Silicon carbide and hafnium tantalum ceramic precursor and preparation method thereof
By preparing silicon carbide and hafnium tantalum ceramic precursors, the problems of easy sintering and corrosion of ceramic materials at high temperatures were solved, and ceramic materials with ultra-high temperature resistance were realized, which are suitable for the aerospace industry.
Patent Information
- Application Number
- CN202411165657.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-23
- Publication Date
- 2026-03-03
AI Technical Summary
Existing ceramic materials are prone to sintering and corrosion at high temperatures, and the drastic phase transformation causes the materials to quickly lose their performance, making it difficult to meet the service requirements of the aerospace industry.
A silicon carbide and hafnium tantalum ceramic precursor with a molar ratio of silicon carbide and hafnium tantalum coordination copolymer of 1:(1-10) was prepared by means of dispersing silicon carbide powder in a solvent, mixing liquid polycarbosilane, heating and curing, co-hydrolyzing pentavalent tantalum salt and tetravalent hafnium salt in an ice bath, stirring, filtering and then pyrolyzing to obtain the silicon carbide and hafnium tantalum ceramic precursor.
The prepared silicon carbide and hafnium tantalum ceramic precursors have high thermal conductivity, ultra-high temperature resistance, are not easily sintered or corroded, avoid performance loss caused by phase transformation, and are suitable for high-temperature environments.
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite material technology, specifically relating to a silicon carbide and hafnium tantalum ceramic precursor and its preparation method. Background Technology
[0002] With the development of the aerospace industry, more and more materials are being used in the aerospace industry. The materials used in aerospace have higher requirements. Often, the materials used need to have the ability to withstand ultra-high temperatures. However, when the operating temperature exceeds 1200℃, ceramic materials are prone to sintering and corrosion, and the violent phase transformation will cause the materials to lose their performance rapidly and make it difficult to meet the service requirements. Summary of the Invention
[0003] The purpose of this invention is to provide a silicon carbide and hafnium tantalum ceramic precursor and its preparation method, which solves the problems that existing ceramic materials are prone to sintering and corrosion, and that drastic phase transformations can cause materials to quickly lose their performance and fail to meet service requirements.
[0004] To achieve the above objectives, the technical solution of the present invention is as follows: a silicon carbide and hafnium tantalum ceramic precursor, wherein the silicon carbide and hafnium tantalum ceramic precursor comprises a silicon carbide and hafnium tantalum coordination copolymer, and the molar ratio of the silicon carbide and hafnium tantalum coordination copolymer is 1:(1-10).
[0005] In some embodiments, the hafnium-tantalum coordination copolymer comprises hafnium carbide and tantalum carbide, wherein the molar ratio of hafnium carbide to tantalum carbide is 1-5:2-6.
[0006] In some embodiments, the thermal conductivity of the silicon carbide and hafnium tantalum ceramic precursor is 0.9–2 W / (m·K). -1 .
[0007] Another technical solution of the present invention is implemented as follows: a method for preparing a silicon carbide and hafnium tantalum ceramic precursor, comprising the following steps:
[0008] Step S1: Disperse silicon carbide powder uniformly in a solvent to obtain a dispersion.
[0009] Step S2: The liquid polycarbosilane and the dispersion from step S1 are mixed, heated, and then solidified to obtain silicon carbide particles;
[0010] Step S3: Mix pentavalent tantalum salt, tetravalent hafnium salt and monohydric alcohol evenly to obtain a mixture. Then place the mixture under ice bath conditions and add a catalyst to carry out a co-hydrolysis reaction to obtain a hafnium tantalum alkoxide solution.
[0011] Step S4: Mix the silicon carbide particles from step S2 and the hafnium tantalum alkoxide solution from step S3, then stir and filter to obtain a solid, and then pyrolyze the solid to obtain silicon carbide and hafnium tantalum ceramic precursors.
[0012] In some embodiments, the solvent in step S2 is any one of ethanol, acetone, benzene, toluene, or n-pentane.
[0013] In some embodiments, the mass-to-volume ratio of the silicon carbide powder to the solvent is 1:10-20.
[0014] In some embodiments, the mass-to-volume ratio of liquid polycarbosilane in step S2 to dispersion in step S1 is 0.2:20-50, the heating temperature is 140-180°C, and the heating time is 15-40 min.
[0015] In some embodiments, the molar volume ratio of the pentavalent tantalum salt, the tetravalent hafnium salt, and the monohydric alcohol in step S3 is 1-5:2-6:1-5:5-10, and the hydrolysis reaction time in step S3 is 3-5 hours.
[0016] In some embodiments, the stirring time in step S4 is 5-9 hours.
[0017] In some embodiments, the solid in step S4 is pyrolyzed under vacuum and at 800-1500°C.
[0018] Compared with the prior art, the thermal conductivity of the silicon carbide and hafnium tantalum ceramic precursors in this invention is suitable for high-temperature ceramics, and they have the ability to withstand ultra-high temperatures. Furthermore, they are not prone to sintering and corrosion in high-temperature environments, and they will not undergo phase transformations that would cause the material to rapidly lose its performance. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0020] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.
[0021] Unless otherwise specified, all medicines / reagents used are commercially available.
[0022] In a first aspect, this invention provides a silicon carbide and hafnium-tantalum ceramic precursor, comprising a silicon carbide and hafnium-tantalum coordination copolymer, wherein the molar ratio of the silicon carbide and hafnium-tantalum coordination copolymer is 1:(1-10). When the molar ratio of the silicon carbide and hafnium-tantalum coordination copolymer is outside this range, it leads to uneven dispersion of hafnium, tantalum, and silicon in the silicon carbide and hafnium-tantalum ceramic precursor; using the molar ratio of this invention, a uniform and dense silicon carbide and hafnium-tantalum ceramic precursor can be prepared.
[0023] The hafnium-tantalum coordination copolymer comprises hafnium carbide and tantalum carbide, wherein the molar ratio of hafnium carbide to tantalum carbide is 1-5:2-6.
[0024] The thermal conductivity of the silicon carbide and hafnium tantalum ceramic precursor is 0.9–2 W / (m·K). -1 .
[0025] Because hafnium and tantalum have high melting points and good stability, the precursor formed by combining with silicon carbide is uniform and dense, has the ability to withstand ultra-high temperatures, and is not easily deformed.
[0026] In a second aspect, the present invention provides a method for preparing silicon carbide and hafnium tantalum ceramic precursors.
[0027] Example 1
[0028] A method for preparing a silicon carbide and hafnium tantalum ceramic precursor includes the following steps:
[0029] Step S1: Silicon carbide powder is uniformly dispersed in ethanol to obtain a dispersion; the mass-to-volume ratio of silicon carbide powder to ethanol is 1:10.
[0030] In step S2, the liquid polycarbosilane and the dispersion from step S1 are mixed, heated, and then solidified to obtain silicon carbide particles; the mass-to-volume ratio of the liquid polycarbosilane in step S2 to the dispersion in step S1 is 0.2:20, the heating temperature is 140℃, and the heating time is 15 min.
[0031] Step S3: Mix the pentavalent tantalum salt, tetravalent hafnium salt, and monohydric alcohol evenly to obtain a mixture. Then, place the mixture under ice bath conditions and add a catalyst to carry out a co-hydrolysis reaction to obtain a hafnium tantalum alkoxide solution. The pentavalent tantalum salt is tantalum pentachloride, and the tetravalent hafnium salt is hafnium tetrachloride. The monohydric alcohol is any one of methanol, ethanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, and neopentyl alcohol. The monohydric alcohol used in Example 1 is methanol.
[0032] The molar volume ratio of tantalum pentachloride, hafnium tetrachloride, and methanol is 1:2:5, and the hydrolysis reaction takes 3 hours.
[0033] Step S4: Mix the silicon carbide particles from Step S2 and the hafnium tantalum alkoxide solution from Step S3, then stir and filter to obtain a solid. The solid is then pyrolyzed to obtain silicon carbide and hafnium tantalum ceramic precursors. The stirring time in Step S4 is 5 hours. The solid in Step S4 is pyrolyzed under vacuum and 800°C to obtain a product with a thermal conductivity of 0.9 W·(m·K). -1 Silicon carbide and hafnium tantalum ceramic precursors.
[0034] Example 2
[0035] A method for preparing a silicon carbide and hafnium tantalum ceramic precursor includes the following steps:
[0036] Step S1: Silicon carbide powder is uniformly dispersed in acetone to obtain a dispersion; the mass-to-volume ratio of silicon carbide powder to acetone is 1:12.
[0037] In step S2, the liquid polycarbosilane and the dispersion from step S1 are mixed, heated, and then solidified to obtain silicon carbide particles; the mass-to-volume ratio of the liquid polycarbosilane in step S2 to the dispersion in step S1 is 0.2:25, the heating temperature is 150℃, and the heating time is 20 min.
[0038] Step S3: Mix the pentavalent tantalum salt, tetravalent hafnium salt, and monohydric alcohol evenly to obtain a mixture. Then, place the mixture under ice bath conditions and add a catalyst to carry out a co-hydrolysis reaction to obtain a hafnium tantalum alkoxide solution. The pentavalent tantalum salt is tantalum pentachloride, and the tetravalent hafnium salt is tantalum tetrachloride. The monohydric alcohol is any one of methanol, ethanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, and neopentyl alcohol. The monohydric alcohol used in Example 2 is ethanol.
[0039] The molar volume ratio of tantalum pentachloride, hafnium tetrachloride, and ethanol is 2:3:6, and the hydrolysis reaction takes 3.5 hours.
[0040] Step S4: Mix the silicon carbide particles from step S2 and the hafnium tantalum alkoxide solution from step S3, then stir and filter to obtain a solid. The solid is then pyrolyzed to obtain silicon carbide and hafnium tantalum ceramic precursors. The stirring time in step S4 is 6 hours. The solid in step S4 is pyrolyzed under vacuum and 900°C to obtain a product with a thermal conductivity of 1 W·(m·K). -1 Silicon carbide and hafnium tantalum ceramic precursors.
[0041] Example 3
[0042] A method for preparing a silicon carbide and hafnium tantalum ceramic precursor includes the following steps:
[0043] Step S1: Silicon carbide powder is uniformly dispersed in ethanol to obtain a dispersion; the mass-to-volume ratio of silicon carbide powder to benzene is 1:15.
[0044] Step S2 involves mixing and heating the liquid polycarbosilane and the dispersion from step S1, followed by curing to obtain silicon carbide particles. The mass-to-volume ratio of the liquid polycarbosilane in step S2 to the dispersion in step S1 is 0.2:35. The heating temperature is 160°C, and the heating time is 20 minutes.
[0045] Step S3: Mix the pentavalent tantalum salt, tetravalent hafnium salt, and monohydric alcohol to obtain a mixture. Then, place the mixture under ice bath conditions and add a catalyst to carry out a co-hydrolysis reaction to obtain a hafnium tantalum alkoxide solution. The pentavalent tantalum salt is tantalum pentachloride, and the tetravalent hafnium salt is hafnium tetrachloride. The monohydric alcohol is any one of methanol, ethanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, and neopentyl alcohol. The monohydric alcohol used in this Example 3 is n-butanol.
[0046] The molar volume ratio of tantalum pentachloride, hafnium tetrachloride and n-butanol is 3:4:3:7, and the hydrolysis reaction takes 4 hours.
[0047] Step S4: Mix the silicon carbide particles from Step S2 and the hafnium tantalum alkoxide solution from Step S3, then stir and filter to obtain a solid. The solid is then pyrolyzed to obtain silicon carbide and hafnium tantalum ceramic precursors. The stirring time in Step S4 is 7 hours. The solid in Step S4 is pyrolyzed under vacuum and 1000℃ conditions to obtain a product with a thermal conductivity of 1.2 W·(m·K). -1 Silicon carbide and hafnium tantalum ceramic precursors.
[0048] Example 4
[0049] A method for preparing a silicon carbide and hafnium tantalum ceramic precursor includes the following steps:
[0050] Step S1: Silicon carbide powder is uniformly dispersed in ethanol to obtain a dispersion; the mass-to-volume ratio of silicon carbide powder to toluene is 1:16.
[0051] In step S2, the liquid polycarbosilane and the dispersion from step S1 are mixed, heated, and then solidified to obtain silicon carbide particles; the mass-to-volume ratio of the liquid polycarbosilane in step S2 to the dispersion in step S1 is 0.2:10, the heating temperature is 160℃, and the heating time is 35 min.
[0052] Step S3: Mix the pentavalent tantalum salt, tetravalent hafnium salt, and monohydric alcohol to obtain a mixture. Then, place the mixture under ice bath conditions and add a catalyst to carry out a co-hydrolysis reaction to obtain a hafnium tantalum alkoxide solution. The pentavalent tantalum salt is tantalum pentachloride, and the tetravalent hafnium salt is hafnium tetrachloride. The monohydric alcohol is any one of methanol, ethanol, n-butanol, isobutanol, tert-butanol, and neopentyl alcohol. The monohydric alcohol used in Example 4 is isobutanol.
[0053] The molar volume ratio of tantalum pentachloride, hafnium tetrachloride and isobutanol is 4:5:7, and the hydrolysis reaction takes 4 hours.
[0054] Step S4: Mix the silicon carbide particles from Step S2 and the hafnium tantalum alkoxide solution from Step S3, then stir and filter to obtain a solid. The solid is then pyrolyzed to obtain silicon carbide and hafnium tantalum ceramic precursors. The stirring time in Step S4 is 7 hours. The solid in Step S4 is pyrolyzed under vacuum and 1100℃ conditions to obtain a product with a thermal conductivity of 1.4 W·(m·K). -1 Silicon carbide and hafnium tantalum ceramic precursors.
[0055] Example 5
[0056] A method for preparing a silicon carbide and hafnium tantalum ceramic precursor includes the following steps:
[0057] Step S1: Silicon carbide powder is uniformly dispersed in ethanol to obtain a dispersion; the mass-to-volume ratio of silicon carbide powder to n-pentane is 1:20.
[0058] In step S2, the liquid polycarbosilane and the dispersion from step S1 are mixed, heated, and then solidified to obtain silicon carbide particles; the mass-to-volume ratio of the liquid polycarbosilane in step S2 to the dispersion in step S1 is 0.2:50, the heating temperature is 180℃, and the heating time is 40 min.
[0059] Step S3: Mix the pentavalent tantalum salt, tetravalent hafnium salt, and monohydric alcohol to obtain a mixture. Then, place the mixture under ice bath conditions and add a catalyst to carry out a co-hydrolysis reaction to obtain a hafnium tantalum alkoxide solution. The pentavalent tantalum salt is tantalum pentachloride, and the tetravalent hafnium salt is hafnium tetrachloride. The monohydric alcohol is any one of methanol, ethanol, n-butanol, isobutanol, tert-butanol, and neopentyl alcohol.
[0060] The molar volume ratio of tantalum pentachloride, hafnium tetrachloride and isobutanol is 5:6:10, and the hydrolysis reaction takes 5 hours.
[0061] Step S4: Mix the silicon carbide particles from step S2 and the hafnium tantalum alkoxide solution from step S3, then stir and filter to obtain a solid. The solid is then pyrolyzed to obtain silicon carbide and hafnium tantalum ceramic precursors. The stirring time in step S4 is 6 hours. The solid in step S4 is pyrolyzed under vacuum and 1500℃ conditions to obtain a product with a thermal conductivity of 2 W·(m·K). -1 Silicon carbide and hafnium tantalum ceramic precursors.
[0062] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A silicon carbide and hafnium tantalum ceramic precursor, characterized in that, The silicon carbide and hafnium tantalum ceramic precursor includes a silicon carbide and hafnium tantalum coordination copolymer, wherein the molar ratio of the silicon carbide and hafnium tantalum coordination copolymer is 1:(1-10).
2. The silicon carbide and hafnium tantalum ceramic precursor according to claim 1, characterized in that, The hafnium-tantalum coordination copolymer comprises hafnium carbide and tantalum carbide, wherein the molar ratio of hafnium carbide to tantalum carbide is 1-5:2-6.
3. The silicon carbide and hafnium tantalum ceramic precursor according to claim 1, characterized in that, The thermal conductivity of the silicon carbide and hafnium tantalum ceramic precursor is 0.9–2 W / (m·K). -1 .
4. A method for preparing a silicon carbide and hafnium tantalum ceramic precursor as described in any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Disperse silicon carbide powder uniformly in a solvent to obtain a dispersion. Step S2: The liquid polycarbosilane and the dispersion from step S1 are mixed, heated, and then solidified to obtain silicon carbide particles; Step S3: Mix pentavalent tantalum salt, tetravalent hafnium salt and monohydric alcohol evenly to obtain a mixture. Then place the mixture under ice bath conditions and add a catalyst to carry out a co-hydrolysis reaction to obtain a hafnium tantalum alkoxide solution. Step S4: Mix the silicon carbide particles from step S2 and the hafnium tantalum alkoxide solution from step S3, then stir and filter to obtain a solid, and then pyrolyze the solid to obtain silicon carbide and hafnium tantalum ceramic precursors.
5. The method for preparing silicon carbide and hafnium tantalum ceramic precursors according to claim 4, characterized in that, In step S2, the solvent is any one of ethanol, acetone, benzene, toluene, or n-pentane.
6. The method for preparing silicon carbide and hafnium tantalum ceramic precursors according to claim 5, characterized in that, The mass-to-volume ratio of the silicon carbide powder to the solvent is 1:10-20.
7. The method for preparing the silicon carbide and hafnium tantalum ceramic precursor according to claim 5, characterized in that, In step S2, the mass-to-volume ratio of liquid polycarbosilane to the dispersion in step S1 is 0.2:20-50, the heating temperature is 140-180℃, and the heating time is 15-40 min.
8. The method for preparing silicon carbide and hafnium tantalum ceramic precursors according to claim 5, characterized in that, In step S3, the molar volume ratio of the pentavalent tantalum salt, the tetravalent hafnium salt, and the monohydric alcohol is 1-5:2-6:5-10, and the hydrolysis reaction time in step S3 is 3-5 hours.
9. The method for preparing the silicon carbide and hafnium tantalum ceramic precursor according to claim 5, characterized in that, The stirring time in step S4 is 5-9 hours.
10. The method for preparing the silicon carbide and hafnium tantalum ceramic precursor according to claim 5, characterized in that, In step S4, the solid is pyrolyzed under vacuum and at 800-1500°C.