CN116178039B - Wave-absorbing complex-phase ceramic and preparation method thereof - Google Patents
Wave-absorbing complex-phase ceramic and preparation method thereof Download PDFInfo
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- 239000000919 ceramic Substances 0.000 title claims abstract description 185
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 52
- -1 rare earth silicate Chemical class 0.000 claims abstract description 48
- 150000001721 carbon Chemical class 0.000 claims abstract description 30
- 239000011159 matrix material Substances 0.000 claims abstract description 28
- SICLLPHPVFCNTJ-UHFFFAOYSA-N 1,1,1',1'-tetramethyl-3,3'-spirobi[2h-indene]-5,5'-diol Chemical compound C12=CC(O)=CC=C2C(C)(C)CC11C2=CC(O)=CC=C2C(C)(C)C1 SICLLPHPVFCNTJ-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000011148 porous material Substances 0.000 claims abstract description 8
- 150000002910 rare earth metals Chemical group 0.000 claims abstract description 4
- 229920003257 polycarbosilane Polymers 0.000 claims description 34
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 24
- 239000012700 ceramic precursor Substances 0.000 claims description 23
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 20
- 239000003054 catalyst Substances 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 16
- 238000001035 drying Methods 0.000 claims description 13
- 238000005245 sintering Methods 0.000 claims description 13
- 238000004227 thermal cracking Methods 0.000 claims description 12
- 239000002131 composite material Substances 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 11
- 239000011230 binding agent Substances 0.000 claims description 10
- 238000005336 cracking Methods 0.000 claims description 10
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 9
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 9
- 238000003756 stirring Methods 0.000 claims description 8
- 238000007598 dipping method Methods 0.000 claims description 7
- 238000009740 moulding (composite fabrication) Methods 0.000 claims description 7
- 238000005470 impregnation Methods 0.000 claims description 6
- 238000001354 calcination Methods 0.000 claims description 4
- 238000003825 pressing Methods 0.000 claims description 4
- 239000012300 argon atmosphere Substances 0.000 claims description 3
- 238000003837 high-temperature calcination Methods 0.000 claims description 3
- 238000010521 absorption reaction Methods 0.000 abstract description 20
- 230000007547 defect Effects 0.000 abstract description 12
- 230000002708 enhancing effect Effects 0.000 abstract description 3
- XUGSDIOYQBRKGF-UHFFFAOYSA-N silicon;hydrochloride Chemical compound [Si].Cl XUGSDIOYQBRKGF-UHFFFAOYSA-N 0.000 abstract description 3
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 7
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- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000000463 material Substances 0.000 description 6
- 238000002791 soaking Methods 0.000 description 6
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- AFCARXCZXQIEQB-UHFFFAOYSA-N N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CCNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 AFCARXCZXQIEQB-UHFFFAOYSA-N 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 239000011358 absorbing material Substances 0.000 description 4
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- 239000008367 deionised water Substances 0.000 description 4
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- 238000001237 Raman spectrum Methods 0.000 description 3
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- 239000002070 nanowire Substances 0.000 description 3
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- 239000006096 absorbing agent Substances 0.000 description 2
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
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- 239000010703 silicon Substances 0.000 description 1
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- H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
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Abstract
The application discloses a wave-absorbing complex-phase ceramic and a preparation method thereof, wherein the wave-absorbing complex-phase ceramic comprises a matrix with a porous structure, siC nanowires and carbon clusters filled in pores of the matrix; the matrix is rare earth silicon hydrochloric acid ceramic with a porous structure. The matrix rare earth silicate ceramic in the wave-absorbing complex phase ceramic of the application presents porous and powdery skeleton structures, and SiC nanowires and carbon clusters in the matrix pore structures enable the wave-absorbing complex phase ceramic to generate heterogeneous interfaces, defects and amorphous structures, thereby enhancing the electromagnetic wave absorption performance of the wave-absorbing complex phase ceramic.
Description
Technical Field
The application relates to the technical field of wave-absorbing materials, in particular to wave-absorbing complex-phase ceramic and a preparation method thereof.
Background
Currently, the rapid development of wireless communication, the increasing popularity of smart home, traffic and medical equipment, brings convenience to fast-paced society. Meanwhile, a large number of electronic devices greatly increase electromagnetic radiation, and serious electromagnetic pollution is caused. These electromagnetic contaminations not only interfere with the operation of the electrical equipment but are also harmful to human health and the natural environment. Therefore, development of high-performance electromagnetic wave absorbing materials, which convert incident electromagnetic waves into heat or dissipate the incident electromagnetic waves through interfaces, has great significance. Moreover, with the wide application of wave-absorbing materials in military weapons, the development of high temperature and water-oxygen environments has put higher demands on strong absorption of electromagnetic waves in terms of oxidation resistance and corrosion resistance.
At present, the traditional ceramic matrix has a relatively high real part of dielectric constant, a large amount of electromagnetic waves can be reflected on the surface of the material, the electromagnetic waves cannot enter the material as much as possible to be absorbed, and the ceramic matrix cannot be applied to the problem of severe environment.
Based on this, a material having excellent absorption performance for electromagnetic waves is in need of development.
Disclosure of Invention
In order to solve the problems that electromagnetic waves of the existing ceramic matrix can reflect on the surface of a material, cannot enter the material as far as possible to be absorbed, and cannot be applied to severe environments, one of the purposes of the application is to provide the wave-absorbing complex-phase ceramic.
The technical scheme for solving the technical problems is as follows:
a wave-absorbing complex phase ceramic comprises a matrix with a porous structure, siC nanowires and carbon clusters, wherein the SiC nanowires and the carbon clusters are filled in pores of the matrix;
the matrix is rare earth silicon hydrochloric acid ceramic with a porous structure.
The beneficial effects of the application are as follows: the matrix rare earth silicate ceramic in the wave-absorbing complex phase ceramic of the application presents porous and powdery skeleton structures, and SiC nanowires and carbon clusters in the matrix pore structures enable the wave-absorbing complex phase ceramic to generate heterogeneous interfaces, defects and amorphous structures, thereby enhancing the electromagnetic wave absorption performance of the wave-absorbing complex phase ceramic.
Based on the technical scheme, the application can also be improved as follows:
further, the sum of the mass fractions of the SiC nanowires and the carbon clusters in the wave-absorbing complex-phase ceramic is 8.2-29.1 wt%.
The beneficial effects of adopting the further technical scheme are as follows: the wave-absorbing composite ceramic in the mass fraction range has better absorption performance on electromagnetic waves.
Further, the rare earth silicate ceramic is Yb 2 Si 2 O 7 And (3) ceramics.
The second object of the application is to provide a preparation method of the wave-absorbing complex phase ceramic, which comprises the following steps:
step 1, adding the solution A into the solution B and stirring to obtain gel C, drying the gel C, and calcining at a high temperature to obtain a silicate ceramic precursor; wherein the solution A comprises rare earth salt, and the solution B comprises ethyl silicate;
step 2, uniformly mixing a silicate ceramic precursor and a binder to obtain a mixture D, and pressing, forming and sintering the mixture D to obtain rare earth silicate ceramic with a porous structure;
step 3, dipping rare earth silicate ceramic in the solution E, and sequentially solidifying and thermally cracking the dipped rare earth silicate ceramic under the anaerobic condition to obtain the rare earth silicate ceramic; wherein the solution E comprises polycarbosilane and a catalyst.
The beneficial effects of the application are as follows: the preparation method of YbSiOC ceramic has the characteristics of simple process and easy implementation, and is suitable for large-scale industrial production application; in addition, the YbSiOC ceramic prepared by the method of the application has porous property and powdery skeleton structure, and SiC is uniformly distributed in matrix Yb in nano crystalline phase, turbine phase and amorphous phase 2 Si 2 O 7 In the ceramic, under an external alternating electromagnetic field, residual defects and nano heterogeneous interfaces in the complex-phase ceramic generate polarization loss, so that the electromagnetic wave absorption performance is enhanced.
Further, in step 1, the rare earth salt is Yb (NO 3 ) 3 ·6H 2 O；Yb(NO 3 ) 3 ·6H 2 The mol ratio of O to ethyl silicate is 1:1-1:1.5.
Further, the conditions for drying the gel C in the step 1 are as follows: drying at 70-90 deg.c for 20-30 hr and then further drying at 110-150 deg.c for 11-13 hr; the high-temperature calcination conditions of the step 1 are as follows: heat treatment is carried out for 2-4 h at 1100-1200 ℃.
Further, in the step 2, the mass ratio of the silicate ceramic precursor to the binder is 3:0.7-1.1; the binder in the step 2 is polyvinyl alcohol; the sintering conditions in the step 2 are as follows: sintering in air at 1500-1600 deg.c for 2-3 hr.
Further, in the step 3, the mass fraction of the catalyst in the solution E is 1wt%, and the mass fraction of the polycarbosilane in the solution E is 20-30 wt%; the catalyst is Co (NO) 3 ) 2 。
By adopting the above methodThe technical scheme has the beneficial effects that: according to the application, the mass fraction of the polycarbosilane is 20-30wt% so as to ensure that more polycarbosilane is impregnated into the porous rare earth silicate ceramic, so that the porous rare earth silicate ceramic matrix is prevented from being blocked due to the polycarbosilane after the impregnation with the excessive concentration, and meanwhile, the polycarbosilane after the impregnation is prevented from easily flowing out of the porous rare earth silicate ceramic; and the catalyst is Co (NO) 3 ) 2 Is beneficial to the generation of SiC nanowires in the anaerobic thermal cracking process.
Further, the impregnation conditions in step 3 are: dipping in vacuum for 25-35 min; the curing conditions in step 3 are: anaerobic treatment is carried out for 2 to 3 hours at the temperature of 100 to 150 ℃; the anaerobic thermal cracking conditions in the step 3 are as follows: thermally cracking for 2-3 h in argon atmosphere at 1100-1550 ℃.
The beneficial effects of adopting the further technical scheme are as follows: the oxygen-free curing can prevent the solution E immersed in the rare earth silicate porous ceramic from flowing out, and simultaneously prevent the polycarbosilane from reacting under the action of oxygen to generate other impurities;
and the anaerobic thermal cracking is carried out within the range of 1100-1550 ℃, so that the situation that the polycarbosilane polymer is an amorphous substance and SiC nanowires cannot be formed when the thermal cracking temperature is lower than 1100 ℃ is avoided.
Further, the preparation method further comprises repeating step 3 at least 5 times.
The application has the following beneficial effects:
1. the application adopts porous Yb with lower dielectric constant 2 Si 2 O 7 The YbSiOC composite ceramic synthesized by the precursor permeation pyrolysis (PIP) of Polycarbosilane (PCS) has excellent electromagnetic wave absorption performance as a matrix of the wave-absorbing composite ceramic; in addition, the content of SiCNws and carbon clusters is controlled by controlling the circulation times of the precursor osmotic pyrolysis (PIP), so that YbSiOC composite phase ceramic with adjustable dielectric constant and electromagnetic wave absorption characteristic is prepared; further, according to the subsequent test of the present application, it is known that when the sum of the mass fractions of SiCNws and carbon clusters in the wave-absorbing complex phase ceramic is higher than 28.2wt%, the YbSiOC ceramic can absorb 99.99% of electromagnetic wavesA wave.
2. The preparation method provided by the application has the advantages of simple process and easiness in implementation, and is suitable for large-scale industrial production application. The wave-absorbing complex phase ceramic prepared by the method has porous property and powdery skeleton structure, and SiC is uniformly distributed in a matrix Yb in a nano crystalline phase, a turbine phase and an amorphous phase 2 Si 2 O 7 In the ceramic, under an external alternating electromagnetic field, residual defects and nano heterogeneous interfaces in the complex-phase ceramic generate polarization loss, so that the electromagnetic wave absorption performance is enhanced.
Drawings
FIG. 1 shows Yb 2 Si 2 O 7 SEM pictures of ceramics and wave-absorbing complex phase ceramics (YbSiOC ceramics) prepared by the application, wherein (a) is Yb prepared by PIP-0 2 Si 2 O 7 SEM images of ceramics, (b) SEM images of YbSiOC ceramics prepared by PIP-1, (c) SEM images of YbSiOC ceramics prepared by PIP-2, (d) SEM images of YbSiOC ceramics prepared by PIP-3, (e) SEM images of YbSiOC ceramics prepared by PIP-4, (f) - (h) SEM images of YbSiOC ceramics prepared by PIP-5;
FIG. 2 is a TEM image of a microwave-absorbing complex phase ceramic (YbSiOC ceramic) prepared according to the present application, wherein (a) is a TEM image of the YbSiOC ceramic, (b) is a SiCNws high resolution image corresponding to the magnification in (a), (c) is a SAED image of SiCNws, (d) to (e) are microstructure diagrams of carbon clusters, and (f) is a carbon layer diagram showing more disk-wound structures;
FIG. 3 is a Raman spectrum of a wave-absorbing complex phase ceramic (YbSiOC ceramic) prepared according to the present application;
FIG. 4 shows Yb 2 Si 2 O 7 Ceramic, and three-dimensional RL curve and two-dimensional RL curve of the wave-absorbing complex phase ceramic (YbSiOC ceramic) prepared by the application, wherein (a) - (b) are Yb prepared by PIP-0 2 Si 2 O 7 Three-dimensional and two-dimensional RL curves of ceramic, and (c) - (d) are Yb prepared from PIP-1 2 Si 2 O 7 Three-dimensional and two-dimensional RL curves of ceramic, and (e) to (f) are Yb prepared from PIP-2 2 Si 2 O 7 Ceramic three-dimensional RL curve and two-dimensional RL curve, and (g) - (h) are Yb prepared from PIP-3 2 Si 2 O 7 A three-dimensional RL curve and a two-dimensional RL curve of the ceramic,(i) Yb prepared for PIP-4 in the following (j) 2 Si 2 O 7 Ceramic three-dimensional RL curve and two-dimensional RL curve, wherein (k) - (l) are Yb prepared from PIP-5 2 Si 2 O 7 A three-dimensional RL curve and a two-dimensional RL curve of the ceramic.
Detailed Description
A wave-absorbing complex phase ceramic and a method for preparing the same according to the present application will be described below with reference to examples.
This application may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein, but rather should be construed in order that the application will be thorough and complete, and will fully convey the scope of the application to those skilled in the art.
The inventor finds that rare earth silicate has low thermal expansion coefficient, good chemical stability and excellent corrosion resistance, and is the most promising environmental barrier coating material of high-temperature silicon-based ceramics. Wherein, rare earth silicate ceramic Yb 2 Si 2 O 7 Is a typical high-temperature structural ceramic and is widely applied to high-temperature oxidation-resistant coatings, corrosion-resistant ceramics and thermal shock-resistant coatings.
At present, a great deal of research is focused on conventional absorbing materials, and conventional electromagnetic wave absorbing ceramics are composed of an absorber and carriers. For rare earth silicate ceramic Yb 2 Si 2 O 7 The composite ceramic for absorbing electromagnetic wave is less researched, the mechanism of dielectric loss and electromagnetic wave absorption is not clear, and the composite ceramic is not applied to microwave absorbing ceramic materials in severe environments.
Based on this, an embodiment of the first aspect of the present application provides a wave-absorbing complex phase ceramic, including a matrix having a porous structure, and SiC nanowires and carbon clusters filled in pores of the matrix; wherein, the matrix is rare earth silicon hydrochloric acid ceramic with a porous structure.
In this embodiment, the matrix rare earth silicate ceramic in the wave-absorbing complex phase ceramic presents a porous and powdery skeleton structure, and the SiC nanowires (i.e., siCnws) and carbon clusters located in the matrix pore structure enable the wave-absorbing complex phase ceramic to generate heterogeneous interfaces, defects and amorphous structures, thereby enhancing the electromagnetic wave absorption performance of the wave-absorbing complex phase ceramic.
In addition, in some embodiments, the sum of the mass fractions of SiC nanowires and carbon clusters in the wave-absorbing complex-phase ceramic is 8.2 to 29.1wt%. In the embodiment, the wave-absorbing complex phase ceramic within the mass fraction range has better absorption performance on electromagnetic waves; preferably, the sum of the mass fractions of the SiC nanowires and the carbon clusters in the wave-absorbing composite ceramic is 28.2-29.1 wt%, and the wave-absorbing composite ceramic with the mass fractions can absorb 99.99wt% of electromagnetic waves.
Additionally, in some embodiments, the rare earth silicate ceramic is Yb 2 Si 2 O 7 A ceramic; yb in the present example 2 Si 2 O 7 Ceramics have a low thermal expansion coefficient, a low dielectric constant, good chemical stability, and excellent corrosion resistance, and as a matrix, the prepared YbSiOC ceramics (i.e., wave-absorbing complex phase ceramics) can be used for absorption of electromagnetic waves in high-temperature and water-oxygen environments.
Embodiments of the second aspect of the present application provide a method for preparing the wave-absorbing complex-phase ceramic (i.e., ybSiOC ceramic) in the embodiments of the first aspect, the preparation method comprising:
step 1, adding the solution A into the solution B and stirring to obtain gel C, drying the gel C, and calcining at a high temperature to obtain a silicate ceramic precursor; wherein the solution A comprises rare earth salt, and the solution B comprises ethyl silicate;
step 2, uniformly mixing a silicate ceramic precursor and a binder to obtain a mixture D, and pressing, forming and sintering the mixture D to obtain rare earth silicate ceramic with a porous structure;
step 3, dipping rare earth silicate ceramic in the solution E, and sequentially solidifying and thermally cracking the dipped rare earth silicate ceramic under the anaerobic condition to obtain the rare earth silicate ceramic; wherein the solution E comprises polycarbosilane and a catalyst.
The preparation method of YbSiOC ceramic in the embodiment has the characteristics of simple process and easy implementation, and is suitable for large-scale industrial production and application; the method comprises the following steps: in the embodiment, a sol-gel method is used for preparing a silicate ceramic precursor, then the silicate ceramic precursor is pressed and molded and sintered to obtain porous rare earth silicate ceramic, then a polymer impregnation thermal cracking method (PIP) is adopted to introduce a mixed solution of polycarbosilane and a catalyst into the porous rare earth silicate ceramic, and then the impregnated rare earth silicate ceramic is sequentially solidified and thermally cracked under the anaerobic condition to obtain the wave-absorbing complex phase ceramic.
In addition, the YbSiOC ceramic prepared by the method in the implementation shows porous property and powdery skeleton structure, and SiC is uniformly distributed in a matrix Yb in a nano crystalline phase, a turbine phase and an amorphous phase 2 Si 2 O 7 In the ceramic, under an external alternating electromagnetic field, residual defects and nano heterogeneous interfaces in the complex-phase ceramic generate polarization loss, so that the electromagnetic wave absorption performance is enhanced.
In the embodiment, in order to control the mass fraction of the SiC nanowires and the carbon clusters in the wave-absorbing complex-phase ceramic, 99.99wt% of electromagnetic waves can be absorbed by the wave-absorbing complex-phase ceramic; in some embodiments, the method of preparing further comprises repeating step 3 at least 5 times.
In addition, in some embodiments, the rare earth salt in step 1 is Yb (NO 3 ) 3 ·6H 2 O；Yb(NO 3 ) 3 ·6H 2 The mol ratio of O to ethyl silicate is 1:1-1:1.5; preferably, yb (NO 3 ) 3 The concentration is 3.5-5 mo/L, and the concentration of the tetraethoxysilane in the solution B is 3.5-5 mo/L. In this example, yb (NO 3 ) 3 ·6H 2 O is dissolved to prepare solution A; the ethyl silicate was dissolved in ethanol to prepare solution B.
In addition, in some embodiments, the conditions for drying gel C in step 1 are: drying at 70-90 deg.c for 20-30 hr and then further drying at 110-150 deg.c for 11-13 hr; the conditions of the high-temperature calcination in the step 1 are as follows: heat treatment is carried out for 2-4 h at 1100-1200 ℃.
In addition, in some embodiments, the mass ratio of silicate ceramic precursor to binder in step 2 is 3:0.7-1.1; the binder in the step 2 is polyvinyl alcohol; in the embodiment, in the mass ratio range, the problem that too many holes in the rare earth silicate ceramic are generated due to excessive amount of polyvinyl alcohol, so that the rare earth silicate porous ceramic cannot be molded is avoided;
the sintering conditions in the step 2 are as follows: sintering in 1500-1600 deg.c air for 2-3 hr. Sintering is carried out in the temperature range, so that rare earth silicate ceramics with porous structures can be generated; avoid the problem that the polyvinyl alcohol cannot be treated cleanly due to too low sintering temperature and also avoid Yb caused by too high sintering temperature 2 Si 2 O 7 The crystal structure is destroyed.
In addition, in some embodiments, the mass fraction of catalyst in solution E in step 3 is 1wt% and the mass fraction of polycarbosilane in solution E is 20-30 wt%; the catalyst is Co (NO) 3 ) 2 . In the embodiment, the mass fraction of the polycarbosilane in the solution E is 20-30wt% so as to ensure that more polycarbosilane is impregnated into the porous rare earth silicate ceramic, prevent the porous rare earth silicate ceramic matrix from being blocked due to the polycarbosilane after being impregnated with the solution E with too high concentration, and simultaneously prevent the polycarbosilane after being impregnated from easily flowing out of the porous rare earth silicate ceramic; and the catalyst is Co (NO) 3 ) 2 Is beneficial to the generation of SiC nanowires in the anaerobic thermal cracking process.
In this example, polysilocarb is dissolved in a solution containing Co (NO 3 ) 2 To thereby prepare a solution E.
In addition, in some embodiments, the conditions of the curing process in step 3 are: anaerobic treatment is carried out for 2 to 3 hours at the temperature of 100 to 150 ℃; the anaerobic thermal cracking conditions in the step 3 are as follows: thermally cracking for 2-3 h in argon atmosphere at 1100-1550 ℃. In the embodiment, the solution E in the rare earth silicate porous ceramic is prevented from flowing out through curing treatment, so that the amounts of SiC nanowires and carbon clusters in the generated wave-absorbing complex-phase ceramic are ensured to a certain extent; and curing under the anaerobic condition can avoid organic reaction of polycarbosilane under the aerobic condition, so that SiC nanowires and carbon clusters can not be generated in the subsequent anaerobic thermal cracking process.
In addition, the anaerobic thermal cracking is carried out within the range of 1100-1550 ℃, so that the existence of an amorphous substance, namely polycarbosilane polymer, at the thermal cracking temperature lower than 1100 ℃ can be avoided, the conductivity is low, and the electromagnetic wave absorption can not be achieved; and this temperature range ensures the generation of SiC nanowires and carbon clusters during anaerobic thermal cracking.
Of course, in order to increase the amount of catalyst and polycarbosilane impregnated into the rare earth silicate ceramic, the impregnation conditions in step 3 are: dipping in vacuum for 25-35 min, and dipping at any vacuum degree.
Examples
Example 1
The preparation of the wave-absorbing complex phase ceramic comprises the following steps:
step 1, yb (NO) 3 ) 3 ·6H 2 O is stirred and dissolved in deionized water to obtain a solution A, and tetraethoxysilane is stirred and dissolved in ethanol to obtain a solution B; adding the solution A into the solution B at room temperature, stirring and mixing to obtain gel C, wherein Yb (NO) 3 ) 3 ·6H 2 The molar ratio of O to ethyl orthosilicate is 1:1.2, yb (NO 3 ) 3 The concentration is 4mo/L, and the concentration of the tetraethoxysilane in the solution B is 4mo/L;
then, sequentially placing the gel C at 80 ℃ and 110 ℃ to be dried for 24h and 13h respectively, and then placing the gel C at 1100 ℃ to be calcined for 2h to obtain a silicate ceramic precursor; grinding the silicate ceramic precursor for 30min by an agate ball milling tank, repeatedly ball milling for 10 times, and obtaining the silicate ceramic precursor Yb at 15min intervals 2 Si 2 O 7 And (3) powder.
Step 2, 3.0g of Yb 2 Si 2 O 7 Uniformly mixing the powder with 0.9g of polyvinyl alcohol to obtain a mixture D, and then compacting the mixture D under a pressure of 20MPa (cold compacting to a size of 35X 15X 4 mm) 3 Cube of (c) and then sintered in air at 1500 c for 2 hours to obtain porous Yb 2 Si 2 O 7 And (3) ceramics.
Step 3, polycarbosilane is dissolved in Co (NO) 3 ) 2 ·6H 2 Forming a solution E in which the mass fraction of polycarbosilane is 25wt% and Co (NO 3 ) 2 ·6H 2 The mass fraction of O is 1wt%; porous Yb under vacuum 2 Si 2 O 7 Soaking the ceramic in the solution E for 30min, and soaking the porous Yb 2 Si 2 O 7 Curing the ceramic for 2 hours at 120 ℃ under anaerobic condition, and then thermally cracking the ceramic for 3 hours at 1550 ℃ under argon condition to thermally crack the polycarbosilane into SiCNws and carbon clusters;
and step 4, repeating the step 3 for 5 times to finally prepare the YbSiOC complex phase ceramic.
Example 2
The preparation of the wave-absorbing complex phase ceramic comprises the following steps:
step 1, yb (NO) 3 ) 3 ·6H 2 O is stirred and dissolved in deionized water to obtain a solution A, and tetraethoxysilane is stirred and dissolved in ethanol to obtain a solution B; at room temperature, adding solution A into solution B, stirring, and mixing to obtain gel C, wherein Yb (NO) 3 ) 3 ·6H 2 The molar ratio of O to ethyl orthosilicate is 1:1.5, yb (NO 3 ) 3 The concentration is 5mo/L, and the concentration of the tetraethoxysilane in the solution B is 5mo/L;
then sequentially placing the gel C at 70 ℃ and 130 ℃ to be dried for 28h and 12h respectively, and then placing the gel C at 1150 ℃ to be heat-treated for 3h to prepare a silicate ceramic precursor; grinding the silicate ceramic precursor for 30min by an agate ball milling tank, repeating ball milling for 10 times, and obtaining the silicate ceramic precursor Yb at 15min intervals 2 Si 2 O 7 And (3) powder.
Step 2, 3.0g of Yb 2 Si 2 O 7 Uniformly mixing the powder with 0.7g of polyvinyl alcohol to obtain a mixture D, and then compacting the mixture D under a pressure of 20MPa (cold compacting to a size of 35X 15X 4 mm) 3 Cube of (c) and sintered in air at 1550 c for 2.5h to obtain porous Yb 2 Si 2 O 7 And (3) ceramics.
Step 3, polycarbosilane is dissolved in a solution containing Co (NO 3 ) 2 ·6H 2 Forming a solution E in which the mass fraction of polycarbosilane is 30wt% and Co (NO 3 ) 2 ·6H 2 The mass fraction of O is 1wt%; porous Yb under vacuum 2 Si 2 O 7 Soaking the ceramic in the solution E for 25min, and soaking the porous Yb 2 Si 2 O 7 Curing the ceramic for 2.5 hours at 110 ℃ under anaerobic condition, and then thermally cracking the ceramic for 2 hours at 1100 ℃ under argon condition to thermally crack the polycarbosilane into SiCNws and carbon clusters;
and step 4, repeating the step 3 for 6 times to finally prepare the YbSiOC complex phase ceramic.
Example 3
The preparation of the wave-absorbing complex phase ceramic comprises the following steps:
step 1, yb (NO) 3 ) 3 ·6H 2 O is stirred and dissolved in deionized water to obtain a solution A, and tetraethoxysilane is stirred and dissolved in ethanol to obtain a solution B; at room temperature, adding solution A into solution B, stirring, and mixing to obtain gel C, wherein Yb (NO) 3 ) 3 ·6H 2 The molar ratio of O to ethyl orthosilicate is 1:1, yb (NO 3 ) 3 The concentration is 3.5mo/L, and the concentration of the tetraethoxysilane in the solution B is 3.5mo/L;
then sequentially placing the gel C at 90 ℃ and 150 ℃ to be dried for 22h and 11h respectively, and then placing the gel C at 1200 ℃ to be heat-treated for 2h to obtain a silicate ceramic precursor; grinding the silicate ceramic precursor for 30min by an agate ball milling tank, repeatedly ball milling for 10 times, and obtaining the silicate ceramic precursor Yb at 15min intervals 2 Si 2 O 7 A powder;
step 2, 3.0g of Yb 2 Si 2 O 7 Uniformly mixing the powder with 1.1g of polyvinyl alcohol to obtain a mixture D, and then compacting the mixture D under a pressure of 20MPa (cold compacting to a size of 35X 15X 4 mm) 3 Cube of (c) and sintered in air at 1600 c for 3 hours to obtain porous Yb 2 Si 2 O 7 A ceramic;
step 3, polycarbosilane is dissolved in a solution containing Co (NO 3 ) 2 ·6H 2 Forming a solution E in the O solution, wherein the mass fraction of polycarbosilane in the solution E is 20wt%, and the mass fraction of polycarbosilane in the solution E is 1wt%; in vacuumPorous Yb under the condition 2 Si 2 O 7 Soaking the ceramic in the solution E for 35min, and soaking the porous Yb 2 Si 2 O 7 Curing the ceramic for 3 hours at 150 ℃ under anaerobic condition, and then thermally cracking the ceramic for 3 hours at 1400 ℃ under argon condition to thermally crack the polycarbosilane into SiCNws and carbon clusters;
and 4, repeating the step 3 for 5 times to finally prepare the YbSiOC complex phase ceramic.
Example 4
The method for producing the wave-absorbing complex phase ceramic in this example is the same as that in example 3, except that: step 3 is not repeated.
Example 5
The method for producing the wave-absorbing complex phase ceramic in this example is the same as that in example 3, except that: and repeating the step 3 for 1 time in the step 4.
Example 6
The method for producing the wave-absorbing complex phase ceramic in this example is the same as that in example 3, except that: and step 4, repeating the step 3 for 2 times.
Example 7
The method for producing the wave-absorbing complex phase ceramic in this example is the same as that in example 3, except that: and repeating the step 3 in the step 4 for 3 times.
Comparative example 1
A preparation method of rare earth silicate ceramic comprises the following steps:
step 1, yb (NO) 3 ) 3 ·6H 2 O is stirred and dissolved in deionized water to obtain a solution A, and tetraethoxysilane is stirred and dissolved in ethanol to obtain a solution B; at room temperature, adding solution A into solution B, stirring, and mixing to obtain gel C, wherein Yb (NO) 3 ) 3 ·6H 2 The molar ratio of O to ethyl orthosilicate is 1:1, yb (NO 3 ) 3 The concentration is 3.5mo/L, and the concentration of the tetraethoxysilane in the solution B is 3.5mo/L;
then the gel C is dried for 22h and 11h respectively at 90 ℃ and 150 ℃ in turn, and then is heat-treated for 2h at 1200 DEG Ch, obtaining a mixture D; grinding the mixture D for 30min by an agate ball milling tank, and repeating the ball milling for 10 times at 15min intervals to obtain silicate ceramic precursor Yb 2 Si 2 O 7 A powder;
step 2, 3.0g of Yb 2 Si 2 O 7 The powder was uniformly mixed with 1.1g of polyvinyl alcohol, and then compression-molded under a pressure of 20MPa (cold-pressed into a size of 35X 15X 4 mm) 3 Cube of (c) and sintered in air at 1600 c for 3 hours to obtain porous Yb 2 Si 2 O 7 And (3) ceramics.
Test analysis:
1. SEM test analysis
YbSiOC complex phase ceramic prepared in examples 3-7 and porous Yb prepared in comparative example 1 2 Si 2 O 7 The ceramic was subjected to SEM test analysis, the test results of which are shown in FIG. 1, wherein (a) is an SEM image of PIP-0 (i.e., porous Yb in comparative example 1 2 Si 2 O 7 SEM images of ceramics), (b) SEM images of PIP-1 (i.e., SEM images of YbSiOC multiphase ceramic in example 4), (c) SEM images of PIP-2 (i.e., SEM images of YbSiOC multiphase ceramic in example 5), (d) SEM images of PIP-3 (i.e., SEM images of YbSiOC multiphase ceramic in example 6), (e) SEM images of PIP-4 (i.e., SEM images of YbSiOC multiphase ceramic in example 7), (f) - (h) SEM images of PIP-5 (i.e., SEM images of YbSiOC multiphase ceramic in example 3);
as can be seen from the above-described fig. 1 (b) to (h), as the PIP cycle times increase, the pores in the YbSiOC composite ceramic are gradually filled with SiCnws and carbon clusters, and a 3D network microstructure is formed, as shown in fig. 1 (a) to (f); to better analyze the nanowires and carbon clusters in the YbSiOC complex phase ceramic of P-5 (i.e., the YbSiOC complex phase ceramic of example 3), the enlarged images of the nanowires and carbon clusters are shown in (g) - (h) of fig. 1; three main phases construct a composite ceramic comprising Yb 2 Si 2 O 7 And SiCNws and carbon cluster absorption phase, wherein SiC/C is in Yb 2 Si 2 O 7 The ceramic is uniformly distributed.
2. TEM test analysis
To observe the dispersion state, morphology and the nano structureLattice, TEM test was conducted on the YbSiOC ceramic prepared in example 3, and the test results are shown in FIG. 2, in which (a) is a TEM image of the YbSiOC ceramic, and it can be seen that SiCNws, carbon clusters and Yb 2 Si 2 O 7 Some new nanometer heterogeneous interfaces are formed between the matrixes, the plane spacing of the nanometer particles is respectively 0.318 nm and 0.270nm (marked by yellow solid lines), and the nanometer particles respectively correspond to Yb 2 Si 2 O 7 The (120) and (031) crystal planes, which correspond to the Selected Area Electron Diffraction (SAED) image (inserted to the upper right); (b) As for the SiCnws high resolution image corresponding to the magnification in (a), it can be seen that the planar pitch of the nanowires is 0.26nm, corresponding to the (111) plane of SiC; in addition, a carbon layer with a thickness of about 4nm was observed at the SiCnws edge, and some defects were also observed; (c) The inset in (c) depicts the SAED image of SiCnws, indicating that the high crystalline SiC mode can be identified as (101), (102) and (103) planes; (d) The carbon layer (about 10 nm) is coiled into a hollow sphere (the middle hollow is an amorphous structure with a diameter of 15 nm) as shown in (e) as the microstructure of the carbon clusters; (f) a carbon layer of a more coiled structure; from the above analysis, heterogeneous interfaces, defects and amorphous structures are beneficial to improving interface polarization loss;
3. raman spectrum test analysis of YbSiOC ceramics
The YbSiOC ceramics prepared in examples 3 to 7 were subjected to raman spectrum test analysis, and the test results are shown in fig. 3.
As can be seen from fig. 3, the samples with different PIP times after heat treatment at 1400 ℃ have both a defect D peak and a graphite structure G peak. I D /I G The value can effectively reflect the graphitization degree and the defect degree; it can be observed that the defect level increases with the PIP period; wherein I of P-5 D /I G The highest value reaches 1.12; the results show that the introduction of the multi-dimensional nanostructured absorbers (SiCnws and carbon) provides more defects, favoring the absorption of electromagnetic waves.
4. 3D, 2D reflectance test of YbSiOC ceramics
YbSiOC ceramics prepared in examples 3 to 7 and porous Yb prepared in comparative example 1 2 Si 2 O 7 Ceramic materialThe results of the test of the 3D and 2D reflectance are shown in FIG. 4, in which (a) and (b) are porous Yb prepared in comparative example 1 2 Si 2 O 7 Ceramic test result charts, (c) - (d) are YbSiOC ceramic test result charts prepared in example 4, (e) - (f) are YbSiOC ceramic test result charts prepared in example 5, (g) - (h) are YbSiOC ceramic test result charts prepared in example 6, (i) - (j) are YbSiOC ceramic test result charts prepared in example 7, and (k) - (l) are YbSiOC ceramic test result charts prepared in example 3.
As can be seen from FIG. 4, when the sum of the mass fractions of SiC nanowires and carbon clusters in the wave-absorbing complex-phase ceramic is 8.2wt%, the minimum reflectance of P-1 (RL min ) Drop to-5.2 dB at a thickness of 3.1mm (fig. 4 (c) - (d)); RL of P-2 min At 10.5GHz, at-10.66 dB, the Effective Absorption Bandwidth (EAB) covers 0.75GHz at a thickness of 3.2mm, reaching below-10 dB for the first time (FIGS. 4 (e) - (f)); RL of P-3 compared to P-2 min The values were further reduced to-14.05 dB at 9.9GHz, and EAB was widened to 0.9GHz (FIGS. 4 (g) - (h)); RL of P-4 min Reaching-50.0 dB at 9.5GHz, which shows that the electromagnetic wave absorption reaches 99.999wt%; EAB was 3.3GHz and the thickness was 3.0mm as shown in FIGS. 4 (i) - (j). However, when the sum of the mass fractions of SiC nanowires and carbon clusters in the wave-absorbing complex-phase ceramic is further increased to 29.1wt%, the RL of P-5 min At 12.1GHz the ratio P-4 increases to-42.47 dB>99.99wt% electromagnetic wave absorption); EAB can reach a maximum of 3.4GHz and a minimum thickness of 2.8mm.
The foregoing description of the preferred embodiments of the application is not intended to limit the application to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the application are intended to be included within the scope of the application.
Claims (7)
1. The wave-absorbing composite ceramic is characterized by comprising a matrix with a porous structure, and SiC nanowires and carbon clusters filled in pores of the matrix;
the matrix is rare earth silicate ceramic with a porous structure; the rare earth silicate ceramic is Yb 2 Si 2 O 7 A ceramic;
the preparation method of the wave-absorbing complex-phase ceramic comprises the following steps:
step 1, adding the solution A into the solution B and stirring to obtain gel C, drying the gel C, and calcining at a high temperature to obtain a silicate ceramic precursor; wherein the solution A comprises rare earth salt, and the solution B comprises ethyl silicate;
step 2, uniformly mixing a silicate ceramic precursor and a binder to obtain a mixture D, and pressing, forming and sintering the mixture D to obtain rare earth silicate ceramic with a porous structure;
step 3, dipping rare earth silicate ceramic in the solution E, and sequentially solidifying and thermally cracking the dipped rare earth silicate ceramic under the anaerobic condition to obtain the rare earth silicate ceramic; wherein the solution E comprises polycarbosilane and a catalyst;
the sum of mass fractions of the SiC nanowires and the carbon clusters in the wave-absorbing complex-phase ceramic is 28.2-29.1wt%;
the mass fraction of the catalyst in the solution E in the step 3 is 1wt%, and the mass fraction of the polycarbosilane in the solution E is 20-30wt%;
the catalyst is Co (NO) 3 ) 2 。
2. The method for preparing the wave-absorbing complex-phase ceramic according to claim 1, comprising the following steps:
step 1, adding the solution A into the solution B and stirring to obtain gel C, drying the gel C, and calcining at a high temperature to obtain a silicate ceramic precursor; wherein the solution A comprises rare earth salt, and the solution B comprises ethyl silicate;
step 2, uniformly mixing a silicate ceramic precursor and a binder to obtain a mixture D, and pressing, forming and sintering the mixture D to obtain rare earth silicate ceramic with a porous structure;
step 3, dipping rare earth silicate ceramic in the solution E, and sequentially solidifying and thermally cracking the dipped rare earth silicate ceramic under the anaerobic condition to obtain the rare earth silicate ceramic; wherein the solution E comprises polycarbosilane and a catalyst;
the sum of mass fractions of the SiC nanowires and the carbon clusters in the wave-absorbing complex-phase ceramic is 28.2-29.1wt%;
the mass fraction of the catalyst in the solution E in the step 3 is 1wt%, and the mass fraction of the polycarbosilane in the solution E is 20-30wt%;
the catalyst is Co (NO) 3 ) 2 。
3. The method according to claim 2, wherein the rare earth salt in step 1 is Yb (NO 3 ) 3 ·6H 2 O；
The Yb (NO) 3 ) 3 ·6H 2 The mol ratio of O to ethyl silicate is 1:1-1:1.5.
4. The method according to claim 2, wherein the conditions for drying the gel C in step 1 are: firstly, drying for 20-30 hours at 70-90 ℃, and then, continuously drying for 11-13 hours at 110-150 ℃;
the high-temperature calcination conditions in the step 1 are as follows: and heat-treating for 2-4 hours at 1100-1200 ℃.
5. The preparation method of claim 2, wherein the mass ratio of silicate ceramic precursor to binder in step 2 is 3:0.7-1.1;
the binder in the step 2 is polyvinyl alcohol; the sintering conditions in the step 2 are as follows: sintering in air at 1500-1600 ℃ for 2-3 h.
6. The method according to claim 2, wherein the impregnation conditions in step 3 are: immersing in vacuum for 25-35 min;
the curing conditions in the step 3 are as follows: anaerobic treatment is carried out for 2-3 hours at the temperature of 100-150 ℃;
the anaerobic thermal cracking conditions in the step 3 are as follows: thermally cracking for 2-3 hours at the temperature of 1100-1550 ℃ in an argon atmosphere.
7. The method according to any one of claims 2 to 6, further comprising repeating the step 3 at least 5 times.
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| CN113896543A (en) * | 2021-10-11 | 2022-01-07 | 西北工业大学 | Wave-absorbing silicon-carbon-nitrogen ceramic with layered structure and preparation method thereof |
| CN114262215A (en) * | 2022-01-05 | 2022-04-01 | 成都大学 | With Sc2Si2O7Preparation method of SiC-based microwave absorbing ceramic used as matrix |
| CN114455943A (en) * | 2022-03-30 | 2022-05-10 | 成都大学 | With Y2Si2O7Si as a matrix3N4/SiO2Preparation method of/SiC-based microwave absorbing ceramic |
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| CN114262215A (en) * | 2022-01-05 | 2022-04-01 | 成都大学 | With Sc2Si2O7Preparation method of SiC-based microwave absorbing ceramic used as matrix |
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