Preparation of hollow ceramic fibers

摘要

Hollow ceramic fibers are prepared by melt spinning an organic silazane polymer, infusibilizing the fiber to form an infusible layer on the surface, and pyrolyzing the fiber to obtain a ceramic fiber having an empty interior. The infusibilizing step includes two steps of treating the fiber with a gas containing the vapor of an infusibilizing silicon, boron, phosphorus or metal compound and further treating with a water vapor-containing gas or ammonia-containing gas. The surface infusible fibers are efficiently sintered into hollow ceramic fibers without fusion bond.