Patent ID: 6187705
Filing Date: 2001-02-13
Classification: C04B

Abstract:
A high strength, high creep resistance, silicon carbide fiber having no boron nitride coating, a density of at least approximately 3.0 g/cm.sup.3, a tensile strength of at least 2.0 GPa and a creep resistance M value of greater than about 0.75 as derived from a Morscher-DiCarlo BSR test procedure carried out at 1400 degrees C for one hour in argon, produced by the process comprising the steps of:(A) providing a boron-doped, silicon carbide fiber which has been sintered at a sintering temperature to densify the fiber;(B) exposing the fiber to a nitrogen-containing atmosphere at a temperature at least equal to the sintering temperature;(C) exposing the fiber to an atmosphere containing carbon monoxide at a temperature sufficient to remove boron and boron nitride from the fiber.