Method for producing aluminium titanates film by using colloidal sols-gel rubber technique

Abstract

The invention discloses a method adopting sol-gel technique to prepare aluminum titanate film. The method comprises the steps as follows: adopting aluminum nitrate as the aluminium source, inducting titanium through titanium alkoxide or titanium tetrachloride, utilizing lower alcohol as the solvent, and applying acetylacetone, acetic acid or glycol as the stabilizer to control the hydrolyzing speed of the titanium precursor, wherein, the PH value is adjusted by nitric acid; the aluminum titanate sol is prepared by utilizing glycerin, butanediol or formamide as the dryness control chemical additive; after aging and vacuum defoaming of the sol, the dipping lifting method is adopted to coat film, and the film is processed by room temperature aging, room temperature drying and drying under 50 DEG C to get dry gel film. The film can be coated repeatedly till the necessary thickness of film. Before repeated coating, a low temperature calcine disposal of 450 DEG C is necessary, and finally the even and compact aluminum titanate film is formed by calcinations under 1350 DEG C. The invention has the advantages of simple process, low cost of raw material, etc.

Description

technical field [0001] The invention belongs to the technical field of inorganic thin film preparation, and in particular relates to a method for preparing an aluminum titanate thin film by using a sol-gel process. Background technique [0002] Aluminum titanate (Al 2 TiO 5 , referred to as AT) set high melting point (1860 ℃) and low expansion (α<1.5×10 -6 / °C) features in one, with low thermal conductivity (1.5W / m·K), good thermal shock resistance and corrosion resistance. The expansion coefficient of aluminum titanate and Si 3 N 4 , SiC and other high-temperature structural ceramic materials match the expansion coefficient, so the aluminum titanate film can be firmly bonded to Si 3 N 4 and SiC substrate, can effectively prevent Si 3 N 4 And high temperature oxidation of SiC, and can also significantly improve their corrosion resistance, thereby increasing their use temperature and extending their service life. Since the thermal conductivity of aluminum titanate...

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Problems solved by technology

The U.S. has two patents (US005407479A and US005565245A) to disclose the method for preparing aluminum titanate thin film and modified aluminum titanate thin film by sol-gel method respectively, and the precursor that it adopts is aluminum sec-butoxide (Al[C 2 h 5 CH(CH 3 )O] 3 ) and tetrabutyl titanate (Ti[CH 3 (CH 2 ) 3 O] 4 ), because the water required for the sol-gel reaction must be introduced through an external method, it is necessary to strictly control the molar ratio of water to the metal alkoxide and the hydrolysis rate of the metal alkoxide. Alcoholates are expensive and their preparation is expensive

Thin Solid Films 2005, Volume 487, pages 109-115, reported that aluminum sec-butoxide and titanium tetrachloride were used as raw materials, using chemical vapor deposition, using a vertical cold-wall CVD reactor, through strict control of deposition parameters, 800 ° C Heat treatment prepares amorphous aluminum titanate film on silicon wafer and glass substrate. This method requires a special CVD reactor and the preparation cost is high

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