POLYCRYSTALLINE CORUNDUM FIBERS AND METHOD FOR THE PRODUCTION THEREOF

摘要

The invention relates to polycrystalline corundum fibers substantially consisting of corundum and an oxide of the elements of the main groups I or II of the periodic table. The crystallites of said corundum fibers have the following grain size distribution: 0 to 0.15 micrometers (34 %), 0.15 to 0.29 micrometers (55 %) and 0.29 to 0.43 micrometers (11 %). Said corundum fibers are produced by mixing nuclei and an oxide former of the elements of the main groups I. and Il of the periodic table with an aluminium chlorohydrate, by adding a water-soluble polymer, then by spinning fibers from said mixture and by calcining said fibers at temperatures above 1100°C.