Patent ID: 6022820
Filing Date: 2000-02-08
Classification: C04B,Y10S

Abstract:
A post-densification process for reducing the boron content of densified silicon carbide fibers, said fibers having been produced by a process chosen from the group of processes consisting of sintering, vapor-phase deposition and heat treatment of organosilicon polymers, comprising the steps of providing densified silicon carbide fibers containing residual boron, said boron having been originally incorporated in the fibers as a densification aid, and subsequently, at a temperature within the range of approximately 1600 to 2200.degree. C. to promote diffusion of the boron to the surface of the fibers, exposing the densified fibers to an atmosphere consisting essentially of inert gas and up to 100 percent carbon monoxide gas in an amount sufficient to react with and remove the boron which has diffused to the surface of the densified fibers, for a period of time sufficient to reduce the amount of boron in the densified fibers.