Effect of Heat Treatment on the Mechanical Strength of Hollow Core Silicon Carbide Fibers

We have determined the tensile mechanical strength of Nicalon CG and Tyranno SAK hollow core silicon carbide fibers after repeated heat treatments at a temperature of 900°C. Analysis of the effect of the number of heat treatment cycles on strength characteristics of the two types of fiber has shown that the statistical strength and Weibull modulus of the Nicalon CG fiber decrease considerably in comparison with those of the Tyranno SAK fiber, which is due to the increase in the number and size of defects on the Nicalon CG fiber as the number of heat treatment cycles increases.