| 摘要 |
PURPOSE:To facilitate the production of a large-sized glass having excellent optical homogeneity, using a sol-gel process by irradiating with ultrasonic radiation during the gelation of a liquid sol in a closed vessel having a prescribed shape. CONSTITUTION:A liquid sol having the composition of objective glass is prepared by using fine particles of a metal alkoxide and a metal oxide as raw materials. The liquid sol is poured into a vessel having a prescribed shape, closed with a lid and gelatinized under irradiation of ultrasonic radiation from an external source. The power of the ultrasonic radiation is controlled in order to prevent the generation of bubbles in the liquid sol caused by cavitation. Fine particles are spontaneously precipitated in the wet gel by this process to prevent a density gradient in the direction of height, eliminate the local difference of shrinkage and suppress the generation of crack and crazing. Accordingly, a homogeneous glass having high quality can be produced by this process. |
