Method for manufacturing hafnium containing SiC ceramic precursor

A ceramic precursor, C-450 technology, applied in the field of preparation of SiC ceramic precursors, can solve the problems of single function, poor oxidation resistance, poor ultra-high temperature resistance, etc., and achieves wide sources and easy large-scale industrial production. , Excellent effect of ultra-high temperature resistance

Inactive Publication Date: 2008-12-10
NAT UNIV OF DEFENSE TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0010] The purpose of the present invention is to overcome the disadvantages of poor ultra-high temperature resistance, poor anti-oxidation performance and single function of SiC ceramics prepared by the existing precursor conversion metho...

Method used

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  • Method for manufacturing hafnium containing SiC ceramic precursor
  • Method for manufacturing hafnium containing SiC ceramic precursor
  • Method for manufacturing hafnium containing SiC ceramic precursor

Examples

Experimental program
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Embodiment 1

[0030] Using PSCS and hafnium acetylacetonate as raw materials, the mass ratio of the two (the proportions described below are all mass ratios) is: hafnium acetylacetonate: PSCS=4:100, the reaction temperature is 450 ° C, the cracking temperature is 500 ° C, and the heat preservation reaction After 14 hours, it was dissolved in xylene and filtered, and the filtrate was distilled under reduced pressure at 390° C. to obtain PHCS with a softening point of 200° C. and a hafnium content of 1.91 wt%, with a precursor yield of 64.9%. N 2 Heat preservation at 1200°C for 1 hour under the atmosphere, and the ceramic yield is 79.6%.

[0031] The infrared spectrogram, GPC spectrogram, TG spectrogram of the obtained PHCS are shown in respectively figure 2 , image 3 , Figure 4 .

[0032] The hafnium-containing SiC ceramic fiber is prepared by using the PHCS precursor through melt-spinning, non-melting in air and firing at high temperature. The fiber diameter is 14μm, and the tensile...

Embodiment 2

[0034] Using PCS and tetraethoxyhafnium as raw materials, tetraethoxyhafnium:PCS=1:100, the reaction temperature is 460°C, the cracking temperature is 450°C, and after the reaction time of 4h, it is dissolved in xylene and filtered, and the filtrate is dissolved at 300°C °C for vacuum distillation to prepare PHCS with a softening point of 210 °C and a hafnium content of 0.63 wt%, with a precursor yield of 71.2%. N 2 The temperature was kept at 1200° C. for 1 hour under the atmosphere, and the ceramic yield was 76.2%.

[0035] The hafnium-containing SiC ceramic fiber is prepared by using the PHCS precursor through melt-spinning, non-melting in air and firing at high temperature. The fiber diameter is 16μm, and the tensile strength is 1.7GPa. The fiber has good ultra-high temperature resistance. After treatment at 1450°C and 1600°C, the strength retention rate is 65% and 37% respectively; the Si-Hf-C-O fiber has good oxidation resistance. After heat treatment at 1000°C for 20 ...

Embodiment 3

[0037] Using PSCS and hafnium tetrachloride as raw materials, the mass ratio of the two is: hafnium tetrachloride:PSCS=15:100, the reaction temperature is 420°C, the cracking temperature is 500°C, after the heat preservation reaction for 3 hours, it is dissolved in xylene and filtered. The filtrate was distilled under reduced pressure at 350° C. to obtain PHCS with a softening point of 165° C. and a hafnium content of 7.75 wt%, with a precursor yield of 56.2%. N 2 Heat preservation at 1200°C for 1 hour under the atmosphere, and the ceramic yield is 69.7%.

[0038] The hafnium-containing SiC ceramic fiber is prepared by using the PHCS precursor through melt-spinning, non-melting in air and firing at high temperature. The fiber diameter is 15μm, and the tensile strength is 2.1GPa. The fiber has good ultra-high temperature resistance. After treatment at 1450°C and 1600°C, the strength retention rate is 68% and 40% respectively; the Si-Hf-C-O fiber has good oxidation resistance....

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Abstract

The invention provides a method for preparing a SiC ceramic precursor containing hafnium, comprising the following steps that: (1) a low molecular weight polymer containing silicon in the main chain is put inside a three-neck flask, and added with hafnium organic compound or chloride the mass of which is 0.5 to 20wt% of the low molecular weight polymer; (2) under the protection of Ar or N2 or the mixture of the two, the temperature of the three-neck flask is increased to between 350 and 500 DEG C according to the temperature increasing rate of 0.1 to 5 DEG C per minute, the temperature of a cracking post is controlled between 450 and 550 DEG C, the pyrolysis recomposition reaction is performed for 0.3 to 30 hours, the PHCS coarse product is produced after the cooling process; and (3) the coarse product is dissolved in the dimethylbenzene and is filtered, the filtrate is decompressed, distilled and cooled at a temperature of between 300 and 390 DEG C. The raw materials are widely available, the reaction process is easy to control, the device is simple, the product has high purity, the re-forming property is good, the super high temperature performance is good; the large-scale industrial production is easy to realize; and the ceramic fiber prepared has good anti-oxidation performance.

Description

technical field [0001] The invention relates to a preparation method of a SiC ceramic precursor containing a heterogeneous element hafnium, in particular to a SiC ceramic precursor containing a heterogeneous element hafnium with a main chain silicon-containing polymer and a hafnium-containing organometallic compound as main raw materials body preparation method. Background technique [0002] With the development of science and technology, national defense, aerospace, energy and other fields have put forward higher and higher requirements for materials such as light weight, high strength, high modulus, high temperature resistance, corrosion resistance, oxidation resistance, and wear resistance. The development of high-performance ceramics and their composite materials to replace traditional high-temperature alloys and refractory metal materials has become the main research direction in the future. High-performance ceramics have many uses in the fields of advanced aerospace s...

Claims

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Application Information

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IPC IPC(8): C04B35/571
Inventor 谢征芳曹淑伟王军王浩薛金根牛加新
Owner NAT UNIV OF DEFENSE TECH
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