| 摘要 |
PROBLEM TO BE SOLVED: To obtain an amorphous fiber having excellent oxidation resistance and useful for composite material, etc., by covering a core containing Si-N bond, etc., with a coating material containing BN crystal having hexagonal crystal structure, etc. SOLUTION: This amorphous fiber contains a core composed of a three- dimensional glassy network accounting for >=80vol.% of the core and containing Si-N bond and B-N bond and optionally containing SiO, Si-C, B-C, C-C, C-N and/or B-O bonds and further contains one or more coating layers containing BN crystal having hexagonal structure and Si bonded to O, B, N and/or C through one or more bonds. The amorphous fiber can be produced by the thermal oxidation of an amorphous fiber containing Si, B and N, composed of a three-dimensional glassy network accounting for >=80vol.% of the fiber, containing Si-N bond and B-N bond and optionally containing SiO, Si-C, B-C, C-C, C-N and/or B-O bonds. |
