Ta. Parthasarathy et al., MICROSTRUCTURAL STABILITY OF NICALON AT 1000-DEGREES-C IN AIR AFTER EXPOSURE TO SALT (NACL) WATER, Journal of the American Ceramic Society, 78(7), 1995, pp. 1992-1996
When either uncoated or BN-coated Nicalon fibers are exposed to water
saturated with NaCl before being annealed in air at 1000 degrees C, ac
celerated degradation of the structure of the fiber occurs. The fiber
surface oxidizes to tridymite instead of vitreous silica, and the crys
tallites of SIC in Nicalon begin to grow. These findings suggest that
prior exposure to salt water may cause appreciable debit in the mechan
ical strength of Nicalon fibers with time at 1000 degrees C in air.