A method for preparing a (zirconium, titanium) b2-(zirconium, titanium) c-sic ceramic resistant to ablation

Abstract

The application relates to a preparation method of a high-temperature-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, and belongs to the field of high-temperature structural ceramics. The application aims to solve the problems of the ZrB2-ZrC-SiC bulk ceramic prepared by the existing method, such as difficult densification sintering, high preparation temperature, easy peeling of the surface ablation layer in the high-temperature ablation process of the ZrB2-ZrC-SiC ceramic and insufficient ablation resistance. The method comprises the following steps: S1, preparing a mixed slurry; S2, preparing a composite powder; and S3, rapid hot-pressing sintering. The application provides a low-temperature preparation method of the high-temperature-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, the high sintering activity of raw material powders ZrSi2, TiSi2, B4C and C is utilized, and the reaction heat among the powders in the reaction sintering process is utilized to promote the densification sintering of the ceramic, so that the low-temperature preparation of the dense bulk ceramic is realized, and the ceramic has excellent ablation resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of high-temperature structural ceramics, and particularly relates to a preparation method of an ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic. BACKGROUND

[0002] Safe service of high-temperature heat-resistant materials in extreme environments is the prerequisite for the development of aerospace technology. SiC ceramics and composite materials have been widely used in the field of aerospace due to their excellent comprehensive performance in high-temperature environments. However, in harsh high-temperature oxygen-rich environments, SiC ceramics will be significantly ablated, mainly because the ablation layer formed on the surface rapidly decomposes under high-temperature heat flow scouring, losing the protective effect on the ceramic matrix. The introduction of ultra-high-temperature ceramics (UHTCs) into SiC can effectively improve the high-temperature stability of the ablation layer and improve the ablation resistance of SiC ceramics.

[0003] Zr-based ultra-high-temperature ceramics (ZrB2, ZrC, etc.) have high melting points and high-temperature stability. The introduction of ZrB2-SiC, ZrC-SiC, etc. two-phase composite ceramics into SiC can significantly improve the ablation resistance of SiC ceramics. On this basis, research shows that ZrB2-ZrC-SiC three-phase composite ceramics have better comprehensive performance than two-phase composite ceramics. This makes ZrB2-ZrC-SiC ceramics show excellent development potential in the field of aerospace heat protection.

[0004] However, there are problems such as difficulty in densification sintering, high sintering temperature, etc. in the preparation process of ZrB2-ZrC-SiC ceramics. In addition, the ablation layer formed during the ablation process of ZrB2-ZrC-SiC ceramics is a loose and porous structure, and the ablation layer is easy to fall off, losing the protective effect on the material, resulting in the need to further improve the ablation resistance of ZrB2-ZrC-SiC ceramics.

[0005] Therefore, it is necessary to develop a low-temperature densification sintering process for ZrB2-ZrC-SiC ceramics to realize the low-temperature rapid preparation of ZrB2-ZrC-SiC dense bulk ceramics. And through the composition design and modification of ZrB2-ZrC-SiC ceramics, a dense and stable ablation layer is formed during the ablation process, which is the key to solving the above problems. SUMMARY

[0006] The purpose of the present application is to solve the problems of ZrB2-ZrC-SiC bulk ceramic prepared by the existing method, such as difficulty in densification sintering, high sintering temperature, and easy falling off of the surface ablation layer during the high-temperature ablation process of ZrB2-ZrC-SiC ceramics, and to provide a preparation method of an ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic.

[0007] A preparation method of an ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, specifically is completed according to the following steps:

[0008] I. Preparation of a mixed slurry:

[0009] ZrSi2, TiSi2, B4C, C powder and anhydrous ethanol are added into a ball mill tank provided with grinding balls, the ball mill tank is flushed with argon and then sealed; the sealed ball mill tank is fixed on a ball mill, so that the ball mill tank is ball milled in an argon environment for a period of time, and a mixed slurry is obtained;

[0010] The molar ratio of the total amount of ZrSi2 and TiSi2 to B4C and C in step one is (5 / 18-1 / 2):(1 / 100-1 / 3):1; the molar ratio of ZrSi2 to TiSi2 is (0.01-0.99):(0.01-0.99);

[0011] II. Preparation of a composite powder:

[0012] The mixed slurry is dried at room temperature and in a vacuum environment for a period of time, and then sieved under the protection of an argon atmosphere to obtain a composite powder;

[0013] III. Rapid hot-pressing sintering:

[0014] First, the composite powder is compacted, and then hot-pressing sintering is performed on the compacted composite powder at 1500-1900 DEG C and an axial pressure of 20-60 MPa for a period of time by using a sintering device, so as to obtain an ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic;

[0015] The hot-pressing sintering time in step three is 5-20 min, and the environmental conditions are vacuum, argon or nitrogen.

[0016] Principle of the present application:

[0017] The application provides a low-temperature preparation method of an ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, which utilizes the high sintering activity of raw material powders ZrSi2, TiSi2, B4C and C and the reaction heat among the powders in a reaction sintering process to promote the densification sintering of the ceramic and realize the low-temperature preparation of the dense bulk ceramic; the composition of the (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic can be regulated by regulating the composition of the reactants. In addition, the application introduces Ti elements into the ZrC-ZrB2-SiC ceramic (part of Zr atoms in the ZrB2 and ZrC lattices are replaced by Ti atoms to form (Zr, Ti)B2 and (Zr, Ti)C solid solutions), utilizes the synergistic effect among the ablation products of each component in the (Zr, Ti)B2-(Zr, Ti)C-SiC multi-component ceramic during the ablation process to build a continuous and dense ablation layer, and ensures that the (Zr, Ti)C-(Zr, Ti)B2-SiC ceramic has more excellent ablation resistance.

[0018] The application has the following beneficial effects:

[0019] The application provides a preparation method of a (Zr, Ti)B2-(Zr, Ti)C-SiC multi-phase ceramic, which utilizes the reaction among the raw material powders ZrSi2, TiSi2, B4C and C powders in a sintering process to obtain the (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, and the reaction process is carried out according to reaction formula (1), wherein MSi2 refers to the mixture of ZrSi2 and TiSi2; the molar ratio of ZrSi2 to TiSi2 in the MSi2 is flexibly adjustable between 0.99:0.01 and 0.01:0.99, so that the Zr / Ti ratio of the (Zr, Ti)C and (Zr, Ti)B2 solid solution in the multi-phase ceramic can be flexibly regulated; in addition, by changing the values of x and y, the (Zr, Ti)B2-(Zr, Ti)C-SiC multi-phase ceramic with any molar ratio of the (Zr, Ti)C and (Zr, Ti)B2 two phases can be obtained.

[0020] (x+y)MSi2+y / 2B4C+(3x+3 / 2y)C=xMC+yMB2+2(x+y)SiC (1)

[0021] In summary, the preparation method of the ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic can flexibly regulate the composition and structure of the (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, which provides a basis and premise for the material optimization design in combination with different service environment requirements;

[0022] In addition, the raw material powders ZrSi2, TiSi2, B4C and C selected by the present application have high sintering activity; in the reaction sintering process, the energy released by the powder reaction provides the driving force for sintering, which helps to reduce the sintering temperature. The present application realizes the low-temperature preparation of (Zr, Ti)B2-(Zr, Ti)C-SiC dense bulk ceramics at 1700℃, solving the problems of high sintering temperature and difficult densification of UHTCs / SiC ceramics in the prior art; the present application greatly reduces the energy consumption in the preparation process.

[0023] On the other hand, the present application proposes to replace part of the Zr atoms in the ZrB2-ZrC-SiC multiphase ceramic with Ti atoms to obtain (Zr, Ti)B2-(Zr, Ti)C-SiC multiphase ceramic; the mutual matching and synergistic effect of the microstructure and melting point between the ablation products of each component ensure that the ceramic can form a continuous and dense oxide layer during ablation, improving the ablation resistance; solving the problems of easy peeling of the existing ZrC-ZrB2-SiC ablation layer and insufficient ablation resistance; when Zr / Ti = 9:1, the linear ablation rate of (Zr, Ti)B2-(Zr, Ti)C-SiC multiphase ceramic is only -0.00077 mm / s, and the mass ablation rate is only 0.00015 g / s, which is improved by 95.21% compared with the mass ablation rate of ZrB2-ZrC-SiC ceramic. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The XRD patterns of the composite powders prepared in Comparative Example 1 and Examples 1-3 in the present application are shown in the figure, where Zr / Ti = 7:3 is Example 3, Zr / Ti = 8:2 is Example 2, Zr / Ti = 9:1 is Example 1, and Zr / Ti = 10:0 is Comparative Example 1;

[0025] Figure 2 The XRD patterns of the multiphase ceramics prepared in Comparative Example 1 and Examples 1-3 in the present application are shown in the figure;

[0026] Figure 3 The XRD patterns of the multiphase ceramics prepared in Examples 4-7 in the present application are shown in the figure;

[0027] Figure 4 The surface SEM images of the multiphase ceramics prepared in Comparative Example 1 and Examples 1-3 in the present application after oxyacetylene ablation are shown in the figure. DETAILED DESCRIPTION

[0028] Specific implementation method one: the present implementation is a method for preparing ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, which is completed according to the following steps:

[0029] I. Preparation of mixed slurry:

[0030] ZrSi2, TiSi2, B4C, C powder and anhydrous ethanol are added into a ball mill tank with grinding balls, the ball mill tank is flushed with argon and then sealed; the sealed ball mill tank is fixed on a ball mill so that the ball mill tank is ball milled for a period of time in an argon environment to obtain a mixed slurry;

[0031] The molar ratio of the total amount of ZrSi2 and TiSi2 to B4C and C in step one is (5 / 18-1 / 2):(1 / 100-1 / 3):1; the molar ratio of ZrSi2 to TiSi2 is (0.01-0.99):(0.01-0.99);

[0032] II. Preparation of composite powder

[0033] The mixed slurry is dried at room temperature and under vacuum for a period of time, and then sieved under argon atmosphere to obtain a composite powder;

[0034] III. Rapid hot-pressing sintering

[0035] First, the composite powder is compacted, and then hot-pressing sintered at 1500-1700°C and an axial pressure of 20-60 MPa for a period of time using a sintering device to obtain an ablation-resistant (Zr,Ti)B2-(Zr,Ti)C-SiC ceramic;

[0036] The hot-pressing sintering time in step three is 5-20 min, and the environmental conditions are vacuum, argon or nitrogen.

[0037] Specific implementation method two: the difference between this implementation method and specific implementation method one is that the material of the grinding ball in step one is ZrO2, and the ball-to-material mass ratio is (10-20):1. The other steps are the same as specific implementation method one.

[0038] Specific implementation method three: the difference between this implementation method and one of specific implementation method one or two is that the rotation speed of the ball mill in step one is 300-500 r / min, and the effective ball milling time is 10-48 h. The other steps are the same as specific implementation method one or two.

[0039] Specific implementation method four: the difference between this implementation method and one of specific implementation methods one to three is that the anhydrous ethanol in step one accounts for 20-50% of the total mass of ZrSi2, TiSi2, B4C and C powder. The other steps are the same as specific implementation methods one to three.

[0040] Specific embodiment five: the difference between this embodiment and the first to fourth specific embodiments is that the mixed slurry is dried at room temperature and under vacuum for 20h-100h in step two. The other steps are the same as the first to fourth specific embodiments.

[0041] Specific embodiment six: the difference between this embodiment and the first to fifth specific embodiments is that the dried mixed slurry is sieved through a 100-200 mesh sieve under an argon atmosphere to obtain a composite powder in step two. The other steps are the same as the first to fifth specific embodiments.

[0042] Specific embodiment seven: the difference between this embodiment and the first to sixth specific embodiments is that the specific method for compacting the composite powder in step three is as follows: graphite paper is tightly attached to the wall of a graphite mold, the composite powder stored in an argon atmosphere is poured into a round graphite mold, and graphite gaskets and the composite powder are separated by graphite paper between the composite powder and the press head; the graphite mold containing the composite powder is placed under a hydraulic machine to manually apply pressure to obtain a green compact of the composite powder. The other steps are the same as the first to sixth specific embodiments.

[0043] Specific embodiment eight: the difference between this embodiment and the first to seventh specific embodiments is that the diameter of the graphite mold is 10mm-40mm. The other steps are the same as the first to seventh specific embodiments.

[0044] Specific embodiment nine: the difference between this embodiment and the first to eighth specific embodiments is that the sintering equipment is a rapid hot-pressing sintering furnace. The other steps are the same as the first to seventh specific embodiments.

[0045] The following examples are used to verify the beneficial effects of the present application:

[0046] Comparative example 1: a method for preparing ZrB2-ZrC-SiC multiphase ceramics, denoted as Z10T0B1C1-S. Specifically, it is completed according to the following steps:

[0047] I. Preparation of mixed slurry:

[0048] ZrSi2, B4C, C powder and anhydrous ethanol are added to a ball mill jar containing grinding balls, argon is flushed into the ball mill jar, and the ball mill jar is sealed; the sealed ball mill jar is fixed on a ball mill to mill under an argon atmosphere, and the effective milling time is 24h. The mixed slurry is obtained;

[0049] The material of the grinding balls in step one is ZrO2, and the ball-to-material ratio is 10:1;

[0050] The rotation speed of the ball mill in step one is 350r / min;

[0051] The molar ratio of ZrSi2, B4C and C in step one is 4:1.05:9.45 (B4C and C are both 5% excess compared with the reaction formula calculation value);

[0052] The anhydrous ethanol in step one accounts for 31.6% of the total mass of ZrSi2, B4C and C powders;

[0053] II. Preparation of composite powder:

[0054] The mixed slurry is dried at room temperature and under vacuum for 24 h, and then sieved through a 140 mesh screen under the protection of argon atmosphere to obtain the composite powder;

[0055] III. Rapid hot-pressing sintering:

[0056] First, the composite powder is compacted, and then rapid hot-pressing sintering is carried out at 1700°C and an axial pressure of 40 MPa for 15 min in a rapid hot-pressing sintering furnace under vacuum conditions to obtain ZrB2-ZrC-SiC multiphase ceramic, which is denoted as Z10T0B1C1-S.

[0057] The specific method for compacting the composite powder in step three is as follows: graphite paper is tightly attached to the wall of a graphite mold, the composite powder stored in an argon atmosphere is poured into the round graphite mold, and graphite gaskets and the composite powder are separated by graphite paper between the composite powder and the pressure head; the graphite mold containing the composite powder is placed under the hydraulic machine for manual pressing to obtain a green compact of the composite powder; the diameter of the graphite mold is 30 mm.

[0058] Example 1: Preparation method of ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, which is completed according to the following steps:

[0059] I. Preparation of mixed slurry:

[0060] Under the protection of argon atmosphere, ZrSi2, TiSi2, B4C, C powder and anhydrous ethanol are added to a ball mill jar, then grinding balls are added to the ball mill jar, and the ball mill jar is sealed; the sealed ball mill jar is fixed on a ball mill, vacuumized, and then argon is introduced to ball mill the ball mill jar in an argon environment for 24 h to obtain a mixed slurry;

[0061] The material of the grinding ball in step one is ZrO2, and the ball-to-material ratio is 10:1;

[0062] The rotating speed of the ball mill in step one is 350 r / min;

[0063] The molar ratio of ZrSi2:TiSi2:B4C:C in step one is 3.6:0.4:1.05:9.45 (B4C and C are both 5% excess compared with the reaction formula calculation value);

[0064] The anhydrous ethanol in step one accounts for 31.6% of the total mass of ZrSi2, TiSi2, B4C and C powders;

[0065] II. Preparation of composite powders

[0066] The mixed slurry is dried at room temperature and under vacuum for 24 hours, and after drying, is passed through a 140-mesh sieve under the protection of an argon atmosphere to obtain the composite powders;

[0067] III. Rapid hot-pressing sintering

[0068] First, the composite powders are compacted, and then sintered at 1700°C and an axial pressure of 40 MPa for 15 minutes in a rapid hot-pressing sintering furnace under vacuum to obtain the ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic, wherein the molar ratio of Zr:Ti in the (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic is 9:1, and the molar ratio of (Zr, Ti)C:(Zr, Ti)B2 is 1:1, and is denoted as Z9T1B1C1-S.

[0069] The specific method for compacting the composite powders in step three is as follows: graphite paper is tightly attached to the wall of a graphite mold, the composite powders stored in an argon atmosphere are poured into the round graphite mold, and graphite gaskets and the composite powders are separated by graphite paper between the composite powders and the press head; the graphite mold containing the composite powders is placed under a hydraulic press to manually apply pressure to obtain a green compact of the composite powders; the diameter of the graphite mold is 30 mm.

[0070] Example 2: The difference between this example and Example 1 is that the molar ratio of ZrSi2:TiSi2:B4C:C in step one is 3.2:0.8:1.05:9.45 (B4C and C are both 5% in excess of the calculated value according to the reaction equation); and the molar ratio of Zr:Ti in the ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic obtained in step three is 8:2, and is denoted as Z8T2B1C1-S. The other steps and parameters are the same as in Example 1.

[0071] Example 3: The difference between this example and Example 1 is that the molar ratio of ZrSi2:TiSi2:B4C:C in step one is 2.8:1.2:1.05:9.45 (B4C and C are both 5% in excess of the calculated value according to the reaction equation); and the molar ratio of Zr:Ti in the ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic obtained in step three is 7:3, and is denoted as Z7T3B1C1-S. The other steps and parameters are the same as in Example 1.

[0072] Example 4: The difference between this example and Example 1 is that the molar ratio of ZrSi2:TiSi2:B4C:C in step one is 0.9:0.1:0:3.3 (C is 10% excess compared to the calculated value in the reaction formula); the ceramic obtained in step three is (Zr,Ti)C-SiC, without the (Zr,Ti)B2 phase, and the molar ratio of Zr:Ti in (Zr,Ti)C is 9:1, denoted as Z9T1B0C1-S. All other steps and parameters are the same as in Example 1.

[0073] Example 5: The difference between this example and Example 1 is that the molar ratio of ZrSi2:TiSi2:B4C:C in step one is 5.4:0.6:1.1:16.5 (B4C and C are in 10% excess according to the reaction formula); in step three, the molar ratio of (Zr,Ti)C:(Zr,Ti)B2 in the ablation-resistant (Zr,Ti)B2-(Zr,Ti)C-SiC ceramic is 2:1, denoted as Z9T1B1C2-S. All other steps and parameters are the same as in Example 1.

[0074] Example 6: The difference between this example and Example 1 is that the molar ratio of ZrSi2:TiSi2:B4C:C in step one is 2.7:0.3:1.1:6.6 (both B4C and C are in excess by 10%); in step three, the molar ratio of (Zr,Ti)C:(Zr,Ti)B2 in the ablation-resistant (Zr,Ti)B2-(Zr,Ti)C-SiC ceramic is 1:2, denoted as Z9T1B2C1-S. All other steps and parameters are the same as in Example 1.

[0075] Example 7: The difference between this example and Example 1 is that the molar ratio of ZrSi2:TiSi2:B4C:C in step one is 1.8:0.2:1.1:3.3 (both B4C and C are in excess by 10%); the ceramic prepared in step three is (Zr,Ti)B2-SiC, without the (Zr,Ti)C phase, wherein the molar ratio of Zr:Ti in (Zr,Ti)B2 is 9:1, denoted as Z9T1B2C0-S. All other steps and parameters are the same as in Example 1.

[0076] Figure 1 The images show the XRD patterns of the composite powders prepared in Comparative Example 1 and Examples 1 to 3 of this invention. In the figures, Zr / Ti = 7:3 represents Example 3, Zr / Ti = 8:2 represents Example 2, Zr / Ti = 9:1 represents Example 1, and Zr / Ti = 10:0 represents Comparative Example 1.

[0077] from Figure 1 It can be seen that as the TiSi2 content increases, the diffraction peaks of TiSi2 in the spectrum become more obvious.

[0078] Figure 2 The XRD patterns of the multiphase ceramics prepared in Comparative Example 1 and Examples 1 to 3 of this invention are shown below.

[0079] from Figure 2 It can be seen that as the Ti content increases, the diffraction peaks of (Zr,Ti)C and (Zr,Ti)B2 shift to larger angles, which further proves the formation of solid solution and causes changes in the lattice constants of (Zr,Ti)C and (Zr,Ti)B2.

[0080] Figure 3 The XRD patterns of the multiphase ceramics prepared in Examples 4 to 7 of this invention are shown.

[0081] from Figure 3 It can be seen that as the B4C / C ratio increases, the phase composition of the multiphase ceramic evolves from (Zr,Ti)C-SiC to (Zr,Ti)B2-(Zr,Ti)C-SiC to (Zr,Ti)B2-SiC. This confirms that the reaction sintering method proposed in this invention can achieve the low-temperature rapid preparation of (Zr,Ti)B2-(Zr,Ti)C-SiC multiphase ceramics with arbitrary Zr / Ti ratios and arbitrary (Zr,Ti)C / (Zr,Ti)B2 two-phase ratios.

[0082] Ablation tests were performed on (Zr,Ti)B2-(Zr,Ti)C-SiC multiphase ceramics using an oxy-acetylene flame as the heat source. The distance from the flame nozzle to the ablated sample surface was 10 mm. The ablated sample diameter was 30 mm and the thickness was 5 mm. The pressure and flow rate of oxygen and acetylene were the same for all samples during the testing process. The linear ablation rate (R0) of the sample was determined. d ) and mass ablation rate (R m ) Calculate according to formula (2) and formula (3).

[0083]

[0084] Where, d b d a m b m a ΔT and ΔT represent the original thickness (mm), the thickness (mm), the original mass (g), the mass (g), and the ablation time (s) of the ablated sample, respectively.

[0085] Figure 4 The images shown are SEM images of the surface of multiphase ceramics after oxyacetylene ablation prepared in Comparative Example 1 and Examples 1 to 3 of this invention.

[0086] Depend on Figure 4It can be seen that the surface phase composition of the ZrB2-ZrC-SiC ceramic prepared in the comparative example after ablation is mainly ZrO2, and the surface morphology presents a loose and porous structure. The ablation layer is easy to be mechanically ablated under the scouring of high-temperature gas flow. After the introduction of Ti element, in addition to ZrO2, there is also a low-melting-point phase containing Ti element in the ablation product. It promotes the formation of a relatively dense / stable ablation layer. It solves the problems of easy peeling of the ablation layer of ZrC-ZrB2-SiC ceramic and insufficient ablation resistance, etc.

[0087] Table 1 is the ablation resistance performance data of the multiphase ceramic prepared in the comparative example 1 and the examples 1-2 in the present application. The pressure and flow of oxygen and acetylene used in the test process of all samples are the same. When the ablation duration is 60s, the surface temperature of all samples is 2100±200K.

[0088] Table 1

[0089]

[0090] It can be seen from Table 1 that the solid solution of a certain content of Ti can effectively improve the ablation resistance performance of the composite ceramic. When Zr / Ti=9:1, the linear ablation rate of the (Zr,Ti)B2-(Zr,Ti)C-SiC ceramic is only-0.00077mm / s. The mass ablation rate is only 0.00015g / s, which is improved by 95.21% compared with the mass ablation rate of ZrB2-ZrC-SiC ceramic.

Claims

1. A method for producing a Zr,Ti)B2-(Zr,Ti)C-SiC ceramic resistant to ablation, characterized in that The preparation method is specifically completed by the following steps: I. Preparation of mixed slurry: ZrSi2, TiSi2, B4C, C powder and anhydrous ethanol are added into a ball mill tank with grinding balls, the ball mill tank is filled with argon and then sealed; the sealed ball mill tank is fixed on a ball mill, so that the ball mill tank is ball milled in an argon environment for a period of time to obtain a mixed slurry; The total amount of substance of ZrSi2 and TiSi2 in step one and the molar ratio of B4C and C are (5 / 18-1 / 2):(1 / 100-1 / 3):1; the molar ratio of ZrSi2 and TiSi2 is (0.01-0.99):(0.01-0.99); II. Preparation of composite powder: The mixed slurry is dried at room temperature and under vacuum conditions for a period of time, and then sieved under argon atmosphere protection to obtain a composite powder; III. Rapid hot-pressing sintering: First, the composite powder is compacted, and then it is hot-pressed and sintered at 1500-1900°C and an axial pressure of 20-60 MPa for a period of time using a sintering device to obtain an ablation-resistant (Zr, Ti)B2-(Zr, Ti)C-SiC ceramic; The hot-pressing sintering time in step three is 5-20 min, and the environmental conditions are vacuum, argon or nitrogen.

2. A method for preparing a (Zr,Ti)B2-(Zr,Ti)C-SiC ceramic resistant to ablation according to claim 1, characterized in that The material of the grinding balls in step one is ZrO2, and the ball-to-material mass ratio is (10-20):

1.

3. The method of claim 1, wherein the method is characterized by The rotation speed of the ball mill in step one is 300-500 r / min, and the effective ball milling time is 10-48 h.

4. The method of claim 1, wherein the method is characterized by The anhydrous ethanol in step one accounts for 20-50% of the total mass of ZrSi2, TiSi2, B4C and C powder.

5. The method of claim 1, wherein the method is characterized by The mixed slurry is dried at room temperature and under vacuum conditions for 20-100 h in step two.

6. The method of claim 1, wherein the method is characterized by The dried mixed slurry is sieved through a 100-200 mesh sieve under argon atmosphere protection to obtain a composite powder in step two.

7. The method of claim 1, wherein the method is characterized by The specific method for compacting the composite powder in step three is as follows: graphite paper is tightly attached to the wall of a graphite mold, the composite powder preserved in an argon atmosphere is poured into a circular graphite mold, and graphite gaskets and the composite powder are separated by graphite paper between the composite powder and the pressure head; the graphite mold containing the composite powder is placed under a hydraulic machine to manually apply pressure to obtain a green compact of the composite powder.

8. A method of producing a (Zr,Ti)B2-(Zr,Ti)C-SiC ceramic resistant to ablation according to claim 7, characterized in that The diameter of the graphite mold is 10-40 mm.

9. The method of claim 1, wherein the method is characterized by The sintering device is a rapid hot-pressing sintering furnace.

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