An interlayer ordered double transition metal max phase material and a preparation method thereof

Abstract

The application discloses an interlayer ordered double transition metal MAX phase material and a preparation method thereof, and comprises the following steps: grinding Mo, V, Al and C element powders to obtain mixed powders; tabletting the mixed powders, performing calcination treatment, and cooling to room temperature to obtain the interlayer ordered double transition metal MAX phase Mo2VAlC2 material. Compared with other discharge plasma sintering or microwave sintering processes in a laboratory, the preparation method is simple, efficient, easy to obtain raw materials and low in cost, and can be further scaled up for industrial production. In addition, the interlayer ordered double transition metal MAX phase Mo2VAlC2 prepared by the application is simple and easy to obtain in terms of raw materials and equipment, and the purity of the obtained product is considerable. In the crystal structure, Mo atoms and V atoms are highly ordered to occupy outer transition metal layers and inner transition metal layers, respectively, and the highly ordered atomic occupation can bring about the regulation potential of physical and chemical properties.

Description

Technical Field

[0001] This invention belongs to the field of MAX phase metal ceramic synthesis technology, and in particular to an interlayer ordered dual transition metal MAX phase material and its preparation method. Background Technology

[0002] MAX phase materials are a type of material with M n+1 AX n MAX phases are layered compounds with the general formula, where M is mainly a pre-transition metal and lanthanide rare earth element, A is a group A element, X represents carbon or nitrogen, and n = 1–3. The M6X octahedrons in MAX phase crystals have a rock-salt-like edge-shaping structure. M atoms and X atoms are bonded by strong MX covalent bonds, giving MAX phases excellent properties similar to ceramics, such as high elastic modulus, strong resistance to acid and alkali corrosion, strong resistance to high-temperature oxidation, and strong thermal stability. Simultaneously, the M atom layer is bonded to the A layer by weaker MA metallic covalent bonds, and the M layer atoms are bonded to each other by MM metallic bonds. This gives MAX phase materials excellent properties similar to metals, such as good machinability, excellent electrical conductivity, and thermal conductivity. Based on these unique properties, MAX phase materials have extremely high application value in fields such as electrical contacts, sensors, microelectromechanical systems (MEMS), protective coatings, and high-temperature structural materials.

[0003] In 2014, a type of MAX material known as the interlayer ordered dual transition metal MAX phase was introduced. Its great value lies in the ordered occupancy of different transition metals in different atomic layers and Wyckoff sites, which makes it possible to control physicochemical properties by simply changing the combination of transition metals in the quaternary MAX phase structure. More importantly, the two-dimensional interlayer ordered dual transition metal MXene material etched from the interlayer ordered dual transition metal MAX phase can exhibit a strong spin-orbit coupling effect when containing 4d or 5d heavy transition metals, which leads to some exotic topological properties in its electronic band structure. In addition, studies have shown that interlayer ordered dual transition metal MXene can exhibit higher electrical conductivity, more complex metal electronic state changes, and more significant pseudocapacitive charge storage and catalytic activity compared with traditional MXene materials.

[0004] Based on the above, the exploration of synthesizing novel interlayer ordered dual transition metal MAX phases is in full swing worldwide. However, to date, due to the complexity of parasitic competing reactions inherent in the synthesis of MAX phases and the difficulty in inferring the reaction process from the sintering products, despite extensive and arduous experimental exploration, only seven o-MAX phases have been synthesized: Cr2TiAlC2, Mo2TiAlC2, Mo2ScAlC2, Cr2VAlC2, Mo2Ti2AlC3, Cr2V2AlC3, and Mo2Nb2AlC3. This has significantly limited the study of the properties and application exploration of this material family. Summary of the Invention

[0005] The purpose of this invention is to provide an interlayer ordered dual transition metal MAX phase material and its preparation method, thereby solving the problem of complex synthesis process of MAX phase in the prior art.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] An interlayer ordered dual transition metal MAX phase material with the chemical formula Mo2VAlC2, wherein Mo atoms and V atoms occupy the outer and inner transition metal layers respectively in an ordered manner in the crystal structure of Mo2VAlC2.

[0008] Furthermore, the purity of the Mo2VAlC2 is 61 wt.% to 91 wt.%.

[0009] A method for preparing the aforementioned interlayer ordered dual transition metal MAX phase material includes:

[0010] Mo, V, Al, and C elemental powders are ground to obtain a mixed powder;

[0011] The mixed powder was compressed into tablets, calcined, and cooled to obtain an interlayer ordered dual transition metal MAX phase Mo2VAlC2 material.

[0012] Furthermore, the molar ratio of the Mo, V, Al, and C elemental powders is 2:1:(1.0~1.4):1.8.

[0013] Furthermore, the Mo element powder has a particle size of 2 micrometers and a purity of 99.5%; the V element powder has a particle size of 300 mesh and a purity of 99.9%; the Al element powder has a particle size of 500 mesh and a purity of 99.95%; and the C element powder has a particle size of 400 mesh and a purity of 99.95%.

[0014] Furthermore, the grinding is performed using ball milling, in which agate balls and anhydrous ethanol are used as the milling media, and the amount of anhydrous ethanol added is 1 wt.% to 5 wt.% of the mixed powder.

[0015] Furthermore, the ball milling speed is 120-150 r / min, and the time is 15-25 h.

[0016] Furthermore, the tableting process is as follows:

[0017] After the fully ball-milled mixed powder is dried, it is cold-pressed into a "round cake" shape under a pressure of 300-400 MPa for 1 minute.

[0018] Furthermore, the calcination process is as follows:

[0019] Under an argon atmosphere, the temperature is first raised to 1400℃ at a heating rate of 8℃ / min, and then raised to a holding temperature of 1520~1560℃ at a heating rate of 4℃ / min, and then held for 4 hours.

[0020] Furthermore, the cooling process is as follows:

[0021] After the heat preservation time is over, the temperature is reduced to 500℃ within 200 minutes, and then allowed to cool naturally to room temperature.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention provides a method for preparing an interlayered ordered dual-transition metal MAX phase material. The method involves mixing Mo, V, Al, and C elemental powders, ball milling, pressing, and high-temperature sintering to obtain the target material Mo2VAlC2. Compared to other laboratory discharge plasma sintering or microwave sintering processes, this method is simple, efficient, uses readily available raw materials, and is low-cost, making it suitable for large-scale industrial production. Furthermore, future research could explore etching this Mo2VAlC2 phase to prepare its derivative, a two-dimensional interlayered ordered dual-transition metal MXene Mo2VC2 material, and investigate its applications in energy storage, catalysis, and other related fields. This would further expand the research scope of subsequent property studies and application exploration in this field, and encourage experimental work related to the synthesis of new MAX phases.

[0024] This invention also provides a Mo2VAlC2 interlayer ordered dual-transition metal MAX phase material, directly adding a new member to the family of interlayer ordered dual-transition metal MAX phases, and becoming the eighth interlayer ordered dual-transition metal MAX phase experimentally synthesized internationally. The Mo2VAlC2 interlayer ordered dual-transition metal MAX phase prepared by this invention requires simple and readily available raw materials and equipment, and the resulting product has a considerable purity of 91.2 wt.%. In its crystal structure, Mo atoms and V atoms occupy the outer and inner transition metal layers with high order, respectively. This highly ordered atomic occupancy provides potential for regulating physicochemical properties.

[0025] Furthermore, adding wet grinding media during ball milling can better disperse the materials and improve the fineness and uniformity of the mixed powder. Wet grinding media is volatile, does not react with or dissolve the powder, and facilitates subsequent separation. The amount of wet grinding media added should be moderate; too little or too much is detrimental to the uniform mixing of the raw materials. Therefore, 1wt.%–5wt.% anhydrous ethanol is added as the wet grinding media. The ball milling speed is 145 r / min. If the speed is too low, the grinding beads will mostly be distributed at the bottom of the milling jar during ball milling; if the speed is too high, they will mostly be distributed at the top of the milling jar, both of which are detrimental to the uniform mixing of the raw materials. A ball milling time of 22 hours is sufficient to obtain a homogeneous mixture.

[0026] Furthermore, the heating and calcination process is the phase synthesis process. First, the temperature is raised to 1400℃ at a heating rate of 8℃ / min, and then raised to the holding temperature at a heating rate of 4℃ / min and held for 4 hours. Appropriate heating rate, temperature and reaction time are conducive to the formation of high-purity and uniform phase. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 XRD analysis and Rietveld refinement of the Mo2VAlC2 MAX phase prepared in Example 1 of this invention.

[0029] Figure 2 The image shows the SEM pattern of the Mo2VAlC2 MAX phase obtained in Example 1 of this invention.

[0030] Figure 3 This is a double aberration-corrected transmission electron microscope image of the Mo2VAlC2 MAX phase obtained in Example 1 of the present invention.

[0031] Figure 4 XRD analysis and Rietveld refinement of the Mo2VAlC2 MAX phase prepared in Example 2 of this invention. Detailed Implementation

[0032] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0033] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0034] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0035] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0036] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0037] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0038] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0039] The present invention will now be described in further detail with reference to the accompanying drawings:

[0040] This invention provides an interlayer ordered dual transition metal MAX phase material with the chemical formula Mo₂VAlC₂. In its crystal structure, Mo atoms and V atoms occupy the outer and inner transition metal layers in a highly ordered manner, respectively, with a purity reaching 61 wt.% to 91 wt.%.

[0041] This invention also provides a method for preparing an interlayer ordered dual-transition metal MAX phase material, comprising the following steps:

[0042] Step (1) Weighing:

[0043] Weigh out the elemental powders of Mo, V, Al, and C in a molar ratio of 2:1:1.0 to 1.4:1.8;

[0044] Step (2) Preparation of interlayer ordered dual-transition metal MAX phase materials:

[0045] The weighed elemental powders were ground to obtain a mixed powder, which was then pressed into tablets, calcined at a higher temperature, and cooled to room temperature to obtain an interlayer ordered dual transition metal MAX phase Mo2VAlC2 material.

[0046] Preferably, the elemental powder specifications in step (1) are as follows: Mo powder has a particle size of 2 micrometers and a purity of 99.5%; V powder has a particle size of 300 mesh and a purity of 99.9%; Al powder has a particle size of 500 mesh and a purity of 99.95%; and C powder has a particle size of 400 mesh and a purity of 99.95%.

[0047] Preferably, the grinding in step (2) is done by ball milling, using agate balls and anhydrous ethanol as the grinding media. The amount of anhydrous ethanol added is 1wt.% to 5wt.%, the ball milling speed is 120 to 150 r / min, and the time is 15 to 25 h.

[0048] Preferably, the tableting process in step (2) is as follows: after the fully ball-milled mixed powder is dried, it is cold-pressed into a "cake" shape under a pressure of 300-400 MPa for 1 minute.

[0049] Preferably, the method for heating and calcining and cooling to room temperature in step (2) is as follows: under an argon atmosphere, the temperature is first raised to 1400°C at a heating rate of 8°C / min, and then raised to a holding temperature of 1520-1560°C at a heating rate of 4°C / min and held for 4 hours; after the holding time is over, the temperature inside the furnace is first reduced to 500°C within 200 minutes by a programmed cooling method, and then naturally cooled to room temperature.

[0050] The present invention will be further described in detail below with reference to specific embodiments:

[0051] Example 1:

[0052] The preparation method of the interlayer ordered dual transition metal MAX phase—Mo2VAlC2—in this embodiment includes the following steps:

[0053] Accurately weigh the following: Mo powder with a particle size of 2 micrometers and a purity of 99.5% (mo:1.0V:1.3Al:1.8C); V powder with a particle size of 300 mesh and a purity of 99.9% (V:1.0V:1.3Al:1.8C); Al powder with a particle size of 500 mesh and a purity of 99.95% (Al:1.3Al:1.8C);

[0054] The weighed elemental powder was placed in an agate ball mill jar, and 2 wt.% anhydrous ethanol was added as a wet milling medium. The powder was ball milled at 145 rpm for 22 h. The resulting powder was then vacuum rotary dried at 50 °C for 1 h to obtain a uniformly mixed raw material powder.

[0055] The powder was pressed into discs using a tablet press at 380 MPa pressure and placed in a conventional high-temperature tube furnace. Under an argon atmosphere, the temperature was first raised to 1400°C at a rate of 8°C / min, then raised to 1540°C at a rate of 4°C / min and held for 4 hours. After the holding time, the furnace temperature was lowered to 500°C within 200 minutes using a programmed cooling method, and then naturally cooled to room temperature to obtain the target Mo2VAlC2 product.

[0056] The performance of the Mo2VAlC2 material prepared in Example 1 was tested:

[0057] (1) XRD characterization analysis of the prepared Mo2VAlC2 material:

[0058] The Mo2VAlC2 material prepared in Example 1 was subjected to XRD tests and Rietveld refinement to determine the phase composition. The results are as follows: Figure 1As shown in the figure: the red curve represents the experimentally measured data; the black curve represents the result of Rietveld fitting; and the blue curve represents the difference between the measured data and the fitted data. The Rwp value refined by Rietveld is 8.66, indicating a reliable fitting result. The Bragg peak positions of each phase are also marked with short vertical lines of different colors in the figure. The refined (x,y,z) coordinates of each element in the Mo2VAlC2 crystal are: Mo (0.66667, 0.33333, 0.13158), V (0.00000, 0.00000, 0.00000), Al (0.00000, 0.00000, 0.25000), C (0.33333, 0.66667, 0.06339). Furthermore, according to the Rietveld refinement results, the lattice constant of the synthesized Mo2VAlC2 is... Furthermore, the contents of the target main phase and various impurity phases in the product are 91.136 wt.% Mo2VAlC2, 3.739 wt.% (MoV)4AlC3, 0.569 wt.% Mo3Al2C, 1.804 wt.% Mo2C, and 2.752 wt.% (MoV)C. Although the synthesized sample still contains a small amount of (Mo,V)4AlC3 solid solution MAX phase, considering that its content is already very low (3.739 wt.%), and comparing it with the purity of several previously reported o-MAX phase samples, the purity of the Mo2VAlC2 sample synthesized by the above preparation method in this invention is quite considerable.

[0059] (2) The prepared Mo2VAlC2 material was characterized by SEM analysis:

[0060] The morphology of the Mo2VAlC2 material obtained in Example 1 was observed by scanning electron microscopy (SEM), and elemental analysis was performed by energy-dispersive X-ray spectroscopy (EDX). The results are as follows: Figure 2 As shown: by Figure 2 As shown in (a) of the image, the typical layered stacked crystal structure of Mo2VAlC2 is clearly visible in the SEM image, with distinct crystal boundaries and good crystallinity. Figure 2 As shown in (b), (c), and (d), Mo, V, and Al are uniformly distributed in the material. Furthermore, although EDX is not precise enough for detecting C element content, it can still be observed... Figure 2 As shown in (e), the relative contents of other elements indicate that the elemental proportions of Mo, V, and Al in the synthesized Mo2VAlC2 sample are very consistent with its stoichiometric ratio of 2:1:1.

[0061] (3) The prepared Mo2VAlC2 material was characterized and analyzed by double spherical aberration corrected transmission electron microscopy:

[0062] The Mo2VAlC2 material obtained in Example 1 was observed as a high-angle annular dark-field phase (HAADF) under a double aberration-corrected transmission electron microscope (AC-TEM), and selected area electron diffraction (SAED) images were captured. The elemental arrangement was characterized at the atomic level using EDX. The results are as follows: Figure 3 As shown: Figure 3 (a) shows Mo2VAlC2 along Atom images with axes and atomic-level EDX detection results. Figure 3 (b) shows Mo2VAlC2 along Selected area electron diffraction pattern with axis, Figure 3 (c) in the figure shows the change in atomic contrast along the direction indicated by the arrows. From Figure 3 Images (a) and (c) in the image clearly show the ordered atomic arrangement between the light and dark layers of Mo₂VAlC₂. Given that the brightness of atoms in HADDF imaging mode is proportional to the square of their atomic number, the observed ordered atomic arrangement indicates that Mo₂VAlC₂ possesses an ordered atomic configuration. More importantly, further combining this with EDX elemental scanning results clearly shows that the inner V atom layer (yellow) of Mo₂VAlC₂ is sandwiched between two outer Mo atom layers (purple), and the Mo atom layers are further bonded to the Al atom layers (green). Furthermore, according to... Figure 3 The selected area electron diffraction pattern shown in (b) further confirms the long-range ordered crystal characteristics of Mo2VAlC2. In summary, it can be finally confirmed that the Mo2VAlC2 synthesized in Example 1 of this invention is an interlayer ordered dual transition metal MAX phase material.

[0063] Example 2:

[0064] The preparation method of the interlayer ordered dual transition metal MAX phase—Mo2VAlC2—in this embodiment includes the following steps:

[0065] Accurately weigh the following: Mo powder with a particle size of 2 micrometers and a purity of 99.5% (mo:1.0V:1.1Al:1.8C); V powder with a particle size of 300 mesh and a purity of 99.9% (V:1.0V:1.1Al:1.8C); Al powder with a particle size of 500 mesh and a purity of 99.95% (Al:1.0V:1.1Al:1.8C);

[0066] The weighed elemental powder was placed in an agate ball mill jar, and 2 wt.% anhydrous ethanol was added as a wet milling medium. The powder was ball milled at 145 rpm for 22 h. The resulting powder was then vacuum rotary dried at 50 °C for 1 h to obtain a uniformly mixed raw material powder.

[0067] The powder was pressed into discs using a tablet press at 380 MPa pressure and placed in a conventional high-temperature tube furnace. Under an argon atmosphere, the temperature was first raised to 1400°C at a rate of 8°C / min, then raised to 1540°C at a rate of 4°C / min and held for 4 hours. After the holding time, the furnace temperature was lowered to 500°C within 200 minutes using a programmed cooling method, and then naturally cooled to room temperature to obtain the target Mo2VAlC2 product.

[0068] The Mo2VAlC2 material prepared in Example 2 was characterized by XRD and refined by Rietveld:

[0069] The Mo2VAlC2 material prepared in Example 2 was subjected to XRD testing and Rietveld refinement to determine the phase composition. The results are as follows: Figure 4 As shown in the figure, the red curve represents the experimentally measured data; the black curve represents the Rietveld fitting result using TOPAS software; the blue curve represents the difference between the measured data and the fitted data; the Rietveld-refined Rwp value is 9.1, indicating a reliable fitting result; the figure uses short vertical lines of different colors to mark the Bragg peak positions of Mo2VAlC2 and impurity phases in the product. According to the Rietveld refinement results, the content of Mo2VAlC2 in the product is 61.061 wt.%, the content of (Mo,V)4AlC3 is 10.365 wt.%, the content of Mo3Al2C is 1.832 wt.%, the content of Mo2C is 16.845 wt.%, and the content of (Mo,V)C is 9.897 wt.%.

[0070] Example 3:

[0071] The preparation method of the interlayer ordered dual transition metal MAX phase—Mo2VAlC2—in this embodiment includes the following steps:

[0072] Accurately weigh the following: Mo powder with a particle size of 2 micrometers and a purity of 99.5% (mo:1.0V:1.3Al:1.8C); V powder with a particle size of 300 mesh and a purity of 99.9% (V:1.0V:1.3Al:1.8C); Al powder with a particle size of 500 mesh and a purity of 99.95% (Al:1.3Al:1.8C);

[0073] The weighed elemental powder was placed in an agate ball mill jar, and 2 wt.% anhydrous ethanol was added as a wet milling medium. The powder was ball milled at 145 rpm for 22 h. The resulting powder was then vacuum rotary dried at 50 °C for 1 h to obtain a uniformly mixed raw material powder.

[0074] The powder was pressed into discs using a tablet press at 380 MPa pressure and placed in a conventional high-temperature tube furnace. Under an argon atmosphere, the temperature was first raised to 1400°C at a rate of 8°C / min, then raised to 1560°C at a rate of 4°C / min and held for 4 hours. After the holding time, the furnace temperature was lowered to 500°C within 200 minutes using a programmed cooling method, and then naturally cooled to room temperature to obtain the target Mo2VAlC2 product.

[0075] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A layered ordered dual-transition metal MAX phase material, characterized in that, The chemical formula is Mo2VAlC2. In the crystal structure of Mo2VAlC2, Mo atoms and V atoms occupy the outer transition metal layer and the inner transition metal layer in an orderly manner, respectively. The purity of the Mo2VAlC2 is 61 wt.%~91 wt.%; The lattice constants of Mo2VAlC2 are a-LP = 2.96(4) Å and c-LP = 18.38(5) Å; Mo, V, Al, and C elemental powders are ground to obtain a mixed powder; The mixed powder was compressed into tablets, calcined, and cooled to obtain an interlayer ordered dual transition metal MAX phase Mo2VAlC2 material. The calcination process is as follows: Under an argon atmosphere, the temperature is first raised to 1400℃ at a heating rate of 8℃ / min, and then raised to a holding temperature of 1520~1560℃ at a heating rate of 4℃ / min and held for 4 hours. The cooling process is as follows: After the heat preservation time is over, the temperature is reduced to 500℃ within 200 minutes, and then allowed to cool naturally to room temperature.

2. The interlayer ordered dual-transition metal MAX phase material according to claim 1, characterized in that, The molar ratio of the Mo, V, Al, and C elemental powders is 2:1:(1.0~1.4):1.

8.

3. The interlayer ordered dual-transition metal MAX phase material according to claim 1, characterized in that, The Mo element powder has a particle size of 2 micrometers and a purity of 99.5%; the V element powder has a particle size of 300 mesh and a purity of 99.9%; the Al element powder has a particle size of 500 mesh and a purity of 99.95%; and the C element powder has a particle size of 400 mesh and a purity of 99.95%.

4. The interlayer ordered dual-transition metal MAX phase material according to claim 1, characterized in that, The grinding is performed by ball milling, and agate balls and anhydrous ethanol are used as the ball milling media during the ball milling process. The amount of anhydrous ethanol added is 1 wt.% to 5 wt.% of the mixed powder.

5. The interlayer ordered dual-transition metal MAX phase material according to claim 1, characterized in that, The ball mill operates at a speed of 120-150 r / min for 15-25 h.

6. The interlayer ordered dual-transition metal MAX phase material according to claim 1, characterized in that, The tableting process is as follows: After the fully ball-milled mixed powder is dried, it is cold-pressed into a "round cake" shape under a pressure of 300~400Mpa for 1 minute.

Images