In-situ preparation method of HfC-based ternary carbide gradient coating on surface of carbon material

Abstract

The invention discloses an in-situ preparation method of an HfC-based ternary carbide gradient coating on the surface of a carbon material. The method comprises the following steps: taking the carbonmaterial as a matrix, hafnium powder or a mixture of the hafnium powder and hafnium oxide powder as a hafnium source, TiO2 as a titanium source, ZrO2 as a zirconium source and ammonium chloride powderas an active agent, uniformly mixing one of the titanium source and the zirconium source with the hafnium source and the active agent to obtain a penetrating agent; placing the penetrating agent in areaction container, and placing the carbon material matrix above the penetrating agent; putting the reaction container with the penetrating agent and the carbon material matrix into a vacuum furnace,repeatedly vacuumizing and introducing inert gas until the pressure in the furnace is close to normal pressure; and heating to 1250-1500 DEG C, keeping the temperature, and cooling to obtain the product. The method is simple and convenient, low in cost and high in operability, and the prepared coating is good in combination with a matrix, good in thermal shock resistance and high in melting point.

Description

technical field [0001] The invention belongs to the technical field of high-temperature materials, and relates to an ultra-high-temperature anti-oxidation coating system and its preparation, in particular to an in-situ preparation method of an HfC-based ternary carbide gradient coating on the surface of a carbon material. Background technique [0002] Carbon materials, as structural materials with excellent high-temperature mechanical properties, have been widely used in high-temperature applications such as metallurgical industry, aerospace, and military. Among them, carbon / carbon composite materials have low density, excellent high-temperature mechanical properties, low thermal expansion coefficient, and heat resistance. A series of excellent properties such as impact, has been widely used in the aerospace field as a high-temperature heat-resistant structural material in recent years. However, the easy oxidation of carbon materials in high-temperature oxidizing environment...

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Problems solved by technology

[0003]At present, the preparation methods of these ternary carbides mainly include hot pressing sintering method, sol-gel method, carbothermal reduction method and self-propagating high-temperature synthesis method, etc. These The methods are all high-temperature synthesis methods, which require high equipment and high cost.

Paper "Microstructure and growth behavior of Hf(Ta)C ceramic coating synthesized by low pressure chemical vapor deposition. Journal of Alloys and Compounds.2017, 705: 79-88. (Preparation of Hf(Ta)C ceramic coating by low pressure chemical vapor deposition method Microstructure and Growth Behavior of Alloys and Compounds), Li et al prepared a ternary carbide coating (Hf,Ta)C on the surface of carbon materials by chemical vapor deposition, but the preparation process of this method is complicated and cycle long, and the prepared ternary carbide coating only covers the surface of the carbon material, and the bonding strength between the coating and the carbon material matrix is ​​not high

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