Preparation method of Y4Si3O12 crystal whiskers

Abstract

The invention relates to a preparation method of Y4Si3O12 crystal whiskers, which comprises the steps of: dissolving Y (NO)3.6H2O and Na2SiO3.9H2O in anhydrous ethanol to obtain solution A; adding ethylenediaminetetraacetic acid (EDTA) and high-density polyethylene (HDPE) into the solution A and magnetically agitating for ultrasonic reaction to obtain solution B; and placing the solution B in a hydrothermal reaction kettle lined with polytetrafluoroethylene for constant-temperature reaction, conducting centrifugal separation, successively washing with distilled water and anhydrous ethanol and finally drying to obtain Y4Si3O12 crystal whiskers. The preparation method of the Y4Si3O12 crystal whiskers has the advantages that the process is simple to control, the cost is lower, the preparation temperature is low, the later-stage crystallization is not required and the possible defects that the crystal grains grow up, are coarsened or curled and the like in the later-stage heat treatment process are avoided to some extent. The appearance control can be realized and the Y4Si3O12 crystal whiskers with high purity and even grain size can be prepared.

Description

technical field [0001] The invention relates to a shape-controllable Y 4 Si 3 o 12 The preparation method, specifically relates to a kind of Y 4 Si 3 o 12 Whisker preparation method. Background technique [0002] The structural characteristics of yttrium silicate material and a series of excellent physical and chemical properties, such as low elastic modulus, low high temperature oxygen permeability, low linear expansion coefficient, low high temperature volatilization rate, chemical corrosion resistance and other characteristics, make it a A high-performance structural material is widely used in the aerospace field. There are three crystal phase structures of yttrium silicate, which are Y 2 SiO 5 , Y 2 Si 2 o 7 and Y 4 Si 3 o 12 . [0003] Currently, although about Y 4 Si 3 o 12 There are very few reports in the literature, and its lattice constant has not yet been reported, but because of its melting point as high as 1950 ° C, it has extremely low high-te...

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Problems solved by technology

[0003] Currently, although about Y 4 Si 3 o 12 There are very few reports in the literature, and its lattice constant has not yet been reported, but because of its melting point as high as 1950 ° C, it has extremely low high-temperature oxygen permeability, and at the same time Y 4 Si 3 o 12 coefficient of thermal expansion (4.31 x 10 - 6K -1 ) and the thermal expansion coefficient of the SiC inner coating (4.5×10 -6 K -1 ) are very close to [Sun ZQ, Zhou YC, Wang JY, et al. γ-Y 2 Si 2 o 7 , amachinable silicate ceramic: mechanical properties and machinability. The American Ceramic Society, 2007, 90(8): 2535-2541.], and Y 4 Si 3 o 12 Good physical and chemical compatibility with SiC [Ogura Y, Kondo M, Morimoto T.Oxygenpermeability of Y 2 SiO 5 .Materials Transactions[J],2001,42(6):1124-1130.], so it is considered to be one of the most ideal outer coating materials in the composite coating structure with SiC as the inner coating. Materials have broad application prospects

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