ZrB2 / SiC ceramic matrix composite material and preparation method and application thereof

Abstract

The application provides a ZrB2 / SiC ceramic matrix composite material and a preparation method and application thereof, and the preparation method comprises the following steps: step 1, cross-linking and solidifying a ZrB2 liquid precursor, grinding the obtained solid to obtain a precursor powder; step 2, pressing the precursor powder to obtain a green body; step 3, low-temperature pyrolysis of the green body to obtain a pyrolyzed green body; step 4, high-temperature pyrolysis of the pyrolyzed green body to obtain a ZrB2 ceramic; step 5, vacuum impregnation of the ZrB2 ceramic in liquid polycarbosilane, and solidification of the ZrB2 ceramic after the impregnation is completed; and step 6, high-temperature pyrolysis of the sample after the solidification in step 5 to obtain a ZrB2 / SiC ultrahigh-temperature ceramic matrix composite material. The obtained ZrB2 / SiC ceramic matrix composite material has the advantages of high-temperature resistance, low density and good wave absorption performance, and widens the application of ultrahigh-temperature ceramics in the field of stealth materials.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wave-absorbing materials, and particularly relates to a ZrB2 / SiC ceramic matrix composite material and a preparation method and application thereof. BACKGROUND

[0002] With the development of a new generation of aircraft, the aircraft is required to have stealth performance in addition to faster flight speed, which needs to be realized by high-temperature electromagnetic wave absorbing materials. However, when the aircraft flies at high speed, the hot end components are exposed to an extremely high-temperature environment, which poses a severe challenge to high-temperature electromagnetic wave absorbing materials. Therefore, it is of great significance to the development of future aircraft to study wave-absorbing materials that can withstand an extremely high-temperature environment.

[0003] At present, the research on high-temperature wave-absorbing material systems is mainly based on silicon-based ceramics, in which magnetic particles or conductive particles are added to achieve good wave-absorbing performance. However, the magnetic particles will lose magnetism and cause the wave-absorbing performance to decrease in a high-temperature environment, and the carbon-based conductive particles also face the problem of easy oxidation. ZrB2 and other ultra-high-temperature ceramics have a higher melting point, higher electrical conductivity, and lower density, and are potential candidate materials for high-temperature wave absorption. The research on the wave-absorbing performance of ZrB2 ultra-high-temperature ceramics is mainly to use it as a wave-absorbing agent. Document 1 “Liu, Y., Su, X., He, X. et al. Dielectric and microwave absorption properties of ZrB2 / Al2O3 composite ceramics. J Mater Sci: Mater Electron 2019, 30: 2630-2637.” prepared a ZrB2 / Al2O3 composite material by hot pressing, and when the content of ZrB2 was 15wt%, the effective wave-absorbing range of the composite material was 1.7GHz in the X wave band, and the density of the composite material was 4.12g / cm 3Document 2“Jia Y, Chowdhury M A R, Zhang D, et al. Wide-Band Tunable Microwave-Absorbing Ceramic Composites Made of Polymer-Derived SiOC Ceramic and in Situ Partially Surface-Oxidized Ultra-High-Temperature Ceramics[J]. Acs Appl Mater Inter, 2019, 11(49): 45862-74.” added nano ZrB2 particles to the polymer-derived SiOC to prepare SiOC-ZrB2 composite materials, successfully built an electrically conductive network inside the composite material, and realized effective absorption of the entire Ka band. However, the content of nano-particle wave-absorbing agent required to form an electrically conductive network is high, which also increases the density of the composite material. The density of SiOC-ZrB2 composite material with 40% ZrB2 content is 2.67 g / cm 3 Due to the limitation of the matrix material, the composite material has a large density, and the material applied to the aircraft requires that its density cannot be too large, so it is of great significance to develop high-temperature wave-absorbing materials that can withstand extreme high-temperature environments and have low density. SUMMARY

[0004] The purpose of the present application is to provide a ZrB2 / SiC ceramic matrix composite material and its preparation method and application, which has the advantages of high temperature resistance, low density, good wave-absorbing performance, etc., and widens the application of ultra-high temperature ceramics in the field of stealth materials.

[0005] The present application is realized by the following technical solutions:

[0006] A preparation method of a ZrB2 / SiC ceramic matrix composite material, comprising the following steps:

[0007] Step 1: crosslinking and curing the ZrB2 liquid precursor at a first preset temperature, grinding the obtained solid after crosslinking and curing to obtain a precursor powder;

[0008] Step 2: pressing the precursor powder to obtain a green body;

[0009] Step 3: low-temperature pyrolysis of the green body at a second preset temperature under an inert atmosphere to obtain a pyrolyzed green body;

[0010] Step 4: high-temperature pyrolysis of the pyrolyzed green body at a third preset temperature under an inert atmosphere to obtain a ZrB2 ceramic;

[0011] Step 5: immerging the ZrB2 ceramic into liquid polycarbosilane, vacuum impregnation, after impregnation, solidifying the ZrB2 ceramic under inert atmosphere and the fourth preset temperature;

[0012] Step 6: high-temperature pyrolysis of the sample after step 5 under inert atmosphere at the fifth preset temperature, obtaining ZrB2 / SiC ultra-high temperature ceramic matrix composite.

[0013] Preferably, in step 1, the first preset temperature is 120-160℃, and the cross-linking solidification time is 2-3h.

[0014] Preferably, in step 1, the ZrB2 liquid precursor includes polyacetylacetone zirconium, boric acid and phenolic resin.

[0015] Preferably, in step 3, the second preset temperature is 300-600℃, and the pyrolysis time is 2-3h.

[0016] Preferably, in step 4, the third preset temperature is 1500-1600℃, and the pyrolysis time is 1-2h.

[0017] Preferably, in step 5, the fourth preset temperature is 140-160℃, and the solidification time is 2-4h.

[0018] Preferably, in step 6, the fifth preset temperature is 1000-1500℃, and the pyrolysis time is 1-2h.

[0019] Preferably, in steps 3-6, the inert atmosphere is argon.

[0020] The ZrB2 / SiC ceramic matrix composite prepared by the preparation method.

[0021] The ZrB2 / SiC ceramic matrix composite as a wave-absorbing material in the field of wave absorption.

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

[0023] The application obtains a ZrB2 / SiC ultra-high temperature ceramic matrix composite material by using polymer conversion method and precursor impregnation pyrolysis method with liquid ZrB2 precursor and liquid polycarbosilane as raw materials. Compared with hot-pressing sintering method and direct sintering method (sintering temperature is above 1700 DEG C or a larger pressure is applied), the polymer conversion method can prepare the ultra-high temperature ceramic at a lower temperature (1500 DEG C). First, the polymer conversion method is used to prepare an ultra-high temperature ceramic matrix, and by controlling the pyrolysis temperature and time in the pyrolysis process, the ultra-high temperature ceramic matrix with a porous structure is obtained, then liquid polycarbosilane is introduced into the ultra-high temperature ceramic matrix by using the vacuum impregnation method, and then the ZrB2 / SiC ultra-high temperature ceramic composite material is obtained through cross-linking and curing and high-temperature pyrolysis.

[0024] The composite material prepared by the application has the characteristics of high temperature resistance, low density and good wave absorption performance, the volume density of the ZrB2 / SiC composite material is 1.46 g / cm 3 , the minimum reflection loss is-40 dB to-57.92 dB, and the effective absorption bandwidth is 5.28 GHz to 8.64 GHz, so the ZrB2 / SiC composite material is an ideal candidate material for high temperature wave absorption materials. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor under the premise of the drawings.

[0026] Figure 1 XRD pattern of the ZrB2 ceramic prepared in Example 3.

[0027] Figure 2Scanning electron microscope photos; (a), (b), (c) are the morphologies of pure ZrB2 ceramics prepared by Comparative Example 1, Comparative Example 2, Comparative Example 3, respectively, (d), (e), (f) are the morphologies of ZrB2 / SiC composite materials in Example 3, Example 4, Example 5, respectively.

[0028] Figure 3 Transmission electron microscope photo of ZrB2 / SiC composite material prepared in Example 3.

[0029] Figure 4 Reflection loss curve of ZrB2 / SiC composite material prepared in Example 3.

[0030] Figure 5 Reflection loss curve of ZrB2 / SiC composite material prepared in Example 4.

[0031] Figure 6 Impedance matching characteristic curve of materials in Example 3, Example 4, Example 5, Comparative Example 2 and Comparative Example 3 when the thickness is 3 mm. DETAILED DESCRIPTION

[0032] The present application is herein described, by way of example only, with reference to certain embodiments thereof. It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting, unless otherwise specifically indicated. It should be noted that various alterations, modifications, and improvements can be made to the embodiments of the present application, and can be practiced or implemented in various ways. The embodiments of this application are not to be understood as being limited to the details explained in the following description.

[0033] It should be noted that the process equipment or device not specifically mentioned in the following examples is the conventional equipment or device in the art.

[0034] It should be noted that the terms "comprising", "having", "including", and any change thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device including a list of steps or units is not necessarily limited to those clearly listed steps or units, but can include other steps or units not clearly listed or inherent to such processes, methods, products, or devices. In addition, unless otherwise specified, the numbering of the method steps is only a convenient tool for identifying the method steps, and is not intended to limit the arrangement order of the method steps or to limit the scope of the application, and changes or adjustments of the relative relationship, without substantial change of the technical content, are also considered as the scope of the application.

[0035] The preparation method of the ZrB2 / SiC ceramic matrix composite material, comprising the following steps:

[0036] Step 1: cross-linking and solidification of the ZrB2 liquid precursor at a first preset temperature, grinding the solid obtained by cross-linking and solidification to obtain a precursor powder;

[0037] Step 2: pressing the precursor powder to obtain a green body;

[0038] Step 3: low-temperature pyrolysis of the green body at a second preset temperature under an inert atmosphere to obtain a pyrolyzed green body;

[0039] Step 4: high-temperature pyrolysis of the pyrolyzed green body at a third preset temperature under an inert atmosphere to obtain a ZrB2 ceramic;

[0040] Step 5: vacuum impregnation of the ZrB2 ceramic in liquid polycarbosilane, and solidification of the ZrB2 ceramic at a fourth preset temperature under an inert atmosphere after impregnation is completed;

[0041] Step 6: high-temperature pyrolysis of the sample after solidification in step 5 at a fifth preset temperature under an inert atmosphere to obtain a ZrB2 / SiC ultra-high-temperature ceramic matrix composite.

[0042] In some embodiments of the application, in step 1, the first preset temperature is 120-160℃, and the cross-linking and solidification time is 2-3h; the ZrB2 liquid precursor is purchased from the Chinese Academy of Sciences Chemistry Institute (main components: polyacetylacetone zirconium, boric acid, phenolic resin (molar ratio 1:2:1)).

[0043] In some embodiments of the application, in step 3, the second preset temperature is 300-600℃, and the pyrolysis time is 2-3h, and the specific process is as follows: heating from room temperature to 300-600℃ at a rate of 5-10℃ / min, holding for 2-3h, then cooling to 300℃ at a rate of 5℃ / min, and then cooling to room temperature in the furnace.

[0044] In some embodiments of the application, in step 4, the third preset temperature is 1500-1600℃, and the pyrolysis time is 1-2h, and the specific process is as follows: heating from room temperature to 1500-1600℃ at a rate of 5-10℃ / min, holding for 1-2h, then cooling to 300℃ at a rate of 4℃ / min, and then cooling to room temperature in the furnace to obtain the ZrB2 ceramic.

[0045] In some embodiments of the application, in step 5, the fourth preset temperature is 140-160℃, and the solidification time is 2-4h.

[0046] In some specific embodiments of the present application, in step 6, the fifth preset temperature is 1000-1500 DEG C, and the cracking time is 1-2 h, and the specific process is as follows: the temperature is increased from room temperature to 1000-1500 DEG C at a rate of 5-10 DEG C / min, and then the temperature is kept for 1-2 h, then the temperature is decreased to 300 DEG C at a rate of 4 DEG C / min, and then the furnace is cooled to room temperature, to obtain the ZrB2 / SiC ultra-high temperature ceramic matrix composite material.

[0047] In some specific embodiments of the present application, in steps 3-6, the inert atmosphere is argon.

[0048] Example 1

[0049] Step 1: The ZrB2 liquid precursor is placed in an oven for cross-linking and curing at 160 DEG C for 2 h, and then the solid after cross-linking and curing is fully ground in a mortar to obtain a precursor powder;

[0050] Step 2: The precursor powder is pressed into a block solid under a dry press;

[0051] Step 3: The block solid pressed in step 2 is placed in a tubular heat treatment furnace under a flowing Ar atmosphere, and the temperature is increased from room temperature to 600 DEG C at a rate of 5 DEG C / min, and then the temperature is kept for 2 h, then the temperature is decreased to 300 DEG C at a rate of 5 DEG C / min, and then the furnace is cooled to room temperature;

[0052] Step 4: The sample after treatment in step 3 is placed in a high-temperature tubular furnace under a flowing Ar atmosphere, and the temperature is increased from room temperature to 1500 DEG C at a rate of 5 DEG C / min, and then the temperature is kept for 2 h, then the temperature is decreased to 300 DEG C at a rate of 4 DEG C / min, and then the furnace is cooled to room temperature, to obtain ZrB2 ceramic;

[0053] Step 5: The ZrB2 ceramic obtained in step 4 is immersed in liquid polycarbosilane for vacuum impregnation, and the sample after impregnation is cured at 160 DEG C for 2 h under an Ar atmosphere;

[0054] Step 6: The sample after curing is placed in a high-temperature tubular furnace under a flowing Ar atmosphere, and the temperature is increased from room temperature to 1000 DEG C at a rate of 5 DEG C / min, and then the temperature is kept for 2 h, then the temperature is decreased to 300 DEG C at a rate of 4 DEG C / min, and then the furnace is cooled to room temperature, to obtain the ZrB2 / SiC ultra-high temperature ceramic matrix composite material.

[0055] Example 2

[0056] Step 1: The ZrB2 liquid precursor is placed in an oven for cross-linking and curing at 160 DEG C for 2 h, and then the solid after cross-linking and curing is fully ground in a mortar to obtain a precursor powder;

[0057] Step 2: The precursor powder is pressed into a block solid under a dry press;

[0058] Step 3: Put the block solid from step 2 into a tube furnace under flowing Ar atmosphere, heat up from room temperature to 600℃ at a rate of 5℃ / min, keep for 2h, then cool down to 300℃ at a rate of 5℃ / min, and cool down to room temperature with furnace;

[0059] Step 4: Put the sample from step 3 into a tube furnace under flowing Ar atmosphere, heat up from room temperature to 1500℃ at a rate of 5℃ / min, keep for 2h, then cool down to 300℃ at a rate of 4℃ / min, and cool down to room temperature with furnace, to get ZrB2 ceramic;

[0060] Step 5: Put the ZrB2 ceramic from step 4 into liquid polycarbosilane, and vacuum impregnate, then solidify the sample at 160℃ for 2h under Ar atmosphere;

[0061] Step 6: Put the solidified sample into a tube furnace under flowing Ar atmosphere, heat up from room temperature to 1100℃ at a rate of 5℃ / min, keep for 2h, then cool down to 300℃ at a rate of 4℃ / min, and cool down to room temperature with furnace, to get ZrB2 / SiC ultra-high temperature ceramic matrix composite.

[0062] Example 3

[0063] Step 1: Put ZrB2 liquid precursor into an oven to cross-link and solidify at 160℃ for 2h, then grind the cross-linked and solidified solid in a mortar to get precursor powder;

[0064] Step 2: Press the precursor powder into a block solid under a dry press;

[0065] Step 3: Put the block solid from step 2 into a tube furnace under flowing Ar atmosphere, heat up from room temperature to 600℃ at a rate of 5℃ / min, keep for 2h, then cool down to 300℃ at a rate of 5℃ / min, and cool down to room temperature with furnace;

[0066] Step 4: Put the sample from step 3 into a tube furnace under flowing Ar atmosphere, heat up from room temperature to 1500℃ at a rate of 5℃ / min, keep for 2h, then cool down to 300℃ at a rate of 4℃ / min, and cool down to room temperature with furnace, to get ZrB2 ceramic;

[0067] Step 5: Put the ZrB2 ceramic from step 4 into liquid polycarbosilane, and vacuum impregnate, then solidify the sample at 160℃ for 2-4h under Ar atmosphere;

[0068] Step 6: Put the cured sample into a high-temperature tube furnace under flowing Ar atmosphere, and increase the temperature from room temperature to 1200℃ at a rate of 5℃ / min, keep for 2h, then decrease the temperature to 300℃ at a rate of 4℃ / min, and cool down to room temperature with the furnace, to obtain ZrB2 / SiC ultra-high temperature ceramic matrix composite material.

[0069] Example 4

[0070] Step 1: Put the ZrB2 liquid precursor into an oven for cross-linking and curing at 160℃ for 2h, then grind the cross-linked and cured solid in a mortar to obtain a precursor powder;

[0071] Step 2: Press the precursor powder into a block solid under a dry press;

[0072] Step 3: Put the block solid pressed in Step 2 into a tube furnace under flowing Ar atmosphere, and increase the temperature from room temperature to 600℃ at a rate of 5℃ / min, keep for 2h, then decrease the temperature to 300℃ at a rate of 5℃ / min, and cool down to room temperature with the furnace;

[0073] Step 4: Put the sample treated in Step 3 into a high-temperature tube furnace under flowing Ar atmosphere, and increase the temperature from room temperature to 1500℃ at a rate of 5℃ / min, keep for 2h, then decrease the temperature to 300℃ at a rate of 4℃ / min, and cool down to room temperature with the furnace, to obtain ZrB2 ceramic;

[0074] Step 5: Immers the ZrB2 ceramic obtained in Step 4 into liquid polycarbosilane for vacuum impregnation, and cure the sample after impregnation at 160℃ for 2~4h under Ar atmosphere;

[0075] Step 6: Put the cured sample into a high-temperature tube furnace under flowing Ar atmosphere, and increase the temperature from room temperature to 1500℃ at a rate of 5℃ / min, keep for 2h, then decrease the temperature to 300℃ at a rate of 4℃ / min, and cool down to room temperature with the furnace, to obtain ZrB2 / SiC ultra-high temperature ceramic matrix composite material.

[0076] Example 5

[0077] Step 1: Put the ZrB2 liquid precursor into an oven for cross-linking and curing at 160℃ for 2h, then grind the cross-linked and cured solid in a mortar to obtain a precursor powder;

[0078] Step 2: Press the precursor powder into a block solid under a dry press;

[0079] Step 3: The pressed block solid in Step 2 was put into a tube furnace under flowing Ar atmosphere, and heated from room temperature to 600℃ at a rate of 5℃ / min, kept for 2h, then cooled to 300℃ at a rate of 5℃ / min, and finally cooled to room temperature with the furnace.

[0080] Step 4: The treated sample in Step 3 was put into a high temperature tube furnace under flowing Ar atmosphere, and heated from room temperature to 1600℃ at a rate of 5℃ / min, kept for 2h, then cooled to 300℃ at a rate of 4℃ / min, and finally cooled to room temperature with the furnace, to obtain ZrB2ceramics.

[0081] Step 5: The ZrB2ceramics obtained in Step 4 was immersed in liquid polycarbosilane for vacuum impregnation, and the impregnated sample was cured at 160℃ for 2h under Ar atmosphere.

[0082] Step 6: The cured sample was put into a high temperature tube furnace under flowing Ar atmosphere, and heated from room temperature to 1200℃ at a rate of 5℃ / min, kept for 2h, then cooled to 300℃ at a rate of 4℃ / min, and finally cooled to room temperature with the furnace, to obtain ZrB2 / SiC ultra-high temperature ceramic matrix composite.

[0083] Comparative Example 1

[0084] Step 1: The ZrB2liquid precursor was placed in an oven and crosslinked and cured at 160℃ for 2h, and then the crosslinked and cured solid was thoroughly ground in a mortar to obtain a precursor powder;

[0085] Step 2: The precursor powder was pressed into a block solid under a dry press;

[0086] Step 3: The pressed block solid in Step 2 was put into a tube furnace under flowing Ar atmosphere, and heated from room temperature to 600℃ at a rate of 5℃ / min, kept for 2h, then cooled to 300℃ at a rate of 5℃ / min, and finally cooled to room temperature with the furnace.

[0087] Step 4: The treated sample in Step 3 was put into a high temperature tube furnace under flowing Ar atmosphere, and heated from room temperature to 1400℃ at a rate of 5℃ / min, kept for 2h, then cooled to 300℃ at a rate of 4℃ / min, and finally cooled to room temperature with the furnace, to obtain ZrB2ceramics.

[0088] Comparative Example 2

[0089] Step 1: The ZrB2liquid precursor was placed in an oven and crosslinked and cured at 160℃ for 2h, and then the crosslinked and cured solid was thoroughly ground in a mortar to obtain a precursor powder;

[0090] Step 2: The precursor powder was pressed into a block solid under a dry presser;

[0091] Step 3: The block solid pressed in Step 2 was put into a tube furnace under flowing Ar atmosphere, and heated from room temperature to 600°C at a rate of 5°C / min, kept for 2h, then cooled to 300°C at a rate of 5°C / min, and cooled to room temperature with the furnace;

[0092] Step 4: The sample treated in Step 3 was put into a high temperature tube furnace under flowing Ar atmosphere, and heated from room temperature to 1500°C at a rate of 5°C / min, kept for 2h, then cooled to 300°C at a rate of 4°C / min, and cooled to room temperature with the furnace, to obtain ZrB2ceramics.

[0093] Comparative Example 3

[0094] Step 1: The ZrB2liquid precursor was put into an oven and cross-linked and cured at 160°C for 2h, and then the cross-linked and cured solid was ground thoroughly in a mortar to obtain a precursor powder;

[0095] Step 2: The precursor powder was pressed into a block solid under a dry presser;

[0096] Step 3: The block solid pressed in Step 2 was put into a tube furnace under flowing Ar atmosphere, and heated from room temperature to 600°C at a rate of 5°C / min, kept for 2h, then cooled to 300°C at a rate of 5°C / min, and cooled to room temperature with the furnace;

[0097] Step 4: The sample treated in Step 3 was put into a high temperature tube furnace under flowing Ar atmosphere, and heated from room temperature to 1600°C at a rate of 5°C / min, kept for 2h, then cooled to 300°C at a rate of 4°C / min, and cooled to room temperature with the furnace, to obtain ZrB2ceramics.

[0098] The volume density of the ZrB2 / SiC composite material prepared in Example 3 was 1.46g / cm 3 .

[0099] Figure 1 The XRD pattern of the ZrB2ceramics prepared in Example 3 showed that the prepared ceramics was pure ZrB2phase without other impurity peaks.

[0100] Figure 2The pure ZrB2 ceramic morphologies prepared in (a), (b), (c) are comparative example 1, comparative example 2, comparative example 3, respectively. The high-temperature pyrolysis temperatures of comparative example 1, comparative example 2, comparative example 3 are 1400℃, 1500℃ and 1600℃, respectively. It can be seen that in comparative example 1, only part of the rod-like ZrB2 ceramic is generated at a lower temperature, while at 1500℃ and 1600℃, the rod-like ZrB2 ceramic is basically formed, which shows that the high-temperature pyrolysis temperature has a great influence on the micro-morphology of ZrB2 ceramic. Figure 2 The ZrB2 / SiC composite material morphologies in (d), (e), (f) are respectively in example 3, example 4, example 5. It can be seen that the SiC in the ZrB2 / SiC composite material is uniformly coated on the surface of ZrB2. By comparing example 3 and example 4, it can be seen that the morphology of SiC will change by changing the pyrolysis temperature of SiC. In example 3, amorphous SiC is obtained at 1200℃, and in example 4, nano-crystalline is precipitated at 1500℃. Compared with comparative example 2, example 4 increases the preparation process of SiC, and compared with comparative example 3, example 5 increases the preparation process of SiC. By comparing (b) and (e), (c) and (f), it can be seen that the preparation process of SiC is successfully coated on the surface of ZrB2.

[0101] Figure 3 The transmission electron microscope photo of the ZrB2 / SiC composite material prepared in example 3 can be seen that the amorphous SiC is uniformly distributed on the surface of ZrB2, and the thickness is about 300nm.

[0102] Figure 4 The reflection loss curve of the ZrB2 / SiC composite material prepared in example 3 at different thicknesses is shown. Taking-10dB as the standard of effective absorption, it can be seen that the minimum reflection loss of the ZrB2 / SiC composite material is-57.92dB, and the effective absorption bandwidth is 5.68GHz.

[0103] Figure 5 The reflection loss curve of the ZrB2 / SiC composite material prepared in example 4 is shown. The minimum reflection loss of the sample is-40dB, and the effective absorption bandwidth is 8.64GHz.

[0104] Figure 6 The impedance matching characteristic curves of the materials in example 3, example 4, example 5, comparative example 2 and comparative example 3 at a thickness of 3mm are shown. The Z inThe closer the Z0 value is to 1, the better the impedance matching is. As can be seen from the figure, the impedance matching of the composite material of Example 4 is better than that of Example 3, which shows that the SiC cracking temperature has a certain influence on the impedance matching, and the higher the cracking temperature of SiC, the better the impedance matching is. As can be seen from the figure, the impedance matching of the composite material of Example 3 is better than that of Example 5, which shows that the high-temperature cracking temperature of ZrB2 also has a certain influence on the impedance matching, and the lower the high-temperature cracking temperature of ZrB2, the better the impedance matching is, which is contrary to the rule of SiC. As can be seen from the comparison between Example 4 and Comparative Example 2 and the comparison between Example 5 and Comparative Example 3, the impedance matching of Example 4 and Example 5 coated with SiC is greatly improved compared with Comparative Example 2 and Comparative Example 3 without coating SiC, which shows that the addition of SiC makes the impedance matching characteristics of the composite material obviously improved.

Claims

1. A method for producing a ZrB2 / SiC ceramic matrix composite material, characterized by, The method comprises the following steps: Step 1: cross-linking and curing ZrB2 liquid precursor at a first preset temperature, grinding the solid obtained by cross-linking and curing to obtain a precursor powder; wherein the ZrB2 liquid precursor comprises polyacetylacetone zirconium, boric acid and phenolic resin; Step 2: pressing the precursor powder to obtain a green body; Step 3: low-temperature pyrolysis of the green body at a second preset temperature under an inert atmosphere to obtain a pyrolyzed green body; Step 4: high-temperature pyrolysis of the pyrolyzed green body at a third preset temperature under an inert atmosphere to obtain ZrB2 ceramic; wherein the third preset temperature is 1500-1600 DEG C; Step 5: immersing the ZrB2 ceramic in liquid polycarbosilane for vacuum impregnation, and then curing the ZrB2 ceramic at a fourth preset temperature under an inert atmosphere after impregnation is completed; Step 6: high-temperature pyrolysis of the sample after curing in step 5 at a fifth preset temperature under an inert atmosphere to obtain ZrB2 / SiC ultra-high temperature ceramic matrix composite.

2. The method of claim 1, wherein the ZrB2 / SiC ceramic matrix composite is prepared by the steps of: In step 1, the first preset temperature is 120-160 DEG C, and the cross-linking and curing time is 2-3 h.

3. The method of claim 1, wherein the ZrB2 / SiC ceramic matrix composite is prepared by the steps of: mixing a ZrB2 powder and a SiC powder to form a mixture; and sintering the mixture at a temperature of 1900°C to 2100°C in a vacuum or an inert gas atmosphere. In step 3, the second preset temperature is 300-600 DEG C, and the pyrolysis time is 2-3 h.

4. The method of making a ZrB2 / SiC ceramic matrix composite according to claim 1, wherein, In step 4, the pyrolysis time is 1-2 h.

5. The method of making a ZrB2 / SiC ceramic matrix composite according to claim 1, wherein, In step 5, the fourth preset temperature is 140-160 DEG C, and the curing time is 2-4 h.

6. The method of making a ZrB2 / SiC ceramic matrix composite according to claim 1, wherein, In step 6, the fifth preset temperature is 1000-1500 DEG C, and the pyrolysis time is 1-2 h.

7. The method of making a ZrB2 / SiC ceramic matrix composite according to claim 1, wherein, In steps 3-6, the inert atmosphere is argon.

8. The ZrB2 / SiC ceramic matrix composite obtained by the preparation method of claim 1.

9. The application of the ZrB2 / SiC ceramic matrix composite of claim 8 as a wave-absorbing material in the field of wave absorption.

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