Mechanical properties and structure of a new commercial SiC-type fibre (Tyranno)

An initial evaluation of a new titanium-doped polymer-pyrolysis SiC fibre, Tyranno (Ube Industries, Ltd) showed a narrow distribution of diameters with a mean of 8.5m; average tensile strengths 3 G Pa, nearly independent of gauge length in the 1 to 4cm range; Weibull parameterm 7.3; and mean Young's modulus 170 G Pa. Heat treatment at 1300 to 1350° C in N₂ appreciably reducedS, m andE; and X-ray diffraction showed that significant crystallite growth as well as some Si₃N₄ formation had occurred. Tyranno fibre properties are compared with those of the well-known Nicalon SiC fibre.