High-lubrication wear-resistant MXene / metal-based self-lubricating composite material and preparation method thereof

Abstract

According to the high-lubrication wear-resistant MXene / metal-based self-lubricating composite material and the preparation method, Mn + 1AXn phase precursor powder is selectively etched through lewis acid molten salt with a one-step method, MXene of a two-dimensional layered open structure is obtained, positive ions in lewis acid are reduced in the etching process, and the MXene / metal-based self-lubricating composite material is obtained. The two-dimensional layered MXene is loaded on the two-dimensional layered MXene in situ in the form of nano metal particles, due to the fact that the MXene has exposed metal sites, the MXene is easily wetted with the nano metal particles loaded in situ in the sintering process, a self-lubricating composite material with good interface bonding is formed, the two-dimensional layered MXene is prone to relative sliding, excellent antifriction and lubricating characteristics are shown, and the self-lubricating composite material can be used as a self-lubricating composite material. The defect that a traditional solid lubricant of a self-lubricating composite material needs surface modification is overcome, the preparation process is simplified, meanwhile, the MXene phase is evenly dispersed in the self-lubricating composite material, a stable lubricating film can be formed easily, and the lubricating wear resistance is further improved.

Description

Technical Field

[0001] This invention relates to the field of metal-based self-lubricating composite materials, specifically to a high-lubricity and wear-resistant MXene / metal-based self-lubricating composite material and its preparation method. Background Technology

[0002] Friction is a pervasive phenomenon in all types of mechanical motion processes and has become one of the key factors limiting equipment performance and service life. Statistics show that energy consumption caused by friction and wear of mechanical parts accounts for approximately 30% of global primary energy consumption, of which about 18%–40% can be avoided by developing new lubricating materials and technologies. With the rapid development of modern industry, traditional liquid and solid lubricants are no longer sufficient to meet practical needs under extreme conditions such as high speed, high load, and high temperature. The most innovative development is the introduction of solid lubricants as reinforcing phases into metal, ceramic, or polymer matrices to solve the problem of friction and wear of parts under extreme conditions. Among these, metal-based self-lubricating composite materials, due to their advantages such as high strength, high toughness, good thermal and electrical conductivity, and processability, have already been widely used in friction reduction and wear resistance applications in the machinery, automotive, smart electronics, and aerospace industries.

[0003] Typical metal-based self-lubricating composite materials can be prepared by casting or powder metallurgy. This involves adding solid lubricating phases, such as graphite, boron nitride, or molybdenum disulfide, to a matrix phase of metals or alloys such as Cu-based, Al-based, Co-based, Fe-based, Ti-based, Mo-based, Ni-based, or Ag-based materials. This preserves the metallic properties of the matrix phase, and during friction and wear, the solid lubricating phase undergoes physical and chemical reactions on the composite surface to form a lubricating film, achieving excellent lubrication performance. The dispersion and wettability of the lubricating phase within the metal matrix phase play a crucial role in the overall performance of the metal-based self-lubricating composite material. Chinese Patent Application No. 201610636303.1 discloses a method for preparing a metal-based self-lubricating material by modifying the graphite surface and then coating it with a layer of palladium, thereby improving the interfacial structure and wettability between the matrix material and graphite. Chinese patent application number 201710526623.6 discloses a method for preparing a wear-resistant metal-based self-lubricating bearing material, which improves the compatibility between graphite and copper powder by depositing nickel on the graphite surface. Since the carbon atoms on the graphite surface are predominantly covalently bonded, which is fundamentally different from the metallic bonds in the metal matrix, and the hydrophobicity of graphite differs greatly from the hydrophilicity of metal, the wettability between graphite and metal is poor. The aforementioned technical solutions all require surface modification of the traditional solid lubricating phase and coating with a metal layer to improve the overall lubrication performance of the composite material, making the process complex and greatly limiting its industrial-scale application. Summary of the Invention

[0004] The purpose of this invention is to provide a high-lubricity and wear-resistant MXene / metal-based self-lubricating composite material and its preparation method, which can improve the shortcomings of traditional solid lubricants that require surface modification, simplify the preparation process, and provide feasibility for mass production.

[0005] In a first aspect, this application provides a method for preparing an MXene / metal-based self-lubricating composite material, comprising the following steps: S1. Provide raw material powder, said raw material powder comprising a composite powder of MXene in-situ supported metal particles, said composite powder being selectively etched by Lewis acid molten salt. n+1 AX n The precursor powder is prepared as follows: n = 1, 2 or 3; M includes at least one of Ti, V, Cr, Zr, Nb, Mo, Hf, Sc or Ta; A includes at least one of Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl or Pb; X includes at least one of C, N or B; and the Lewis acid includes at least one of CuCl2, CoCl2, ZnCl2, FeCl3, NiCl2, AgCl, FeCl2 or CdCl2. S2. Powder sintering: The raw material powder is sintered to prepare the MXene / metal-based self-lubricating composite material.

[0006] Optionally, in step S1, the composite powder is selectively etched by Lewis acid molten salt to form M. n+1 AX n The precursor powder was prepared by means of: S1-1. Weigh Lewis acid, molten salt, and M according to the proportions. n+1 AX n The precursor powder is mixed evenly and then formed into a green body. Then, additional Lewis acid and molten salt are weighed according to the formula and the additional Lewis acid and molten salt are covered on the green body. S1-2. Heating reaction, Lewis acid selectively converts M... n+1 AX n The A-layer atoms in the phase precursor powder are etched away to form a two-dimensional layered structure of MXene, while the metal cations in the Lewis acid are reduced to the metal particles and loaded in situ on the MXene to form a composite powder. S1-3. Wash and dry to obtain the composite powder.

[0007] Optionally, in step S1-1, the Lewis acid includes at least one of CuCl2 or NiCl2; and / or, The molten salt includes at least one of a halide salt; and / or, The M n+1 AXn The A in the phase includes Al; and / or, Step S1-2. The temperature for heating the reaction is 680~720℃, and the holding time is 20~80min.

[0008] Optionally, step S1-1: Weigh Lewis acid, molten salt, and M according to the proportions. n+1 AX n In the phase precursor powder, the Lewis acid, molten salt and M n+1 AX n The molar ratio of the phase precursor powder is 1~3:10~30:0.5~1.5. Then, according to the formula, additional Lewis acid and molten salt are weighed. The additional Lewis acid, molten salt, and M... n+1 AX n The molar ratio of the phase precursor powder is 2~6:10~40:0.5~1.5.

[0009] Optionally, the metal particles are nanoparticles, which are in situ loaded on the interlayer and surface of the two-dimensional layered structure of MXene, and the particle size of the nanoparticles is less than 500 nm.

[0010] Optionally, in step S2, the powder sintering temperature is 800~1100℃, the holding time is 5~15min, and the sintering pressure is 50~150MPa.

[0011] Optionally, in step S1, the raw material powder further includes additional metal particles, wherein the additional metal particles are selected from at least one of Al, Cu, Zn, Ni, Co, Ag, Fe, Ti or Mo, and the content of the additional metal particles is 0.1 to 90 wt% based on the mass of the raw material powder.

[0012] Optionally, the content of the additional metal particles is 55-65 wt% based on the mass of the raw material powder.

[0013] Secondly, the present invention provides an MXene / metal-based self-lubricating composite material, obtained by the aforementioned method for preparing MXene / metal-based self-lubricating composite materials.

[0014] Optionally, the MXene / metal-based self-lubricating composite material includes a matrix phase and an MXene phase. The matrix phase includes a particulate matrix phase and a lamellar matrix phase distributed between the MXene phase layers. The particle size of the particulate matrix phase is less than 100 μm, and the lamellar matrix phase has a lamellar thickness of less than 3 μm.

[0015] In summary, the present invention has at least one of the following beneficial technical effects: 1. This invention employs a one-step Lewis acid molten salt selective etching method for M. n+1 AX n Precursor powder was used to obtain MXene material with a two-dimensional layered open structure. During the etching process, the cations in the Lewis acid were reduced and loaded in situ as nano-metal particles on the interlayer and surface of the two-dimensional layered open structure of MXene. The two-dimensional layered MXene is easy to slide relative to each other, exhibiting excellent friction-reducing and lubricating properties. Moreover, the etched MXene material has exposed metal sites, which are easy to wet with the in-situ loaded nano-metal particles during subsequent sintering, forming a self-lubricating composite material with good interfacial bonding. This improves the defect of traditional solid lubricants that require surface modification, simplifies the preparation process, and is easy to mass-produce.

[0016] 2. This invention improves upon the shortcomings of traditional molten salt etching processes, which often result in excessively large metal particles or even metal sheets during MXene preparation, hindering the formation of a uniformly dispersed lubricating and matrix phases in the subsequent sintering of the self-lubricating material. This invention optimizes the molten salt etching process, preventing the formation of such particles and hindering the formation of a uniformly dispersed lubricating and matrix phases. It produces layered MXene and nano-metal particle composite powders with uniform particle size distribution. The in-situ loaded nano-metal particles are fine, uniformly dispersed, and exhibit good wettability. The sintered self-lubricating composite material has a dense structure with fine and uniformly dispersed phases, facilitating the formation of a stable lubricating film and further improving lubrication and wear resistance. Furthermore, using two or more etching agents allows for the in-situ loading of two or more nano-metal elements onto the MXene surface. Subsequent sintering forms alloyed metal solid solution reinforcement, enhancing the mechanical strength of the metal matrix composite and further improving its wear resistance. In subsequent embodiments, the prepared copper-based self-lubricating composite material exhibits an average friction coefficient below 0.215 at room temperature (10 N), preferably below 0.156, and a volumetric wear rate of 3.124 × 10⁻⁶. -5 mm 3 N -1 m -1 The following is a better result, which can reach 2.5×10. -5 The average coefficient of friction of the aluminum-based self-lubricating composite material can reach below 0.2, and the volumetric wear rate can reach 8.58 × 10⁻⁶. -4 mm 3 N -1 m -1 the following.

[0017] 3. This invention prepares a high-lubricity, wear-resistant MXene metal-based self-lubricating composite material through powder metallurgy sintering. The matrix phase and lubricating phase have a good interfacial bond and a microtextured structure, which improves the strength of the composite material and facilitates efficient MXene spreading during friction, fully utilizing its self-lubricating properties. This makes it particularly suitable for harsh friction and wear conditions such as high loads. Compared to MXene coating materials, the high-lubricity, wear-resistant MXene metal-based self-lubricating composite material prepared by this invention has the advantages of low cost, large-scale production capability, and easy processing. It can be used to manufacture various structural components such as balls, bushings, bearings, gaskets, and sliders, thereby improving the mechanical properties and lifespan of these components. Attached Figure Description

[0018] Figure 1 XRD patterns of the composite powder prepared by the molten salt method in Example 1 and the MXene-reinforced copper-based composite material; Figure 2 SEM image of surface-loaded Cu nanoparticle MXene powder prepared by the molten salt method in Example 1; Figure 3 SEM image of the MXene-reinforced copper-based solid lubricant prepared in Example 1; Figure 4 The average coefficient of friction of the MXene-reinforced copper-based solid lubricant prepared in Example 1 at different temperatures; Figure 5 SEM image of the composite powder prepared by the molten salt method in Comparative Example 1; Figure 6 XRD pattern of the composite powder prepared in Comparative Example 1; Figure 7 SEM image of the MXene-reinforced copper-based solid lubricant prepared in Comparative Example 1; Figure 8 The average friction coefficient of the MXene-reinforced copper-based solid lubricant prepared in Comparative Example 1; Figure 9 XRD pattern of the MXene-enhanced copper-based solid lubricant prepared in Example 2; Figure 10 SEM image of the MXene-reinforced copper-based solid lubricant prepared in Example 2; Figure 11 The average friction coefficient of the MXene-reinforced copper-based solid lubricant prepared in Example 2 under different loads on the Al2O3 grinding pair; Figure 12 The average friction coefficient of the MXene-reinforced copper-based solid lubricant prepared in Example 2 under different grinding pairs; Figure 13 XRD pattern of the MXene-enhanced copper-based solid lubricant prepared in Example 3; Figure 14 SEM image of the MXene-reinforced copper-based solid lubricant prepared in Example 3; Figure 15 The average friction coefficient of the MXene-reinforced copper-based solid lubricant prepared in Example 3; Figure 16 XRD pattern of the MXene-enhanced copper-based solid lubricant prepared in Example 4; Figure 17 SEM image of the MXene-reinforced copper-based solid lubricant prepared in Example 4; Figure 18 The average friction coefficient of the MXene-reinforced copper-based solid lubricant prepared in Example 4; Figure 19 XRD pattern of the MXene-enhanced copper-based solid lubricant prepared in Example 5; Figure 20 SEM image of the MXene-reinforced copper-based solid lubricant prepared in Example 5; Figure 21 The average friction coefficient of the MXene-enhanced copper-based solid lubricant prepared in Example 5; Figure 22 XRD patterns of the composite powder and MXene-reinforced copper-nickel alloy-based solid lubricant prepared in Example 6; Figure 23 The average friction coefficient of the MXene-reinforced copper-nickel alloy-based solid lubricant prepared in Example 6 under different loads; Figure 24 XRD pattern of the MXene-reinforced aluminum-copper alloy-based solid lubricant prepared in Example 7; Figure 25 The average coefficient of friction is the MXene-reinforced aluminum-copper alloy-based solid lubricant prepared in Example 7 and pure aluminum. Detailed Implementation

[0019] MXene, as a novel type of two-dimensional transition metal carbide, nitride, and / or boride, has attracted widespread research attention. Its general chemical formula is M. n+1 X n T x (n=1, 2, 3), where M represents a transition metal element (such as Ti, V, Cr, Zr, Nb, Mo, Hf, Sc, or Ta, etc.), X represents carbon, nitrogen, and / or boron, and T represents... x These represent functional groups on the surface of the material (such as -OH, -O, or -Cl). After extensive research, the inventors discovered that typical MXenes can be selectively etched to form M... n+1 AX nThe MXene is prepared by etching an A-atom layer from a precursor (n=1, 2, 3, M including at least one of Ti, V, Cr, Zr, Nb, Mo, Hf, Sc, or Ta; A including at least one of Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl, or Pb; X including at least one of C, N, or B). The resulting two-dimensional material exhibits weak interlayer bonding, facilitating relative sliding and demonstrating excellent friction-reducing and lubricating properties. Furthermore, the etched MXene exhibits an open structure with exposed metal sites, which facilitates strong interfacial bonding with the metal matrix. The surface functional groups contribute to good hydrophilicity, further enhancing wettability with the metal matrix. Therefore, this application creatively proposes an MXene / metal-based self-lubricating composite material and its preparation method, which involves selectively etching M-atom layers using Lewis acid molten salts. n+1 AX n When the MAX phase precursor powder is immersed in molten Lewis acid salt at high temperature, due to the weaker MA metallic bond, the A-site atoms (including at least one of Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl, or Pb) are oxidized to a higher oxidation state by the cations in Lewis acids (including at least one of CuCl2, CoCl2, ZnCl2, FeCl3, NiCl2, AgCl, FeCl2, or CdCl2) with higher redox potentials. These cations then react with anions in the system (such as Cl-). - ,Br - I - SO 2- or NO - (etc.) combine to form volatile substances, which are then vaporized at high temperatures, thereby selectively removing A-site elements. The resulting MXene material exhibits a clear "accordion"-like open layered structure. Simultaneously, the cations in the Lewis acid are reduced and in situ loaded as metal particles between and on the surface of the MXene material's layered structure. Meanwhile, the open-cell unsaturated M... n+1 X n The lamellae readily combine with anions in the system, becoming the surface functional groups T of MXene. xThe in-situ loading of metal particles onto the two-dimensional layered structure of MXene promotes the wetting and sintering of the lubricating phase and the metal during sintering, overcoming the shortcomings of traditional solid lubricants that require surface modification, simplifying the preparation process, and improving the overall performance of metal-based composite self-lubricating materials. By optimizing the molten salt etching process and precisely controlling the particle size of the displaced metal particles, uniform dispersion of the in-situ loaded nano-metal particles with MXene is achieved, which is beneficial for the efficient spread of MXene during friction. The strong interfacial bonding between the matrix and the lubricating phase fully utilizes its self-lubricating properties, enhancing wear resistance and the overall performance of the composite material. Furthermore, using two or more etchants can obtain in-situ loading of two or more elemental metal particles onto the MXene surface, further improving the strength of the sintered composite material and enhancing its adaptability under heavy-load and other frictional and wear conditions. This invention is based on these principles.

[0020] In some embodiments of the present invention, a method for preparing an MXene / metal-based self-lubricating composite material is provided, comprising the following steps: S1. Provide raw material powder, said raw material powder comprising a composite powder of MXene in-situ supported metal particles, said composite powder being selectively etched by Lewis acid molten salt. n+1 AX n The precursor powder is prepared as follows: n = 1, 2 or 3; M includes at least one of Ti, V, Cr, Zr, Nb, Mo, Hf, Sc or Ta; A includes at least one of Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl or Pb; X includes at least one of C, N or B; and the Lewis acid includes at least one of CuCl2, CoCl2, ZnCl2, FeCl3, NiCl2, AgCl, FeCl2 or CdCl2. S2. Powder sintering: The raw material powder is sintered to prepare the MXene / metal-based self-lubricating composite material.

[0021] In some embodiments of the present invention, in step S1, the composite powder is selectively etched by Lewis acid molten salt M. n+1 AX n The precursor powder was prepared by means of: S1-1. Weigh the Lewis acid, molten salt, and M according to the proportions. n+1 AX n The precursor powder is mixed evenly and then formed into a green body. Then, additional Lewis acid and molten salt are weighed according to the formula and coated onto the green body. Optionally, in step S1-1, the Lewis acid includes at least one of CuCl2 or NiCl2; the molten salt includes at least one of a halide salt, optionally including at least one of sodium chloride or potassium chloride; the M...n+ 1AX n The precursor powder contains A, which includes Al. Optionally, the M... n+1 AX n The precursor powder includes Ti3AlC2; optionally, the M n+1 AX n The particle size of the phase precursor powder is less than 300 μm, preferably less than 75 μm, and more preferably less than 50 μm. Optionally, in step S1-1, Lewis acid, molten salt, and M are weighed according to the specified ratio. n+1 AX n In the phase precursor powder, the Lewis acid, molten salt and M n+ 1AX n The molar ratio of the precursor powder is 1~3:10~30:0.5~1.5, preferably 1.5~2.5:15~25:0.5~1.5. Preferably, the molten salt comprises potassium chloride and sodium chloride, and the Lewis acid, potassium chloride, sodium chloride, and M... n+1 AX n The molar ratio of the phase precursor powder is 1~3:5~15:5~15:0.5~1.5, preferably 1.5~2.5:8~12:8~12:0.5~1.5. Then, additional Lewis acid and molten salt are weighed according to the ratio. The additional Lewis acid, molten salt, and M... n+1 AX n The molar ratio of the phase precursor powder is 2~6:10~40:0.5~1.5, preferably 3.5~4.5:15~35:0.5~1.5, with additional Lewis acid, potassium chloride, sodium chloride and said M n+1 AX n The molar ratio of the phase precursor powder is 2~6:10~20:10~20:0.5~1.5, preferably 2.5~5:10~15:10~15:0.5~1.5.

[0022] S1-2. Heating reaction, Lewis acid selectively converts M... n+1 AX n The A-layer atoms in the precursor powder are etched away to form a two-dimensional layered MXene structure, while the metal cations in the Lewis acid are reduced to metal particles that are in situ loaded onto the MXene to form a composite powder. Optionally, in step S1-2, the heating temperature is 680~720℃, and the holding time is 20~80min, preferably 20~40min. In step S1-2, the metal particles are nanoparticles, and the nanoparticles are in situ loaded on the interlayer and surface of the two-dimensional layered MXene structure. Optionally, the particle size of the nanoparticles is less than 500nm, preferably less than 350nm, and more preferably 50~250nm.

[0023] S1-3. Wash and dry to obtain the composite powder. Optionally, wash with water to remove molten salt and residual Lewis acid, and then centrifuge and dry the washed product.

[0024] In some embodiments of the present invention, step S2. powder sintering may be selected as spark plasma sintering, the temperature of step S2. powder sintering is 800~1100℃, preferably 850~1000℃, the holding time is 5~15min, and the sintering pressure is 50~150MPa.

[0025] In some embodiments of the present invention, in step S1, the raw material powder further includes additional metal particles, wherein the additional metal particles are selected from at least one of Al, Cu, Zn, Ni, Co, Ag, Fe, Ti, or Mo. Preferably, the particle size of the additional metal particles is 50 μm or less, more preferably 25 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. Optionally, the content of the additional metal particles, based on the mass of the raw material powder, is 0.1 to 90 wt%, preferably 10 to 80 wt%, and more preferably 55 to 65 wt%.

[0026] In some embodiments of the present invention, the sintered MXene / metal-based self-lubricating composite material includes a matrix phase and an MXene phase. Optionally, the matrix phase includes a granular matrix phase and a lamellar matrix phase distributed between the MXene phase layers. The particle size of the granular matrix phase is less than 100 μm, preferably less than 60 μm, and the lamellar matrix phase has a lamellar thickness of less than 3 μm, preferably 0.5 to 1.5 μm. Optionally, the MXene phase includes a Ti3C2MXene phase, the matrix phase includes a Cu phase and a TiC phase, the Cu phase includes a granular Cu phase and a lamellar Cu phase distributed between the Ti3C2MXene phase layers. The lamellar Cu phase has a lamellar thickness of less than 3 μm, preferably 0.5 to 1.5 μm, and the granular Cu phase has a size of less than 100 μm, preferably less than 60 μm.

[0027] In some embodiments of the present invention, step S1-1 involves weighing Lewis acid, molten salt, and M according to the specified ratio. n+1 AX nIn the precursor powder, NiCl2 powder, CuCl2 powder, KCl powder, NaCl powder, and Ti3AlC2 powder were weighed according to the molar ratio NiCl2:CuCl2:KCl:NaCl:Ti3AlC2 = 0.5~1.5:0.5~1.5:8~12:8~12:0.5~1.5; then, additional NiCl2, CuCl2 powder, KCl powder, and NaCl powder were weighed according to the molar ratio NiCl2:CuCl2:KCl:NaCl:Ti3AlC2 = 1.5~2.5:1.5~2.5:12~14:12~14:0.5~1.5; the sintered MXene / metal-based self-lubricating composite material includes Cu 0.5 Ni 0.5 Phase and Ti3C2MXene phase.

[0028] In some embodiments of the present invention, in step S1, the mass ratio of composite powder, Cu particles and Al particles in the raw material powder is 10~20:10~20:60~80; in step S2, powder sintering, the sintering temperature is 500~600℃ and the pressure is 30~60MPa, and the MXene / metal-based self-lubricating composite material obtained by sintering includes Al phase, CuAl2 phase and Ti3C2MXene phase.

[0029] The present invention will be further described in detail below with reference to specific embodiments. In the embodiments of the present invention, unless otherwise specified, the raw materials are all commercially available.

[0030] Example 1 A method for preparing an MXene / metal-based self-lubricating composite material includes the following steps: S1. Provide raw material powder, which is a composite powder of Ti3C2MXene in situ supported Cu particles. The composite powder is prepared by selectively etching Ti3AlC2 phase precursor powder with Lewis acid molten salt. The Lewis acid is CuCl2 powder, and the molten salt is KCl powder and NaCl powder. S1-1. Weigh out CuCl2 powder (99.7% purity), KCl powder (99.7% purity), NaCl powder (99.7% purity), and Ti3AlC2 powder (particle size 5~35μm, purity 99.5%) according to the molar ratio CuCl2:KCl:NaCl:Ti3AlC2=2:9.7:9.7:1, and grind and mix them evenly in an agate crucible. Then, load the mixed powder into a 29mm diameter cold-pressing mold. The blank was held under 10 MPa pressure for 10 seconds and then cold-pressed and demolded. The blank was placed at the bottom of a 200 ml corundum crucible. The amount of Ti3AlC2 powder mentioned above was measured according to the molar ratio CuCl2:KCl:NaCl:Ti3AlC2=4:13.3:13.3:1. Additional CuCl2 powder, KCl powder and NaCl powder were weighed, ground and mixed evenly, and then covered on top of the blank to achieve molten salt encapsulation and etchant replenishment. S1-2. Heating reaction: Specifically, place the covered corundum crucible in a muffle furnace without a protective atmosphere, and heat to 700°C at a rate of 10°C / min. Hold at this temperature for 30 minutes. At this high temperature, the molten salt melts, and the Lewis acid CuCl2 selectively reacts with M, which is immersed in the molten salt. n+1 AX n The A-layer atoms in the Ti3AlC2 precursor powder are etched away to form a two-dimensional layered Ti3C2MXene material, while the metal cations in the Lewis acid CuCl2 are reduced to metal Cu particles and loaded in situ on the MXene to form a composite powder. S1-3. Washing and drying: Specifically, remove the reaction product from the crucible, place it in a beaker, add 600 ml of deionized water, stir for 1 h until the salt block is completely dissolved, then centrifuge at 7000 rpm / min for 7 min, discard the supernatant, retain the precipitate, and wash repeatedly to remove residual molten salt and Lewis acid. Finally, dry the precipitate in a vacuum drying oven at 80℃ for 5 h to obtain a composite powder of Ti3C2MXene in situ supported Cu particles.

[0031] S2. Powder sintering: The raw material powder is sintered to prepare MXene / metal-based self-lubricating composite material. Specifically, the raw material powder is sintered by spark plasma. The composite powder is loaded into a sintering mold and placed in a spark plasma sintering furnace. The vacuum is evacuated to a vacuum degree lower than 5×10⁻²Pa. The initial pressure of the pressure head is set to 10MPa. The temperature is increased from room temperature to 900℃ at a rate of 50℃ / min and held for 10min. During the heating process, the pressure is automatically increased to 100MPa. The pressure is maintained during the holding process. After the holding period, the furnace is cooled to 600℃ and the pressure is released. After cooling to room temperature, the mold is removed, and the product is demolded to obtain the MXene / metal-based self-lubricating composite material.

[0032] X-ray diffraction (XRD) was used to characterize the phase composition of the Ti3C2MXene in-situ supported Cu particle composite powder and the sintered MXene / metal-based self-lubricating composite material prepared in Example 1. The test results are as follows: Figure 1 As shown, from Figure 1 It can be seen that the phase composition of the composite powder is Cu phase and Ti3C2MXene phase, and no other phases were detected. In addition to Cu phase and Ti3C2MXene phase, a small amount of TiC phase also appeared in the sintered composite material, indicating that some Ti3C2MXene decomposed to form TiC phase during the sintering process.

[0033] The microstructure of the Ti3C2MXene in-situ supported Cu particle composite powder and the sintered MXene / metal-based self-lubricating composite material prepared in Example 1 was characterized using scanning electron microscopy (SEM). The results are as follows: Figure 2 and Figure 3 As shown. From Figure 2 It can be seen that the Ti3C2MXene composite powder has an open two-dimensional layered structure with a large number of nano-sized Cu particles attached between the layers and on the surface. The particle size of the nano-sized Cu particles is 50~250nm. Figure 3 The MXene / metal-based self-lubricating composite material was shown to include a grayish-white Cu phase, a grayish-black MXene phase, and a black TiC phase. Further evidence confirmed that some MXene decomposed. The grayish-white Cu phase included fine lamellar Cu phases distributed between the lamellar MXene phases and granular Cu phases distributed between the MXene phases. The lamellar Cu phase had a thickness of 0.5~1.5μm, and the granular Cu phase had a maximum size of 55μm. The phases were small and uniformly dispersed.

[0034] The average coefficient of friction of the composite material at different temperatures in air was tested using a Bruker friction testing machine (USA). The friction pair consisted of alumina balls with a diameter of 6 mm, and the friction load was 10 N. The test curves for the average coefficient of friction are shown below. Figure 4 As shown in the figure. The average coefficients of friction at 10 N and at room temperature and 200 °C were measured to be 0.146 and 0.227, respectively. The experimental results show that the MXene-reinforced copper-based self-lubricating material prepared in Example 1 has excellent self-lubricating properties under different temperatures and heavy loads.

[0035] Comparative Example 1 The difference between Comparative Example 1 and Example 1 lies in step S1-1. In step S1-1, KCl powder, NaCl powder, and Ti3AlC2 powder are weighed according to a molar ratio of KCl:NaCl:Ti3AlC2 = 3:3:1 and ground and mixed evenly in an agate crucible. The mixed powder is then placed into a 29mm diameter cold-pressing mold and held under 10MPa pressure for 10s. After cold pressing, the molded blank is obtained and placed at the bottom of a 200ml corundum crucible. Using the aforementioned amount of Ti3AlC2 powder, CuCl2, KCl powder, and NaCl powder are weighed according to a molar ratio of CuCl2:KCl:NaCl:Ti3AlC2 = 6:20:20:1. After grinding and mixing evenly, the mixture is applied over the blank to encapsulate the molten salt and etchant. The remaining preparation steps are the same as in Example 1, resulting in the preparation of the MXene / metal-based self-lubricating composite material.

[0036] The microstructure composition of the composite powder and composite material of Comparative Example 1 was characterized using the same method as in Example 1, and the test results are as follows: Figure 5 , Figure 6 and Figure 7 As shown. Figure 5 The composite powder image shows that there is no large amount of copper nanoparticle loading on the surface and between layers of Ti3C2MXene. This is because the copper particles have grown to the micrometer scale, with a particle size of 1~3μm, making intercalation and loading between Ti3C2MXene layers difficult. Figure 6 The XRD results show that the composite powder prepared in Comparative Example 1 has a phase structure of Cu phase and Ti3C2MXene phase. Figure 7 SEM results showed that the MXene / metal-based self-lubricating composite material of Comparative Example 1 included a grayish-white Cu phase, a grayish-black MXene phase, and a black TiC phase. The grayish-white Cu phase included fine lamellar Cu phases distributed between the layered MXene phase sheets and granular Cu phases distributed between the MXene phases. The particle size distribution of the granular Cu phase was uneven, with the largest copper phase particle size exceeding 250 μm. The grayish-black structure was Ti3C2MXene. Compared with Example 1, the structure distribution of Comparative Example 1 was extremely uneven, with a significant reduction in the fine lamellar Cu phase and a significant increase in the size of the granular Cu phase.

[0037] The friction properties of the composite material in Comparative Example 1 were tested using the same method as in Example 1. The friction test results are as follows: Figure 8 As shown. The MXene / metal-based self-lubricating material prepared in Comparative Example 1 has an average coefficient of friction of 0.162 at room temperature (10 N) and a volumetric wear rate of 3.09 × 10⁻⁶. -5 mm 3 N -1 m -1Compared to Example 1, the average friction coefficient increased and the lubrication performance decreased. The main reason is that during the friction process, large-diameter copper particles are not conducive to the formation of a uniformly distributed MXene lubricating layer. Oxidation fatigue wear is prone to occur where copper accumulates, leading to an increase in the average friction coefficient.

[0038] Example 2 The difference between Example 2 and Example 1 is that in Step S1. of Example 2, the raw material powder includes a composite powder of Ti3C2MXene in situ supported on Cu particles. The preparation method of the composite powder of Ti3C2MXene in situ supported on Cu particles is the same as Steps S1-1, S1-2, and S1-3 of Example 1. Furthermore, the raw material powder also includes additional Cu particles (particle size less than 1 μm, purity 99.5%). The Cu particle content is 60 wt% based on the mass of the raw material powder. The composite powder and the additional Cu particles are mixed uniformly through three-dimensional mixing (rotation speed 60 rpm / min, rotation for 30 min, rest for 10 min, for a total of 5 h). The remaining preparation steps of Example 2 are the same as those of Example 1, resulting in an MXene / metal-based self-lubricating composite material.

[0039] The microstructure of the MXene / metal-based self-lubricating composite material of Example 2 was characterized using the same method as in Example 1, and the test results are as follows: Figure 9 , 10 As shown. From Figure 9 The XRD results show that the phase structure of the MXene-reinforced copper-based self-lubricating composite material prepared in Example 2 is Cu phase and Ti3C2MXene phase, and no other phases were detected. Figure 10 The self-lubricating composite material is shown to include a grayish-white Cu phase, a grayish-black Ti3C2MXene phase, and a black TiC phase. It is further confirmed that some Ti3C2MXene decomposes to form TiC. The phases are fine and uniformly dispersed. The grayish-white Cu phase includes fine lamellar Cu phases distributed between the lamellar MXene phases and granular Cu phases distributed between the MXene phases. The maximum size of the granular Cu phase is 30 μm.

[0040] The frictional properties of the self-lubricating composite material of Example 2 were tested using the same method as in Example 1, and the friction coefficient curve is shown below. Figure 11 and Figure 12 As shown. Figure 11 The average friction coefficient curves for the Al2O3 grinding pair under different friction loads are shown. At room temperature, the average friction coefficients for friction loads of 5N, 10N, 20N, 30N, and 40N are 0.150, 0.140, 0.147, 0.138, and 0.146, respectively, with volumetric wear rates of 2.1 × 10⁻⁶. -5 3.124×10-5 3.13×10 -5 3.802×10 -5 and 1.785×10 -4 mm 3 N -1 m -1 Example 2 shows that the average coefficient of friction remains at 0.14±0.01 within the load range of 5–40 N, with no obvious load dependence, exhibiting stable ultra-low friction behavior and high lubricity and wear resistance. Figure 12 The average friction coefficients for the grinding pairs of Al2O3, SiC, GCr15, and GH4169 were 0.140, 0.143, 0.213, and 0.197 respectively under a room temperature load of 10 N. The average friction coefficients of the ceramic grinding pairs (Al2O3, SiC) were significantly lower than those of the metal materials (GH4169, GCr15), demonstrating better friction matching and lubrication stability. No significant running-in period was observed during the entire test, and a stable lubricating film formed on the surface of the ceramic grinding pairs, resulting in low interfacial shear resistance. The average friction coefficient of the metal grinding pairs increased significantly and exhibited periodic fluctuations, reflecting the alternation of interfacial adhesion and film rupture, but still maintaining a stable periodic state. Compared to Example 1, the self-lubricating properties of Example 2 showed no significant change, but the average friction coefficient decreased slightly. The main reason for this is that the added copper can achieve a synergistic effect of MXene's layered lubrication and copper's soft metal lubrication, resulting in better friction performance. On the other hand, it can also improve the mechanical properties of the composite material.

[0041] Example 3 The difference between Example 3 and Example 2 is that, in step S1, providing the raw material powder, the content of additional Cu particles added is 70 wt% based on the mass of the raw material powder. The remaining preparation steps are the same as in Example 2, and the MXene / metal-based self-lubricating composite material is prepared.

[0042] The microstructure composition of the composite material in Example 3 was characterized using the same method as in Example 2, and the test results are as follows: Figure 13 , 14 As shown. From Figure 13 The XRD results show that the phase structure of the MXene-reinforced copper-based self-lubricating composite material prepared in Example 3 consists of Cu and Ti3C2MXene phases, with no other phases detected. Figure 14The SEM images show that the self-lubricating composite material includes a grayish-white Cu phase, a grayish-black Ti3C2MXene phase, and a small amount of black TiC phase. The structure of each phase is fine and uniform. The grayish-black Ti3C2MXene phase and the black TiC phase are uniformly dispersed in the Cu matrix phase and have good interfacial bonding. The grayish-white Cu phase includes fine lamellar Cu phase distributed between the layered MXene phase sheets and granular Cu phase distributed between the MXene phases.

[0043] The friction properties of the MXene / metal-based self-lubricating composite material of Example 3 were tested using the same method as in Example 2. The friction test results are as follows: Figure 15 As shown. The solid lubricant prepared in Example 3 has an average coefficient of friction of 0.156 and a volumetric wear rate of 1.20 × 10⁻⁶. -5 mm 3 N -1 m -1 Compared to Example 2, the average friction coefficient increased while the volumetric wear rate decreased. Increasing the copper content can improve the mechanical properties and wear resistance of the composite material, but decrease its lubricity.

[0044] Example 4 The difference between Example 4 and Example 2 is that, in step S1, providing the raw material powder, the content of additional Cu particles added is 80 wt% based on the mass of the raw material powder. The remaining preparation steps are the same as in Example 2, and the MXene / metal-based self-lubricating composite material is prepared.

[0045] The microstructure composition of the composite material of Example 4 was characterized using the same method as in Example 2, and the test results are as follows: Figure 16 , 17 As shown. From Figure 16 The XRD results show that the phase structure of the MXene / metal-based self-lubricating composite material prepared in Example 4 includes a Cu phase and a Ti3C2MXene phase, with no other phases detected. Figure 17 The SEM images show that the self-lubricating composite material includes a grayish-white Cu phase, a grayish-black Ti3C2MXene phase, and a small amount of black TiC phase. The microstructure of each phase is fine and uniform. The grayish-black Ti3C2MXene phase and the black TiC phase are uniformly dispersed in the Cu matrix phase and have good interfacial bonding.

[0046] The friction properties of the MXene / metal-based self-lubricating composite material of Example 4 were tested using the same method as in Example 2. The friction test results are as follows: Figure 18 As shown. The solid lubricant prepared in Example 4 has an average coefficient of friction of 0.150 and a volumetric wear rate of 2.5 × 10⁻⁶. -5 mm 3 N -1 m-1 In conjunction with Examples 2, 3, and 4, as the amount of Cu added increases, the average coefficient of friction increases, while volumetric wear initially decreases and then increases.

[0047] Example 5 The difference between Example 5 and Example 2 is that, in step S1, providing the raw material powder, the content of additional Cu particles added is 90 wt% based on the mass of the raw material powder. The remaining preparation steps are the same as in Example 2, and the MXene / metal-based self-lubricating composite material is prepared.

[0048] The microstructure composition of the composite material of Example 5 was characterized using the same method as in Example 2, and the test results are as follows: Figure 19 , 20 As shown. From Figure 19 The XRD results show that the composite material prepared in Example 5 includes a Cu phase and a Ti3C2MXene phase, with no other phases detected. Figure 20 The SEM images show that the grayish-white Cu phase forms a continuous matrix phase, with a small amount of Ti3C2MXene phase distributed in the Cu matrix phase.

[0049] The friction properties of the MXene / metal-based self-lubricating composite material of Example 5 were tested using the same method as in Example 2. The friction test results are as follows: Figure 21 As shown, the average coefficient of friction increased to 0.183, and the volumetric wear rate was 2.23 × 10⁻⁶. -5 mm 3 N - 1 m -1 The curve was above 0.17 throughout and fluctuated significantly, with no steady-state low-friction plateau. Compared with Examples 1-4, the high copper phase volume fraction made copper the dominant lubricant source, and the interlayer slip of MXene only played an auxiliary role; the copper phase underwent adhesion transfer in the early stage of sliding, making it difficult to form a continuous self-lubricating film, which suppressed the solid lubrication properties of MXene, significantly increased the average friction coefficient and decreased stability.

[0050] Example 6 A method for preparing an MXene / metal-based self-lubricating composite material includes the following steps: S1. Provide raw material powder, which is a composite powder of Ti3C2MXene in situ supported on Cu and Ni particles. The composite powder is selectively etched with Lewis acid molten salt to obtain Ti3AlC2 phase precursor powder. The Lewis acid is CuCl2 powder and NiCl2 powder, and the molten salt is KCl powder and NaCl powder; including: S1-1. Weigh NiCl2 powder, CuCl2 powder, KCl powder, NaCl powder, and Ti3AlC2 powder according to the molar ratio NiCl2:CuCl2:KCl:NaCl:Ti3AlC2=1:1:9.7:9.7:1, and grind and mix them evenly in an agate crucible. Put the mixed powder into a cold-pressing mold with a diameter of 29mm, hold it under a pressure of 10MPa for 10s, and demold it after cold pressing to obtain a blank. Place the blank at the bottom of a 200ml corundum crucible. Measure the amount of Ti3AlC2 powder mentioned above, and weigh additional NiCl2, CuCl2 powder, KCl powder, and NaCl powder according to the molar ratio NiCl2:CuCl2:KCl:NaCl:Ti3AlC2=2:2:13.3:13.3:1. Grind and mix them evenly and cover them on top of the blank to achieve molten salt encapsulation and etchant replenishment. S1-2. Heating reaction: Specifically, place the covered corundum crucible in a muffle furnace without a protective atmosphere, and heat to 700°C at a rate of 10°C / min. Hold at this temperature for 30 minutes. At this high temperature, the molten salt melts, and the Lewis acids CuCl2 and NiCl2 selectively react with M, which is immersed in the molten salt. n+1 AX n The A-layer atoms in the Ti3AlC2 precursor powder are etched away to form a two-dimensional layered Ti3C2MXene material, while the metal cations in Lewis acids CuCl2 and NiCl2 are reduced to metal Cu and Ni particles, which are then loaded in situ onto Ti3C2MXene to form a composite powder. S1-3. Washing and drying: Specifically, remove the reaction product from the crucible, place it in a beaker, add 600 ml of deionized water, stir for 1 h until the salt block is completely dissolved, then centrifuge at 7000 rpm / min for 7 min, discard the supernatant, retain the precipitate, and wash repeatedly to remove residual molten salt and Lewis acid. Finally, dry the precipitate in a vacuum drying oven at 80℃ for 5 h to obtain a composite powder of Ti3C2MXene in situ supported on Cu and Ni particles.

[0051] S2. Powder sintering: The raw material powder is sintered to prepare MXene / metal-based self-lubricating composite material. Specifically, the raw material powder is sintered by spark plasma. The composite powder is loaded into a sintering mold and placed in a spark plasma sintering furnace. The vacuum is evacuated to a vacuum degree lower than 5×10⁻²Pa. The initial pressure of the pressure head is set to 10MPa. The temperature is increased from room temperature to sintering temperature of 1000℃ at a rate of 50℃ / min and held for 10min. During the heating process, the pressure is automatically increased to sintering pressure of 50MPa. The pressure is maintained during the holding process. After the holding period, the furnace is cooled to 600℃ and the pressure is released. After cooling to room temperature, the mold is removed, and the product is demolded to obtain the MXene / metal-based self-lubricating composite material.

[0052] X-ray diffraction (XRD) was used to characterize the phase composition of the Ti3C2MXene in-situ supported Cu and Ni particle composite powder and the sintered MXene / metal-based self-lubricating composite material prepared in Example 6. The test results are as follows: Figure 22 As shown, from Figure 22 It can be seen that the phase composition of the composite powder is Cu phase, Ni phase and Ti3C2MXene phase, while the phase composition of the sintered composite material is Ti3C2MXene phase and Cu. 0.5 Ni 0.5 The phase indicates that Ni and Cu undergo a solid solution reaction during sintering to form Cu. 0.5 Ni 0.5 It is a solid solution, and no other phases were detected.

[0053] Using the same test method as in Example 1, the average coefficient of friction of the composite material obtained in Example 6 under different loads in air was tested, and the test results are as follows: Figure 23 As shown. The average friction coefficients of the composite material prepared in Example 6 were measured to be 0.211 and 0.170 under loads of 10N and 20N, respectively, and the volumetric wear rate was 4.83 × 10⁻⁶ at a friction load of 20N. -6 mm 3 N -1 m -1 Compared with Example 1, although the self-lubricating performance was reduced, the wear resistance was good, which is mainly attributed to the Cu-Ni solid solution strengthening effect, which improved the strength of the composite material.

[0054] Example 7 The difference between Example 7 and Example 2 is that in Step S1. of Example 7, the raw material powder includes additional Al particles (99.5% purity, 5-10 μm particle size). The mass ratio of the composite powder, Cu particles, and Al particles in the raw material powder is 15:15:70. The mixture is homogeneously mixed using three-dimensional mixing (60 rpm / min, 30 min rotation, 10 min rest, 5 h total). In Step S2. of powder sintering, the sintering temperature in Example 7 is 540 °C, and the pressure is 40 MPa. The remaining preparation steps of Example 7 are the same as in Example 2, resulting in the preparation of an MXene / metal-based self-lubricating composite material.

[0055] The phase composition of the sintered MXene / metal-based self-lubricating composite material of Example 7 was characterized by X-ray diffraction (XRD). The test results are as follows: Figure 24 As shown, from Figure 24 It can be seen that the phase composition of the composite material is Al phase, CuAl2 phase and Ti3C2MXene phase, and no other phases were detected.

[0056] The friction properties of the MXene / metal-based self-lubricating composite material of Example 7 were tested using the same method as in Example 2. The friction test results are as follows: Figure 25 As shown. From Figure 25 As can be seen, the friction coefficient of the MXene-reinforced aluminum-based self-lubricating material prepared in Example 7 rapidly decreased to around 0.20 under Al2O3 friction pair conditions, and then fluctuated steadily at 0.223±0.01 throughout the process. In contrast, the pure Al curve remained above 0.6, with a peak value close to 0.65. The lubricating film formed by MXene was fully established during the running-in period, reducing the average friction coefficient by approximately 66% compared to pure aluminum, and significantly narrowing the fluctuation range, exhibiting continuous and stable self-lubricating properties. Simultaneously, the volumetric wear rate decreased from 6.17×10⁻⁶ for pure Al. -3 mm 3 N -1 M -1 Reduced to 8.58×10 -4 mm 3 N -1 M -1 The wear resistance is significantly improved.

[0057] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for preparing an MXene / metal-based self-lubricating composite material, characterized in that, Includes the following steps: S1. Provide raw material powder, said raw material powder comprising a composite powder of MXene in-situ supported metal particles, said composite powder being selectively etched by Lewis acid molten salt. n+1 AX n The precursor powder is prepared as follows: n = 1, 2 or 3; M includes at least one of Ti, V, Cr, Zr, Nb, Mo, Hf, Sc or Ta; A includes at least one of Al, Si, P, S, Ga, Ge, As, Cd, In, Sn, Tl or Pb; X includes at least one of C, N or B; and the Lewis acid includes at least one of CuCl2, CoCl2, ZnCl2, FeCl3, NiCl2, AgCl, FeCl2 or CdCl2. S2. Powder sintering: The raw material powder is sintered to prepare the MXene / metal-based self-lubricating composite material.

2. The method for preparing the MXene / metal-based self-lubricating composite material according to claim 1, characterized in that, In step S1, the composite powder is selectively etched by Lewis acid molten salt to form M. n+1 AX n The precursor powder was prepared by means of: S1-1. Weigh Lewis acid, molten salt, and M according to the proportions. n+1 AX n The precursor powder is mixed evenly and then formed into a green body. Then, additional Lewis acid and molten salt are weighed according to the formula and the additional Lewis acid and molten salt are covered on the green body. S1-2. Heating reaction, Lewis acid selectively converts M... n+1 AX n The A-layer atoms in the phase precursor powder are etched away to form a two-dimensional layered structure of MXene, while the metal cations in the Lewis acid are reduced to the metal particles and loaded in situ on the MXene to form a composite powder. S1-3. Wash and dry to obtain the composite powder.

3. The method for preparing the MXene / metal-based self-lubricating composite material according to claim 2, characterized in that, In step S1-1, the Lewis acid includes at least one of CuCl2 or NiCl2; and / or, The molten salt includes at least one of a halide salt; and / or, The M n+1 AX n The A in the phase includes Al; and / or, Step S1-2. The temperature for heating the reaction is 680~720℃, and the holding time is 20~80min.

4. The method for preparing the MXene / metal-based self-lubricating composite material according to claim 2, characterized in that, Step S1-1. Weigh Lewis acid, molten salt and M according to the ratio. n+1 AX n In the phase precursor powder, the Lewis acid, molten salt and M n+1 AX n The molar ratio of the phase precursor powder is 1~3:10~30:0.5~1.

5. Then, according to the formula, additional Lewis acid and molten salt are weighed. The additional Lewis acid, molten salt, and M... n+1 AX n The molar ratio of the phase precursor powder is 2~6:10~40:0.5~1.

5.

5. The method for preparing the MXene / metal-based self-lubricating composite material according to claim 1 or 2, characterized in that, The metal particles are nanoparticles, which are in situ loaded on the interlayer and surface of the two-dimensional layered structure of MXene, and the particle size of the nanoparticles is less than 500 nm.

6. The method for preparing the MXene / metal-based self-lubricating composite material according to claim 1 or 2, characterized in that, Step S2. The powder sintering temperature is 800~1100℃, the holding time is 5~15min, and the sintering pressure is 50~150MPa.

7. The method for preparing the MXene / metal-based self-lubricating composite material according to claim 1 or 2, characterized in that, In step S1, the raw material powder also includes additional metal particles, which are selected from at least one of Al, Cu, Zn, Ni, Co, Ag, Fe, Ti or Mo, and the content of the additional metal particles is 0.1 to 90 wt% based on the mass of the raw material powder.

8. The method for preparing the MXene / metal-based self-lubricating composite material according to claim 7, characterized in that, The content of the additional metal particles is 55-65 wt% based on the mass of the raw material powder.

9. An MXene / metal-based self-lubricating composite material, obtained by the preparation method of the MXene / metal-based self-lubricating composite material according to any one of claims 1 to 8.

10. The MXene / metal-based self-lubricating composite material according to claim 9, characterized in that, The MXene / metal-based self-lubricating composite material includes a matrix phase and an MXene phase. The matrix phase includes a granular matrix phase and a lamellar matrix phase distributed between the MXene phase layers. The particle size of the granular matrix phase is less than 100 μm, and the lamellar matrix phase has a lamellar thickness of less than 3 μm.

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