spraying distance is selected from 10-50 mm.

4. The process for preparing the one-way pulley of the engine according to claim 1 or 3, characterized in that: Step 4 includes: Step 4-1: subjecting the pulley obtained in step 3-3 to vacuum hot pressing; 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. to 900° C.; and the heating rate is selected from 10-15° C. / min; Step 4-2: After completing the vacuum hot pressing treatment, the pulley is allowed to cool in the furnace. When the temperature drops to 200° C., air is introduced and the temperature is further lowered to room temperature to obtain the surface-modified pulley.

5. An engine one-way pulley, 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 to 4.

Images