Preparation method and application of HfC ceramic precursor

A ceramic precursor and reaction technology, which is applied in the field of preparation of HfC ceramic precursors, can solve the problems of low yield of ultra-high temperature resistant ceramics and low content of ultra-high temperature resistant components, and achieve good high temperature resistance and good processing performance , cheap effect

Active Publication Date: 2016-07-13
NAT UNIV OF DEFENSE TECH
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Problems solved by technology

[0007] The purpose of the present invention is to provide a preparation method and application of a HfC ceramic precursor, which solves the technical problems of low yield and low content of ultra-high temperature resistant components in the preparation of ultra-high temperature resistant ceramics by the precursor conversion method in the prior art

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  • Preparation method and application of HfC ceramic precursor
  • Preparation method and application of HfC ceramic precursor
  • Preparation method and application of HfC ceramic precursor

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preparation example Construction

[0025] The preparation method of the HfC ceramic precursor provided by the invention comprises the following steps:

[0026] Add cyanamide organic compounds into the organometallic hafnium compound solution in the form of solution, heat to 30-150°C at a heating rate of 0.1-2.0°C / min, keep at this temperature for 1-30 hours, then adjust the temperature to 30- After 160°C, distill under reduced pressure for 0.5-3 hours to react. After the reaction, cool to room temperature to obtain the HfC ceramic precursor; the organometallic hafnium compound and the cyanamide organic compound are mixed in a molar ratio of 1:0.1-10.

[0027] The method can improve the ceramic yield when the prepared precursor is used to prepare ultra-high temperature resistant HfC ceramics. Bring it up to 40%. It can also effectively increase the proportion of HfC contained in the obtained ceramic material, which is mainly because the homogeneity of HfC in the obtained precursor is provided, and at the same t...

Embodiment 1

[0037] (1) Take hafnium tetrachloride 0.03mol, dicyandiamide 0.03mol;

[0038] (2) hafnium tetrachloride and dicyandiamide are dissolved in acetonitrile;

[0039] (3) Vacuumize and fill the 250ml three-necked flask with agitator, constant pressure funnel and distillation device three times, and then cool the reactor to minus 30°C;

[0040] (4) Add the acetonitrile solution of hafnium tetrachloride into a three-necked flask protected by dry argon, and then add the acetonitrile solution of dicyandiamide into the constant pressure funnel. While stirring, the acetonitrile solution of dicyandiamide is added in the three-necked flask in a dropwise manner;

[0041] (5) After the dropwise addition, the reactor was heated to 50° C. at a rate of 1.0° C. / min, and kept at this temperature for 8 hours;

[0042](6) Reduce the temperature of the reactor to 30° C., distill under reduced pressure at this temperature for 0.5 hours (vacuum degree 1 kPa), and cool to room temperature to obtain ...

Embodiment 2

[0048] This embodiment includes the following steps:

[0049] (1) Weigh 0.03mol of hafnium dichloride and 0.03mol of dicyandiamide;

[0050] (2) hafnium dichloride and dicyandiamide are dissolved in acetonitrile;

[0051] (3) Vacuumize and fill the 250ml three-necked flask with agitator, constant pressure funnel and distillation device three times, and then cool the reactor to minus 30°C;

[0052] (4) Add the acetonitrile solution of hafnocene dichloride into a three-necked flask protected by dry argon, and then add the acetonitrile solution of dicyandiamide into the constant pressure funnel. While stirring, the acetonitrile solution of dicyandiamide is added in the three-necked flask in a dropwise manner;

[0053] (5) After the dropwise addition, the reactor was heated to 100° C. at a rate of 1.0° C. / min, and kept at this temperature for 8 hours;

[0054] (6) Reduce the temperature of the reactor to 30° C., distill under reduced pressure at this temperature for 0.5 hours (...

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Abstract

The invention provides a preparation method and application of an HfC ceramic precursor.The preparation method includes the steps of firstly, adding solvent into a reactor, adding organic hafnium compound and cyanamide organic matter, and vacuumizing and drying the reactor; secondly, rising the temperature, performing continuous stirring reaction under the protection of nitrogen atmosphere, and evaporating the reaction products to remove the solvent so as to obtain white solid.The HfC ceramic precursor prepared by the method is high in ceramic yield, good in high-temperature resistance and suitable for being used to prepare high-performance hafnium carbide ceramics and composite materials thereof, and the ultrahigh-temperature HfC component content of the ceramic materials prepared by the HfC ceramic precursor is higher than 79%.

Description

technical field [0001] The invention relates to the technical field of ultra-high temperature resistant materials, in particular to a preparation method and application of an HfC ceramic precursor. Background technique [0002] With the rapid development of science and technology, all walks of life have put forward higher and higher requirements for materials. Especially in the field of aerospace, the nose cone, wing leading edge and other key components of high-speed aerospace vehicles such as hypersonic vehicles, transatmospheric space combat vehicles, and space-to-earth shuttle systems will have severe friction with the air, resulting in localized high temperatures. When the speed of a hypersonic vehicle reaches Mach 8, its tip part needs to be able to withstand temperatures as high as 1800°C. At the same time, the temperature of the combustion chamber of the scramjet engine used in hypersonic vehicles often reaches as high as 1700-2800°C. In order to realize the reusab...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/56
CPCC04B35/5622C04B2235/48
Inventor 王军程军王小宙王浩邵长伟简科
Owner NAT UNIV OF DEFENSE TECH
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