PREPARATION METHOD OF SILICA RADOME USING SOLIDIFICATION

摘要

PURPOSE: A method for preparing a silica radome using the solidification is provided, to reduce the amount of the impurities contained in silica and to increase the sintering temperature by employing the granulated fumed silica of high purity as a source material and to solidify the sol by controlling the pH, thereby enhancing the sintering efficiency and the mechanical strength of the silica radome. CONSTITUTION: The method comprises the steps of dispersing the fumed silica with a specific surface area of 20-300 m2/g into distilled water in the ratio of 1:99 to 60:40 by weight and homogenizing it to prepare a primary silica slurry; drying and calcining the primary silica slurry and pulverizing it mechanically to prepare a granular secondary silica slurry; re-dispersing the secondary silica slurry into distilled water in the ratio of 20:80 to 70:30 by weight and ball milling the solution to prepare the final slurry; adding a strong base containing ammonium ions to the silica slurry to adjust pH to be 9.5-13.5, maintaining the pH for 24 hours at a room temperature, and defoaming it; adding a pH lowering agent to the solution to adjust pH to be 7.5-9.5 to solidify the solution; and drying, calcining and sintering the molded one to prepare a silica radome. Preferably the strong base is tetramethylammonium hydroxide or tetraethylammonium hydroxide; and the pH lowering agent is methyl formate.