CN115231911B - In situ reaction Polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and preparation method thereof - Google Patents
In situ reaction Polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and preparation method thereof Download PDFInfo
- Publication number
- CN115231911B CN115231911B CN202210652517.3A CN202210652517A CN115231911B CN 115231911 B CN115231911 B CN 115231911B CN 202210652517 A CN202210652517 A CN 202210652517A CN 115231911 B CN115231911 B CN 115231911B
- Authority
- CN
- China
- Prior art keywords
- sioc
- ceramic
- scandium nitrate
- temperature
- heat treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/16—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on silicates other than clay
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
- C04B35/5603—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides with a well-defined oxygen content, e.g. oxycarbides
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
- C04B35/565—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide
- C04B35/571—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on silicon carbide obtained from Si-containing polymer precursors or organosilicon monomers
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3224—Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/48—Organic compounds becoming part of a ceramic after heat treatment, e.g. carbonising phenol resins
- C04B2235/483—Si-containing organic compounds, e.g. silicone resins, (poly)silanes, (poly)siloxanes or (poly)silazanes
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6562—Heating rate
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/656—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes characterised by specific heating conditions during heat treatment
- C04B2235/6567—Treatment time
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/658—Atmosphere during thermal treatment
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention relates to an in-situ reaction polymer conversion Sc 2 Si 2 O 7 the-SiOC complex phase ceramic and the preparation method thereof adopt scandium nitrate modified polysiloxane precursor to obtain Sc through in-situ reaction in the processes of precursor cracking and heat treatment 2 Si 2 O 7 -SiOC ceramics. At lower heat treatment temperatures, sc (NO) 3 ) 3 Sc obtained by pyrolysis 2 O 3 In-situ reaction of nanocrystalline with Si-O atomic cluster in amorphous SiOC ceramic to generate Sc 2 Si 2 O 7 A ceramic; the unreacted Si-O atom cluster in the SiOC ceramic and the amorphous disordered carbon are subjected to carbon thermal reduction reaction to generate SiC nano-crystalline grains, and a small amount of Sc of the SiC nano-crystalline grains in dispersion distribution is formed 2 Si 2 O 7 -SiOC complex phase ceramic, solves Sc 2 Si 2 O 7 The ceramic synthesis conditions are harsh, and the crystallization degree of the SiOC ceramic is low, the thermal stability is poor and the like. By regulating Sc (NO) 3 ) 3 Content and heat treatment temperature, sc can be optimized 2 Si 2 O 7 Contents of ceramic and SiC nanocrystals, sc obtained 2 Si 2 O 7 the-SiOC complex phase ceramic has the performances of high temperature resistance, oxidation resistance, dielectric tunable property and the like, and is expected to prepare a high-temperature-bearing broadband wave-absorbing ceramic matrix composite material.
Description
Technical Field
The invention belongs to the technical field of preparation of high-temperature-resistant antioxidant ceramic matrix composite materials, and relates to in-situ reaction polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and a preparation method thereof.
Background
In order to meet the urgent need of a stealth tail jet component of an aero-engine for a high-temperature bearing broadband wave-absorbing ceramic matrix composite material, 31598, a high-temperature resistant, oxidation-resistant and dielectric tunable ceramic matrix needs to be developed. The polymer converted SiOC ceramic (PDCs-SiOC) has the advantages of simple preparation process, low cost, low density, good oxidation resistance, thermal stability, chemical stability and the like, and is a key matrix material for preparing the bearing and wave-absorbing integrated ceramic matrix composite. Research shows that (Wenyan Duan, et al. Synthesis and microwave absorption properties of SiC nanowires reinformed SiOC Ceramic [ J ]. Journal of the European Ceramic Society 34 (2014) 257-266) ferrocene modified PDCs-SiOC Ceramic can catalyze and separate out SiC nanowires at about 1350 ℃, thereby improving the wave absorbing performance of the PDCs-SiOC Ceramic. However, the crystallization degree of the PDCs-SiOC ceramic is low, and the carbon phase is easily oxidized. Therefore, the high-temperature stability and the oxidation resistance of the PDCs-SiOC ceramic are required to be further improved.
In recent years, researchers have often improved the thermal stability of ceramics by introducing foreign elements into SiOC, which form high temperature stable phases during heat treatment. Chinese patent CN 111747750A discloses a preparation method of SiHfOC ceramic material, which combines a sol-gel method with a polymer conversion method to prepare HfOCl 2 Combining the sol and silicon resin to form a Hf modified polysiloxane precursor, performing crosslinking curing and pyrolysis on the Hf modified polysiloxane precursor to obtain SiHfOC ceramic, and generating HfO in situ at high temperature of the SiHfOC ceramic 2 The thermal stability of the ceramic is obviously improved compared with that of SiOC ceramic. Chinese patent CN109824364A discloses a synthesis method of SiAlZrOC ceramic, which takes methyltrimethoxysilane, dimethyldimethoxysilane, al source and Zr source as raw materials and adopts a sol-gel method combined with a polymer conversion method to prepare the SiAlZrOC ceramic. The obtained SiAlZrOC ceramic has good high temperature resistance and oxidation resistance. Based on the above, a preparation process for generating the SiOC complex-phase ceramic with high temperature resistance, oxidation resistance and electromagnetic tunability by in-situ reaction in the process of polymer conversion is explored.
Disclosure of Invention
Technical problem to be solved
In order to avoid the defects of the prior art, the invention provides an in-situ reaction polymer for converting high-temperature oxidation-resistant Sc with low dielectric constant and low loss characteristics 2 Si 2 O 7 -SiOC complex phaseThe ceramic and the preparation method solve the problem that the oxidation resistance and the wave-absorbing performance of the PDCs-SiOC ceramic are insufficient. By in-situ formation of Sc in an amorphous SiOC matrix 2 Si 2 O 7 Ceramics and SiC nanocrystals using Sc 2 Si 2 O 7 Excellent high-temperature oxidation resistance and wave absorbing performance of SiC nano crystal grains, and the Sc is synergistically improved 2 Si 2 O 7 -high temperature resistance, oxidation resistance and electromagnetic wave loss performance of SiOC complex phase ceramics. Sc is prepared by adopting scandium nitrate modified polysiloxane precursor through crosslinking, curing and cracking 2 O 3 Nano-phase reinforced SiOC ceramic, sc at lower heat treatment temperature (1300 ℃ C.) 2 O 3 Chemically reacting with SiOC (Sc) 2 O 3 +2SiO 2 →Sc 2 Si 2 O 7 ) In situ generation of Sc 2 Si 2 O 7 And precipitating SiC nano-crystalline grains from the ceramic. By controlling the heat treatment temperature and the heat preservation time, the Sc is effectively regulated and controlled 2 Si 2 O 7 And the content and the grain size of SiC nano-crystalline grains to obtain Sc of SiC nano-crystalline grains in dispersion distribution 2 Si 2 O 7 -SiOC complex phase ceramics. The invention solves the problems of low crystallization degree, poor high-temperature stability, insufficient oxidation resistance and wave-absorbing property and the like of the SiOC ceramic, and expands Sc 2 Si 2 O 7 The preparation method of the ceramic has the advantages of simple process, easy operation, strong applicability and the like.
Technical scheme
In-situ reaction polymer conversion Sc 2 Si 2 O 7 -SiOC composite ceramics, characterized by Sc (NO) 3 ) 3 Sc obtained by pyrolysis 2 O 3 In-situ reaction of Si-O atom cluster in nanocrystalline and amorphous SiOC ceramic to generate Sc 2 Si 2 O 7 The SiC nano-crystals are precipitated in the amorphous SiOC ceramic in situ to form Sc with the SiC nano-crystals distributed in a dispersed manner 2 Si 2 O 7 -SiOC complex phase ceramics; the Sc 2 Si 2 O 7 The microstructure of the-SiOC complex phase ceramic is monoclinic phase Sc 2 Si 2 O 7 And cubic phase Sc 2 O 3 Nanocrystalline particles and SiC nanoparticlesThe crystal is dispersed and distributed in the amorphous SiOC matrix to form a structure with the continuous distribution of the crystal phase/the amorphous.
Conversion of said in situ reaction polymer Sc 2 Si 2 O 7 The preparation method of the-SiOC complex phase ceramic is characterized by comprising the following steps:
the content of scandium nitrate in the scandium nitrate modified polysiloxane precursor is 3-65 wt.%;
the curing temperature is 200-250 ℃, and the curing time is 1.5-3 h;
the cracking temperature is 900-1050 ℃, and the cracking time is 1-3 h;
the heat treatment temperature is 1200-1600 ℃, and the heat treatment time is 0.5-3 h.
The mass concentration of the polysiloxane precursor solution and the mass concentration of the scandium nitrate solution are both 10wt.% to 30wt.%.
And the inert atmosphere in the step 2 and the step 3 is argon or nitrogen.
The heating rate in the step 2 and the step 3 is 1-8 ℃/min.
Advantageous effects
The invention provides an in-situ reaction polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and preparation method thereof, scandium nitrate (Sc (NO) is adopted 3 ) 3 ) A modified polysiloxane precursor, wherein Sc is obtained by in-situ reaction in the processes of precursor cracking and heat treatment 2 Si 2 O 7 -SiOC ceramics. At a lower heat treatment temperature (1200-1500 ℃), sc (NO) 3 ) 3 Sc obtained by pyrolysis 2 O 3 In-situ reaction of Si-O atom cluster in nanocrystalline and amorphous SiOC ceramic to generate Sc 2 Si 2 O 7 A ceramic; the unreacted Si-O atom cluster in the SiOC ceramic and the amorphous disordered carbon are subjected to carbon thermal reduction reaction to generate SiC nano-crystalline grains, and a small amount of Sc of the SiC nano-crystalline grains in dispersion distribution is formed 2 Si 2 O 7 -SiOC complex phase ceramic, solved Sc 2 Si 2 O 7 The ceramic synthesis conditions are harsh, the crystallization degree of the SiOC ceramic is low, the thermal stability is poor and the like. By regulating Sc (NO) 3 ) 3 Content and heat treatment temperature, sc can be optimized 2 Si 2 O 7 Contents of ceramic and SiC nanocrystals, sc obtained 2 Si 2 O 7 the-SiOC complex phase ceramic has the performances of high temperature resistance, oxidation resistance, dielectric tunable property and the like, and is expected to prepare a high-temperature-bearing broadband wave-absorbing ceramic matrix composite material. The invention expands Sc 2 Si 2 O 7 Preparation process of ceramic and obtained Sc 2 Si 2 O 7 the-SiOC complex phase ceramic has the advantages of simple preparation process, short preparation period, adjustable and controllable microstructure and dielectric property and the like.
Compared with the prior art, the invention has the beneficial effects that:
1. the method has the advantages of simple preparation process, small operation difficulty, good process stability, high repetition rate, short preparation period and strong applicability, is convenient for technicians in the field to operate and apply, and the prepared Sc 2 Si 2 O 7 The yield of the-SiOC complex phase ceramic is high.
2. The invention prepares Sc with high temperature resistance, oxidation resistance and tunable dielectric 2 Si 2 O 7 -SiOC complex phaseThe ceramic effectively solves the problems of insufficient high-temperature thermal stability, insufficient oxidation resistance and the like of the SiOC ceramic.
3. The invention provides a method for preparing Sc by combining a polymer conversion method with an in-situ reaction method 2 Si 2 O 7 Ceramic, effectively reduces Sc 2 Si 2 O 7 The preparation temperature is about 1500 ℃ to about 1400 ℃, and a new idea is provided for preparing the high-temperature-resistant, oxidation-resistant, bearing and wave-absorbing integrated ceramic matrix composite.
Drawings
FIG. 1 is an SEM image of the scandium nitrate-modified SiOC ceramic of example 1 after heat treatment at 1400 ℃. As can be seen, the Sc nitrate modified SiOC ceramic is subjected to in-situ reaction after being subjected to heat treatment at 1400 ℃ to generate Sc 2 Si 2 O 7 Ceramics, with increasing content of scandium nitrate, sc 2 Si 2 O 7 Increased in content, and Sc 2 Si 2 O 7 The particle size gradually increases.
FIG. 2 is an XRD pattern of the scandium nitrate-modified SiOC ceramic of example 1 after heat treatment at 1400 ℃. It can be seen that two amorphous packets appear in the unmodified SiOC ceramic, indicating that the degree of crystallization of the SiOC ceramic is low; sc appears in the scandium nitrate modified SiOC ceramic 2 Si 2 O 7 And as the content of scandium nitrate increases, sc 2 Si 2 O 7 The intensity of the diffraction peak is gradually increased; sc is present in the complex phase ceramic when the scandium content is increased to 11wt. -% 2 O 3 And Sc 2 Si 2 O 7 The diffraction peak of (1).
FIG. 3 is an SEM photograph of the multiphase ceramic before and after heat treatment when the scandium content is 11wt.% in example 2.
FIG. (a) is a morphology of a complex phase ceramic without heat treatment; and (b) is a morphology of the complex phase ceramic after heat treatment at 1500 ℃. It can be seen that Sc is mainly present in the non-heat-treated complex phase ceramic 2 O 3 Nanocrystalline and amorphous SiOC matrix; after heat treatment at 1500 ℃, the multiphase ceramic is treated with Sc 2 Si 2 O 7 Ceramic is used as the main component, and a small amount of SiC nanocrystalline is dispersed and distributed.
FIG. 4 shows the unmodified and the modifiedWhen the scandium content is 11wt.%, the dielectric properties of the multiphase ceramic before and after heat treatment at 1500 ℃. It can be seen that the real part and imaginary part of the dielectric constant of the unmodified SiOC ceramic after heat treatment at 1500 ℃ are still low; the scandium nitrate modified multiphase ceramic has a large amount of Sc under the cracking condition of 1000 DEG C 2 O 3 Nanocrystalline and heterogeneous interface, resulting in the increase of the imaginary part of the dielectric constant of the complex phase ceramic; after the scandium nitrate modified multiphase ceramic is subjected to heat treatment at 1500 ℃, most of Sc 2 O 3 In-situ reaction of nanocrystalline and Si-O atomic cluster to generate Sc 2 Si 2 O 7 A large amount of transmission/wave absorption nano heterogeneous interfaces are formed in the ceramic, and the carbothermal reduction reaction is carried out on (2C + SiO) 2 →SiC+CO 2 ) Generating SiC nanometer crystal with higher dielectric constant, which is beneficial to improving the dielectric constant of the complex phase ceramic.
Detailed Description
The invention will now be further described with reference to the following examples and drawings:
all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, and the technical terms used are only used for describing specific embodiments and are not intended to limit the scope of the present invention. Unless otherwise specifically stated, various starting materials, reagents, instruments and equipment used in the following examples of the present invention are commercially available. The polysiloxane used is MK resin, white solid powder; the scandium nitrate used was hydrated scandium nitrate, the molecular weight was 248.986, white solid powder, the purity was 99.99%, and purchased from Shanghai Aladdin Biotech Co.
Example 1
This embodiment 1 includes the following steps:
(1) Weighing 0.5-7 g of polysiloxane and 2-28 g of dimethylbenzene to prepare a uniform polysiloxane precursor solution; weighing 3-10 g of hydrated scandium nitrate and 12-40 g of absolute ethyl alcohol to prepare a scandium nitrate solution; and slowly adding the scandium nitrate solution into the polysiloxane precursor solution under the magnetic stirring effect at room temperature, and fully mixing to obtain the scandium nitrate modified polysiloxane precursor.
(2) Protecting the scandium nitrate modified polysiloxane precursor obtained in the step (1) in an argon atmosphereThen, crosslinking and curing are carried out, the furnace temperature is increased to 200 ℃ at the temperature increase rate of 5 ℃/min, and the temperature is kept for 2h. Grinding and sieving (200 meshes) the obtained cured product, pressing the cured product into a ceramic blank, putting the ceramic blank into a tubular furnace, and cracking the ceramic blank in the protection of argon atmosphere at the cracking temperature of 900-1000 ℃, at the heating rate of 5 ℃/min and at the heat preservation time of 2h to prepare Sc 2 O 3 Modified SiOC ceramics.
(3) Subjecting the Sc obtained in step (2) 2 O 3 Placing the modified SiOC ceramic in a tubular furnace to carry out heat treatment under the protection of argon atmosphere, wherein the heating rate is 5 ℃/min, the heat treatment temperature is 1400 ℃, and the heat preservation time is 2h to prepare Sc 2 Si 2 O 7 -SiOC complex phase ceramics.
Example 2
The present embodiment 2 comprises the following steps:
(1) 3.908g of polysiloxane and 15.632g of dimethylbenzene are weighed to prepare a uniform polysiloxane precursor solution; weighing 6.092g of hydrated scandium nitrate and 24.368g of absolute ethyl alcohol to prepare a scandium nitrate solution; and slowly adding the scandium nitrate solution into the polysiloxane precursor solution under the magnetic stirring effect at room temperature, and fully mixing to obtain the scandium nitrate modified polysiloxane precursor.
(2) And (2) carrying out cross-linking curing on the scandium nitrate modified polysiloxane precursor obtained in the step (1) under the protection of an argon atmosphere, heating the furnace to 200 ℃ at the heating rate of 5 ℃/min, and keeping the temperature for 2h. Grinding and sieving (200 meshes) the obtained cured product, pressing the cured product into a ceramic blank, putting the ceramic blank into a tubular furnace, and cracking the ceramic blank in the protection of argon atmosphere at the cracking temperature of 1000 ℃, at the heating rate of 5 ℃/min and at the heat preservation time of 2h to prepare Sc 2 O 3 Modified SiOC ceramics.
(3) Subjecting the Sc obtained in step (2) 2 O 3 Placing the modified SiOC ceramic in a tube furnace to carry out heat treatment under the protection of argon atmosphere, wherein the heat treatment temperature is 1400-1500 ℃, the heating rate is 5 ℃/min (below 1400 ℃) and 1 ℃/min (1400-1500 ℃), the heat preservation time is 2h, and preparing Sc 2 Si 2 O 7 -SiOC complex phase ceramics.
Example 3
This embodiment 3 includes the following steps:
(1) Weighing 4.462g of polysiloxane and 17.848g of xylene to prepare a uniform polysiloxane precursor solution; weighing 5.538g of hydrated scandium nitrate and 22.152g of absolute ethyl alcohol to prepare a scandium nitrate solution; and slowly adding the scandium nitrate solution into the polysiloxane precursor solution under the magnetic stirring effect at room temperature, and fully mixing to obtain the scandium nitrate modified polysiloxane precursor.
(2) And (2) carrying out cross-linking curing on the scandium nitrate modified polysiloxane precursor obtained in the step (1) under the protection of an argon atmosphere, heating the furnace to 200 ℃ at the heating rate of 5 ℃/min, and keeping the temperature for 2h. Grinding and sieving (200 meshes) the obtained cured product, pressing the cured product into a ceramic blank, putting the ceramic blank into a tubular furnace, and cracking the ceramic blank in the presence of argon atmosphere at the cracking temperature of 950 ℃, at the heating rate of 5 ℃/min and at the heat preservation time of 2h to prepare Sc 2 O 3 Modified SiOC ceramics.
(3) Subjecting the Sc obtained in step (2) 2 O 3 Placing the modified SiOC ceramic in a tube furnace for heat treatment under the protection of argon atmosphere, wherein the heat treatment temperature is 1350 ℃, the heating rate is 5 ℃/min, the heat preservation time is 3h, and preparing Sc 2 Si 2 O 7 -SiOC complex phase ceramics.
Claims (5)
1. High-temperature antioxidant Sc with low dielectric and low loss characteristics 2 Si 2 O 7 -SiOC complex phase ceramics, characterised in that Sc (NO) 3 ) 3 Sc obtained by pyrolysis 2 O 3 In-situ reaction of Si-O atom cluster in nanocrystalline and amorphous SiOC ceramic to generate Sc 2 Si 2 O 7 The SiC nano-crystals are precipitated in the amorphous SiOC ceramic in situ to form Sc with the SiC nano-crystals distributed in a dispersed manner 2 Si 2 O 7 -SiOC complex phase ceramics; the Sc 2 Si 2 O 7 The microstructure of the-SiOC complex-phase ceramic is monoclinic phase Sc 2 Si 2 O 7 And cubic phase Sc 2 O 3 The nano-crystalline grains and the SiC nano-crystalline grains are dispersed and distributed in the amorphous SiOC matrix to form a crystalline phase/amorphous continuous phaseThe structure of the cloth.
2. High temperature antioxidant Sc with low dielectric constant and low loss characteristics as defined in claim 1 2 Si 2 O 7 The preparation method of the in-situ reaction polymer conversion of the SiOC complex-phase ceramic is characterized by comprising the following steps:
step 1, preparation of a scandium nitrate modified polysiloxane precursor: preparing a polysiloxane precursor solution by using dimethylbenzene as a solvent, preparing a scandium nitrate solution by using absolute ethyl alcohol as a solvent, and adding the scandium nitrate solution into the polysiloxane precursor solution under the magnetic stirring action at room temperature to mix the scandium nitrate solution and the polysiloxane precursor solution to obtain a scandium nitrate modified polysiloxane precursor;
the content of scandium nitrate in the scandium nitrate modified polysiloxane precursor is 3-65 wt.%;
step 2, sc 2 O 3 Preparation of modified SiOC ceramics: carrying out cross-linking curing on the scandium nitrate modified polysiloxane precursor under the protection of inert atmosphere, grinding and sieving the obtained cured product, pressing the cured product into a ceramic blank, putting the ceramic blank into a tubular furnace for cracking, and preparing Sc 2 O 3 A modified SiOC ceramic;
the curing temperature is 200-250 ℃, and the curing time is 1.5-3 h;
the cracking temperature is 900-1050 ℃, and the cracking time is 1-3 h;
step 3, sc 2 Si 2 O 7 -preparation of SiOC complex phase ceramics: subjecting Sc to 2 O 3 Placing the modified SiOC ceramic in a tube furnace for heat treatment under the protection of inert atmosphere to prepare Sc 2 Si 2 O 7 -SiOC complex phase ceramics;
the heat treatment temperature is 1200-1600 ℃, and the heat treatment time is 0.5-3 h.
3. The method of claim 2, wherein: the mass concentration of the polysiloxane precursor solution and the mass concentration of the scandium nitrate solution are both 10wt.% to 30wt.%.
4. The method of claim 2, wherein: and the inert atmosphere in the step 2 and the step 3 is argon or nitrogen.
5. The method of claim 2, wherein: the heating rate in the step 2 and the step 3 is 1-8 ℃/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210652517.3A CN115231911B (en) | 2022-06-07 | 2022-06-07 | In situ reaction Polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210652517.3A CN115231911B (en) | 2022-06-07 | 2022-06-07 | In situ reaction Polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115231911A CN115231911A (en) | 2022-10-25 |
| CN115231911B true CN115231911B (en) | 2023-03-31 |
Family
ID=83670083
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210652517.3A Active CN115231911B (en) | 2022-06-07 | 2022-06-07 | In situ reaction Polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115231911B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115710126B (en) * | 2022-12-30 | 2023-11-24 | 中国人民解放军空军工程大学 | SiOC wave-absorbing ceramic with in-situ growth heterostructure and preparation method thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104291791A (en) * | 2014-09-24 | 2015-01-21 | 西安交通大学 | Preparation method of amorphous SiOC ceramic powder |
| CN105503229A (en) * | 2015-12-30 | 2016-04-20 | 西北工业大学 | Preparation method of Al2O3f/SiOC radar wave-absorbing composite material |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10753010B2 (en) * | 2014-09-25 | 2020-08-25 | Pallidus, Inc. | Vapor deposition apparatus and techniques using high puritiy polymer derived silicon carbide |
-
2022
- 2022-06-07 CN CN202210652517.3A patent/CN115231911B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104291791A (en) * | 2014-09-24 | 2015-01-21 | 西安交通大学 | Preparation method of amorphous SiOC ceramic powder |
| CN105503229A (en) * | 2015-12-30 | 2016-04-20 | 西北工业大学 | Preparation method of Al2O3f/SiOC radar wave-absorbing composite material |
Non-Patent Citations (2)
| Title |
|---|
| 徐天恒 等.聚硅氧烷转化SiOC陶瓷微观结构的研究进展.材料科学与工程学报.2010,第28卷(第05期),第773-777，760页. * |
| 马青松 等.以聚硅氧烷为先驱体制备Al-SiCp/Si-O-C陶瓷复合材料.中国有色金属学报.2004,第14卷(第07期),第1133-1138页. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115231911A (en) | 2022-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111454061B (en) | Polycarbosilane non-melting pretreatment and cracking conversion method for three-dimensional ceramic | |
| US5340417A (en) | Process for preparing silicon carbide by carbothermal reduction | |
| CN107721429B (en) | Zirconium carbide-silicon carbide composite powder material and preparation method thereof | |
| CN115231911B (en) | In situ reaction Polymer conversion Sc 2 Si 2 O 7 -SiOC complex phase ceramic and preparation method thereof | |
| KR100972601B1 (en) | Process for producing nano-sized silicon carbide powder | |
| CN109437203A (en) | A kind of preparation method of high-purity one dimension SiC nano material | |
| CN111377449A (en) | Preparation method of boron carbide nanoparticles | |
| Simonenko et al. | Preparation of HfB 2/SiC composite powders by sol–gel technology | |
| Simonenko et al. | Preparation of MB 2/SiC and MB 2/SiC-MC (M= Zr or Hf) powder composites which are promising materials for design of ultra-high-temperature ceramics | |
| CN111187075A (en) | Precursor conversion method preparation process of self-dispersion superfine ZrC-SiC ceramic composite powder | |
| CN110668447A (en) | Synthesis method of silicon carbide nanowire | |
| JP2009269797A (en) | Method for producing silicon carbide powder | |
| CN102093055B (en) | Method for preparing silicon carbide/titanium carbide composite ceramics | |
| KR101627371B1 (en) | Preparing method of size-controlled silicon carbide powder | |
| CN102502642A (en) | Method for preparing nanometer silicon carbide fiber in phenolic resin atmosphere | |
| CN111533131B (en) | Based on CaCl2Preparation method of nano silicon carbide particles of shape regulator | |
| KR100684649B1 (en) | Manufacturing method of metal doped polycarbosilane and manufacturing method of nano-crystallized silicon carbide fiber comprising the smae, and sic fiber thereby | |
| CN101696011B (en) | Method for improving purity of silicon carbide nano material prepared by using organosilicon-polymer cracking method | |
| JPS6225603B2 (en) | ||
| JP3154773B2 (en) | Method for producing particulate silicon carbide | |
| CN1125892C (en) | Process for preparing nm-class silicon carbonite whisker/fibre | |
| KR100872832B1 (en) | Aluminum nitride nanopowders prepared by using melamine and the fabrication method thereof | |
| CN116143524B (en) | Three-dimensional reticular silicon carbide nanowire and preparation method thereof | |
| JP4111478B2 (en) | Method for producing silicon carbide microspheres | |
| CN114477185B (en) | beta-SiC with lamellar structure and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |