FFF SiC fibers have been evaluated for room temperature tensile strength and elastic modulus. The single fiber tensile test procedure yields strengths in the 4 to 6 GigaPascal (GPa) range, while estimates of the Young’s modulus from a spring fiber format are approximately 390 GPa.
FFF can apply in-situ coatings on LCVD produced fibers as these fibers are formed in a reactor and continuously transferred to second rig dedicated to coating. The coatings can be formed as a single layer or as multiple, overlaid layers, from a range of different compositions which include boron nitride, carbon, silicon carbide, among other options.
Similar to the fiber diameter control afforded by the LCVD technique, fiber coating thicknesses can be varied, with demonstration ranges shown from less than 100 nanometers to greater than 5 microns.