A Ti3C2T x @Ag composite particle reinforced copper-based self-lubricating material and its preparation method

Abstract

The application provides a Ti3C2T x Ag composite particle reinforced copper-based self-lubricating material and a preparation method thereof, and relates to the technical field of metal matrix composite materials. The method comprises the following steps: etching Ti3AlC2 powder to obtain multilayer Ti3C2T x particles; then, silver particles are plated on the surfaces of the Ti3C2T x particles by a chemical plating process to obtain Ti3C2T x Ag composite particles; and finally, the composite particles are mixed with copper-based powder, and the mixture is formed and sintered by a powder metallurgy process to obtain Ti3C2T x Ag composite particle reinforced copper-based self-lubricating material. The application solves the problems of easy agglomeration of Ti3C2T x and silver particles in the matrix and uneven dispersion by constructing a core-shell structure of the reinforcing phase, realizes lubrication synergy of the two at different temperatures, and has the advantages of simple operation, economy, good repeatability, excellent tribological performance of the prepared material, and widened application of copper-based composite materials.

Description

Technical Field

[0001] This invention relates to the field of metal matrix composite material preparation technology, and particularly to a Ti3C2T x @Ag composite particle reinforced copper-based self-lubricating material and its preparation method. Background Technology

[0002] Copper-based composite materials possess properties such as high thermal conductivity, oxidation resistance, resistance to high-temperature adhesion, abrasion resistance, stable coefficient of friction, and strong environmental adaptability, making them widely used in electronics, electrical engineering, machinery, transportation, energy, aerospace, and defense industries. However, their low strength and poor wear resistance limit their development. Two-dimensional layered materials (such as graphene and MoS2) are widely used to improve the performance of copper-based composite materials due to their unique structure and properties. However, lubricants such as graphene and MoS2 suffer from insufficient resistance to high-temperature oxidation. Numerous studies have shown that these lubricants begin to oxidize at approximately 200°C, and the oxidation rate accelerates sharply with increasing temperature, reaching near-complete oxidation at 400°C, thus losing their lubricating function.

[0003] MXenes, as a new member of the two-dimensional material family, have attracted widespread attention since their initial synthesis. As a two-dimensional layered transition metal carbide, it plays a crucial role in improving the lubrication and tribological properties of materials due to its abundant active sites, excellent mechanical properties, superior thermal properties, and outstanding interlayer slip capability. Ti3C2T is a typical MXene material. x (T represents the functional groups such as -OH and -F attached to its surface, and x represents the number of functional groups) has been widely used to improve the tribological properties of composite materials. Xu et al. added 1 wt% Ti3C2T to epoxy resin. x Afterwards, the wear rate decreased by 72.1% (Xu Z, Shen X, Wang T, et al. Investigation on Tribological and Thermo-Mechanical Properties of Ti3C2 Nanosheets / Epoxy Nanocomposites. ACSOmega 2021; 6(43): 29184–29191.). Hu et al. utilized Ti3C2T x Reinforcing Al-based composites revealed that their friction coefficient was reduced by a factor of 2 compared to pure Al (Hu J, Li S, Zhang J, et al. Mechanical properties and frictional resistance of Al composites reinforced with Ti3C2T).x MXene[J].Chinese Chemical Letters,2020,31(04): 996-999.). Research found that Ti3C2T... x Due to its relatively weak interlayer bonding force, MXene nanosheets can be released to the friction interface through shear force during friction, which is beneficial for reducing the coefficient of friction and wear rate (Jie X, Lian W, Mai Y, et al. Two-dimensional Ti3C2coating as an emerging protective solid-lubricant for tribology[J].CeramicsInternational, 2018, 44: 20154-20162.). Furthermore, Ti3C2T... x The lubrication and anti-wear properties of Ti3C2T are greatly affected by temperature. Studies by Si Xiaoyang et al. have found that Ti3C2T... x Oxidation of TiO2 and other oxides in an alkaline environment during powder preparation can play a role in low- and medium-temperature lubrication (Si Xiaoyang, Chen Fanyan, Deng Qihuang, et al. Preparation and performance study of MXene / copper alloy composites [J]. Journal of Inorganic Materials, 2018, 33(6): 603-608.). To solve the problem of Ti3C2T x The problem of poor tribological properties of materials at medium and high temperatures is usually addressed by using Ti3C2T. x It can be used in combination with medium and high temperature lubricants (such as metal nanoparticles such as Ag, Cu, and Au). Metal nanoparticles can enter the friction interface during the friction process. With their excellent ductility, they can not only fill the surface damage caused by friction, but also form a lubricating protective layer on the friction surface, avoiding mutual contact between the friction pairs, thereby improving the tribological properties of the composite material (Moumita Sarkar[a][b], Nilrudra Mandal[a][b]PersonEnvelope. Solid lubricant materials for high temperature application: Areview[J]. Materials Today: Proceedings,2022,Vol.66(9): 3762-3768.). However, when Ti3C2T is used... x When used in combination with Ag, the mixed particles are not evenly dispersed in the copper matrix and are prone to agglomeration, which in turn affects the stability of the material's mechanical properties and tribological properties.

[0004] Therefore, there is an urgent need to provide a solution to improve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a Ti3C2T x @Ag composite particle reinforced copper-based self-lubricating material and its preparation method.

[0006] Firstly, this invention provides a Ti3C2T x The preparation method of @Ag composite particle reinforced copper-based self-lubricating material is characterized by comprising the following steps: S1. Etching of Ti3AlC2 powder yields a multilayered accordion-like structure of Ti3C2T. x Particles; S2. Through a chemical plating process, on the Ti3C2T x Silver particles are plated onto the surface of the particles to obtain Ti3C2T. x @Ag composite particles; S3, the Ti3C2T x @Ag composite particles are mixed with copper-based powder and then formed and sintered using powder metallurgy to obtain the Ti3C2T. x @Ag composite particle reinforced copper-based self-lubricating material.

[0007] Optionally, in step S1, the particle size of the Ti3AlC2 powder is 300-500 mesh.

[0008] Optionally, in step S1, the etching solution used in the etching process is a hydrofluoric acid solution; the concentration of the hydrofluoric acid solution is 35%-45%.

[0009] Optionally, in step S1, the water bath temperature during the etching process is 35℃-45℃, and the time is 20h-28h.

[0010] Optionally, in step S2, the chemical plating process includes: plating Ti3C2T x The particles are dispersed in a silver ammonia complex solution and react under the action of a reducing agent and a pH adjuster.

[0011] Optionally, Ag in the silver ammonia complex solution + The concentration is 5 g / L - 25 g / L.

[0012] Optionally, the reducing agent is glucose.

[0013] Optionally, the pH adjuster is an alkaline substance; the alkaline substance includes sodium hydroxide solution.

[0014] Optionally, the reaction is carried out at a pH of 12-13 and a temperature of 30°C-60°C.

[0015] Optionally, in step S3, the Ti3C2T x The mass ratio of the Ag composite particles to the copper-based powder is (3:97) - (1:9).

[0016] Optionally, the Ti3C2T x The mass ratio of the Ag composite particles to the copper-based powder is (3:97) to (1:19).

[0017] Optionally, in step S3, the mixing is ball milling; the ball milling medium during ball milling is zirconia balls.

[0018] Optionally, in step S3, the ball-to-material mass ratio during ball milling is (4:1) to (8:1).

[0019] Optionally, in step S3, the pressure during molding is 110T-120T, and the pressure is held for 22s-23s.

[0020] Optionally, in step S3, the sintering is carried out under a protective atmosphere.

[0021] Optionally, in step S3, the heating rate of sintering is 10℃ / min; the sintering temperature is 950℃-1000℃; and the holding time is 1.5h-2h.

[0022] Optionally, the ball milling speed is 350 rpm - 400 rpm; the time is 5 h - 6 h.

[0023] Optionally, the protective atmosphere is composed of nitrogen and hydrogen in a volume ratio of 4:1.

[0024] Secondly, the present invention also provides a Ti3C2T prepared by any of the above-mentioned optional preparation methods. x @Ag composite particle reinforced copper-based self-lubricating material.

[0025] Compared with the prior art, the present invention has the following beneficial effects: (1) The preparation method provided by the present invention uses a chemical silver plating process on Ti3C2T x Ti3C2T was successfully constructed by in-situ growth and coating of a dense, uniform layer of silver particles on the particle surface. x @Ag core-shell composite particles solve the problems of uneven dispersion and easy agglomeration of the reinforcing phase in traditional physical mixing; (2) The preparation method provided by the present invention utilizes Ti3C2T x By combining the interlayer slip properties at medium and low temperatures with the film-forming properties of silver at high temperatures, the lubrication function of the two is organically combined in the microstructure, so that the resulting composite material has a wide temperature range of stable lubrication capability from room temperature to 600℃. (3) Ti3C2T prepared by the present invention x @Ag composite particles reinforce copper-based self-lubricating materials significantly improve the hardness of the material while maintaining high density. For example, the hardness can reach 42.11 HBW when 5 wt.% composite particles are added, which is about 140% higher than that of pure copper. (4) Ti3C2T prepared by the present invention x @Ag composite particle reinforced copper-based self-lubricating material exhibits excellent friction reduction and wear resistance during friction. The coefficient of friction and wear rate are significantly reduced in the load range of 40-80N, and the coefficient of friction can still be maintained even lower after high-temperature pre-oxidation, with a significant improvement in wear resistance. (5) The overall process route provided by the present invention is simple, requires low equipment, does not use complex organic solvents, is environmentally friendly and has good repeatability, and is suitable for large-scale preparation. Attached Figure Description

[0026] Figure 1 The original Ti3AlC2 particles and the etched Ti3C2T particles in Example 1 of this invention. x SEM images of the particles; where Figure 1 (a) in the image is a SEM image of the original Ti3AlC2 particles; Figure 1 (b) in the image represents the etched Ti3C2T. x SEM image of the particles; Figure 2 The Ti3C2T prepared in Examples 1, 2, 3, and 4 of this invention x SEM images of @Ag particles; where Figure 2 (a) in the text refers to the Ti3C2T prepared in Example 1. x SEM image of @Ag particles; Figure 2 (b) in the text refers to the Ti3C2T prepared in Example 2. x SEM image of @Ag particles; Figure 2 (c) in the text refers to the Ti3C2T prepared in Example 3. x SEM image of @Ag particles; Figure 2 (d) in the text refers to the Ti3C2T prepared in Example 4. x SEM image of @Ag particles; Figure 3 The Ti3C2T prepared in Example 4 of this invention x XRD pattern of Ag particles; Figure 4 The Ti3C2T prepared in Example 4 of this invention x XPS graph of @Ag particles; among which... Figure 4 (a) in the text refers to the Ti3C2T prepared in Example 4. x Elemental spectrum of @Ag particles; Figure 4 (b) in the text refers to the Ti3C2T prepared in Example 4. x C element spectrum of @Ag particles; Figure 4 (c) in the text refers to the Ti3C2T prepared in Example 4. x Ti element spectrum of @Ag particles; Figure 4 (d) in the text refers to the Ti3C2T prepared in Example 4. x Ag elemental spectrum of @Ag particles; Figure 5 The Ti3C2T prepared in Examples 5, 6, and 7 of this invention x Optical microscope images of Ag / Cu composite materials; among which... Figure 5 (a) in the text refers to the Ti3C2T prepared in Example 5. x Optical microscope images of Ag / Cu composite materials; Figure 5 (b) in the figure is the Ti3C2T prepared in Example 6. x Optical microscope images of Ag / Cu composite materials; Figure 5 (c) in the text refers to the Ti3C2T prepared in Example 7. x Optical microscope images of Ag / Cu composite materials; Figure 6 The Ti3C2T prepared in Examples 5, 6, and 7 of this invention x The friction coefficient and wear rate of Ag / Cu composite materials under different loads; among which... Figure 6 (a) in the text refers to the Ti3C2T prepared in Examples 5, 6, and 7. x Friction coefficient of Ag / Cu composite material under different loads; Figure 6 (b) in the text refers to the Ti3C2T prepared in Examples 5, 6, and 7. x Wear rate of Ag / Cu composite material under different loads; Figure 7 The Ti3C2T prepared in Example 6 of this invention x The friction coefficient and wear rate of Ag / Cu composite materials at different pre-oxidation temperatures; among which... Figure 7 (a) in the text refers to the Ti3C2T prepared in Example 6. x Friction coefficient of Ag / Cu composite material at different pre-oxidation temperatures; Figure 7 (b) in the text refers to the Ti3C2T prepared in Example 6. x Wear rate of Ag / Cu composite material at different pre-oxidation temperatures. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. 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. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0028] This invention provides a Ti3C2T x The preparation method of @Ag composite particle reinforced copper-based self-lubricating material includes first etching Ti3AlC2 powder to prepare multilayer Ti3C2T x Particles; subsequently, a chemical plating process was used on Ti3C2T. x Silver particles are plated onto the surface of the particles to obtain Ti3C2T. x @Ag composite particles; then the obtained Ti3C2T x Ag particles were mixed with copper-based powder and then shaped and sintered using powder metallurgy to produce Ti3C2T. x @Ag composite particle-reinforced copper-based self-lubricating material. In fact, this invention solves the Ti3C2T problem by constructing a core-shell structured reinforcing phase. x This invention addresses the problem of silver particles easily agglomerating and unevenly dispersing in the matrix, achieving synergistic lubrication between the two at different temperatures. The preparation method of this invention is simple to operate, economical, requires minimal equipment, and has good repeatability. Simultaneously, the resulting composite material exhibits excellent tribological properties, broadening the application of copper-based composite materials under harsh friction conditions.

[0029] In some embodiments, the Ti3AlC2 powder used in step S1 has a particle size of 300-500 mesh.

[0030] In some embodiments, the etching solution used in step S1 is a hydrofluoric acid solution. Specifically, the concentration of the hydrofluoric acid solution used is 35%-45%.

[0031] In some embodiments, the water bath temperature during the etching process in step S1 is 35°C-45°C, and the time is 20h-28h.

[0032] In some embodiments, the chemical plating process in step S2 includes: plating Ti3C2T x The particles are dispersed in a silver ammonia complex solution and react under the action of a reducing agent and a pH adjuster.

[0033] In some embodiments, the silver ammonia complex solution used contains Ag +The concentration is 5 g / L - 25 g / L.

[0034] In some embodiments, glucose is used as the reducing agent.

[0035] In some embodiments, the pH adjuster used is an alkaline substance. Specifically, the alkaline substance includes sodium hydroxide solution.

[0036] In some embodiments, the reaction is carried out at a pH of 12-13 and a temperature of 30°C-60°C.

[0037] In some embodiments, in step S3, Ti3C2T x The mass ratio of Ag composite particles to copper-based powder is (3:97) - (1:9).

[0038] In some embodiments, Ti3C2T x The mass ratio of Ag composite particles to copper-based powder is (3:97) - (1:19).

[0039] In some embodiments, the mixing in step S3 is ball milling. Specifically, the milling medium used in ball milling is zirconia balls.

[0040] In some embodiments, the ball-to-material mass ratio during ball milling is (4:1) to (8:1).

[0041] In some embodiments, the molding pressure is 110T-120T, and the holding pressure is 22s-23s.

[0042] In some embodiments, sintering is performed under a protective atmosphere.

[0043] In some embodiments, the sintering heating rate is 10℃ / min; the sintering temperature is 950℃-1000℃; and the holding time is 1.5h-2h.

[0044] In some embodiments, the ball milling speed is 350 rpm - 400 rpm; the time is 5 h - 6 h.

[0045] In some embodiments, the protective atmosphere used consists of nitrogen and hydrogen in a volume ratio of 4:1.

[0046] The present invention also provides a Ti3C2T prepared using any of the above embodiments. x @Ag composite particle reinforced copper-based self-lubricating material. Example 1

[0047] This embodiment 1 provides a Ti3C2T x The preparation method of @Ag particles includes the following steps: S1. Preparation of Ti3C2T xParticles: 20 mL of 40% HF and 15 mL of deionized water were poured into a PTFE reactor. Then, 2 g of Ti3AlC2 was added gradually to the PTFE reactor while heating and stirring. After stirring, the mixture was centrifuged and washed five to six times with deionized water until the filtrate was neutral. The precipitate was then collected by filtration and drying. The original Ti3AlC2 particles and the etched Ti3C2T particles were compared. x like Figure 1 (a) and Figure 1 As shown in (b), the Ti3AlC2 particles have a relatively dense structure and exhibit obvious layered crystal structure characteristics, reflecting the original layered structure morphology of the MAX phase material; the etched Ti3C2T x It exhibits a typical accordion shape, consisting of a loose structure formed by the stacking of multiple nanosheets. There are obvious peelings and wrinkles between the layers, and it has void characteristics, reflecting the morphological characteristics of two-dimensional sheets of MXene material after etching.

[0048] S2, Preparation of Ti3C2T x @Ag particles: Add 2% ammonia solution dropwise to 50 mL of AgNO3 (5 g / L) until excess to prepare a silver ammonia solution. Then weigh 0.5 g of the Ti3C2T prepared in step S1. x Add the prepared silver ammonia solution, and then stir continuously at 40°C for 20 minutes in a constant temperature water bath; prepare 50 mL (0.15 mol / L) glucose solution as a reducing agent, add the glucose solution to the above solution, and adjust the pH to 12-13 by adding NaOH (4 g / 50 mL) solution dropwise, stir for 40 minutes, and then let stand for 10 minutes; wash the resulting solution two to three times with anhydrous ethanol until the filtrate is neutral, and then process the washed Ti3C2T x @Ag was filtered and then placed in a drying oven at 50°C for 12 hours.

[0049] The Ti3C2T prepared in Example 1 x @Ag particles, their scanning electron microscope (SEM) images are as follows Figure 2 As shown in (a) of the image. Ti3C2T x @Ag particles and etched Ti3C2T x Compared to particles, Ti3C2T x The surface of the Ag particles has only a few silver crystal nuclei. This may be related to the low concentration of silver nitrate and the slow reaction; the particle size is around 500 nm. Example 2

[0050] This embodiment 2 provides a Ti3C2T x The preparation method of @Ag particles includes the following steps: S1. Preparation of Ti3C2T xParticles: Pour 20 mL of 40% HF and 15 mL of deionized water into a polytetrafluoroethylene (PTFE) reactor, then add 2 g of Ti3AlC2 to the PTFE reactor in small batches and heat and stir. After stirring, centrifuge and wash with deionized water five to six times until the filtrate is neutral, then filter, dry and collect the precipitate. S2, Preparation of Ti3C2T x @Ag particles: Add 2% ammonia solution dropwise to 100mL of AgNO3 (15g / L) until excess to prepare a silver ammonia solution. Then weigh 1.2g of the Ti3C2T prepared in step S1. x Add the prepared silver ammonia solution, and then stir continuously at 30°C for 20 minutes in a constant temperature water bath; prepare 100 mL (0.15 mol / L) glucose solution as a reducing agent, add the glucose solution to the above solution, and adjust the pH to 12-13 by adding NaOH (4 g / 50 mL) solution dropwise, stir for 60 minutes, and then let stand for 10 minutes; wash the resulting solution two to three times with anhydrous ethanol until the filtrate is neutral, and then process the washed Ti3C2T x @Ag was filtered and then placed in a drying oven at 50°C for 12 hours.

[0051] The Ti3C2T prepared in Example 2 x @Ag particles, their scanning electron microscope (SEM) images are as follows Figure 2 As shown in (b) of the image. Ti3C2T x @Ag particles and etched Ti3C2T x Compared to particles, Ti3C2T x @Ag particles are sparsely distributed and small in size on the surface, with particle sizes ranging from 50 to 100 nm. This may be due to the slow reaction speed caused by the low reaction temperature. Example 3

[0052] This embodiment 3 provides a Ti3C2T x The preparation method of @Ag particles includes the following steps: S1. Preparation of Ti3C2T x Particles: Pour 20 mL of 40% HF and 15 mL of deionized water into a polytetrafluoroethylene (PTFE) reactor, then add 2 g of Ti3AlC2 to the PTFE reactor in small batches and heat and stir. After stirring, centrifuge and wash with deionized water five to six times until the filtrate is neutral, then filter, dry and collect the precipitate. S2, Preparation of Ti3C2T x @Ag particles: Add 2% ammonia solution dropwise to 100mL of AgNO3 (15g / L) until excess to prepare a silver ammonia solution. Then weigh 1.2g of the Ti3C2T prepared in step S1. xAdd the prepared silver ammonia solution, and then stir continuously at 60°C for 20 minutes in a constant temperature water bath; prepare 100 mL (0.15 mol / L) glucose solution as a reducing agent, add the glucose solution to the above solution, and adjust the pH to 12-13 by adding NaOH (4 g / 50 mL) solution dropwise, stir for 60 minutes, and then let stand for 10 minutes; wash the resulting solution two to three times with anhydrous ethanol until the filtrate is neutral, and then process the washed Ti3C2T x @Ag was filtered and then placed in a drying oven at 50°C for 12 hours.

[0053] The Ti3C2T prepared in Example 3 x @Ag particles, their scanning electron microscope (SEM) images are as follows Figure 2 As shown in (c) of the figure, the reaction was too intense due to the excessively high temperature, resulting in the rapid formation of silver crystal nuclei, some of which did not have enough time to deposit on Ti3C2T. x The surface is severely agglomerated, and it appears as large particles with a particle size of about 1-2 μm. Example 4

[0054] This embodiment 4 provides a Ti3C2T x The preparation method of @Ag particles includes the following steps: S1. Preparation of Ti3C2T x Particles: Pour 20 mL of 40% HF and 15 mL of deionized water into a polytetrafluoroethylene (PTFE) reactor, then add 2 g of Ti3AlC2 to the PTFE reactor in small batches and heat and stir. After stirring, centrifuge and wash with deionized water five to six times until the filtrate is neutral, then filter, dry and collect the precipitate. S2, Preparation of Ti3C2T x @Ag particles: Add 2% ammonia solution dropwise to 50 mL of AgNO3 (15 g / L) until excess to prepare a silver ammonia solution. Then weigh 0.5 g of the Ti3C2T prepared in step S1. x Add the prepared silver ammonia solution, and then stir continuously at 40°C for 20 minutes in a constant temperature water bath; prepare 50 mL (0.15 mol / L) glucose solution as a reducing agent, add the glucose solution to the above solution, and adjust the pH to 12-13 by adding NaOH (4 g / 50 mL) solution dropwise, stir for 40 minutes, and then let stand for 10 minutes; wash the resulting solution two to three times with anhydrous ethanol until the filtrate is neutral, and then process the washed Ti3C2T x @Ag was filtered and then placed in a drying oven at 50°C for 12 hours.

[0055] The Ti3C2T prepared in Example 4 xThe mass of the @Ag particle sample was weighed to be 1.1 g, that is, about Ti3C2T was contained in 10 g of this sample prepared x The mass was 5 g, and Ti3C2T under this Example 4 x Ti3C2T in @Ag x The mass fraction was about 50%.

[0056] The Ti3C2T prepared in this Example 4 x @Ag particles, and its scanning electron microscope (SEM) image is as Figure 2 shown in (d) of. It can be seen that the Ag particles on the surface of Ti3C2T x are evenly distributed and dense, and their particle size is uniform, and the crystallinity is good. Its X-ray diffraction (XRD) spectrum and XPS spectrum are as Figure 3 , 4 shown. From Figure 3 it can be seen that in addition to the Ti3C2T x peak, peaks corresponding to the (111), (200), (220), and (311) crystal planes of Ag at 2θ of 37.5°, 43.9°, 63.5°, and 76.8° respectively also appear; from Figure 4 XPS of shows that a very high peak of Ag appears in the sample after silver plating treatment, and the results together indicate that a layer of silver particles is plated on the surface of Ti3C2T x particles by electroless silver plating.

[0057] Ti3C2T x The morphology of the silver particles on the surface has a great influence on its bonding with the copper matrix. When the silver particle coverage rate is low, it will affect the tribological properties of the copper-based composite material. When the silver particles agglomerate severely and the particle size is too large, local bonding will be loose during the sintering process, thus affecting the mechanical properties of the copper-based composite material. In summary, the electroless silver plating process of this Example 4 is the best. Example 5

[0058] This Example 5 provides a preparation method of a Ti3C2T x @Ag composite particle reinforced copper-based self-lubricating material, including the following steps: The Ti3C2T x @Ag composite particles prepared in Example 4 are ball-milled and sintered with copper powder according to a content ratio of 3%. Add 3 g of the Ti3C2T prepared in Example 4 to the ball-milling tank x@Ag and copper powder with corresponding content ratio, along with 400g of zirconia grinding balls (ball-to-material ratio 4:1), were ball-milled for 5 hours at 350 rpm. The ball-milled powder was then pressed under 118T pressure for 22.5 seconds using a hydraulic press. Sintering was then performed in a hot-press sintering furnace under a protective gas N2:H2 ratio of 4:1 and a heating rate of 10℃ / min, reaching 350℃ before entering the reduction stage. This stage was held for 1 hour to allow the reduction-generated gases to be fully expelled. Subsequently, heating continued at a rate of 10℃ / min to 950℃ and holding for 2 hours. Finally, the sample was water-cooled to room temperature to obtain the final sample. Example 6

[0059] This embodiment 6 provides a Ti3C2T x The preparation method of @Ag composite particle reinforced copper-based self-lubricating material includes the following steps: The Ti3C2T prepared in Example 4 x Ag composite particles and copper powder were ball-milled and sintered at a ratio of 5%. 5g of Ti3C2T prepared in Example 4 was added to the ball mill jar. x @Ag and copper powder with corresponding content ratio, along with 800g of zirconia grinding balls (ball-to-material ratio 8:1), were ball-milled for 6 hours at 350 rpm. The ball-milled powder was then pressed under 118T pressure for 22.5 seconds using a hydraulic press. Sintering was then performed in a hot-press sintering furnace under a protective gas N2:H2 = 4:1 atmosphere and a heating rate of 10℃ / min, reaching 350℃ before entering the reduction stage. This stage was held for 1 hour to allow the reduction-generated gases to be fully expelled. Subsequently, heating continued at 10℃ / min to 950℃ and holding for 1.5 hours. Finally, the sample was water-cooled to room temperature to obtain the final sample. Example 7

[0060] This embodiment 7 provides a Ti3C2T x The preparation method of @Ag composite particle reinforced copper-based self-lubricating material includes the following steps: The Ti3C2T prepared in Example 4 x Ag composite particles and copper powder were ball-milled and sintered at a ratio of 10%. 10g of the Ti3C2T prepared in Example 4 was added to the ball mill jar. x @Ag and copper powder with corresponding content ratio, along with 800g of zirconia grinding balls (ball-to-material ratio 8:1), were ball-milled for 6 hours at 400 rpm. The ball-milled powder was then pressed under 118T pressure for 22.5 seconds using a hydraulic press. Sintering was then performed in a hot-press sintering furnace under a protective gas N2:H2 = 4:1 atmosphere and a heating rate of 10℃ / min, reaching 350℃ before entering the reduction stage. This stage was held for 1 hour to allow the reduction-generated gases to be fully expelled. Subsequently, the temperature was further increased to 1000℃ at a heating rate of 10℃ / min and held for 1.5 hours. Finally, the sample was water-cooled to room temperature to obtain the final sample.

[0061] Figure 5 Ti3C2T prepared by sintering in Examples 5, 6, and 7 x Optical microscope image of @Ag composite particle-reinforced copper-based self-lubricating material; Figure 5 (a) in the figure is the Ti3C2T prepared by sintering in Example 5. x Optical microscope image of @Ag composite particle-reinforced copper-based self-lubricating material; Figure 5 (b) in the figure is the Ti3C2T prepared by sintering in Example 6. x Optical microscope image of @Ag composite particle-reinforced copper-based self-lubricating material; Figure 5 (d) in the figure represents the Ti3C2T prepared by sintering in Example 7. x Optical microscope image of @Ag composite particle-reinforced copper-based self-lubricating material. Figure 5 (a) and Figure 5 As can be seen in (b), the yellow phase on the surface of samples with 3% and 5% content is copper, and the gray phase is Ti3C2T. x @Ag phase, the sample surface is dense with no obvious defects. Figure 5 As can be seen in (c), the sample with 10% content has poor wettability and bonding, resulting in a large area of ​​black hole defects on the sample surface.

[0062] Table 1 shows the Ti3C2T prepared by sintering in Examples 5, 6, and 7. x The table shows the physical and mechanical properties of the @Ag composite particle-reinforced copper-based self-lubricating material, and compares them with those of pure copper. Table 1 shows that with the increase of Ti3C2T... x The density of the @Ag composite particles decreases with increasing content, which is due to the Ti3C2T x The low density of the @Ag composite particles is the cause. However, their porosity continuously increases due to the Ti3C2T... x The wettability between Ag and copper is poor, and excessive Ag content leads to poor bonding and increased porosity. Simultaneously, the hardness initially increases and then decreases. This is because at low content, TiO2 acts as a strengthening agent, enhancing hardness; however, as the content increases and porosity increases, the hardness decreases and deteriorates.

[0063] Table 1: Ti3C2T prepared by sintering in Examples 5, 6, and 7 x Data table of physical and mechanical properties of @Ag composite particle reinforced copper-based self-lubricating material and pure copper.

[0064]

[0065] The tribological properties of pure copper and samples with different copper contents were studied using an Rtec friction testing machine. The upper sample was a sintered copper-based composite material (10 mm × 10 mm × 8 mm). The mating pair was a friction disk made of 30CrSiMoVA with a density of 7.85 g / cm³. 3 The hardness is approximately 35 HRC, and the dimensions are φ95mm × 20mm. During the friction test, the friction radius was set to 38mm, the pressure to be 40-80N, the friction speed to be 800rpm, and the test time to be 3min per test.

[0066] Figure 6 Friction coefficient curves and wear rates for samples with different contents under different loads are presented. The relationship between the Ti3C2T content in the samples and the wear rate under different loads is also analyzed. x With increasing @Ag composite particle content, the friction coefficient and wear of the sample initially decreased and then increased. This is because at low Ti3C2T content... x @Ag has superior lubrication and mechanical properties, but Ti3C2T x When the Ag content is too high, the coefficient of friction of the sample will increase. This is because Ti3C2T x Excessive Ag content leads to increased TiO2, hindering its tribological properties. The increased wear rate of the sample is due to Ti3C2T... x Ag has poor wettability with copper; excessive Ag content leads to poor bonding and increased wear rate. Adding an appropriate amount of Ti3C2T to the composite material... x @Ag (5wt.%) can achieve the best friction reduction and wear resistance.

[0067] The sample with the optimal content (5 wt.%) was pre-oxidized at 25℃, 200℃, 400℃, and 600℃ before being subjected to friction tests. Figure 7 It can be seen that the average friction coefficient at room temperature and at a pre-oxidation temperature of 200℃ is similar, due to the lower degree of oxidation. When the pre-oxidation temperature rises to 400℃, the friction coefficient of the sample decreases significantly compared to room temperature. This is because Ag is dispersed on the wear surface, forming a lubricating film. When the pre-oxidation temperature rises to 600℃, the friction coefficient of the sample decreases further, because Ag at high temperatures... x O₂ becomes the primary lubricating component, forming a lubricating film that minimizes direct contact with the friction surfaces, thus significantly reducing the sample's coefficient of friction. The wear rate of the sample decreases with increasing pre-oxidation temperature, possibly because the higher the pre-oxidation temperature, the more TiO₂ agglomerates on the sample surface, increasing the sample's hardness. Some researchers have pointed out that wear rate is related to hardness; higher hardness results in lower wear rate. Therefore, Ti₃C₂T x The addition of @Ag enhanced the wear resistance of the sample, and the sample showed more stable improvement in wear rate under different temperature conditions.

[0068] This invention provides a Ti3C2T x @Ag composite particle-reinforced copper-based self-lubricating material and its preparation method, and further illustrate that silver plating process can be used to process Ti3C2T x The surface is modified, and then Ti3C2T is used. x @Ag is used to reinforce copper-based composite materials, thereby significantly improving the physical, mechanical, and tribological properties of the materials.

[0069] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A Ti3C2T x The method for preparing Ag composite particle-reinforced copper-based self-lubricating materials is characterized by... Includes the following steps: S1. Etching of Ti3AlC2 powder yields a multilayered accordion-like structure of Ti3C2T. x Particles; S2. Through a chemical plating process, on the Ti3C2T x Silver particles are plated onto the surface of the particles to obtain Ti3C2T. x @Ag composite particles; S3, the Ti3C2T x @Ag composite particles are mixed with copper-based powder and then formed and sintered using powder metallurgy to obtain the Ti3C2T. x @Ag composite particle reinforced copper-based self-lubricating material.

2. The preparation method according to claim 1, characterized in that, In step S1, the particle size of the Ti3AlC2 powder is 300-500 mesh; and / or, the etching solution used in the etching process is a hydrofluoric acid solution; the concentration of the hydrofluoric acid solution is 35%-45%; and / or, the water bath temperature during the etching process is 35℃-45℃, and the time is 20h-28h.

3. The preparation method according to claim 1, characterized in that, In step S2, the chemical plating process includes: plating Ti3C2T x The particles are dispersed in a silver ammonia complex solution and react under the action of a reducing agent and a pH adjuster.

4. The preparation method according to claim 3, characterized in that, Ag in silver ammonia complex solution + The concentration is 5 g / L - 25 g / L.

5. The preparation method according to claim 3, characterized in that, The reducing agent is glucose; and / or the pH adjuster is an alkaline substance; the alkaline substance includes sodium hydroxide solution; and / or the reaction is carried out at a pH of 12-13 and a temperature of 30℃-60℃.

6. The preparation method according to claim 1, characterized in that, In step S3, the Ti3C2T x The mass ratio of the Ag composite particles to the copper-based powder is (3:97) - (1:9).

7. The preparation method according to claim 6, characterized in that, The Ti3C2T x The mass ratio of the Ag composite particles to the copper-based powder is (3:97) to (1:19).

8. The preparation method according to claim 1, characterized in that, In step S3, the mixing is ball milling; the ball milling medium is zirconia balls; and / or, the ball-to-material mass ratio during ball milling is (4:1)-(8:1); and / or, the pressure during molding is 110T-120T, and the holding pressure is 22s-23s; and / or, the sintering is carried out under a protective atmosphere; and / or, the heating rate during sintering is 10℃ / min; the sintering temperature is 950℃-1000℃; and the holding time is 1.5h-2h.

9. The preparation method according to claim 8, characterized in that, The ball milling speed is 350 rpm - 400 rpm; the time is 5 h - 6 h; and / or the protective atmosphere is composed of nitrogen and hydrogen in a volume ratio of 4:

1.

10. A Ti3C2T prepared by the preparation method according to any one of claims 1-9 x @Ag composite particle reinforced copper-based self-lubricating material.

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