Preparation method of nanometer rare earth silicate powder

Abstract

The invention relates to a preparation method of nano-rare earth silicate powder, which is characterized in that a certain stoichiometric ratio of rare earth oxides or rare earth soluble salts and silicon sources are formulated into solutions respectively, and the two solutions are mixed, and continuously After reacting for 6-24 hours, filtering and drying, monodisperse particles with a particle diameter of 20-30 nm can be obtained. Compared with the commonly used solid-phase reaction method and co-precipitation-calcination method, the synthesis method provided by the present invention has a synthesis temperature lowered by 1000-1300°C, which is more environmentally friendly and energy-saving; the obtained product has good oxidation resistance and compatibility with the substrate Physical and chemical compatibility of materials. The powder obtained by the method of the invention can be used to prepare the anti-oxidation coating on the surface of C / C composite materials and non-oxide silicon-based ceramic materials.

Description

Preparation method of nano rare earth silicate powder technical field The invention relates to a preparation method of nanometer rare earth silicate powder, belonging to the field of thermal barrier materials. Background technique Silicon-based non-oxide ceramics SiC, Si 3 N 4 The high temperature mechanical properties have reached σ=720MPa (1400°C), K IC =15-20MPa (900°C), and has shown good stability in the laboratory dry environment, so it is considered to be the most promising structural material to replace nickel-based superalloys for engine hot-end parts. However, the engine operating environment often contains water vapor. Water vapor reacts with silicon-based non-oxide ceramics at high temperature to form volatile silicon-containing products, which will cause serious surface degradation and quality loss of silicon-based ceramics. Therefore, how to improve the surface stability of silicon-based non-oxide ceramics in the working environment of the engine becomes...

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Problems solved by technology

But so far, there has been no report on the method of synthesizing nano-scale rare earth silicate powder at low temperature

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