The FFF SiC fiber has been exposed to high temperature environments for up to 200 hours in temperature range from 1500oC to 1650oC. The gas environments evaluated were open air (oxygen) and argon, fed into the furnace at ambient conditions. A thin silica layer forms on the fiber surface, less than 1 micron in thickness, or about 3% of a fiber diameter. This compares very favorably with the oxide layers that form on polymer-precursor-derived fibers, which grow to thickness as high as 25% in the same conditions.
Grain growth of the laser printed LP-30SC silicon carbide fibers has been studied as well at various temperatures, exposure times and gas environments using X-Ray diffraction (XRD) techniques as seen below. Curiously, the grain size seems to achieve a limit of sorts in the mid-30 micron range. This augers well for high temperature creep performance of this SiC fiber.