摘要 |
PURPOSE:To obtain preform having stable and uniform structure of tissue by prepg. a homogeneous dispersion by treating SiC whisker with a strong acid then drying wet whisker remaining after filtration. CONSTITUTION:SiC whisker comprising fine short fibrous crystal having ca.0.1-5mum dia. and ca. 10-500mum length is stirred in >=1 N aq. strong acid such as HCl. obtd. homogeneous dispersion is filtered, and remaining wet whisker cake is washed with water, which is dried as it is or after compressing to a specified density. Further, the pH of the dispersion after the strong acid treatment is adjusted to 4-6.5, and then filtered under stabilized condition of dispersion, thus the working efficiency is improved. By this method, the variation of sedimentation velocity due to difference of the shape of the whisker, particularly the aspect ratio is prevented and formation of preform having stably uniform structure of the tissue is permitted. |