Powder metallurgy transmission plate material for clutch and preparation method therefor

Abstract

A powder metallurgy transmission plate material for a clutch, comprising in percentage by mass: 55%-65% of high-purity atomized iron powder, 8%-12% of electrolytic copper powder, 4%-8% of nickel hydroxide powder, 1.5%-4% of ferromolybdenum powder, 1%-3% of chromium powder, 0.3%-1.5% of lanthanum powder, 1.5%-3.5% of nano silicon carbide particles, 0.8%-2% of carbon fiber, 0.5%-1.5% of whisker-like alumina, 0.3%-1% of cellulose nanocrystals, 0.5%-2% of rare earth oxides, 2.3%-6% of a lubricating agent and 0.5%-1.8% of a binder. A transmission plate prepared by using the material component ensures the reliability and durability of the transmission plate in a complex mechanical environment, prolongs the service life of the transmission plate, and reduces safety risks. Also comprised is a preparation method for a powder metallurgy transmission plate material for a clutch.

Description

A powder metallurgy transmission plate material for clutches and its preparation method

[0001] Cross-references

[0002] This application is based on and claims priority to Chinese Patent Application No. 202411920568.5, filed on December 25, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of transmission plate material technology, specifically to a powder metallurgy transmission plate material for clutches and its preparation method. Background Technology

[0004] With the continuous development of the vehicle industry and various mechanical transmission systems, the performance requirements for clutches, as key components in transmission systems, are becoming increasingly stringent. Powder metallurgy transmission plates play important roles in clutches, such as transmitting torque, buffering shocks, and ensuring smooth power connection and disconnection. Therefore, optimizing and improving their performance has always been a focus of research in related fields.

[0005] In the field of traditional powder metallurgy transmission plate materials, conventional metal powder formulations are often used, such as a certain proportion of iron powder mixed with a small amount of other alloying element powders, supplemented with simple lubricants and binders. This traditional formulation can meet basic usage requirements to a certain extent, but its limitations are becoming increasingly apparent as modern machinery operates under more complex conditions, such as higher speeds, greater torque loads, and harsher working environments. For example, the strength and hardness of existing materials often fail to remain stable under high temperature and high stress conditions, easily leading to accelerated wear, deformation, and even failure. This not only affects the overall performance and service life of the clutch but may also pose safety hazards.

[0006] Therefore, there is a need in the art for a powder metallurgy transmission plate material for clutches and a method for preparing the same to solve the above problems. Summary of the Invention

[0007] In order to solve the above-mentioned technical problems, namely the poor overall performance of existing clutch transmission plate materials under high temperature and high stress conditions, which affects the service life of the clutch and even causes safety hazards.

[0008] In one aspect, the present invention provides a powder metallurgy transmission plate material for a clutch, the transmission plate material comprising, by weight percentage: 55%-65% high-purity atomized iron powder, 8%-12% electrolytic copper powder, 4%-8% nickel hydroxyl powder, 1.5%-4% ferromolybdenum powder, 1%-3% chromium powder, 0.3%-1.5% lanthanum powder, 1.5%-3.5% nano-silicon carbide particles, 0.8%-2% carbon fiber, 0.5%-1.5% whisker-like alumina, 0.3%-1% cellulose nanocrystals, 0.5%-2% rare earth oxides, 2.3%-6% lubricant, and 0.5%-1.8% binder.

[0009] In some preferred embodiments, the lubricant comprises 1.5%-3.5% flake graphite and 0.8%-2.5% nano-molybdenum disulfide.

[0010] In some preferred embodiments, the adhesive comprises 0.3%-1% polyethylene glycol and 0.2%-0.8% sodium carboxymethyl cellulose.

[0011] In some preferred embodiments, the rare earth oxide is yttrium oxide; or,

[0012] The rare earth oxide is cerium oxide; or...

[0013] The rare earth oxides include 0.4%-1.6% cerium oxide and 0.1%-0.4% yttrium oxide.

[0014] The powder metallurgy transmission plate material for clutches of the present invention has the following beneficial effects:

[0015] In this invention, the powder metallurgy transmission plate material for the clutch uses high-purity atomized iron powder as the base component, providing a basic material skeleton and ensuring a certain level of strength and toughness. Its large proportion ensures the stability of the overall structure. Electrolytic copper powder imparts good thermal and electrical conductivity, helping to dissipate heat promptly during clutch operation and ensuring the stability of electrical signal transmission. Combined with iron powder, it enhances the overall physical properties of the material. Nickel hydroxyl powder effectively increases the material's strength and corrosion resistance, enabling the transmission plate to resist corrosion and maintain structural strength in complex environments. Iron molybdenum powder further improves the material's hardness and high-temperature performance, allowing the transmission plate to maintain good mechanical properties under high-temperature conditions. Together with chromium powder, it enhances the material's wear and corrosion resistance. The addition of lanthanum powder utilizes the characteristics of rare earth elements to refine the grains, enhancing the uniformity and density of the material's internal structure, thereby improving overall strength and... Toughness: Nano-silicon carbide particles, whisker-like alumina, and carbon fibers reinforce the material from different dimensions. Nano-silicon carbide particles increase hardness and wear resistance, whisker-like alumina focuses on enhancing high-temperature strength and wear resistance, and carbon fibers improve the material's strength and toughness. The three complement each other and synergistically enhance the material's mechanical properties. Cellulose nanocrystals, while providing a certain strength and stiffness, can adsorb additives such as lubricants due to their special structure and adsorption properties, which helps to play a better lubrication role during friction and reduce the material density to achieve lightweighting. Rare earth oxides are stable at high temperatures, can refine grains, inhibit grain growth, and form a protective film, improving the material's oxidation resistance and high-temperature stability. Through the combination of the above components and their proportions, the comprehensive performance of the clutch transmission plate is greatly improved, ensuring the reliability and durability of the transmission plate in complex mechanical environments, increasing service life, and reducing safety risks.

[0016] In another aspect, the present invention also provides a method for preparing the above-described powder metallurgy transmission plate material for clutches, the method comprising:

[0017] S1: Pretreatment of high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, carbon fiber, and cellulose nanocrystals;

[0018] S2: The pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano silicon carbide particles, rare earth oxides, polyethylene glycol and sodium carboxymethyl cellulose are added to a high-speed mixer for a first mixing. Then, flake graphite, nano molybdenum disulfide and whisker alumina are added to the mixture from the first mixing in the high-speed mixer for a second mixing. Then, carbon fiber and cellulose nanocrystals are added to the mixture from the second mixing in the high-speed mixer for a third mixing.

[0019] S3: The mixture of three mixtures is shaped using a two-way pressing method;

[0020] S4: The shaped material is subjected to low-temperature pre-sintering and high-temperature sintering in sequence;

[0021] S5: Machining, surface treatment and heat treatment of the sintered material.

[0022] In some preferred embodiments, step S1 specifically includes:

[0023] S11: High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder and lanthanum powder are vacuum dried separately at a temperature of 110-130℃ for 5-7 hours.

[0024] S12: Soak nano-silicon carbide particles in a composite treatment agent of silane coupling agent and titanate coupling agent, stir evenly and then perform ultrasonic treatment for 3-5 hours at a temperature of 60-80℃, and then dry at 80-100℃ for 4-6 hours.

[0025] S13: After the carbon fiber is chopped, it is soaked in a dopamine solution with a concentration of 1-3 g / L and a pH of 8-9. The mixture is stirred and reacted at room temperature for 12-24 hours. Then the carbon fiber is removed, rinsed with deionized water, and dried at 60-80℃ for 3-5 hours.

[0026] S14: Disperse cellulose nanocrystals in a silane coupling agent, sonicate for 2-4 hours, then filter and dry.

[0027] In some preferred embodiments, in step S2, during the first mixing process, the mixture is stirred and mixed at 60-80°C for 1-2 hours; during the second mixing process, the mixture is stirred and mixed for 1-2 hours; and during the third mixing process, the mixture is stirred and mixed for 1-2 hours. The first, second, and third mixing processes are all combined with ultrasonic-assisted mixing.

[0028] In some preferred embodiments, step S3 specifically includes:

[0029] S31: Load the mixed powder into the mold, pre-press it with a pressure of 200-300MPa, a holding time of 5-10 seconds, and a pressing speed of 5-10 mm / s;

[0030] S32: The pre-pressed material is subjected to bidirectional pressing at a pressure of 600-900MPa, a holding time of 15-25 seconds, and a pressing speed of 3-8 mm / s. During the bidirectional pressing process, the mold is heated to 100-150℃ at a heating rate of 15-25℃ / min.

[0031] In some preferred embodiments, step S4 specifically includes:

[0032] S41: The molded material is subjected to a vacuum of 1×10⁻⁶. -3 -1×10 -2 Low-temperature pre-sintering is carried out under vacuum conditions at a temperature of 800-1000℃ for 1-2 hours, with a heating rate of 10-20℃ / minute.

[0033] S42: The pre-sintered material is placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering at a temperature of 1200-1400℃ for 2-3 hours, with a heating rate of 15-25℃ / minute. During the high-temperature sintering process, microwave-assisted sintering is used with a microwave frequency of 2.45GHz and a microwave power of 5-10kW.

[0034] In some preferred embodiments, step S5 specifically includes:

[0035] S51: Machining the sintered material;

[0036] S52: The machined material is first subjected to phosphating treatment at a temperature of 50-70℃ for 20-30 minutes. The spraying pressure of the phosphating solution is 0.1-0.3MPa. The phosphating solution formula is: 20-30g / L zinc dihydrogen phosphate, 50-70g / L zinc nitrate, and 1-3g / L sodium fluoride, with a pH value of 2-3.

[0037] S53: For phosphated materials, electroplating or chemical copper plating is performed, with a current density of 1-3 A / dm³ when electroplating. 2 The electroplating time is 10-30 minutes. When using chemical copper plating, the plating solution temperature is 40-60℃ and the deposition rate is 2-5μm / h.

[0038] S54: The material is heat-treated under nitrogen protection. The heat treatment involves heating the material to 200-300°C at a heating rate of 10-20°C / min, holding it at that temperature for 1-2 hours, and then slowly cooling it to room temperature at a cooling rate of 5-10°C / min.

[0039] The method for preparing powder metallurgy transmission plate material for clutches of the present invention has the following beneficial effects:

[0040] This invention first pre-treats the key raw materials, specifically by vacuum drying the metal powder to remove moisture and gas, thus preventing defects in subsequent processing. Step S2 involves a multi-step mixing process: first, the metal powder, key reinforcing particles, and rare earth oxides are mixed with a binder to initially and uniformly combine the basic components and important additives, and the binder initially stabilizes the structure. Next, flake graphite, nano-molybdenum disulfide, and whisker-like alumina are added to further enrich the material's performance components and are mixed uniformly again. Finally, carbon fiber and cellulose nanocrystals are added to ensure that each special reinforcing component is uniformly dispersed in the system. By gradually increasing the stirring speed and using ultrasonic-assisted mixing, the thoroughness and uniformity of the mixing are ensured, resulting in a good synergistic effect among the components. Furthermore, the use of a bidirectional pressing method makes the density of the green body more uniform, ensuring the material's quality from the forming stage. To ensure consistent and stable performance and avoid localized performance differences caused by uneven density, a two-stage sintering process is employed. Low-temperature pre-sintering removes organic matter and adsorbed gases, initially densifying the material. High-temperature sintering, under a specific atmosphere, promotes the full fusion of metal powders to form a dense metallurgical bond. Microwave-assisted sintering technology improves sintering speed and uniformity, ensuring a stable and high-performance microstructure. Post-machining surface treatment utilizes a composite surface treatment technology: phosphating enhances corrosion and wear resistance, copper plating further improves conductivity and corrosion resistance, and heat treatment improves material performance stability. Each post-treatment step works sequentially, comprehensively optimizing the transmission plate from macroscopic shape to surface properties and overall performance stability, ensuring that the final powder metallurgy transmission plate for clutches meets the requirements for high performance and high reliability. Attached Figure Description

[0041] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings:

[0042] Figure 1 is a flowchart of the preparation method of the powder metallurgy transmission plate material for clutch of the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Based on the background art, existing clutch transmission plate materials exhibit poor overall performance under high temperature and high stress conditions, which affects the service life of the clutch and even causes safety hazards. This invention provides a powder metallurgy transmission plate material for clutches and its preparation method, aiming to significantly improve the overall performance of clutch transmission plates, ensure the reliability and durability of transmission plates in complex mechanical environments, increase service life, and reduce safety risks.

[0045] The powder metallurgical transmission plate material for the clutch of the present invention comprises, by weight percentage: 55%-65% high-purity atomized iron powder, 8%-12% electrolytic copper powder, 4%-8% nickel hydroxyl powder, 1.5%-4% ferromolybdenum powder, 1%-3% chromium powder, 0.3%-1.5% lanthanum powder, 1.5%-3.5% nano-silicon carbide particles, 0.8%-2% carbon fiber, 0.5%-1.5% whisker-like alumina, 0.3%-1% cellulose nanocrystals, 0.5%-2% rare earth oxides, 2.3%-6% lubricant, and 0.5%-1.8% binder; wherein, the purity of the high-purity atomized iron powder is preferably greater than or equal to 99%.

[0046] Preferably, the lubricant comprises 1.5%-3.5% flake graphite and 0.8%-2.5% nano molybdenum disulfide; the binder comprises 0.3%-1% polyethylene glycol and 0.2%-0.8% sodium carboxymethyl cellulose.

[0047] The rare earth oxide can be yttrium oxide or cerium oxide alone. Of course, a mixture of cerium oxide and yttrium oxide is preferred. More preferably, the rare earth oxide comprises 0.4%-1.6% cerium oxide and 0.1%-0.4% yttrium oxide.

[0048] In the powder metallurgy transmission plate material for clutches of this invention, high-purity atomized iron powder serves as the main matrix component, providing a basic structural framework and a certain strength foundation for the transmission plate. Its excellent formability allows other components to effectively combine with it and jointly construct a stable material structure. Electrolytic copper powder, with its excellent thermal and electrical conductivity, can quickly conduct the heat generated during clutch operation and ensure good electrical signal transmission. Moreover, during sintering, it can form alloys or intermetallic compounds with iron powder, enhancing the strength and hardness of the material through solid solution strengthening, while improving toughness. Together with iron powder, it lays the foundation for the material's mechanical and physical properties. Nickel hydroxyl powder increases the material's strength and corrosion resistance. In conjunction with other metal powders, it further enhances the durability of the material under complex working conditions. Uniformly distributed within the iron powder matrix, it synergistically enhances the material's resistance to environmental factors with electrolytic copper powder, ensuring the structural and performance stability of the transmission plate during long-term use. Molybdenum-iron powder improves the material's hardness and high-temperature performance, and in conjunction with chromium powder, significantly enhances the material's wear and corrosion resistance. Especially in the high-temperature, high-friction clutch operating environment, the reinforcing phase formed by molybdenum-iron powder and chromium powder effectively prevents surface wear and oxidation. Combined with the matrix structure of high-purity atomized iron powder, it strengthens the overall stability of the material under extreme conditions. The addition of rare earth element lanthanum powder refines the grain size and enhances the uniformity of the material's internal structure. In addition to its density, it interacts with other metal powders to optimize the crystal structure of the material, making the stress distribution more uniform when the material is subjected to external forces, thus improving the overall strength and toughness and synergistically enhancing the comprehensive mechanical properties of the material. The uniform dispersion of nano-silicon carbide particles within the material effectively improves the overall hardness and wear resistance, and its synergistic effect with whisker-like alumina—the whisker structure of which effectively prevents crack propagation—further enhances the material's wear resistance and maintains a stable strengthening effect at high temperatures. Together with the metal powder matrix, it constructs a high-strength, high-wear-resistant, and high-temperature-resistant material system. Carbon fibers, in synergy with reinforcing agents such as nano-silicon carbide particles and whisker-like alumina, enhance the material's wear resistance under various conditions. When subjected to external forces, the cellulose nanocrystals distribute stress to other reinforcing components through their own load-bearing and stress-transfer effects, thereby enhancing the material's impact resistance and mechanical stability. Cellulose nanocrystals provide the material with a certain strength and stiffness, and their unique structure and adsorption properties allow them to adsorb lubricants such as flake graphite and nano-molybdenum disulfide, resulting in better lubrication during friction, reducing wear, and lowering material density for lightweighting. Together with other reinforcing agents, they optimize the material's overall performance, achieving a balance between mechanical properties, wear resistance, and lightweighting. Flake graphite provides excellent self-lubricating properties, while nano-molybdenum disulfide reduces the coefficient of friction; together, they significantly reduce friction and wear on the transmission plates during operation.Meanwhile, the flake structure of flake graphite facilitates the formation of a lubricating film during friction, while the nanoscale particles of molybdenum disulfide better fill pores, enhancing the material's density. These components, in synergy with cellulose nanocrystals, further improve the material's lubrication and structural stability. Polyethylene glycol aids in powder forming and pressing, increasing the material's density and uniformity, while sodium carboxymethyl cellulose enhances the material's adhesion and improves its strength after forming. The combination of these two components ensures tight bonding during powder forming, enabling the mixed powder to form a stable green structure. This provides a solid foundation for subsequent sintering and other processes, guaranteeing the final reliability and consistency of the transmission plate's performance.

[0049] Furthermore, through repeated experiments, analysis, and comparisons, the inventors discovered that during the sintering process of the material, cerium oxide and yttrium oxide can play a pinning role at grain boundaries. These rare earth oxide particles adsorb onto the boundaries of growing grains, and yttrium oxide interacts with iron powder atoms at the grain boundaries. Due to the difference in atomic size and chemical properties between rare earth oxides and iron powder atoms, they hinder the normal migration of grain boundaries. When grains attempt to grow, the movement of grain boundaries is impeded by these adsorbed rare earth oxide particles, much like setting up barriers at grain boundaries, thus inhibiting excessive grain growth. Cerium oxide and yttrium oxide can also serve as nuclei for heterogeneous nucleation. During the solidification or recrystallization process of the material, atoms need to aggregate on certain nuclei to form new grains. The presence of rare earth oxide particles provides additional nucleation sites for metal atoms. The surface energy and crystal structure of these particles differ from those of the metal matrix, making it easier for metal atoms to aggregate and nucleate on their surface. The crystal structure of cerium oxide forms a unique relationship with the metal matrix. A specific lattice mismatch causes surrounding metal atoms to deposit on the surface in a certain orientation, forming new grains and increasing the number of grains, thus refining the grain size. At high temperatures, cerium oxide and yttrium oxide can form a dense protective film on the material surface. Oxygen atoms in rare earth oxides are chemically bonded to metal atoms (such as iron atoms). In high-temperature and oxygen-rich environments, oxygen atoms in cerium oxide and yttrium oxide react with metal atoms on the material surface, preferentially forming an oxide protective film. Cerium oxide forms a composite oxide film on the material surface containing cerium, oxygen, and other metal elements (such as iron and chromium). This film has a dense structure, preventing oxygen molecules from further diffusing into the material. Rare earth oxides can also regulate the oxidation state of the material surface through redox reactions. At high temperatures, when metal atoms on the material surface begin to oxidize, cerium oxide and yttrium oxide can provide or accept electrons, controlling the rate of the oxidation reaction. Cerium oxide can... 3+ and Ce 4+ Redox transformations occur between them; when metal atoms (such as iron) on the material surface are oxidized to Fe... 2+ or Fe 3+ At that time, Ce4+ It is acceptable for electrons to be reduced to Ce. 3+ This inhibits excessive oxidation of metal atoms and maintains the chemical stability of the material surface. During sintering, cerium oxide and yttrium oxide are distributed between metal grains, altering the sintering behavior of the metal powder. On one hand, by refining the grains, the bonding between metal powders becomes tighter. Between iron powder particles, the rare earth oxides refine the grains, increasing the contact area and making the growth of the sintering neck more uniform, thus improving the material's density. On the other hand, they can react with impurities in the metal powder, purifying the material's microstructure. Cerium oxide can react with small amounts of sulfur, phosphorus, and other impurities in the metal powder to form stable compounds, reducing the impact of these impurities on the material. The adverse effects on performance; cerium oxide and yttrium oxide can also optimize the distribution and effect of reinforcing agents; taking nano-silicon carbide particles as an example, because rare earth oxides refine the grains, nano-silicon carbide particles are more easily and uniformly dispersed between the refined grains; at the same time, the presence of rare earth oxides at the grain boundaries can regulate the properties of the grain boundaries, so that reinforcing agents such as whisker-like alumina can better play the role of preventing crack propagation at the grain boundaries; when the material is subjected to external force, rare earth oxides and reinforcing agents work together to share and transfer stress, and through the optimization of microstructure, the overall strength and toughness of the material are improved; in this invention, after repeated experiments and comparisons by the inventors, the best effect is achieved when the ratio of cerium oxide to yttrium oxide is 4:1.

[0050] As shown in Figure 1, the preparation method of the powder metallurgy transmission plate material for the clutch of the present invention includes:

[0051] S1: Pretreatment of high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, carbon fiber, and cellulose nanocrystals;

[0052] In a preferred embodiment, step S1 specifically includes:

[0053] S11: High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder are vacuum dried separately to remove moisture and adsorbed gases. The drying temperature is 110-130℃, the drying time is 5-7 hours, and the heating rate is controlled at 25-35℃ / hour to avoid powder agglomeration. Then, the above metal powders are ball-milled separately. Stainless steel balls are used as the ball milling media, the ball-to-material ratio is 5:1-8:1, the ball milling time is 10-15 hours, and the ball milling speed is 200-300 rpm. An appropriate amount of ethanol or acetone is added as a dispersant, and the amount of dispersant is 0.5%-1.5% of the mass of each metal powder.

[0054] S12: Soak nano-silicon carbide particles in a composite treatment agent of silane coupling agent and titanate coupling agent. The concentration of the treatment agent solution is 2%-5%. After stirring evenly, perform ultrasonic treatment at a frequency of 20-40kHz for 3-5 hours at a temperature of 60-80℃. Then dry at 80-100℃ for 4-6 hours.

[0055] S13: After the carbon fiber is chopped, it is soaked in a dopamine solution with a concentration of 1-3 g / L and a pH of 8-9. The mixture is stirred and reacted at room temperature for 12-24 hours. Then the carbon fiber is removed, rinsed with deionized water, and dried at 60-80℃ for 3-5 hours.

[0056] S14: Disperse cellulose nanocrystals in a solution containing 1%-3% silane coupling agent, sonicate at 300-500W for 2-4 hours, then filter and dry at 60-80℃ for 3-5 hours.

[0057] S2: The pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano silicon carbide particles, rare earth oxides, polyethylene glycol and sodium carboxymethyl cellulose are added to a high-speed mixer for a first mixing. Then, flake graphite, nano molybdenum disulfide and whisker alumina are added to the mixture from the first mixing in the high-speed mixer for a second mixing. Then, carbon fiber and cellulose nanocrystals are added to the mixture from the second mixing in the high-speed mixer for a third mixing.

[0058] In a preferred embodiment, in step S2 above, during the first mixing process, the mixture is stirred at 60-80°C for 1-2 hours, with an initial stirring speed of 500-800 rpm, gradually increasing to 1000-1500 rpm. During the second mixing process, the mixture is stirred for 1-2 hours, with a stirring speed of 1200-1800 rpm. During the third mixing process, the mixture is stirred for 1-2 hours, with a stirring speed of 1500-2000 rpm. The first, second, and third mixing processes are all combined with ultrasonic-assisted mixing.

[0059] S3: The mixture of three mixtures is shaped using a two-way pressing method;

[0060] In a preferred embodiment, step S3 specifically includes:

[0061] S31: Load the mixed powder into the mold, pre-press it with a pressure of 200-300MPa, a holding time of 5-10 seconds, and a pressing speed of 5-10 mm / s;

[0062] S32: The pre-pressed material is subjected to biaxial pressing at a pressure of 600-900MPa, a holding time of 15-25 seconds, and a pressing speed of 3-8 mm / s. During the biaxial pressing process, the mold is heated to 100-150℃ at a heating rate of 15-25℃ / min.

[0063] More preferably, an electromagnetic coil capable of generating a strong magnetic field is surrounded around the mold. Pre-pressing is performed simultaneously with the application of the magnetic field, the magnetic field strength of which can be controlled between 0.5-2 Tesla, the pre-pressing pressure is 100-200 MPa, and the holding time is 3-5 seconds. Then, bidirectional pressing is performed under the continuous action of the magnetic field, the pressing pressure is 600-900 MPa, and the holding time is 15-25 seconds. For metal powders in powder metallurgy materials (such as high-purity atomized iron powder, electrolytic copper powder, etc.), under the action of the magnetic field, the electrons inside will undergo directional movement, resulting in a certain degree of magnetization of the powder particles. The magnetized powder particles will align along the direction of the magnetic field, so that the material forms a certain preferred orientation during the molding process. This preferred orientation can improve the mechanical properties of the material in a specific direction, such as improving the strength and hardness of the material in the direction of the magnetic field. At the same time, the presence of the magnetic field can also promote the enhanced interaction between the metal powder and other additives (such as rare earth oxides, nano-silicon carbide particles, etc.), because the magnetic field affects the distribution of the electron cloud around these particles, making their bonding tighter, thereby improving the overall performance of the material.

[0064] S4: The shaped material is subjected to low-temperature pre-sintering and high-temperature sintering in sequence;

[0065] In a preferred embodiment, step S4 specifically includes:

[0066] S41: The molded material is subjected to a vacuum of 1×10⁻⁶. -3 -1×10 -2 Low-temperature pre-sintering is carried out under vacuum conditions at a temperature of 800-1000℃ for 1-2 hours, with a heating rate of 10-20℃ / minute.

[0067] S42: The pre-sintered material is placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering. The hydrogen content is 8%-12%, the sintering temperature is 1200-1400℃, the sintering time is 2-3 hours, and the heating rate is 15-25℃ / minute. During the high-temperature sintering process, microwave-assisted sintering is used with a microwave frequency of 2.45GHz and a microwave power of 5-10kW.

[0068] S5: Machining, surface treatment and heat treatment of the sintered material.

[0069] In a preferred embodiment, step S5 specifically includes:

[0070] S51: Machining of sintered materials, such as grinding and polishing, using low-stress machining methods, with a grinding speed of 10-20 m / s and a feed rate of 0.05-0.15 mm / revolution, to achieve the required dimensions and surface accuracy;

[0071] S52: The machined material is first subjected to phosphating treatment at a temperature of 50-70℃ for 20-30 minutes. The spraying pressure of the phosphating solution is 0.1-0.3MPa. The phosphating solution formula is: 20-30g / L zinc dihydrogen phosphate, 50-70g / L zinc nitrate, and 1-3g / L sodium fluoride, with a pH value of 2-3.

[0072] S53: For phosphated materials, electroplating or chemical copper plating is performed, with a current density of 1-3 A / dm³ when electroplating. 2 The electroplating time is 10-30 minutes. When using chemical copper plating, the plating solution temperature is 40-60℃ and the deposition rate is 2-5μm / h.

[0073] S54: The material is heat-treated under nitrogen protection. The heat treatment involves heating the material to 200-300°C at a heating rate of 10-20°C / min, holding it at that temperature for 1-2 hours, and then slowly cooling it to room temperature at a cooling rate of 5-10°C / min.

[0074] The technical solution of the present invention will be further illustrated below with reference to several embodiments and comparative examples.

[0075] Example 1

[0076] The powder metallurgy transmission plate material for clutches, measured by mass percentage, includes: 65% high-purity atomized iron powder, 12% electrolytic copper powder, 7% nickel hydroxyl powder, 3% ferromolybdenum powder, 2% chromium powder, 0.5% lanthanum powder, 1.5% nano-silicon carbide particles, 1% carbon fiber, 1.2% whisker-like alumina, 0.8% cellulose nanocrystals, 0.8% cerium oxide, 0.2% yttrium oxide, 2.5% flake graphite, 1.5% nano-molybdenum disulfide, 0.6% polyethylene glycol, and 0.4% sodium carboxymethyl cellulose.

[0077] The preparation method of the above-mentioned powder metallurgy transmission plate material for clutches includes:

[0078] High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder were vacuum dried separately at 120℃ for 6 hours, with a heating rate controlled at 30℃ / hour. The metal powders were then ball-milled using stainless steel balls at a ball-to-powder ratio of 6:1 for 12 hours at a speed of 250 rpm. A suitable amount of ethanol or acetone was added as a dispersant, at a concentration of 1% of the mass of each metal powder. Nano-silicon carbide particles were then immersed in a composite treatment agent containing silane coupling agent and titanate coupling agent at a concentration of 3%. After thorough stirring, the mixture was ultrasonically treated at a frequency of 30 kHz for 4 hours at 70℃, followed by drying at 90℃ for 5 hours. After shaving the carbon fibers, they were immersed in a dopamine solution with a concentration of 2 g / L and a pH of 8.5. The mixture was stirred and reacted at room temperature for 18 hours. The carbon fibers were then removed, rinsed with deionized water, and dried at 70°C for 4 hours. Cellulose nanocrystals were dispersed in a solution containing 2% silane coupling agent, sonicated at a power of 400 W for 3 hours, filtered, and dried at 70°C for 4 hours.

[0079] Pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, rare earth oxides, polyethylene glycol, and sodium carboxymethyl cellulose were added to a high-speed mixer for a first ultrasonic mixing. During the first ultrasonic mixing, the mixture was stirred at 70°C for 1.5 hours, with the initial stirring speed of 600 rpm gradually increasing to 1200 rpm. Then, flake graphite, nano-molybdenum disulfide, and whisker-like alumina were added to the mixture from the first ultrasonic mixing in the high-speed mixer for a second ultrasonic mixing. During the second ultrasonic mixing, the mixture was stirred for 1.5 hours at a stirring speed of 1500 rpm. Finally, carbon fiber and cellulose nanocrystals were added to the mixture from the second ultrasonic mixing in the high-speed mixer for a third ultrasonic mixing. During the third ultrasonic mixing, the mixture was stirred for 1.5 hours at a stirring speed of 1800 rpm.

[0080] The mixed powder is loaded into a mold, and a magnetic field with a strength of 1 Tesla is applied around the mold. Pre-compression is performed simultaneously with the magnetic field applied, with a pressure of 250 MPa, a holding time of 8 seconds, and a pressing speed of 8 mm / s. The pre-compressed material is then subjected to bidirectional compression with a pressure of 700 MPa, a holding time of 20 seconds, and a pressing speed of 5 mm / s. During the bidirectional compression process, the mold is heated to 120°C at a heating rate of 20°C / min.

[0081] The molded material is then subjected to a vacuum of 5×10⁻⁶. -3Low-temperature pre-sintering was carried out under vacuum conditions at a temperature of 900℃ for 1.5 hours with a heating rate of 15℃ / min. The pre-sintered material was then placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering at a hydrogen content of 10% at a sintering temperature of 1300℃ for 2.5 hours with a heating rate of 20℃ / min. Microwave-assisted sintering was used during the high-temperature sintering process, with a microwave frequency of 2.45GHz and a microwave power of 8kW.

[0082] The sintered material is ground and polished using a low-stress machining method at a grinding speed of 15 m / s and a feed rate of 0.1 mm / rpm to achieve the required dimensions and surface precision. The machined material is then subjected to phosphating treatment at 60℃ for 25 minutes at a spray pressure of 0.2 MPa. The phosphating solution formulation consists of 25 g / L zinc dihydrogen phosphate, 60 g / L zinc nitrate, and 2 g / L sodium fluoride, with a pH of 2.5. Finally, the phosphated material is electroplated with copper at a current density of 2 A / dm³. 2 The electroplating time is 20 minutes; the material is heat-treated under nitrogen protection, heated to 250°C at a heating rate of 15°C / min, held for 1.5 hours, and then slowly cooled to room temperature at a cooling rate of 8°C / min.

[0083] Example 2

[0084] The powder metallurgy transmission plate material for clutches, measured by mass percentage, includes: 65% high-purity atomized iron powder, 12% electrolytic copper powder, 7% nickel hydroxyl powder, 3% ferromolybdenum powder, 2% chromium powder, 0.5% lanthanum powder, 1.5% nano-silicon carbide particles, 1% carbon fiber, 1.2% whisker-like alumina, 0.8% cellulose nanocrystals, 0.8% cerium oxide, 0.2% yttrium oxide, 2.5% flake graphite, 1.5% nano-molybdenum disulfide, 0.6% polyethylene glycol, and 0.4% sodium carboxymethyl cellulose.

[0085] The preparation method of the above-mentioned powder metallurgy transmission plate material for clutches includes:

[0086] High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder were vacuum dried separately at 110℃ for 5 hours, with a heating rate controlled at 25℃ / hour. The metal powders were then ball-milled using stainless steel balls at a ball-to-powder ratio of 5:1 for 10 hours at a speed of 200 rpm. A suitable amount of ethanol or acetone was added as a dispersant, at a concentration of 0.5% of the mass of each metal powder. Nano-silicon carbide particles were then immersed in a composite treatment agent of silane coupling agent and titanate coupling agent at a concentration of 2%. After thorough stirring, the mixture was ultrasonically treated at a frequency of 20 kHz for 3 hours at 60℃, followed by drying at 80℃ for 4 hours. After shaving the carbon fibers, they were immersed in a dopamine solution with a concentration of 1 g / L and a pH of 8. The mixture was stirred and reacted at room temperature for 12 hours. The carbon fibers were then removed, rinsed with deionized water, and dried at 60°C for 3 hours. Cellulose nanocrystals were dispersed in a solution containing 1% silane coupling agent, sonicated at 300 W for 2 hours, filtered, and dried at 60°C for 3 hours.

[0087] Pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, rare earth oxides, polyethylene glycol, and sodium carboxymethyl cellulose were added to a high-speed mixer for a first ultrasonic mixing. During the first ultrasonic mixing, the mixture was stirred at 60°C for 1 hour, with the initial stirring speed of 500 rpm gradually increasing to 1000 rpm. Then, flake graphite, nano-molybdenum disulfide, and whisker-like alumina were added to the mixture from the first ultrasonic mixing in the high-speed mixer for a second ultrasonic mixing. During the second ultrasonic mixing, the mixture was stirred for 1 hour at a stirring speed of 1200 rpm. Then, carbon fiber and cellulose nanocrystals were added to the mixture from the second ultrasonic mixing in the high-speed mixer for a third ultrasonic mixing. During the third ultrasonic mixing, the mixture was stirred for 1 hour at a stirring speed of 1500 rpm.

[0088] The mixed powder is loaded into a mold, and a magnetic field with a strength of 0.5 Tesla is applied around the mold. Pre-compression is performed simultaneously with the magnetic field applied, with a pressure of 200 MPa, a holding time of 5 seconds, and a pressing speed of 5 mm / s. The pre-compressed material is then subjected to bidirectional compression with a pressure of 600 MPa, a holding time of 15 seconds, and a pressing speed of 3 mm / s. During the bidirectional compression process, the mold is heated to 100°C at a heating rate of 15°C / min.

[0089] The molded material is then subjected to a vacuum of 1×10⁻⁶. -3Low-temperature pre-sintering was carried out under vacuum conditions at a temperature of 800℃ for 1 hour at a heating rate of 10℃ / min. The pre-sintered material was then placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering at a hydrogen content of 8% at a sintering temperature of 1200℃ for 2 hours at a heating rate of 15℃ / min. Microwave-assisted sintering was used during the high-temperature sintering process, with a microwave frequency of 2.45GHz and a microwave power of 5kW.

[0090] The sintered material was ground and polished using a low-stress machining method at a grinding speed of 10 m / s and a feed rate of 0.05 mm / rpm to achieve the required dimensions and surface precision. The machined material was then subjected to phosphating at 50°C for 20 minutes, with a phosphating solution spray pressure of 0.1 MPa. The phosphating solution formulation consisted of 20 g / L zinc dihydrogen phosphate, 50 g / L zinc nitrate, and 1 g / L sodium fluoride, with a pH of 2. The phosphated material was then subjected to electroless copper plating at 40°C and a deposition rate of 2 μm / h. Finally, the material was heat-treated under nitrogen protection, heated to 200°C at a heating rate of 10°C / min, held for 1 hour, and then slowly cooled to room temperature at a cooling rate of 5°C / min.

[0091] Example 3

[0092] The powder metallurgy transmission plate material for clutches, measured by mass percentage, includes: 65% high-purity atomized iron powder, 12% electrolytic copper powder, 7% nickel hydroxyl powder, 3% ferromolybdenum powder, 2% chromium powder, 0.5% lanthanum powder, 1.5% nano-silicon carbide particles, 1% carbon fiber, 1.2% whisker-like alumina, 0.8% cellulose nanocrystals, 0.8% cerium oxide, 0.2% yttrium oxide, 2.5% flake graphite, 1.5% nano-molybdenum disulfide, 0.6% polyethylene glycol, and 0.4% sodium carboxymethyl cellulose.

[0093] The preparation method of the above-mentioned powder metallurgy transmission plate material for clutches includes:

[0094] High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder were vacuum dried separately at 130℃ for 7 hours, with a heating rate controlled at 35℃ / hour. The metal powders were then ball-milled using stainless steel balls at a ball-to-powder ratio of 8:1 for 15 hours at a speed of 300 rpm. A suitable amount of ethanol or acetone was added as a dispersant, at a concentration of 1.5% of the mass of each metal powder. Nano-silicon carbide particles were then immersed in a composite treatment agent of silane coupling agent and titanate coupling agent at a concentration of 5%. After thorough stirring, the mixture was ultrasonically treated at a frequency of 40 kHz for 5 hours at 80℃, followed by drying at 100℃ for 6 hours. After shaving the carbon fibers, they were immersed in a dopamine solution with a concentration of 3 g / L and a pH of 9. The mixture was stirred and reacted at room temperature for 24 hours. The carbon fibers were then removed, rinsed with deionized water, and dried at 80°C for 5 hours. Cellulose nanocrystals were dispersed in a solution containing 3% silane coupling agent, sonicated at 500 W for 4 hours, filtered, and dried at 80°C for 5 hours.

[0095] Pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, rare earth oxides, polyethylene glycol, and sodium carboxymethyl cellulose were added to a high-speed mixer for a first ultrasonic mixing. During the first ultrasonic mixing, the mixture was stirred at 80°C for 2 hours, with the initial stirring speed of 800 rpm gradually increasing to 1500 rpm. Then, flake graphite, nano-molybdenum disulfide, and whisker-like alumina were added to the mixture from the first ultrasonic mixing in the high-speed mixer for a second ultrasonic mixing. During the second ultrasonic mixing, the mixture was stirred for 2 hours at a stirring speed of 1800 rpm. Finally, carbon fiber and cellulose nanocrystals were added to the mixture from the second ultrasonic mixing in the high-speed mixer for a third ultrasonic mixing. During the third ultrasonic mixing, the mixture was stirred for 2 hours at a stirring speed of 2000 rpm.

[0096] The mixed powder is loaded into a mold, and a magnetic field with a strength of 2 Tesla is applied around the mold. Pre-compression is performed simultaneously with the magnetic field applied, with a pressure of 300 MPa, a holding time of 10 seconds, and a pressing speed of 10 mm / s. The pre-compressed material is then subjected to bidirectional compression with a pressure of 900 MPa, a holding time of 25 seconds, and a pressing speed of 8 mm / s. During the bidirectional compression process, the mold is heated to 150°C at a heating rate of 25°C / min.

[0097] The molded material is then subjected to a vacuum of 1×10⁻⁶. -2Low-temperature pre-sintering was carried out under vacuum conditions at a temperature of 1000℃ for 2 hours with a heating rate of 20℃ / min. The pre-sintered material was then placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering at a hydrogen content of 12% at a sintering temperature of 1400℃ for 3 hours with a heating rate of 25℃ / min. Microwave-assisted sintering was used during the high-temperature sintering process, with a microwave frequency of 2.45GHz and a microwave power of 10kW.

[0098] The sintered material is ground and polished using a low-stress machining method at a grinding speed of 20 m / s and a feed rate of 0.15 mm / rpm to achieve the required dimensions and surface precision. The machined material is then subjected to phosphating treatment at 70℃ for 30 minutes at a spray pressure of 0.3 MPa. The phosphating solution formulation consists of 30 g / L zinc dihydrogen phosphate, 70 g / L zinc nitrate, and 3 g / L sodium fluoride, with a pH of 3. Finally, the phosphated material is electroplated with copper at a current density of 3 A / dm³. 2 The electroplating time is 30 minutes; the material is heat-treated under nitrogen protection, heated to 300°C at a heating rate of 20°C / min, held for 2 hours, and then slowly cooled to room temperature at a cooling rate of 10°C / min.

[0099] Example 4

[0100] The powder metallurgy transmission plate material for clutches, measured by weight percentage, includes: 60% high-purity atomized iron powder, 10% electrolytic copper powder, 8% nickel hydroxyl powder, 4% ferromolybdenum powder, 3% chromium powder, 1.5% lanthanum powder, 3.5% nano-silicon carbide particles, 2% carbon fiber, 1.2% whisker-like alumina, 0.8% cellulose nanocrystals, 0.8% cerium oxide, 0.2% yttrium oxide, 2.5% flake graphite, 1.5% nano-molybdenum disulfide, 0.6% polyethylene glycol, and 0.4% sodium carboxymethyl cellulose.

[0101] The preparation method of the above-mentioned powder metallurgy transmission plate material for clutches includes:

[0102] High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder were vacuum dried separately at 120℃ for 6 hours, with a heating rate controlled at 30℃ / hour. The metal powders were then ball-milled using stainless steel balls at a ball-to-powder ratio of 6:1 for 12 hours at a speed of 250 rpm. A suitable amount of ethanol or acetone was added as a dispersant, at a concentration of 1% of the mass of each metal powder. Nano-silicon carbide particles were then immersed in a composite treatment agent containing silane coupling agent and titanate coupling agent at a concentration of 3%. After thorough stirring, the mixture was ultrasonically treated at a frequency of 30 kHz for 4 hours at 70℃, followed by drying at 90℃ for 5 hours. After shaving the carbon fibers, they were immersed in a dopamine solution with a concentration of 2 g / L and a pH of 8.5. The mixture was stirred and reacted at room temperature for 18 hours. The carbon fibers were then removed, rinsed with deionized water, and dried at 70°C for 4 hours. Cellulose nanocrystals were dispersed in a solution containing 2% silane coupling agent, sonicated at a power of 400 W for 3 hours, filtered, and dried at 70°C for 4 hours.

[0103] Pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, rare earth oxides, polyethylene glycol, and sodium carboxymethyl cellulose were added to a high-speed mixer for a first ultrasonic mixing. During the first ultrasonic mixing, the mixture was stirred at 70°C for 1.5 hours, with the initial stirring speed of 600 rpm gradually increasing to 1200 rpm. Then, flake graphite, nano-molybdenum disulfide, and whisker-like alumina were added to the mixture from the first ultrasonic mixing in the high-speed mixer for a second ultrasonic mixing. During the second ultrasonic mixing, the mixture was stirred for 1.5 hours at a stirring speed of 1500 rpm. Finally, carbon fiber and cellulose nanocrystals were added to the mixture from the second ultrasonic mixing in the high-speed mixer for a third ultrasonic mixing. During the third ultrasonic mixing, the mixture was stirred for 1.5 hours at a stirring speed of 1800 rpm.

[0104] The mixed powder is loaded into a mold, and a magnetic field with a strength of 1 Tesla is applied around the mold. Pre-compression is performed simultaneously with the magnetic field applied, with a pressure of 250 MPa, a holding time of 8 seconds, and a pressing speed of 8 mm / s. The pre-compressed material is then subjected to bidirectional compression with a pressure of 700 MPa, a holding time of 20 seconds, and a pressing speed of 5 mm / s. During the bidirectional compression process, the mold is heated to 120°C at a heating rate of 20°C / min.

[0105] The molded material is then subjected to a vacuum of 5×10⁻⁶. -3Low-temperature pre-sintering was carried out under vacuum conditions at a temperature of 900℃ for 1.5 hours with a heating rate of 15℃ / min. The pre-sintered material was then placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering at a hydrogen content of 10% at a sintering temperature of 1300℃ for 2.5 hours with a heating rate of 20℃ / min. Microwave-assisted sintering was used during the high-temperature sintering process, with a microwave frequency of 2.45GHz and a microwave power of 8kW.

[0106] The sintered material is ground and polished using a low-stress machining method at a grinding speed of 15 m / s and a feed rate of 0.1 mm / rpm to achieve the required dimensions and surface precision. The machined material is then subjected to phosphating treatment at 60℃ for 25 minutes at a spray pressure of 0.2 MPa. The phosphating solution formulation consists of 25 g / L zinc dihydrogen phosphate, 60 g / L zinc nitrate, and 2 g / L sodium fluoride, with a pH of 2.5. Finally, the phosphated material is electroplated with copper at a current density of 2 A / dm³. 2 The electroplating time is 20 minutes; the material is heat-treated under nitrogen protection, heated to 250°C at a heating rate of 15°C / min, held for 1.5 hours, and then slowly cooled to room temperature at a cooling rate of 8°C / min.

[0107] Example 5

[0108] The powder metallurgy transmission plate material for clutches, measured by weight percentage, includes: 60% high-purity atomized iron powder, 10% electrolytic copper powder, 8% nickel hydroxyl powder, 4% ferromolybdenum powder, 3% chromium powder, 1.5% lanthanum powder, 3.5% nano-silicon carbide particles, 2% carbon fiber, 1.2% whisker-like alumina, 0.8% cellulose nanocrystals, 0.8% cerium oxide, 0.2% yttrium oxide, 2.5% flake graphite, 1.5% nano-molybdenum disulfide, 0.6% polyethylene glycol, and 0.4% sodium carboxymethyl cellulose.

[0109] The preparation method of the above-mentioned powder metallurgy transmission plate material for clutches includes:

[0110] High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder were vacuum dried separately at 110℃ for 5 hours, with a heating rate controlled at 25℃ / hour. The metal powders were then ball-milled using stainless steel balls at a ball-to-powder ratio of 5:1 for 10 hours at a speed of 200 rpm. A suitable amount of ethanol or acetone was added as a dispersant, at a concentration of 0.5% of the mass of each metal powder. Nano-silicon carbide particles were then immersed in a composite treatment agent of silane coupling agent and titanate coupling agent at a concentration of 2%. After thorough stirring, the mixture was ultrasonically treated at a frequency of 20 kHz for 3 hours at 60℃, followed by drying at 80℃ for 4 hours. After shaving the carbon fibers, they were immersed in a dopamine solution with a concentration of 1 g / L and a pH of 8. The mixture was stirred and reacted at room temperature for 12 hours. The carbon fibers were then removed, rinsed with deionized water, and dried at 60°C for 3 hours. Cellulose nanocrystals were dispersed in a solution containing 1% silane coupling agent, sonicated at 300 W for 2 hours, filtered, and dried at 60°C for 3 hours.

[0111] Pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, rare earth oxides, polyethylene glycol, and sodium carboxymethyl cellulose were added to a high-speed mixer for a first ultrasonic mixing. During the first ultrasonic mixing, the mixture was stirred at 60°C for 1 hour, with the initial stirring speed of 500 rpm gradually increasing to 1000 rpm. Then, flake graphite, nano-molybdenum disulfide, and whisker-like alumina were added to the mixture from the first ultrasonic mixing in the high-speed mixer for a second ultrasonic mixing. During the second ultrasonic mixing, the mixture was stirred for 1 hour at a stirring speed of 1200 rpm. Then, carbon fiber and cellulose nanocrystals were added to the mixture from the second ultrasonic mixing in the high-speed mixer for a third ultrasonic mixing. During the third ultrasonic mixing, the mixture was stirred for 1 hour at a stirring speed of 1500 rpm.

[0112] The mixed powder is loaded into a mold, and a magnetic field with a strength of 0.5 Tesla is applied around the mold. Pre-compression is performed simultaneously with the magnetic field applied, with a pressure of 200 MPa, a holding time of 5 seconds, and a pressing speed of 5 mm / s. The pre-compressed material is then subjected to bidirectional compression with a pressure of 600 MPa, a holding time of 15 seconds, and a pressing speed of 3 mm / s. During the bidirectional compression process, the mold is heated to 100°C at a heating rate of 15°C / min.

[0113] The molded material is then subjected to a vacuum of 1×10⁻⁶. -3Low-temperature pre-sintering was carried out under vacuum conditions at a temperature of 800℃ for 1 hour at a heating rate of 10℃ / min. The pre-sintered material was then placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering at a hydrogen content of 8% at a sintering temperature of 1200℃ for 2 hours at a heating rate of 15℃ / min. Microwave-assisted sintering was used during the high-temperature sintering process, with a microwave frequency of 2.45GHz and a microwave power of 5kW.

[0114] The sintered material was ground and polished using a low-stress machining method at a grinding speed of 10 m / s and a feed rate of 0.05 mm / rpm to achieve the required dimensions and surface precision. The machined material was then subjected to phosphating at 50°C for 20 minutes, with a phosphating solution spray pressure of 0.1 MPa. The phosphating solution formulation consisted of 20 g / L zinc dihydrogen phosphate, 50 g / L zinc nitrate, and 1 g / L sodium fluoride, with a pH of 2. The phosphated material was then subjected to electroless copper plating at 40°C and a deposition rate of 2 μm / h. Finally, the material was heat-treated under nitrogen protection, heated to 200°C at a heating rate of 10°C / min, held for 1 hour, and then slowly cooled to room temperature at a cooling rate of 5°C / min.

[0115] Example 6

[0116] The powder metallurgy transmission plate material for clutches, measured by weight percentage, includes: 60% high-purity atomized iron powder, 10% electrolytic copper powder, 8% nickel hydroxyl powder, 4% ferromolybdenum powder, 3% chromium powder, 1.5% lanthanum powder, 3.5% nano-silicon carbide particles, 2% carbon fiber, 1.2% whisker-like alumina, 0.8% cellulose nanocrystals, 0.8% cerium oxide, 0.2% yttrium oxide, 2.5% flake graphite, 1.5% nano-molybdenum disulfide, 0.6% polyethylene glycol, and 0.4% sodium carboxymethyl cellulose.

[0117] The preparation method of the above-mentioned powder metallurgy transmission plate material for clutches includes:

[0118] High-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder were vacuum dried separately at 130℃ for 7 hours, with a heating rate controlled at 35℃ / hour. The metal powders were then ball-milled using stainless steel balls at a ball-to-powder ratio of 8:1 for 15 hours at a speed of 300 rpm. A suitable amount of ethanol or acetone was added as a dispersant, at a concentration of 1.5% of the mass of each metal powder. Nano-silicon carbide particles were then immersed in a composite treatment agent of silane coupling agent and titanate coupling agent at a concentration of 5%. After thorough stirring, the mixture was ultrasonically treated at a frequency of 40 kHz for 5 hours at 80℃, followed by drying at 100℃ for 6 hours. After shaving the carbon fibers, they were immersed in a dopamine solution with a concentration of 3 g / L and a pH of 9. The mixture was stirred and reacted at room temperature for 24 hours. The carbon fibers were then removed, rinsed with deionized water, and dried at 80°C for 5 hours. Cellulose nanocrystals were dispersed in a solution containing 3% silane coupling agent, sonicated at 500 W for 4 hours, filtered, and dried at 80°C for 5 hours.

[0119] Pretreated high-purity atomized iron powder, electrolytic copper powder, nickel hydroxyl powder, ferromolybdenum powder, chromium powder, lanthanum powder, nano-silicon carbide particles, rare earth oxides, polyethylene glycol, and sodium carboxymethyl cellulose were added to a high-speed mixer for a first ultrasonic mixing. During the first ultrasonic mixing, the mixture was stirred at 80°C for 2 hours, with the initial stirring speed of 800 rpm gradually increasing to 1500 rpm. Then, flake graphite, nano-molybdenum disulfide, and whisker-like alumina were added to the mixture from the first ultrasonic mixing in the high-speed mixer for a second ultrasonic mixing. During the second ultrasonic mixing, the mixture was stirred for 2 hours at a stirring speed of 1800 rpm. Finally, carbon fiber and cellulose nanocrystals were added to the mixture from the second ultrasonic mixing in the high-speed mixer for a third ultrasonic mixing. During the third ultrasonic mixing, the mixture was stirred for 2 hours at a stirring speed of 2000 rpm.

[0120] The mixed powder is loaded into a mold, and a magnetic field with a strength of 2 Tesla is applied around the mold. Pre-compression is performed simultaneously with the magnetic field applied, with a pressure of 300 MPa, a holding time of 10 seconds, and a pressing speed of 10 mm / s. The pre-compressed material is then subjected to bidirectional compression with a pressure of 900 MPa, a holding time of 25 seconds, and a pressing speed of 8 mm / s. During the bidirectional compression process, the mold is heated to 150°C at a heating rate of 25°C / min.

[0121] The molded material is then subjected to a vacuum of 1×10⁻⁶. -2Low-temperature pre-sintering was carried out under vacuum conditions at a temperature of 1000℃ for 2 hours with a heating rate of 20℃ / min. The pre-sintered material was then placed in a mixed atmosphere of nitrogen and hydrogen for high-temperature sintering at a hydrogen content of 12% at a sintering temperature of 1400℃ for 3 hours with a heating rate of 25℃ / min. Microwave-assisted sintering was used during the high-temperature sintering process, with a microwave frequency of 2.45GHz and a microwave power of 10kW.

[0122] The sintered material is ground and polished using a low-stress machining method at a grinding speed of 20 m / s and a feed rate of 0.15 mm / rpm to achieve the required dimensions and surface precision. The machined material is then subjected to phosphating treatment at 70℃ for 30 minutes at a spray pressure of 0.3 MPa. The phosphating solution formulation consists of 30 g / L zinc dihydrogen phosphate, 70 g / L zinc nitrate, and 3 g / L sodium fluoride, with a pH of 3. Finally, the phosphated material is electroplated with copper at a current density of 3 A / dm³. 2 The electroplating time is 30 minutes; the material is heat-treated under nitrogen protection, heated to 300°C at a heating rate of 20°C / min, held for 2 hours, and then slowly cooled to room temperature at a cooling rate of 10°C / min.

[0123] Comparative Example 1

[0124] Transmission plate material composition: 75% high-purity atomized iron powder, 15% electrolytic copper powder, 5% graphite powder, 3% zinc stearate, and 2% nickel powder.

[0125] Preparation method of transmission plate material:

[0126] High-purity atomized iron powder, electrolytic copper powder, and nickel powder are mixed for 30 minutes using a stirring device at a speed of 500 rpm. Graphite powder and zinc stearate are added, and mixing continues for 15 minutes. The mixed powder is then directly loaded into a mold and pressed using unidirectional pressing at a pressure of 400 MPa for 10 seconds. Sintering is then performed in a sintering furnace at 1100℃ for 3 hours. After sintering, grinding is carried out at a speed of 8 m / s and a feed rate of 0.2 mm / rpm.

[0127] Comparative Example 2

[0128] Transmission plate material composition: 80% high-purity atomized iron powder, 10% electrolytic copper powder, 6% tungsten carbide powder, 2% ferrophosphorus powder, and 2% paraffin wax.

[0129] Preparation method:

[0130] High-purity atomized iron powder and electrolytic copper powder for the transmission plate material are mixed for 20 minutes at a stirring speed of 400 rpm. Tungsten carbide powder, ferrophosphorus powder, and paraffin wax are then added and mixed for another 10 minutes. The powder is then loaded into a mold and cold isostatically pressed at 300 MPa. Sintering is carried out in a vacuum furnace at a vacuum degree of 1×10⁻⁶. -1 The material was sintered at 1000℃ for 2.5 hours and then polished.

[0131] The following table compares the performance parameters of the transmission plate materials in Examples 1-6 and Comparative Examples 1 and 2:

[0132] Through the above comparison, in terms of hardness, the high-purity atomized iron powder in the example group, as the main matrix component, provides a certain foundation for hardness. Meanwhile, the addition of alloying elements such as ferromolybdenum powder and chromium powder helps to improve the material's hardness. Nano-silicon carbide particles possess high hardness characteristics, and their uniform dispersion in the material effectively enhances the overall hardness. For example, in Examples 4 and 6, the content of nano-silicon carbide particles is relatively high (3.5%), and their hardness values ​​reach 290.1 ​​HV and 295.8 HV respectively, which are relatively high. The presence of rare earth oxides can refine the grains, making the crystal structure more compact. This also has a positive impact on hardness. In the preparation method, the ball milling of metal powder and the pretreatment of nano-silicon carbide particles are beneficial to the uniform mixing and dispersion strengthening of each component, which further improves the hardness. Comparative Examples 1 and 2 adopted relatively traditional material formulations and lacked the synergistic effect of multiple high-performance additives as in the examples. In Comparative Example 1, the content of high-purity atomized iron powder was too high, and other elements that enhance hardness were relatively few. Moreover, it did not undergo special pretreatment and optimized preparation process, resulting in hardness of only 190.1 HV and 203.5 HV, which is far lower than that of the examples.

[0133] In terms of strength, the electrolytic copper powder and nickel hydroxide powder in the example group form a good alloy system with iron powder in the material, which enhances the strength of the material. Carbon fiber and whisker alumina have high strength and good load-bearing capacity, and play a role in reinforcing the skeleton inside the material. For example, the synergistic effect of each component in Example 6 is good, and the strength reaches 900.1 MPa. In the preparation process, multi-step ultrasonic mixing makes the components mixed evenly. Magnetic field assisted molding and bidirectional pressing process can make the powder particles more compact and improve the density of the material, thereby improving the strength. During high-temperature sintering, the diffusion and reaction between each component forms a stable microstructure, which also helps to improve the strength. The materials in the comparative examples do not have the rich alloy system and reinforcing phase combination of the examples. The iron powder content in Comparative Example 2 is as high as 80%, and other reinforcing components are few and simple. At the same time, its preparation method, such as cold isostatic pressing and ordinary vacuum sintering process, cannot effectively improve the density and microstructure uniformity of the material as the magnetic field assisted molding and microwave assisted sintering processes in the examples. Therefore, the strength is lower, at 650.2 MPa and 600.3 MPa, respectively.

[0134] Regarding the coefficient of friction, the flake graphite and nano-molybdenum disulfide in the example group play a key role as lubricants in the material. They form a lubricating film on the friction surface, reducing the coefficient of friction. In Examples 3, 4, and 6, due to the optimized mixing process during preparation, the lubricant is evenly distributed in the material, and the coefficients of friction are as low as 0.11, 0.10, and 0.09, respectively. The special structure of cellulose nanocrystals (0.8%) may also contribute to the adhesion of the lubricant and the improvement of friction performance to some extent. The comparative examples lack the optimized lubricant combination and uniform distribution process of the examples. Comparative Examples 1 and 2 mainly use simple graphite powder or paraffin as lubricants, and do not have the multi-step ultrasonic mixing process of the examples to ensure uniform dispersion of the lubricant, resulting in higher coefficients of friction, 0.25 and 0.22, respectively, which easily generate large frictional forces during the friction process.

[0135] Regarding wear rate, the high hardness and good lubrication properties of the materials in the example groups worked together to reduce the wear rate. The synergistic effect of components that improve hardness, such as nano-silicon carbide particles and chromium powder, as well as lubricants such as flake graphite and nano-molybdenum disulfide, was significant. For example, in Examples 4 and 6, the materials had high hardness and good lubrication, with wear rates of 0.45 mg / h and 0.41 mg / h, respectively, which were relatively low. The phosphating treatment during the preparation process could also improve the wear resistance of the material surface to a certain extent and reduce the wear rate. Due to the lower hardness and poor lubrication, the wear rate of the comparative examples was significantly higher than that of the examples. In Comparative Examples 1 and 2, the material surface was prone to wear during friction, with wear rates reaching 1.63 mg / h and 1.27 mg / h, respectively, because they lacked the synergistic effect of the various components and processes that enhance hardness and improve lubrication in the examples.

[0136] Regarding thermal conductivity, the electrolytic copper powder in the example group exhibits good thermal conductivity, and its content remains relatively stable throughout the examples, ensuring the material's thermal conductivity. Simultaneously, the uniform distribution and good bonding of the components within the material also facilitate heat conduction. In Example Six, the components show good mixing uniformity, and possibly due to its high density, the thermal conductivity reaches 88 W / (m·K). During the preparation process, the high-temperature sintering process helps improve the material's density, thereby enhancing its thermal conductivity. In contrast, the material formulation and preparation process in the comparative examples are not conducive to improving thermal conductivity. The metal powders in Comparative Examples One and Two were not specially treated to improve their bonding performance, and unlike the examples, the material's density was not improved through process optimization, resulting in poor thermal conductivity of 60.1 W / (m·K) and 65.2 W / (m·K), respectively. Heat conduction within the material is easily hindered.

[0137] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0138] The various embodiments in this invention are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0139] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this disclosure is limited to these examples; within the framework of this disclosure, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of the present invention as described above, which are not provided in detail for the sake of brevity.

[0140] Although this disclosure has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0141] One or more embodiments of the present invention are intended to cover all such substitutions, modifications, and variations that fall within the scope of protection of the present invention. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of the present invention should be included within the scope of protection of this disclosure.

Claims

1. A powder metallurgical drive plate material for clutches, characterized in that The transmission sheet material comprises, in terms of mass percentage, high-purity atomized iron powder 55-65%, electrolytic copper powder 8-12%, hydroxyl nickel powder 4-8%, molybdenum iron powder 1.5-4%, chromium powder 1-3%, lanthanum powder 0.3-1.5%, nano silicon carbide particles 1.5-3.5%, carbon fiber 0.8-2%, whisker-shaped alumina 0.5-1.5%, cellulose nanocrystal 0.3-1%, rare earth oxide 0.5-2%, lubricant 2.3-6%, and binder 0.5-1.8%.

2. The powder metallurgy drive plate material for clutches according to claim 1, characterized in that, The lubricant comprises flaky graphite 1.5-3.5% and nano molybdenum disulfide 0.8-2.5%.

3. The powder metallurgy drive plate material for clutches of claim 1 wherein, The binder comprises polyethylene glycol 0.3-1% and sodium carboxymethyl cellulose 0.2-0.8%.

4. The powder metallurgy drive plate material for clutches of claim 1 wherein, The rare earth oxide is yttrium oxide; or The rare earth oxide is cerium oxide; or The rare earth oxide comprises cerium oxide 0.4-1.6% and yttrium oxide 0.1-0.4%.

5. A method of producing a powder metallurgical friction plate material for a clutch as claimed in any one of claims 1 to 4, characterized in that The preparation method comprises: S1: pretreating the high-purity atomized iron powder, electrolytic copper powder, hydroxyl nickel powder, molybdenum iron powder, chromium powder, lanthanum powder, nano silicon carbide particles, carbon fiber, and cellulose nanocrystal; S2: adding the pretreated high-purity atomized iron powder, electrolytic copper powder, hydroxyl nickel powder, molybdenum iron powder, chromium powder, lanthanum powder, nano silicon carbide particles, and rare earth oxide, polyethylene glycol, and sodium carboxymethyl cellulose into a high-speed mixer for primary mixing, then adding flaky graphite, nano molybdenum disulfide, and whisker-shaped alumina into the primary mixed mixture in the high-speed mixer for secondary mixing, and then adding carbon fiber and cellulose nanocrystal into the secondary mixed mixture in the high-speed mixer for tertiary mixing; S3: forming the tertiary mixed mixture by adopting a bidirectional pressing mode; S4: sequentially performing low-temperature pre-sintering and high-temperature sintering on the formed material; S5: performing mechanical processing, surface treatment, and heat treatment on the sintered material.

6. The method of producing a powder metallurgy clutch plate material according to claim 5, characterized by, Step S1 specifically comprises: S11: vacuum drying the high-purity atomized iron powder, electrolytic copper powder, carbonyl nickel powder, molybdenum iron powder, chromium powder, and lanthanum powder respectively, with a drying temperature of 110-130°C and a drying time of 5-7 hours; S12: soaking the nano silicon carbide particles in a composite treatment agent of silane coupling agent and titanate coupling agent, uniformly stirring, and then performing ultrasonic treatment, with an ultrasonic treatment time of 3-5 hours and a temperature of 60-80°C, and then drying at 80-100°C for 4-6 hours; S13: soaking the short-cut carbon fiber in a dopamine solution after short-cut treatment, with a dopamine solution concentration of 1-3g / L and a pH value of 8-9, stirring and reacting at room temperature for 12-24 hours, then taking out the carbon fiber, washing it with deionized water, and drying it at 60-80°C for 3-5 hours; S14: dispersing the cellulose nanocrystal in silane coupling agent, performing ultrasonic treatment for 2-4 hours, and then filtering and drying.

7. The method of producing a powder metallurgy clutch plate material according to claim 5, characterized by, In step S2, the mixing is stirred at 60-80℃ for 1-2 hours in the process of the first mixing, stirred for 1-2 hours in the process of the second mixing, and stirred for 1-2 hours in the process of the third mixing, wherein the first mixing, the second mixing and the third mixing are all assisted by ultrasonic mixing.

8. The method of producing a powder metallurgy clutch plate material according to claim 5, characterized by, Step S3 specifically comprises: S31: The mixed powder is loaded into a mold, pre-pressed at a pressure of 200-300 MPa for 5-10 seconds, and the pressing speed is 5-10 mm / s; S32: The pre-pressed material is subjected to bidirectional pressing at a pressure of 600-900 MPa for 15-25 seconds, and the pressing speed is 3-8 mm / s, wherein the mold is heated to 100-150℃ during the bidirectional pressing, and the heating rate is 15-25℃ / min.

9. The method of producing a powder metallurgy clutch plate material according to claim 5, characterized by, Step S4 specifically comprises: S41: The molded material is subjected to a vacuum of 1×10⁻⁶. -3 -1×10 -2 Low-temperature pre-sintering is carried out under vacuum conditions at a temperature of 800-1000℃ for 1-2 hours, with a heating rate of 10-20℃ / minute. S42: The pre-sintered material is subjected to high-temperature sintering in a mixed atmosphere of nitrogen and hydrogen at a temperature of 1200-1400℃ for 2-3 hours, and the heating rate is 15-25℃ / min, wherein microwave-assisted sintering is used during high-temperature sintering, the microwave frequency is 2.45 GHz, and the microwave power is 5-10 kW.

10. The method of producing a powder metallurgy clutch plate material according to claim 5, characterized by, Step S5 specifically comprises: S51: The sintered material is subjected to mechanical processing; S52: The mechanically processed material is first subjected to phosphating treatment at a temperature of 50-70℃ for 20-30 minutes, and the phosphating liquid spraying pressure is 0.1-0.3 MPa, wherein the phosphating treatment liquid formula is: zinc dihydrogen phosphate 20-30 g / L, zinc nitrate 50-70 g / L, and sodium fluoride 1-3 g / L, and the pH value is 2-3; S53: For phosphated materials, electroplating or chemical copper plating is performed, with a current density of 1-3 A / dm³ when electroplating. 2 The electroplating time is 10-30 minutes. When using chemical copper plating, the plating solution temperature is 40-60℃ and the deposition rate is 2-5μm / h. S54: The material is subjected to heat treatment under nitrogen protection, heated to 200-300℃ at a heating rate of 10-20℃ / min, and the holding time is 1-2 hours, and then slowly cooled to room temperature at a cooling rate of 5-10℃ / min.

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