A TiC-Ti3C2T x Method for preparing MXene composite

Abstract

This invention discloses a TiC-Ti3C2T x The preparation method of MXene composite material includes: acid etching of Ti3AlC2 ceramic powder, washing of etching products, centrifugation, and ultrasonic layering to obtain single-layer and few-layer Ti3C2T. x Colloidal solution, then freeze-dried to obtain monolayer and few-layer Ti3C2T x Powder; TiC powder, dried Ti3C2T x TiC-Ti3C2T was prepared by high-shear emulsification and mixing of powder and polytetrafluoroethylene dissolved in anhydrous ethanol, followed by rotary evaporation, drying, and spark plasma sintering. x MXene composite material. This invention solves the problem of reinforcement dispersion in TiC ceramic matrix and addresses the issue of Ti3C2T under high-temperature sintering conditions. x The MXene phase transformation and oxidation problems are addressed, and the TiC matrix is ​​strengthened and toughened by inducing matrix grain refinement, crack deflection, crack bridging, and lamellar pull-out, thereby improving bending strength and fracture toughness.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field, and more particularly, relates to a TiC-Ti3C2T x The application belongs to the technical field, and more particularly, relates to a TiC-Ti3C2T x MXene high-temperature phase transition cross-scale toughening TiC-Ti3C2T x The application belongs to the technical field, and more particularly, relates to a TiC-Ti3C2T BACKGROUND

[0002] Titanium carbide (TiC) as a typical ultra-high temperature ceramic has the characteristics of high melting point, low density, high hardness, etc., and has special application scenarios in the fields of aerospace, energy storage, nuclear industry, etc. However, the intrinsic brittleness of ceramic materials determines that they have poor toughness, which seriously limits their practical application. It has important practical significance to toughen the ultra-high temperature ceramic materials by preparing composite materials and improve their bearing capacity. Two-dimensional materials are considered to be excellent reinforcing materials for ceramic matrix composites due to the "nanometer effect", the large specific surface area, and the excellent mechanical strength and flexibility. A kind of two-dimensional layered MXene material is expected to be widely used as a reinforcing material in ceramic matrix structural composites because of its rich surface functional groups, excellent electronic conductivity, high elastic modulus, and excellent mechanical properties, and the internal transition metal carbide / nitride core of MXene makes it suitable as a stable high-temperature reinforcing material.

[0003] However, the simple and efficient dispersion of MXene in the ceramic matrix has always been a key problem to be solved. The wettability between MXene and the ceramic matrix is poor, and it is difficult to form a firm interface bond, which is not conducive to the transfer of load between the matrix and the reinforcing material, so that the mechanical properties of the MXene-reinforced ceramic matrix composite are limited. MXene is easily oxidized or undergoes phase transition at high temperatures, becoming a non-stoichiometric carbide. SUMMARY

[0004] The purpose of the application is to solve the above problems, and provide a TiC-Ti3C2T x The application belongs to the technical field, and more particularly, relates to a TiC-Ti3C2T x MXene phase transition and oxidation problems, and toughen the TiC matrix through the strong interface bonding between MXene and TiC, the grain refinement of the matrix, crack deflection, crack bridging, and sheet layer pull-out, etc., thereby significantly improving the bending strength and fracture toughness of the TiC matrix. x The application belongs to the technical field, and more particularly, relates to a TiC-Ti3C2T

[0005] To achieve the above purpose, the application is realized by the following technical scheme:

[0006] The application provides a TiC-Ti3C2T x A preparation method of a MXene composite material comprises the following steps:

[0007] The Ti3AlC2 ceramic powder is subjected to acid corrosion, and the corrosion product is washed, centrifuged and ultrasonically layered to obtain single-layer and few-layer Ti3C2T x A colloidal solution is obtained, and then freeze-drying is performed to obtain single-layer and few-layer Ti3C2T x powder;

[0008] The TiC powder, the dried Ti3C2T x powder and polytetrafluoroethylene dissolved in anhydrous ethanol are mixed through high-shear emulsification, and then rotary evaporation, drying and spark plasma sintering are performed to obtain the TiC-Ti3C2T x MXene composite material.

[0009] Further, the preparation steps of the Ti3AlC2 ceramic powder comprise the following steps:

[0010] The Ti, Al and C powders are uniformly mixed, and pressureless sintering is performed at 1300-1400 DEG C to obtain a ternary layered Ti3AlC2 ceramic block;

[0011] The Ti3AlC2 ceramic block is ground to a Ti3AlC2 ceramic powder with a fineness of 100-1200 meshes.

[0012] Further, the molar ratio of the Ti, Al and C powders is 3:(1-1.4):2, and preferably 3:1.2:2.

[0013] Further, the acid corrosion comprises the following steps: the Ti3AlC2 ceramic powder is placed in a mixed solution of hydrochloric acid and lithium fluoride or an aqueous solution of hydrofluoric acid, and is fully stirred at 20-70 DEG C to obtain a corrosion mixture suspension. Preferably, the stirring time is 12-96 h. Preferably, the concentration of the hydrochloric acid is 9-12 mol / mL, the volume-mass ratio of the hydrochloric acid to the lithium fluoride is (5-25) mL:(0.2-2) g, and the concentration of the hydrofluoric acid in the aqueous solution of the hydrofluoric acid is 10-70 wt. %.

[0014] Further, the step of washing the corrosion product comprises the following steps:

[0015] The corrosion mixture suspension is washed with deionized water and centrifuged, and the supernatant is poured out, and the operation is repeated for multiple times until the pH value of the supernatant is greater than or equal to 6;

[0016] The washing and centrifuging are continuously performed with deionized water, the supernatant is poured out, and the operation is repeated for 3-5 times, and the washing is completed.

[0017] Further, the single-layer and few-layer Ti3C2Tx The preparation steps of the colloidal solution include:

[0018] The cleaned corrosion product is added with deionized water, and is subjected to ultrasonic delamination treatment under the protection of an argon atmosphere; preferably, the temperature during the ultrasonic treatment is maintained below 35°C;

[0019] After the ultrasonic treatment, the mixed solution is subjected to centrifugal treatment, and the upper layer solution is taken to obtain monolayer and few-layer Ti3C2T x colloidal solution.

[0020] Further, the dried monolayer and few-layer Ti3C2T x The preparation steps of the powder include:

[0021] The monolayer and few-layer Ti3C2T x The colloidal solution is pre-frozen at -20 to -100°C for 6 to 48 hours, and then is dried in a freeze dryer at -40 to -80°C for 1 to 3 days to obtain the dried monolayer and few-layer Ti3C2T x powder.

[0022] Further, the high-shear emulsification mixing is performed by using an emulsifier at a rotation speed of 1000 rpm to 10000 rpm for 0.1 to 10 hours. Preferably, the high-shear emulsification mixing is performed at 6000 rpm for 2 hours at 25°C.

[0023] Further, the step of rotary evaporation includes:

[0024] The emulsification-mixed suspension is placed in a rotary evaporator, and is subjected to rotary heating in a water bath at 40 to 100°C under vacuum to -0.01 to -0.10 MPa to remove anhydrous ethanol. Preferably, the rotary evaporation is performed at -0.09 MPa and 55°C.

[0025] Further, the drying after the rotary evaporation is performed by using a drying agent for 6 to 72 hours to obtain a completely dried TiC-MXene composite powder; preferably, the drying time is 48 hours.

[0026] Further, the step of spark plasma sintering includes:

[0027] The product after the rotary evaporation and drying is pressurized at a uniaxial pressure of 10 to 100 MPa, is heated at a speed of 10 to 100°C / min, and is subjected to spark plasma sintering at 1500 to 2200°C under vacuum for 1 to 15 min. Preferably, the product is pressurized at a uniaxial pressure of 50 MPa, is heated at a speed of 100°C / min to 1900°C, and is subjected to spark plasma sintering for 10 min.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] The TiC-Ti3C2T x The preparation method of the MXene composite material can effectively prevent Ti3C2T x MXene is completely oxidized or phase changed after high-temperature sintering at 1900 DEG C, can toughen TiC matrix across scales, and has simple process and low cost;

[0030] The Ti3C2T x MXene is fully mixed with TiC powder, and a TiC-Ti3C2T x MXene composite material is prepared by a spark plasma sintering method; x The lattice mismatch degree of the (0001) surface of Ti3C2T x and the (111) surface structure of TiC is only 0.4%, so that a strong chemical bond interface is formed between Ti3C2T x and TiC, and stability constraint is applied to the Ti atom layer on the surface of Ti3C2T x MXene is phase changed into non-stoichiometric TiC y at 1900 DEG C; meanwhile, the un-phase-changed laminar Ti3C2T x causes TiC matrix grain refinement, improves load transmission efficiency, causes crack deflection and improves energy loss by pulling out when the material is damaged, and significantly improves the bending strength and fracture toughness of the TiC matrix; finally, the TiC-Ti3C2T x MXene composite material has a bending strength increased by 15.6%, and a fracture toughness and a critical energy release rate during crack propagation increased by 49.9% and 111.5% respectively;

[0031] The method has controllable conditions, can quantitatively add the amount of single-layer and few-layer Ti3C2T x , and prepare a composite material with uniform dispersion of the reinforcing body and different Ti3C2T x addition ratios. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The TiC-Ti3C2T x MXene composite material is prepared by the method of the present application;

[0033] Figure 2 (a) (b) (c) are respectively TiC powder, freeze-dried Ti3C2T x powder and TiC-10wt.% Ti3C2T x MXene composite powder in the present application example 1;

[0034] Figure 3 TiC-10wt.%Ti3C2T x XRD pattern of MXene composite material;

[0035] Figure 4 TiC-5wt.%Ti3C2T x Process of exfoliating layered material in MXene composite material using focused ion beam-scanning electron microscope; (b) is a transmission electron microscope picture of the layered material, and (c) is a selected area diffraction pattern of the layered material in the square in (b);

[0036] Figure 5 Ti3C2T x Ti3C2T x Interface model of MXene and TiC matrix and theoretical calculation results;

[0037] Figure 6 TiC-Ti3C2T x Analysis diagram of density of states data of MXene composite material obtained by first-principle calculation;

[0038] Figure 7 (a) is the flexural strength of the composite material with different mass fractions of Ti3C2T x Figure 7 (b) is the comparison of fracture toughness and critical energy release rate values of the composite material with different mass fractions of Ti3C2T x

[0039] Figure 8 TiC-Ti3C2T x Fracture surface morphology of flexural failure of MXene composite material, (a, b), (c, d), and (e, f) are pure TiC, TiC-5wt.%Ti3C2T x MXene composite material and TiC-10wt.%Ti3C2T x MXene composite material;

[0040] Figure 9 TiC-Ti3C2T x Fracture surface morphology of fracture toughness failure of MXene composite material, (a, b), (c, d), and (e, f) are pure TiC, TiC-5wt.%Ti3C2T x ​​MXene composite and TiC-10wt.%Ti3C2T x MXene composite;

[0041] Figure 10 (a) TiC-50wt.%Ti3C2T prepared from Comparative Example 1 x Scanning electron microscope photos of MXene composite; Figure 10 (b) TiC-Ti3C2T prepared from Comparative Example 2 x Scanning electron microscope photos of MXene composite. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings and specific examples.

[0043] The present application provides a TiC-Ti3C2T x The preparation method of MXene composite can effectively prevent Ti3C2T x MXene high-temperature phase transition and cross-scale toughening TiC, comprising the following steps:

[0044] Ti3AlC2 ceramic powder is acid-etched, the etching product is washed, centrifuged and ultrasonically layered to obtain single-layer and few-layer Ti3C2T x Colloidal solution, and then freeze-drying to obtain single-layer and few-layer Ti3C2T x Powder;

[0045] TiC powder, dried Ti3C2T x Powder, polytetrafluoroethylene dissolved in anhydrous ethanol are mixed by high-shear emulsification, and then rotary evaporation, drying and spark plasma sintering to obtain TiC-Ti3C2T x MXene composite.

[0046] The specific preparation steps are provided below in combination with different examples.

[0047] Example 1

[0048] The present example provides a TiC-10wt.%Ti3C2T x The preparation method of MXene composite, specifically comprising the following steps:

[0049] I. Single-layer and few-layer Ti3C2T x Preparation of MXene powder:

[0050] (1) Ti, Al, C powders are mixed according to a molar ratio of 3:1.2:2, and a high-purity ternary layered Ti3AlC2 ceramic bulk material is prepared by pressureless sintering process at 1350°C. The prepared Ti3AlC2 ceramic material is drilled into powder by a drilling machine to obtain Ti3AlC2 ceramic powder; and the prepared Ti3AlC2 ceramic powder is treated by passing through a 325 mesh screen;

[0051] (2) The Ti3AlC2 ceramic powder, hydrochloric acid with a concentration of 12 mol / mL, and lithium fluoride are mixed according to a ratio of 1g:10mL:1.0g, a magnetic rotor is added, and stirring is performed in an oil bath environment at 35°C for 24h to remove the Al atomic layer in Ti3AlC2;

[0052] (3) The mixture suspension after corrosion is washed with 50mL of deionized water and centrifuged, and the supernatant is poured off. The operation is repeated multiple times until the PH value of the supernatant is greater than or equal to 6;

[0053] (4) After the PH value of the supernatant is greater than or equal to 6, the mixture is washed with 40mL of deionized water and centrifuged, and the supernatant is poured off. The operation is repeated 8-10 times;

[0054] (5) After the final cleaning of the mixture is completed, 20mL of deionized water is added, and ultrasonic delamination treatment is performed under the protection of argon atmosphere. The temperature during ultrasonic treatment is kept below 35°C. After ultrasonic treatment, the mixture is centrifuged, and the upper solution is single-layer and few-layer Ti3C2T x colloidal solution;

[0055] (6) The single-layer and few-layer Ti3C2T x colloidal solution is pre-frozen at -80°C for 24h, and then dried in a freeze dryer at -56°C for 3 days to obtain freeze-dried Ti3C2T x powder.

[0056] II. Preparation of TiC-Ti3C2T x MXene composite material

[0057] (1) 3g of dried Ti3C2T x powder and 27g of TiC powder are added to a polytetrafluoroethylene tank containing 500mL of anhydrous ethanol, and high-shear emulsification mixing is performed using an emulsifier at a speed of 6000rpm for 2h;

[0058] (2) After mixing is completed, all the mixture is transferred to a rotary evaporator, the rotary evaporator is vacuumed to -0.09MPa, and then rotary heating is performed in a water bath at 55°C to remove anhydrous ethanol;

[0059] (3) The mud-like mixture after rotary evaporation is further dried using a desiccant for 48h to obtain completely dried TiC-10wt.%Ti3C2Tx MXene composite powder;

[0060] (4) The thoroughly dried mixed powder was loaded into a graphite mold with a diameter of 40 mm, and was subjected to spark plasma sintering at 1900℃ and a uniaxial pressure of 50 MPa for 10 min in a vacuum of 5 Pa to obtain TiC-10wt.%Ti3C2T x MXene composite material, such as Figure 1 shown.

[0061] The TiC powder, freeze-dried Ti3C2T x powder and TiC-10wt.%Ti3C2T x MXene composite powder were taken during the preparation process of this example, and were photographed by a scanning electron microscope, as shown in Figure 2 It can be seen that the appearance of the TiC powder presents an extremely irregular geometric shape, the particle size distribution is relatively uneven, and there are many small debris attached to the large particles. These debris fill the gaps between the large particles under the load during the process of using spark plasma sintering, and are beneficial to form “sintering necking”, so that the sintered block is more compact; Ti3C2T x After freeze-drying treatment, they form a three-dimensional network skeleton and present a porous foam structure with an open macroporous structure; Ti3C2T x MXene has been dispersed in the titanium carbide powder.

[0062] Figure 3 The XRD pattern of the TiC-10wt.%Ti3C2T x MXene composite material prepared in this example, from the figure, it can be seen that the peaks of the sintered block sample are still identified as TiC, and are consistent with the TiC peaks before sintering. The characteristic diffraction peaks of Ti3C2T x disappear, in addition to the possibility that the surface of Ti3C2T x contact with the titanium carbide matrix, resulting in a decrease in the exposed two-dimensional characteristic surface, it is also possible that the characteristic peaks are covered due to the low content of MXene compared to TiC.

[0063] Example 2

[0064] This example provides a preparation method of TiC-5wt.%Ti3C2T x MXene composite material, specifically comprising the following steps:

[0065] I. Preparation of single-layer and few-layer Ti3C2T x MXene powder:

[0066] (1) Ti, Al, C powders are mixed according to a molar ratio of 3:1.2:2, and then a high-purity ternary layered Ti3AlC2 ceramic bulk material is prepared by pressureless sintering at 1350°C. The prepared Ti3AlC2 ceramic material is drilled into powder using a drill press to obtain Ti3AlC2 ceramic powder; and the prepared Ti3AlC2 ceramic powder is treated by passing through a 325 mesh screen;

[0067] (2) The Ti3AlC2 ceramic powder, hydrochloric acid with a concentration of 9 mol / mL, and lithium fluoride are mixed according to a ratio of 1 g:20 mL:1.8 g, a magnetic rotor is added, and stirring is performed in an oil bath environment at 37°C for 36 h to remove the Al atomic layer in Ti3AlC2;

[0068] (3) The mixture suspension after corrosion is washed with 50 mL of deionized water and centrifuged, and the supernatant is poured off. The process is repeated multiple times until the supernatant has a pH value greater than or equal to 6;

[0069] (4) After the supernatant has a pH value greater than or equal to 6, the mixture is washed with 40 mL of deionized water and centrifuged, and the supernatant is poured off. The process is repeated 3-5 times;

[0070] (5) The finally cleaned mixture is added with 20 mL of deionized water, and ultrasonic delamination treatment is performed under an argon atmosphere. The temperature during ultrasonic treatment is kept below 35°C. After ultrasonic treatment, the mixture is centrifuged, and the upper layer solution is single-layer and few-layer Ti3C2T x colloidal solution;

[0071] (6) The single-layer and few-layer Ti3C2T x colloidal solution is pre-frozen at -50°C for 24 h, and then dried in a freeze dryer at -56°C for 2 days to obtain freeze-dried Ti3C2T x powder.

[0072] II. Preparation of TiC-Ti3C2T x MXene composite material

[0073] (1) 1.5 g of dried Ti3C2T x powder and 28.5 g of TiC powder are added to a polytetrafluoroethylene tank containing 300 mL of anhydrous ethanol, and high-shear emulsification mixing is performed using an emulsifier at a speed of 8000 rpm for 3 h;

[0074] (2) After mixing is completed, all the mixture is transferred to a rotary evaporator, which is vacuumed to -0.09 MPa, and then rotary heating is performed in a water bath at 50°C to remove anhydrous ethanol;

[0075] (3) The mud-like mixture after rotary evaporation is further dried using a desiccant for 48 h to obtain completely dried TiC-5wt.%Ti3C2Tx MXene composite powder;

[0076] (4) The rotary-dried mixed powder was loaded into a graphite mold with a diameter of 40 mm, and subjected to discharge plasma sintering at 1900 °C and uniaxial pressure of 50 MPa in a vacuum of 5 Pa for 10 min to obtain TiC-5wt.%Ti3C2T x MXene composite material.

[0077] The TiC-5wt.%Ti3C2T prepared in this embodiment was used. x MXene composite materials were sampled and exfoliated using focused ion beam scanning electron microscopy to examine the layered structure within the composite material. Figure 4 As shown, (a) shows the process of peeling and sampling; (b) is a transmission electron microscope image of the layered material; and (c) is the selected diffraction pattern of the layered material within the box in Figure (b). It can be seen that after peeling off the layered material in the composite material, the selected diffraction pattern shows a standard regular hexagonal arrangement. After measuring and calibrating the interplanar spacing and angle, it can be determined that it is still Ti3C2T. x No oxidation or phase transition occurred.

[0078] Example 3

[0079] This embodiment provides a TiC-1wt.%Ti3C2T x The preparation method of MXene composite material specifically includes the following steps:

[0080] I. Single-layer and few-layer Ti3C2T x Preparation of MXene powder:

[0081] (1) Ti, Al, and C powders were mixed in a molar ratio of 3:1.15:2 and high-purity ternary layered Ti3AlC2 ceramic bulk material was prepared by pressureless sintering at 1350℃. The prepared Ti3AlC2 ceramic material was drilled to obtain Ti3AlC2 ceramic powder. The prepared Ti3AlC2 ceramic powder was then passed through a 325-mesh sieve.

[0082] (2) Mix Ti3AlC2 ceramic powder with 40% hydrofluoric acid at a ratio of 1g:10mL, add it to a magnetic rotor and stir in an oil bath at 40℃ for 48h to remove the Al atomic layer in Ti3AlC2.

[0083] (3) Wash the corroded mixture suspension with 100 mL of deionized water and centrifuge. Discard the supernatant and repeat several times until the pH value of the supernatant is greater than or equal to 6.

[0084] (4) After the supernatant PH value is greater than or equal to 6, continue to wash with 50 mL of deionized water and centrifuge, pour off the supernatant, and repeat 5 times;

[0085] (5) After the final cleaning of the mixture, 15 mL of deionized water is added, and ultrasonic delamination treatment is carried out under the protection of an argon atmosphere, and the temperature is kept below 35 DEG C during ultrasonic treatment; after ultrasonic treatment, the mixture is centrifuged, and the upper solution is monolayer and few-layer Ti3C2T x colloidal solution;

[0086] (6) The monolayer and few-layer Ti3C2T x colloidal solution is pre-frozen at -80 DEG C for 24 h, and then dried at -56 DEG C for 24 h using a freeze dryer to obtain freeze-dried Ti3C2T x powder.

[0087] II. Preparation of TiC-Ti3C2T x MXene composite material

[0088] (1) 0.3 g of dried Ti3C2T x powder and 29.7 g of TiC powder are added to a polytetrafluoroethylene tank containing 400 mL of anhydrous ethanol, and high shear emulsification mixing is carried out using an emulsifier at a speed of 8000 rpm for 4 h;

[0089] (2) After mixing is completed, all the mixture is transferred to a rotary evaporator, which is vacuumed to -0.09 MPa, and then rotary heated in a 60 DEG C water bath to remove anhydrous ethanol;

[0090] (3) The mud-like mixture after rotary evaporation is further dried using a desiccant for 24 h to obtain completely dried TiC-1wt.%Ti3C2T x MXene composite powder;

[0091] (4) The completely dried mixed powder is loaded into a graphite mold with a diameter of 50 mm, and discharge plasma sintering is carried out at 5 Pa under the conditions of 1900 DEG C and uniaxial pressure of 50 MPa for 10 min to obtain TiC-1wt.%Ti3C2T x MXene composite material.

[0092] Figure 5 Ti3C2T x MXene composite material obtained by first-principles calculation xThe interface model and theoretical calculation results of MXene and TiC matrix show that the interfacial adsorption energy of Ti3C2O2 / TiC(111) is -1.85eV, which is significantly greater than that of Ti3C2OF / TiC(111) (-0.46eV).

[0093] Figure 6 The TiC-Ti3C2T in the method of this invention x Analysis of the fractional density data obtained from first-principles calculations of MXene composites reveals that the electron densities at both the Ti3C2O2 / TiC(111) and Ti3C2OF / TiC(111) interfaces are significant near the Fermi level, indicating that these two interfaces exhibit pronounced metallic properties. x Both the O and F functional groups on the surface can form chemical bonds with TiC(111), among which O and Ti... A / Ti B The bond strength between them is stronger than that between F and Ti. A / Ti B The bond strength between them.

[0094] Figure 7 Ti3C2T was prepared according to the method in Example 1. x Composite materials with mass fractions of 0%, 1%, 2%, 5%, and 10% were tested for flexural strength and fracture toughness. (a) shows a comparison of flexural strength. Figure 7 (b) Comparison of fracture toughness and critical energy release rate values. Figure 7 In the text, 0, 1, 2, 5, and 10 refer to Ti3C2T in the TiC-MXene composite material, respectively. x The mass fractions were 0%, 1%, 2%, 5%, and 10%, respectively. (From...) Figure 7 (a) It can be seen that, with Ti3C2T x As the mass fraction of Mxene increases, the bending properties first increase and then decrease, especially when Ti3C2T... x When the Mxene content is 5 wt.%, TiC-Ti3C2T x The flexural strength of the MXene composite material reaches its maximum value. (The text abruptly ends here.) Figure 7 (b) It can be seen that with Ti3C2T x With increasing Mxene content, fracture toughness and critical energy release rate values ​​continue to rise. Figure 7 This fully demonstrates the capabilities of Ti3C2T. x Mxene for TiC-Ti3C2T x The strengthening and toughening effect of MXene composite materials.

[0095] Figure 8TiC-Ti3C2T MXene composite in the present application embodiment 1, 2 x The fracture surface morphology of the bending failure of the MXene composite, (a, b), (c, d) and (e, f) are pure TiC, TiC-5wt.%Ti3C2T x MXene composite and TiC-10wt.%Ti3C2T x MXene composite; Figure 9 TiC-Ti3C2T MXene composite in the present application embodiment 1, 2 x The fracture surface morphology of the bending failure of the MXene composite, (a, b), (c, d) and (e, f) are pure TiC, TiC-5wt.%Ti3C2T x MXene composite and TiC-10wt.%Ti3C2T x MXene composite; It can be clearly seen from the figure that intergranular fracture is the main failure mode of the bending failure of several ceramic materials, and the sheet layer pull-out of MXene and the crack deflection caused thereby are the main reasons for the strengthening and toughening of the TiC matrix. In addition, the grain refinement of the TiC matrix caused by the addition of MXene also contributes to the strengthening and toughening of the TiC matrix.

[0096] Comparative example 1

[0097] The present comparative example provides a TiC-50wt.%Ti3C2T x MXene composite, the same preparation method as example 1 is adopted, but the mass fraction of Ti3C2T x MXene is changed to 50%.

[0098] Comparative example 2

[0099] The present comparative example provides a TiC-Ti3C2T x MXene composite, no uniaxial pressure is applied during the sintering process, and other preparation steps are the same as example 1.

[0100] Figure 10 (a) TiC-50wt.%Ti3C2T prepared by comparative example 1 x The scanning electron microscope photo of the MXene composite can be seen, because Ti3C2T x MXene is too much, and it cannot guarantee that Ti3C2T x MXene and TiC are in full contact to form an interfacial bond, which causes that Ti3C2T x The surface Ti atomic layer is subjected to stability constraints and phase change; Figure 10 (b) TiC-Ti3C2T prepared by comparative example 2 xThe scanning electron microscope photo of MXene composite can be seen that due to no pressure applied, Ti3C2T x MXene cannot be in close contact with TiC to form interface bonding, and the prepared composite is not only not dense in structure, but also MXene has undergone significant phase change.

[0101] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and technical principles of the described embodiments, and these modifications and changes should also be considered as the protection scope of the present application.

Claims

1. A TiC-Ti3C2T x A method for preparing a MXene composite material, characterized by, include: Ti3AlC2 ceramic powder is acid-etched, and the etching product is centrifuged and ultrasonically separated after washing to obtain single-layer and few-layer Ti3C2T x colloidal solution, and then freeze-dried to obtain single-layer and few-layer Ti3C2T x powder; TiC powder, dry Ti3C2T x The powder is dissolved in anhydrous ethanol and placed in a polytetrafluoroethylene tank for high-shear emulsification mixing, then rotary evaporation, drying, and spark plasma sintering to obtain TiC-Ti3C2T x MXene composite material; The TiC powder, dry Ti3C2T x The ratio of the powder and anhydrous ethanol needs to meet the Ti3C2T x The mass fraction of MXene is 0.001wt.%~ 20wt.%. The spark plasma sintering step includes: The product after rotary evaporation and drying is pressurized under uniaxial pressure of 10-100 MPa, heated at a rate of 10-100 °C / min, and sintered by spark plasma at 1500-2200 °C under vacuum for 1-15 min.

2. The TiC-Ti3C2T of claim 1 x A method for preparing a MXene composite material, characterized by, The preparation steps of the Ti3AlC2 ceramic powder include: Ti, Al, and C powders were mixed evenly and sintered without pressure at 1300–1400℃ to obtain a ternary layered Ti3AlC2 ceramic bulk. Ti3AlC2 ceramic blocks were ground into Ti3AlC2 ceramic powder with a fineness of 100-1200 mesh.

3. The TiC-Ti3C2T of claim 2 x A method for preparing a MXene composite material, characterized by, The molar ratio of the Ti, Al, and C powders is 3:(1~1.4):

2.

4. The TiC-Ti3C2T according to claim 1 x The method for preparing MXene composite materials is characterized by, The acid corrosion includes: Ti3AlC2 ceramic powder was placed in a mixed solution of hydrochloric acid and lithium fluoride or an aqueous solution of hydrofluoric acid and stirred thoroughly at 20–70°C to obtain a suspension of the corroded mixture.

5. The TiC-Ti3C2T according to claim 1 x The method for preparing MXene composite materials is characterized by, The single and few layers of Ti3C2T x The preparation step of the colloidal solution comprises: The corrosion products after cleaning were added to deionized water and subjected to ultrasonic layering treatment under argon atmosphere protection. After ultrasonic treatment, the mixed solution was centrifuged, and the upper layer solution was obtained to obtain monolayer and few-layer Ti3C2T x colloidal solution.

6. The TiC-Ti3C2T according to claim 1 x The method for preparing MXene composite materials is characterized by, The dried single and few layer Ti3C2T x The powder preparation step includes: The single-layer and few-layer Ti3C2T x The colloidal solution is pre-frozen at -20 to -100 °C for 6 to 48 h, and then dried at -40 to -80 °C for 1 to 3 days using a freeze dryer to obtain the dried single-layer and few-layer Ti3C2T x powder.

7. The TiC-Ti3C2T according to claim 1 x The method for preparing MXene composite materials is characterized by, The high-shear emulsification mixing is carried out using an emulsifier with a rotation speed of 1000 rpm to 10000 rpm and an emulsification time of 0.1 to 10 hours.

8. The TiC-Ti3C2T according to claim 1 x The method for preparing MXene composite materials is characterized by, The rotary evaporation step includes: The emulsified suspension was placed in a rotary evaporator and evacuated to a negative pressure of -0.01 to -0.10 MPa. The anhydrous ethanol was removed by rotary heating in a water bath at 40 to 100°C.

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