We extended subcritical crack-growth studies in SiCf/SiC composites to include composites reinforced with Hi-Nicalon fibers and a broader test temperature range. These studies were in addition to more systematic tests on materials reinforced with Nicalon-CG fibers. We tested 0/90 woven composites with a carbon interphase in argon at 1373K and 1473K and compared the results with previous tests in argon from 1173K to 1373K. The results in inert environments are copnsistent with a proposed fiber-creep-controlled crack-growth mechanism. Measured nonlinear creep equations for both fiber types. Estimates of local strains during crack growth are in reasonable agreement with estimated fiber creep strains for the given times and temperatures.
Revised: September 21, 2011 |
Published: October 26, 2001
Citation
Henager C.H., C.A. Lewinsohn, and R.H. Jones. 2001.Subcritical Crack Growth in CVI SiCf/SiC Composites at Elevated Temperatures: Effect of Fiber Creep Rate.Acta Materialia 49, no. 18:3727-3738.PNNL-SA-32904.