CN119753473A - A Ti3AlC2 reinforced Fe-based high temperature resistant self-lubricating composite material and preparation method thereof - Google Patents

Abstract

The invention discloses a high-temperature-resistant Fe-based self-lubricating composite material. Wherein the non-stoichiometric compound is a nitride, carbide or boride of a transition metal (Ti, V, cr, zr, nb, mo, hf, ta, W), the solid lubricating phase comprising a ternary lamellar compound of group M _n+1AX_n (n=1, 2, 3). The raw material mixing of the high-temperature resistant Fe-based self-lubricating composite material comprises the steps of mixing the Fe alloy raw material, the non-stoichiometric compound raw material and the solid lubricating phase raw material through a ball milling mixing method, or mixing the metal simple substance powder of the Fe alloy component, the non-stoichiometric compound raw material and the solid lubricating phase raw material through a ball milling mixing method, and prepressing and forming the prepared composite powder. Finally, preparing the high-temperature-resistant Fe-based self-lubricating composite material sintered body by adopting a powder metallurgy sintering method. The invention synthesizes the high temperature resistant Fe-based self-lubricating composite material by adopting various powder and sintering preparation methods, and has excellent comprehensive performance.

Description

Ti 3AlC2 reinforced Fe-based high-temperature-resistant self-lubricating composite material and preparation method thereof

Technical Field

The invention relates to the technical field of composite materials, in particular to a preparation method of a Ti ₃AlC₂ reinforced Fe-based high-temperature-resistant self-lubricating composite material.

Background

With the continuous research and development of Fe alloy and continuous improvement of performance, the current rotating friction fields of aerospace bearings, aerospace landing gear and the like are also trying to apply Fe-based self-lubricating composite materials. Because the ternary lamellar compounds Ti ₃SiC₂ and Ti ₃AlC₂ have excellent characteristics of metal and ceramic, such as high melting point, high elastic modulus, good corrosion resistance and self-lubricity, the ternary lamellar compounds Ti ₃SiC₂ and Ti ₃AlC₂ can be applied to the aspects of wear-resistant materials, corrosion-resistant parts and the like, and the research of a plurality of scientific researchers is caused.

Feng Shaoliang [ Feng Shaoliang. Influence of Ti ₃SiC₂ on frictional wear properties of Fe-based sliding bearing materials [ D ]. Yan Shanda, 2017 ] A Ti ₃SiC₂ -Fe-based composite material was prepared by SPS method, and the friction wear properties of the prepared Fe-based composite material at the temperature of 500 ℃ were found to be poor, the friction coefficients were 0.432 and 0.333, respectively, and the corresponding wear rates were 2.4X10 ^-4mm³N^-1m^-1 and 2.15X10 ^-4mm³N^-1m^-1, mainly due to poor interface bonding between Ti ₃SiC₂ and the matrix. Therefore Guan Yong [ Guan Yong. Ti ₃SiC₂-TiC_0.4 -TiAl self-lubricating composite material preparation, friction and wear performance study [ D ]. Yan Shanda, 2019 ] adopts the addition of non-stoichiometric TiC _0.4 as a binding agent to enhance the interface combination between Ti ₃SiC₂ and a matrix. It was found that the TiAl-based composite material achieved effective friction reduction at both 25 and 550 ℃ due to TiC _0.4 making the interface bonding between the matrix and Ti ₃SiC₂ more perfect, thereby reducing the abrasive wear caused by the Ti ₃SiC₂ particles being detached from the matrix, and thus reducing the coefficient of friction and wear rate, which were 0.47 and 0.41 at room temperature and 550 ℃, respectively, with corresponding wear rates of 0.095mg/m and 0.015mg/m. meanwhile, the research shows that the bonding strength of the metal bonds in different MAX phases is not similar. Hu Jieqiong et Al [ Hu Jieqiong, xie Ming, chen Gulin, et Al, ti ₃AC₂ (A=Si, sn, al, ge) electronic structure, The first principle study of elastic properties [ J ]. Physical theory, 2017, 66 (5): 270-279 ] shows that the bonding strength of Ti-Si in Ti ₃SiC₂ is higher than that of Ti-Al bond in Ti ₃AlC₂ through calculation, which is the main reason for the difference of mechanical properties and surface properties of Ti ₃SiC₂ and Ti ₃AlC₂, so that the ceramic phase Ti ₃AlC₂ is selected as a solid lubricant in the study to improve the mechanical properties and the wear resistance of Fe-based composite materials.

Chen Lin and the like are used for researching the Ti ₃AlC₂/Fe-based material, the Ti ₃AlC₂/Fe composite material is prepared under the hot pressing conditions of 1300 ℃ and 30MPa and the heat preservation time of 30min, the strength of other samples except 30vol.% of Ti ₃AlC₂/Fe is basically unchanged or slightly increased after 800 ℃ thermal shock of the composite material, and the fracture mode of the material is basically unchanged before and after the thermal shock, so that the composite material has good thermal shock resistance. demonstrating good impact resistance. [ Chen Lin, hongxiang, huang Zhenying, xu Hao. Preparation and mechanical Properties of Ti ₃AlC₂/Fe composite [ J ]. Programming of intraocular lens, 2015, 4 (11): 3288-3291 ], where studies have noted that Ti ₃AlC₂ has good lubricating properties, but if Ti ₃AlC₂ is well preserved after failing to sinter, it is likewise failing to achieve lubricating effect, where Chen Xinhua et Al found by studying the interaction of Ti ₃AlC₂ with Fe at high temperatures, that at sintering temperatures of 760-1045 ℃, the reaction between Ti ₃AlC₂ and Fe was weaker and started to form TiC _0.6 phases, and theoretical analysis found that precipitation of Al in Ti ₃AlC₂ was the main factor causing Ti ₃AlC₂ to react with Fe well below its decomposition temperature. Reaction behavior of Ti ₃AlC₂ with Fe at high temperature (English) [ J ]. Rare Metal materials and engineering, 2011,40 (S1): 499-502 ]. As previously studied, too low a dissolution temperature of the mixed metal material of Ti ₃AlC₂ will result in substantial decomposition of Ti ₃AlC₂, so that a suitable sintering temperature will result in successful material preparation, wang Xiujuan et al, after Ti ₃AlC₂ was prepared into Ti ₃AlC₂ -Cu material by electroless copper plating, copper powder, The Ti ₃AlC₂ material is sintered at 850 ℃ to obtain a material Ti ₃AlC₂ which is uniformly distributed, the friction coefficient of 15vol.% Ti ₃AlC₂ can be as low as 0.15 under a larger friction pressure, and the abrasion performance is improved by approximately 20% after electroless copper plating. [ Wang Xiujuan ] preparation of Ti ₃AlC₂/Cu composite material and performance study [ D ] university of fertilizer combination industry, 2014]; chen Lulu and the like study the temperature effect of Ti ₃AlC₂ material and Fe-based material, and it is proposed that Al escapes from Ti ₃AlC₂ to form TiCx when the volume content of raw material Ti ₃AlC₂ is changed from 10 vol to 40 vol at 1400 ℃ so as to prepare TiCx-Fe-based composite material in situ. [ Chen Lulu ] influence of TiCx content on hot pressing to prepare TiCx-Fe-based composite material [ A ] Special ceramic division of China silicate society [ C ] Special ceramic division of China silicate society [ 2016:1], preparing Fe ₃ Al powder with different Al contents by adopting mechanical alloying combined annealing treatment process, and carrying out vacuum hot pressing sintering to obtain Fe ₃ Al intermetallic compound block material. The room temperature mechanical property of the Fe ₃ Al sintered block material is obviously improved compared with the room temperature flexural strength of 1000-1400 MPa, the compressive yield strength and the compressive strain of 1150-1800 MPa and 10-15% respectively, the Rockwell hardness of 55-60 HRC, and the change of the Al content has certain influence on the microstructure and the mechanical property. [ Li Jing, yin Yansheng, liu Yingcai, et al ] microstructure and mechanical properties of hot pressed sintered FeAl intermetallic compounds [ J ]. Materials heat treatment journal (04) ]. The above studies demonstrate that Ti ₃AlC₂ has good lubricating properties, but Ti ₃AlC₂ is easily detached from the matrix, resulting in the overall properties of the composite material, especially the lubricating properties, being affected.

Disclosure of Invention

The invention aims to provide a Ti ₃AlC₂ reinforced Fe-based self-lubricating composite material and a preparation method thereof, wherein a non-stoichiometric compound TiCx plays a role of a binding agent so as to solve the problem of Ti ₃AlC₂ in the composite material in an Fe matrix.

The high-temperature-resistant Fe-based self-lubricating composite material comprises, by mass, 25-50% of Fe alloy in the high-temperature-resistant Fe-based self-lubricating composite material, 16.7-25% of nonstoichiometric compound TiC _0.4, and 33.3-50% of solid lubricating phase Ti ₃AlC₂.

The invention also provides a preparation method of the high-temperature-resistant Fe-based self-lubricating composite material, which comprises the following steps of S1 preparation of a non-stoichiometric compound, S2 Fe alloy raw material preparation, S3 raw material mixing and S4 SPS sintering, wherein:

S1, preparing a non-stoichiometric compound raw material, wherein TiCx powder is prepared in China, CN108754275B;

S2, preparing Fe alloy powder, namely weighing metal simple substance powder of the Fe alloy component as a raw material according to a preset proportion, preparing the Fe alloy powder by adopting a mechanical alloying method, wherein the ball-to-material ratio is 6:1, the rotating speed is 200r/min, and the ball milling time is 4 hours;

s3, mixing raw materials, wherein the method comprises the following two steps:

a. Carrying out ball milling on Fe alloy powder, tiCx powder and Ti ₃AlC₂ particles in a preset proportion in an argon atmosphere to obtain composite powder, wherein the ball-material ratio is 6:1, the rotating speed is 200r/min, and the ball milling time is 2-10 h;

b. Ball milling is carried out on Cu powder, cr powder, ni powder, fe powder, tiCx powder and Ti ₃AlC₂ particles in an argon atmosphere according to a given proportion to prepare composite powder, wherein the ball-material ratio is 6:1, the rotating speed is 200r/min, and the ball milling time is 2h;

s4, powder metallurgy sintering, which comprises the steps of (1) SPS sintering and (2) vacuum hot-pressing sintering, wherein:

(1) SPS sintering, namely pre-pressing the composite powder obtained by mixing the raw materials in the step S3 for 30 seconds at 20MPa, then performing SPS sintering at 80-200 Pa vacuum degree, 30MPa sintering temperature of 1000-1150 ℃ and heating rate of 70 ℃ per minute for 10 minutes, and cooling and releasing pressure to obtain a high-temperature-resistant Fe-based self-lubricating composite material;

(2) Pre-pressing the composite powder obtained by mixing the raw materials in the step S3, wherein the pre-pressing pressure is 20 MPa, the pre-pressing is 30S, then performing vacuum hot-pressing sintering, the vacuum degree is 80-200 Pa, the sintering pressure is 30MPa, the sintering temperature is 1000-1150 ℃, the heating rate is 70 ℃ per minute, the heat preservation time is 10 minutes, and then cooling and pressure relief are performed to obtain the high-temperature-resistant Fe-based self-lubricating composite material;

in the preparation method S3, the high-temperature resistant Fe-based self-lubricating composite powder is prepared by pre-pressing and molding in the raw material mixing process.

In the preparation method, after a blank is obtained in the step S4 powder metallurgy sintering method (1) spark plasma sintering and (2) vacuum hot-pressing sintering, the prepared blank is subjected to surface grinding and deburring treatment to obtain the high-temperature-resistant Fe-based self-lubricating composite material.

Compared with the prior art, the invention has the beneficial effects that:

The preparation process of the high-temperature-resistant Fe-based self-lubricating composite material comprises the steps of raw material preparation, mixing and sintering, and is suitable for preparing all Fe-based self-lubricating composite materials.

The Fe alloy phase selected in the invention can be mixed by directly adding metal simple substance powder, and meanwhile, the material can be taken out in the air, so that the preparation process can be simplified to a certain extent, and the production cost can be reduced;

the invention improves the mechanical property of the composite material by the unique property of the Fe material.

The addition of the solid lubricating phase Ti ₃AlC₂ can provide a good lubricating effect, so that the solid lubricating phase Ti ₃AlC₂ has a stable friction coefficient within the range of 25-500 ℃. The addition of TiC _0.4 can improve the interface combination between each phase and simultaneously improve the mechanical property of the composite material.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation on the invention. In the drawings:

FIG. 1 is a flow chart of a preparation process of a high temperature resistant Fe-based self-lubricating composite material according to an embodiment of the present invention;

FIG. 2 is an XRD pattern of the high temperature resistant Fe-based self-lubricating composite material prepared in example 1;

FIG. 3 is an SEM image of a high temperature resistant Fe-based self-lubricating composite material prepared in example 1;

FIG. 4 is a graph of atomic percent of each region of FIG. 3;

FIG. 5 is a surface sweep of a sintered body of the high temperature resistant Fe-based self-lubricating composite material prepared in example 1;

FIG. 6 is a fracture morphology diagram of the high temperature resistant Fe-based self-lubricating composite material sintered body prepared in example 1;

FIG. 7 is a graph showing the frictional wear surface morphology of the sintered compact of the high temperature resistant Fe-based self-lubricating composite material prepared in example 1;

FIG. 8 is the atomic percent of region A of FIG. 7;

FIG. 9 is an SEM image of the friction wear fracture of the high temperature resistant Fe-based self-lubricating composite material sintered body obtained in example 1;

FIG. 10 is a surface morphology diagram of a sintered compact of the high temperature resistant Fe-based self-lubricating composite material prepared in example 4;

FIG. 11 is an atomic percent of each region of FIG. 10;

FIG. 12 is a graph showing the room temperature frictional wear profile of the high temperature resistant Fe-based self-lubricating composite material prepared in example 4;

FIG. 13 is a surface morphology diagram of a sintered compact of the high temperature resistant Fe-based self-lubricating composite material prepared in example 5;

FIG. 14 is a graph showing the room temperature frictional wear profile of the high temperature resistant Fe-based self-lubricating composite material prepared in example 5.

Detailed Description

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other. The described embodiments are only some, but not all, embodiments of the invention. The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The relative arrangement of the steps set forth in these examples does not limit the scope of the invention unless specifically stated otherwise. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate. Any particular values in all examples shown and discussed herein are to be construed as merely illustrative and not a limitation. Thus, other examples of the exemplary embodiments may have different values.

The technical solutions in the embodiments of the present invention will be clearly and completely described below.

The invention discloses a Ti3AlC2 reinforced Fe-based composite self-lubricating composite material which comprises an Fe alloy, a non-stoichiometric compound and a solid lubricating phase, wherein the non-stoichiometric compound comprises non-stoichiometric nitrides, carbides or borides of transition group metals, the solid lubricating phase comprises a ternary lamellar compound of Mn+1AXn (n=1, 2, 3) groups, the mass fraction of the Fe alloy in the high-temperature-resistant Fe-based composite material is 25-50wt%, the mass fraction of the non-stoichiometric compound is 16.7-25wt%, and the mass fraction of the solid lubricating phase is 33.3-50wt%.

The non-stoichiometric compound includes a non-stoichiometric nitride, carbide, or boride of a transition group metal (Ti, V, cr, zr, nb, mo, hf, ta, W).

The solid lubricant is MAX materials such as Ti3SiC2, ti3AlC2, ti2AlC, ti2AlN, ta2AlC and the like. The TiCx powder is prepared in China, and CN108754275B is shown.

Wherein the source of the solid lubricating phase is commercially available.

Fig. 1 is a flowchart of a process for preparing a high temperature resistant Fe-based self-lubricating composite material according to an embodiment of the present invention, and will be specifically described below with reference to examples 1 to 5.

Example 1

The high temperature resistant Fe-based self-lubricating composite material consists of 35wt.% of Fe alloy raw material, 16.67wt.% of nonstoichiometric compound TiC _0.4 powder and 43.33wt.% of solid lubricating phase Ti ₃AlC₂ particles. The preparation of Fe alloy powder is shown in China as CN109022992A, the preparation of TiCx powder is shown in China as CN108754275B, then Fe alloy powder, tiCx powder and Ti ₃AlC₂ particles are proportionally put into a steel ball milling tank, steel grinding balls are put into the steel ball milling tank according to the ball material mass ratio of 6:1, ball milling mixing is carried out in argon atmosphere (the rotating speed is 200r/min, the ball milling time is 2h, and the machine is stopped for 30min every 1h for heat dissipation), material is taken out in a glove box, the diameters of the steel grinding balls are 8mm and 5mm respectively, the mass ratio of large balls to medium balls is 6:1, and the mixture is put into a graphite die for prepressing, wherein the prepressing pressure is 20MPa, and the prepressing time is 30s. Then SPS sintering is carried out, the vacuum degree is 40 Pa, the pressure is increased to 30MPa, then the temperature is heated to 600 ℃ from room temperature by 5 min time, the temperature is kept at 10 min at 600 ℃, the temperature is further increased to 1100 ℃ from 600 ℃ at the temperature increasing rate of 70 ℃ per minute, and the temperature is kept at 10 min. And cooling along with the furnace to obtain a blank. And (3) grinding and polishing the surface of the blank to obtain the high-temperature-resistant Fe-based self-lubricating composite material. Referring to FIGS. 2 to 9, it can be seen that the density, hardness, room temperature friction coefficient and wear rate, and friction coefficient and wear rate at 500℃of the Fe-based self-lubricating composite material samples obtained at this time were 5.3g/cm ³, 10.1GPa, 0.52 and 4.5X10 ^-9mm³N^-1m^-1, 0.45 and 7.4X10 ^-9mm³N^-1m^-1, respectively.

Example 2

The high temperature resistant Fe-based self-lubricating composite material consisted of 50wt.% Fe total raw material, 16.67wt.% non-stoichiometric compound TiC _0.4 powder content and 33.33wt.% solid lubricating phase Ti ₃AlC₂ particle content. The preparation of Fe alloy powder is shown in China as CN109022992A, the preparation of TiCx powder is shown in China as CN108754275B, then Fe alloy powder, tiCx powder and Ti ₃AlC₂ particles are proportionally put into a steel ball milling tank, steel grinding balls are put into the steel ball milling tank according to the ball material mass ratio of 6:1, ball milling mixing is carried out in argon atmosphere (the rotating speed is 200r/min, the ball milling time is 2h, and the machine is stopped for 30min every 1h for heat dissipation), material is taken out in a glove box, the diameters of the steel grinding balls are 8mm and 5mm respectively, the mass ratio of large balls to medium balls is 6:1, and the mixture is put into a graphite die for prepressing, wherein the prepressing pressure is 20MPa, and the prepressing time is 30s. Then SPS sintering is carried out, the vacuum degree is 40Pa, the pressure is increased to 30MPa, then the temperature is kept for 10min at 600 ℃ after being heated to 600 ℃ from room temperature for 5min, and then the temperature is kept for 10min after being increased from 600 ℃ to 1150 ℃ at the temperature increasing rate of 70 ℃ per min. And cooling along with the furnace to obtain a blank. And (3) grinding and polishing the surface of the blank to obtain the high-temperature-resistant Fe-based self-lubricating composite material. The density, hardness, room temperature friction coefficient and wear rate of the Fe-based self-lubricating composite material samples obtained at this time were 5.6g/cm ³, 8.9GPa, 0.65 and 5.6X10 ^-6mm³N^-1m^-1, respectively.

Example 3

The high temperature resistant Fe-based self-lubricating composite material consists of 35 percent of Fe alloy raw material wt percent, 32.5 percent wt percent of nonstoichiometric compound TiC _0.4 powder content and 32.5 percent wt percent of solid lubricating phase Ti ₃AlC₂ particles content. The preparation of Fe alloy powder is shown in China as CN109022992A, the preparation of TiCx powder is shown in China as CN108754275B, then Fe alloy powder, tiCx powder and Ti ₃AlC₂ particles are proportionally put into a steel ball milling tank, steel balls are put into the steel ball milling tank according to the ball material mass ratio of 6:1, ball milling and mixing are carried out in argon atmosphere (the rotating speed is 200r/min, the ball milling time is 2h, and the machine is stopped for 30min every 1h for heat dissipation), material is taken out in a glove box, the diameters of the steel balls are 8mm and 5mm respectively, the mass ratio of large balls to medium balls is 6:1, and the mixture is put into a graphite die for prepressing, wherein the prepressing pressure is 20MPa and the prepressing pressure is 30s. Then SPS sintering is carried out, the vacuum degree is 40Pa, the pressure is increased to 30MPa, then the temperature is heated to 600 ℃ from room temperature for 5min, the temperature is kept at 600 ℃ for 10min, the temperature is increased to 1100 ℃ from 600 ℃ at the temperature increasing rate of 70 ℃/min, and the temperature is kept for 10min. And cooling along with the furnace to obtain a blank. And (3) grinding and polishing the surface of the blank to obtain the high-temperature-resistant Fe-based self-lubricating composite material. The density, hardness, room temperature friction coefficient and wear rate of the Fe-based self-lubricating composite material samples obtained at this time were 5.4g/cm ³, 10.7GPa, 0.72 and 1.7X10 ^-8mm³N^-1m^-1, respectively.

Example 4

The high temperature resistant Fe-based self-lubricating composite material consists of 35-wt percent of Fe alloy raw material, 11.81-wt percent of Ti powder, 9.86-wt percent of TiC powder and 43.33 wt percent of solid lubricating phase Ti ₃AlC₂ particles. The preparation of Fe alloy powder is shown in China as CN109022992A, then Fe alloy powder, tiC powder, ti powder and Ti ₃AlC₂ particles are proportionally filled into a steel ball milling tank, steel grinding balls are filled according to the ball material mass ratio of 6:1, ball milling mixing is carried out in an argon atmosphere (the rotating speed is 200r/min, the ball milling time is 2h, and the machine is stopped for 30min every 1 h), material is taken in a glove box, the diameters of the steel grinding balls are 8mm and 5mm respectively, the mass ratio of large balls to medium balls is 6:1, and the mixture is filled into a graphite mould for prepressing, wherein the prepressing pressure is 20MPa, and the prepressing pressure is 30s. Then SPS sintering is carried out, the vacuum degree is 40Pa, the pressure is increased to 30MPa, then the temperature is heated to 600 ℃ from room temperature for 5min, the temperature is kept at 600 ℃ for 10min, and then the temperature is increased to 1100 ℃ from 600 ℃ at the temperature increasing rate of 70 ℃/min, and the temperature is kept for 10min. And cooling along with the furnace to obtain a blank. And (3) grinding and polishing the surface of the blank to obtain the high-temperature-resistant Fe-based self-lubricating composite material. Referring to FIGS. 10 to 12, the density, hardness, room temperature friction coefficient and wear rate of the Fe-based self-lubricating composite material samples obtained at this time were 5.4g/cm ³, 10.6GPa, 0.61 and 2.2X10 ^-8mm³N^-1m^-1, respectively.

Example 5

The high temperature resistant Fe-based self-lubricating composite consists of 31.71 wt% Fe powder, 2.45 wt% Cu powder, 0.28 wt% Cr powder, 0.56 wt% Ni powder, 16.67 wt% non-stoichiometric compound TiC _0.4 powder, and 43.33 wt% solid lubricating phase Ti ₃AlC₂ particles. The preparation of Fe alloy powder is shown in China as CN109022992A, the preparation of TiCx powder is shown in China as CN108754275B, then Fe alloy powder, tiCx powder and Ti ₃AlC₂ particles are proportionally put into a steel ball milling tank, steel grinding balls are put into the steel ball milling tank according to the ball material mass ratio of 6:1, ball milling mixing is carried out in argon atmosphere (the rotating speed is 200r/min, the ball milling time is 2h, and the machine is stopped for 30min every 1h for heat dissipation), material is taken out in a glove box, the diameters of the steel grinding balls are 8mm and 5mm respectively, the mass ratio of large balls to medium balls is 6:1, and the mixture is put into a graphite die for prepressing, wherein the prepressing pressure is 20MPa, and the prepressing time is 30s. Then SPS sintering is carried out, the vacuum degree is 40Pa, the pressure is increased to 30MPa, then the temperature is heated to 600 ℃ from room temperature for 5min, the temperature is kept at 600 ℃ for 10min, and then the temperature is increased to 1100 ℃ from 600 ℃ at the temperature increasing rate of 70 ℃/min, and the temperature is kept for 10min. And cooling along with the furnace to obtain a blank. And (3) grinding and polishing the surface of the blank to obtain the high-temperature-resistant Fe-based self-lubricating composite material. Referring to FIGS. 13 to 14, the density, hardness, room temperature friction coefficient and wear rate of the Fe-based self-lubricating composite material samples obtained at this time were 5.4g/cm ³, 10.2GPa, 0.51 and 1.5X10 ^-8mm³N^-1m^-1, respectively.

In summary, the preparation process of the high-temperature-resistant Fe-based self-lubricating composite material comprises the steps of raw material preparation, mixing and sintering, and is suitable for preparing all Fe-based self-lubricating composite materials. The Fe alloy phase selected in the invention can be mixed by directly adding metal simple substance powder, and can be taken out in the air, so that the preparation process can be simplified to a certain extent, the production cost can be reduced, and the mechanical property of the composite material can be improved by the unique property of the Fe material. The addition of the solid lubricating phase Ti ₃AlC₂ can provide a good lubricating effect, so that the solid lubricating phase Ti ₃AlC₂ has a stable friction coefficient within the range of 25-500 ℃. The addition of TiC _0.4 can improve the interface combination between each phase and simultaneously improve the mechanical property of the composite material.

The non-stoichiometric compounds herein include non-stoichiometric nitrides, carbides or borides of transition group metals (Ti, V, cr, zr, nb, mo, hf, ta, W). The solid lubricant is Ti ₃SiC₂、Ti₃AlC₂、Ti₂AlC、Ti₂AlN、Ta₂ AlC and other MAXFe materials. In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (7)

1. The Ti ₃AlC₂ reinforced Fe-based composite self-lubricating composite material consists of an Fe alloy, a non-stoichiometric compound and a solid lubricating phase, wherein the non-stoichiometric compound comprises non-stoichiometric nitrides, carbides or borides of transition group metals, the solid lubricating phase comprises a ternary lamellar compound of M _n+1AX_n (n=1, 2, 3), the mass fraction of the Fe alloy in the high-temperature resistant Fe-based composite material is 25-50wt%, the mass fraction of the non-stoichiometric compound is 16.7-25wt%, and the mass fraction of the solid lubricating phase is 33.3-50wt%.

2. The Ti ₃AlC₂ reinforced Fe-based composite self-lubricating composite of claim 1, wherein the non-stoichiometric compound comprises a non-stoichiometric nitride, carbide, or boride of a transition group metal (Ti, V, cr, zr, nb, mo, hf, ta, W).

3. The Ti ₃AlC₂ reinforced Fe-based composite self-lubricating composite material of claim 1, wherein the solid lubricant is a MAX material such as Ti ₃SiC₂、Ti₃AlC₂、Ti₂AlC、Ti₂AlN、Ta₂ AlC.

4. The Ti ₃AlC₂ reinforced Fe-based composite self-lubricating composite material as set forth in claim 1, wherein TiCx powder is prepared in chinese CN108754275B.

5. The Ti ₃AlC₂ reinforced Fe-based composite self-lubricating composite material as set forth in claim 1, wherein the source of the solid lubricating phase is commercially available.

6. A method of preparing a Ti ₃AlC₂ reinforced Fe-based composite self-lubricating composite material as claimed in claim 1, including but not limited to the following two methods:

The preparation method of the composite powder comprises the following steps of (a) ball milling Fe alloy powder (Fe powder, cu powder, cr powder and Ni powder), tiCx powder and Ti ₃AlC₂ particles with a preset proportion in an argon atmosphere to obtain the composite powder, wherein the ball-material ratio is 6:1, the rotating speed is 200-400 r/min, the ball milling time is 2-10 h, and (b) ball milling the Fe powder, cu powder, cr powder, ni powder, tiCx powder and Ti ₃AlC₂ particles with the preset proportion in the argon atmosphere to obtain the composite powder, the ball-material ratio is 6:1, the rotating speed is 200r/min, and the ball milling time is 2-10 h;

S2, prepressing, namely drying the mixed powder in an argon atmosphere or in air, and filling the dried mixed powder into a die for prepressing forming, wherein the prepressing pressure is 20MPa, and prepressing for 30S to obtain a prepressing raw material block;

The method comprises the steps of (1) Spark Plasma Sintering (SPS) of the pre-pressed raw material block to obtain a blank test piece, wherein firstly, pressure is slowly applied to a sample to 30MPa, then, the vacuum degree is pumped to 80-200 Pa, then, the temperature is kept at 600 ℃ for 10 min by heating to 600 ℃ at 5min, the temperature is kept at 1000-1150 ℃ at 70 ℃ per minute, the temperature is kept at 10 min, the blank is obtained by cooling with a furnace, the prepared blank is subjected to surface grinding and deburring treatment to obtain a high-temperature-resistant Fe-based self-lubricating composite material, and (2) the pre-pressed raw material block is subjected to vacuum hot-press sintering to obtain the blank test piece, firstly, the pressure is applied to the sample to 30MPa, then, the vacuum degree is pumped to 80-200 Pa, the temperature is kept at 900 ℃ from room temperature to 900 ℃ at 20min at 20 ℃ per minute, the temperature is kept at 1000-1150 ℃ at 70 ℃ per minute, the high temperature is kept at 10 ℃ per minute, the prepared blank is subjected to surface grinding and deburring treatment to obtain the high-temperature-resistant Fe-based self-lubricating composite material, and the high-temperature-resistant Fe-lubricating composite material is obtained by carrying out surface grinding and deburring treatment.

7. The method for preparing the Ti ₃AlC₂ -reinforced Fe-based high-temperature-resistant self-lubricating composite material as set forth in claim 6, wherein the particle size of the metal simple substance powder is 10-50 μm, the particle size of the nonstoichiometric compound powder is 20-50 μm, and the particle size of the solid lubricating phase particles is 90-900 μm.