Polykrystallinsk, keramisk höytemperaturfiber, fremgangsmåte for fremstilling av denne, og sintringsbart filament og konstruksjonsmateriale forsterket med fiberen

A high temperature, polycrystalline, ceramic fiber having a selectable diameter of between 1 and 200 microns. The fiber is stable in an inert atmosphere at a temperature above about 1700 DEG C and is often stable even in air at a temperature above 1500 DEG C. The fiber comprises a sintered ceramic powder having a maximum particle size less than the diameter of the fiber and an average particle size less than 0.2 times the diameter of the fiber. The ceramic powder is also stable in an inert atmosphere at a temperature above about 1700 DEG C. At least 90% of the ceramic is selected from borides, nitrides, carbides, and silicides. The fiber is characterized by a smooth surface and is preferably out of round. Also disclosed is filament which may be processed into a texture and sintered, comprising a flexible polymer matrix containing high temperature sinterable ceramic powder particles. The ceramic powder particles are selected from ceramic borides, nitrides, carbides, and silicides. The diameter of the filament is from 2 to 300 microns. Also disclosed is a method for making said filament by fiberizing a mixture of a polymer and a sinterable non-oxide materials and the method wherein the high temperature ceramic fiber is prepared by sintering the textilable sinterable filament as previously described.