Quaternary dual-phase high-entropy ceramic material and preparation method thereof

Abstract

The application discloses a quaternary dual-phase high-entropy ceramic material and a preparation method thereof, and relates to the technical field of high-entropy ceramic materials. The quaternary dual-phase high-entropy ceramic material is prepared from raw materials comprising HfO2, ZrO2, Ta2O5, TiO2, B4C and graphite powder. The preparation method comprises the steps of ball milling of slurry preparation, powder firing and sintering of finished products. The product material has excellent thermal performance and mechanical strength performance, can play the effects of high-temperature oxidation resistance and burning wear, can be effectively applied to special fields such as hypersonic aircrafts, and can play excellent protection effects.

Description

Technical Field

[0001] This application relates to the field of high-entropy ceramic materials technology, specifically to a quaternary two-phase high-entropy ceramic material and its preparation method. Background Technology

[0002] Hypersonic vehicles possess immense military and potential economic value due to their high speed and strong penetration capabilities. However, during service, these vehicles are subjected to severe start-up heating, making critical components made of C / C composite materials susceptible to ablation and failure. Therefore, protective coatings are typically applied to their surfaces for protection.

[0003] High-entropy ceramic materials are a new type of ceramic material that has been developed in recent years. Due to their large configurational entropy and unique structure and properties, they have gradually become a research hotspot.

[0004] Conventional protective measures have limited effectiveness in special fields such as hypersonic vehicles, and their protective effect is unsatisfactory; while the application scenarios of existing high-entropy ceramic materials are limited, making them difficult to apply to special fields such as hypersonic vehicles. Summary of the Invention

[0005] The purpose of this application is to provide a quaternary two-phase high-entropy ceramic material and its preparation method. The product material has excellent thermal and mechanical strength properties, and can resist high-temperature oxidation and burning wear. It can be effectively applied in special fields such as hypersonic aircraft and can provide excellent protection.

[0006] The technical solution of this application is as follows:

[0007] On the one hand, embodiments of this application provide a quaternary two-phase high-entropy ceramic material, which is prepared from raw materials including the following components: HfO2, ZrO2, Ta2O5, TiO2, B4C and graphite powder.

[0008] Furthermore, in some embodiments of this application, the raw material components, by weight, are: 50-55 parts HfO2, 30-35 parts ZrO2, 50-60 parts Ta2O5, 15-20 parts TiO2, 5-10 parts B4C and 30-35 parts graphite powder.

[0009] Furthermore, in some embodiments of this application, the two-phase composition and ratio of the product material are (Hf 0.25 Zr 0.25 Ta 0.25 Ti 0.25 B2: (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25C equals 3:7.

[0010] On the other hand, this application also provides a method for preparing a quaternary two-phase high-entropy ceramic material, which includes the following steps:

[0011] Preparation of ball mill slurry: HfO2, ZrO2, Ta2O5, TiO2, B4C and graphite powder were taken separately, mixed with ethanol, and then ball milled in a ball mill to obtain ball mill slurry;

[0012] Powder sintering: The ball mill slurry is dried, then ground and sieved to obtain the first powder; the first powder is then placed in a vacuum furnace for sintering to obtain the second powder;

[0013] Finished product sintering: The second powder is ground and then sintered by SPS to obtain the finished material.

[0014] Furthermore, in some embodiments of this application, in the above-mentioned ball milling slurry preparation step, the weight ratio of ethanol added to other raw materials is 2:1.

[0015] Furthermore, in some embodiments of this application, in the above-described ball milling slurry preparation step, the ball milling process is carried out at a rotation speed of 250–350 r / min for 4–8 h to obtain the ball milling slurry.

[0016] Furthermore, in some embodiments of this application, in the above-mentioned powder calcination step, the ball-milled slurry is placed in an oven and dried for 24 to 48 hours, then ground and passed through a 20 to 60 mesh sieve to obtain the first powder.

[0017] Furthermore, in some embodiments of this application, in the above-mentioned powder sintering step, the first powder is placed in a vacuum furnace and heated to 1650°C at a heating rate of 10°C / min for sintering treatment, held at that temperature for 2 hours, and then cooled with the furnace to obtain the second powder.

[0018] Furthermore, in some embodiments of this application, in the above-mentioned finished product sintering step, SPS sintering is carried out under the conditions of argon atmosphere, heating rate of 100℃ / min, sintering temperature of 2000℃, uniaxial pressure of 30MPa, and sintering time of 20min to obtain the finished material.

[0019] Compared with the prior art, the embodiments of this application have at least the following advantages or beneficial effects:

[0020] Regarding the first aspect, embodiments of this application provide a quaternary two-phase high-entropy ceramic material, which uses HfO2, ZrO2, Ta2O5, TiO2, B4C and graphite powder as raw materials, according to (Hf 0.25 Zr 0.25 Ta 0.25 Ti 0.25B2: (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 A quaternary two-phase high-entropy ceramic material was designed with a C ratio of 3:7.

[0021] The ceramic material of this product incorporates four metallic components—Hf, Zr, Ta, and Ti—at site A. Due to the different melting points of their oxides (HfO2 2920℃, ZrO2 2700℃, TiO2 1843℃, and Ta2O5 1827℃), they can synergistically resist oxidation at high temperatures. Furthermore, the differences in their coefficients of thermal expansion are considered; specifically, their coefficients of thermal expansion are 5.8 × 10⁻⁶. 6 10×10 6 8×10 6 2.94×10 6 They are all on the same order of magnitude, thus preventing stress cracking caused by mismatched coefficients of thermal expansion, which could lead to material failure.

[0022] In addition, the density of its product materials is increased through the eutectic effect of carbon and boron, preventing oxygen permeation caused by coating defects from further causing material failure.

[0023] Regarding the second aspect, this application also provides a method for preparing quaternary two-phase high-entropy ceramic materials. The method involves obtaining two-phase high-entropy ceramic powder through a one-step boron-carbon thermal reduction method, and then further preparing a uniform and dense two-phase high-entropy ceramic material product through SPS sintering. The preparation method is simple and clear, and the prepared ceramic material has excellent performance, wide application range, and extremely high economic benefits. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, 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 this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a graph of the XRD detection results obtained in Experiment Example 1 of this application;

[0026] Figure 2 This is a scanning electron microscope (SEM) image of the product material in Test Example 2 of this application;

[0027] Figure 3 This is a scanning electron microscope (SEM) mapping image of the product material in Test Example 2 of this application;

[0028] Figure 4 This is a single-element electron microscopy mapping image of the product material in Test Example 2 of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0030] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the term "comprising," or any other variation thereof, is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes it.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0032] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0033] Example 1

[0034] This application provides a quaternary two-phase high-entropy ceramic material, which is prepared by the following method:

[0035] With (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 B2: (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 The design of a two-phase ceramic with a C-C ratio of 3:7 includes the following steps:

[0036] Preparation of ball mill slurry: 52.44 g of HfO2, 30.70 g of ZrO2, 55.05 g of Ta2O5, 19.89 g of TiO2, 9.91 g of B4C and 31.99 g of graphite powder were weighed and mixed to obtain a mixed powder. Ethanol was added to the mixed powder at a weight ratio of 2:1 and the mixture was placed in a planetary ball mill and ball milled at 350 r / min for 6 h to obtain a ball mill slurry.

[0037] Powder sintering: The ball mill slurry was dried in an oven for 48 hours, then ground through a 40-mesh sieve to obtain the first powder; the first powder was placed in a vacuum furnace and heated to 1650℃ at a heating rate of 10℃ / min for sintering treatment, held for 2 hours, and then cooled with the furnace to obtain the second powder;

[0038] Finished product sintering: The second powder is ground and then sintered under argon atmosphere, heating rate of 100℃ / min, sintering temperature of 2000℃, uniaxial pressure of 30MPa, and sintering time of 20min using SPS to obtain the finished material.

[0039] The raw material powders used were all purchased from Beijing Zhongjinyan New Material Technology Co., Ltd., with a purity of 99.9% and a particle size of 500nm.

[0040] Example 2

[0041] This application provides a quaternary two-phase high-entropy ceramic material, which is prepared by the following method:

[0042] With (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 B2: (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 The design of a two-phase ceramic with a C-C ratio of 3:7 includes the following steps:

[0043] Preparation of ball mill slurry: 52.44 g of HfO2, 30.70 g of ZrO2, 55.05 g of Ta2O5, 19.89 g of TiO2, 9.91 g of B4C and 31.99 g of graphite powder were weighed and mixed to obtain a mixed powder. Ethanol was added to the mixed powder at a weight ratio of 2:1 and the mixture was placed in a planetary ball mill and ball milled at 250 r / min for 4 h to obtain a ball mill slurry.

[0044] Powder sintering: The ball mill slurry was dried in an oven for 24 hours, then ground and passed through a 20-mesh sieve to obtain the first powder; the first powder was placed in a vacuum furnace and heated to 1650℃ at a heating rate of 10℃ / min for sintering treatment, held for 2 hours, and then cooled with the furnace to obtain the second powder;

[0045] Finished product sintering: The second powder is ground and then sintered under argon atmosphere, heating rate of 100℃ / min, sintering temperature of 2000℃, uniaxial pressure of 30MPa, and sintering time of 20min using SPS to obtain the finished material.

[0046] The raw material powders used were all purchased from Beijing Zhongjinyan New Material Technology Co., Ltd., with a purity of 99.9% and a particle size of 500nm.

[0047] Example 3

[0048] This application provides a quaternary two-phase high-entropy ceramic material, which is prepared by the following method:

[0049] With (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 B2: (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 The design of a two-phase ceramic with a C-C ratio of 3:7 includes the following steps:

[0050] Preparation of ball mill slurry: 52.44 g of HfO2, 30.70 g of ZrO2, 55.05 g of Ta2O5, 19.89 g of TiO2, 9.91 g of B4C and 31.99 g of graphite powder were weighed and mixed to obtain a mixed powder. Ethanol was added to the mixed powder at a weight ratio of 2:1 and the mixture was placed in a planetary ball mill and ball milled at 300 r / min for 8 h to obtain a ball mill slurry.

[0051] Powder sintering: The ball mill slurry was dried in an oven for 36 hours, then ground through a 60-mesh sieve to obtain the first powder; the first powder was placed in a vacuum furnace and heated to 1650℃ at a heating rate of 10℃ / min for sintering treatment, held for 2 hours, and then cooled with the furnace to obtain the second powder;

[0052] Finished product sintering: The second powder is ground and then sintered under argon atmosphere, heating rate of 100℃ / min, sintering temperature of 2000℃, uniaxial pressure of 30MPa, and sintering time of 20min using SPS to obtain the finished material.

[0053] The raw material powders used were all purchased from Beijing Zhongjinyan New Material Technology Co., Ltd., with a purity of 99.9% and a particle size of 500nm.

[0054] Experimental Example 1

[0055] Phase analysis was performed on a quaternary two-phase high-entropy ceramic material provided in Example 1 of this application:

[0056] Testing equipment: X'Pert PROMPD polycrystalline X-ray diffraction analyzer from PANalytical, Netherlands.

[0057] Detection parameters: scanning range 10–90°, slit size DS = 0.957°, PSD = 2.12, scanning speed 2° / min. The test used a Cu-Kα target and a Ni filter; the instrument's maximum tube voltage and current were 40kV and 40mA, respectively.

[0058] Test results as follows Figure 1 As shown in the figure, the powder is the second powder obtained in Example 1, and the SPS block is the finished material obtained by SPS sintering.

[0059] pass Figure 1 It can be seen that the powder sintered in the graphite vacuum furnace has many impurity peaks and incomplete solid solution, while after SPS sintering, a two-phase high-entropy ceramic is formed by solid solution.

[0060] Experimental Example 2

[0061] Electron microscopy morphology observation of a quaternary two-phase high-entropy ceramic material provided in Embodiment 1 of this application:

[0062] The morphology of the product material provided in Example 1 was observed using an S-4800 cold field emission scanning electron microscope (SEM) manufactured by Japan High Technology Co., Ltd., and the elemental composition and distribution of the sample were detected by the energy dispersive spectroscopy (EDS) instrument built into the scanning electron microscope.

[0063] Testing conditions: vacuum environment, applied voltage 15kV, working distance 15mm.

[0064] The results are as follows Figures 2-4 As shown.

[0065] Depend on Figure 2 As can be seen under a scanning electron microscope, the synthesized quaternary two-phase high-entropy ceramic material product shows a clear boundary between the B phase and the C phase.

[0066] Depend on Figures 3-4 It can be observed that the metallic components Hf, Zr, Ta, and Ti are uniformly distributed in the quaternary two-phase high-entropy ceramic material of the product. Figure 4 It shows the distribution of each individual element in the product material; these metal components can generate dense, high-melting-point oxides for thermal protection during high-temperature oxidation.

[0067] In summary, this application provides a quaternary two-phase high-entropy ceramic material and its preparation method. The ceramic material incorporates four metallic components—Hf, Zr, Ta, and Ti—at the A-site, enabling synergistic effects at high temperatures to resist oxidation. Simultaneously, the thermal expansion coefficients of the raw material components are all on the same order of magnitude, preventing stress cracking due to mismatched thermal expansion coefficients, which could lead to material failure. Furthermore, the eutectic effect of carbon and boron enhances density, preventing oxygen permeation caused by coating defects from further contributing to material failure. The resulting material exhibits excellent thermal and mechanical strength properties, resisting high-temperature oxidation and scorching abrasion, making it suitable for specialized applications such as hypersonic vehicles, providing excellent protection. The preparation method is simple and straightforward, yielding a ceramic material with superior performance, wide application range, and high economic benefits.

[0068] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A quaternary two-phase high-entropy ceramic material, characterized in that, It is prepared from raw materials comprising the following components: 50-55 parts HfO2, 30-35 parts ZrO2, 50-60 parts Ta2O5, 15-20 parts TiO2, 5-10 parts B4C, and 30-35 parts graphite powder. The two-phase composition and proportion of the product material are as follows: (Hf...) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 B2: (Hf) 0.25 Zr 0.25 Ta 0.25 Ti 0.25 C equals 3:7, where, The preparation method of the quaternary two-phase high-entropy ceramic material includes the following steps: Preparation of ball mill slurry: HfO2, ZrO2, Ta2O5, TiO2, B4C and graphite powder were taken separately, mixed with ethanol, and then ball milled in a ball mill to obtain ball mill slurry; Powder sintering: The ball mill slurry is dried, then ground and sieved to obtain the first powder; the first powder is then placed in a vacuum furnace and heated to 1650℃ at a heating rate of 10℃ / min for sintering treatment, held at that temperature for 2 hours, and then cooled with the furnace to obtain the second powder. Finished product sintering: The second powder is ground and then sintered under argon atmosphere, heating rate of 100℃ / min, sintering temperature of 2000℃, uniaxial pressure of 30 MPa, and sintering time of 20 min to obtain the finished material.

2. A method for preparing a quaternary two-phase high-entropy ceramic material as described in claim 1, characterized in that, It includes the following steps: Preparation of ball mill slurry: HfO2, ZrO2, Ta2O5, TiO2, B4C and graphite powder were taken separately, mixed with ethanol, and then ball milled in a ball mill to obtain ball mill slurry; Powder sintering: The ball mill slurry is dried, then ground and sieved to obtain the first powder; the first powder is then placed in a vacuum furnace for sintering to obtain the second powder; Finished product sintering: The second powder is ground and then sintered by SPS to obtain the finished material.

3. The method for preparing a quaternary two-phase high-entropy ceramic material according to claim 2, characterized in that, In the ball milling slurry preparation step, the weight ratio of ethanol added to other raw materials is 2:

1.

4. The method for preparing a quaternary two-phase high-entropy ceramic material according to claim 2, characterized in that, In the ball milling slurry preparation step, the ball milling process is carried out at a rotation speed of 250-350 r / min for 4-8 h to obtain the ball milling slurry.

5. The method for preparing a quaternary two-phase high-entropy ceramic material according to claim 2, characterized in that, In the powder firing step, the ball-milled slurry is placed in an oven and dried for 24–48 hours, then ground and passed through a 20–60 mesh sieve to obtain the first powder.

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