Creep of SiC-SiC microcomposites

The creep behavior of SiC/C/SiC microcomposites at 1200-1400 degrees C and 140-450 MPa was investigated in the presence and absence of matrix cracking . The microcomposites consisted of single Hi Nicalon or Carborundum fibers coated with a CVD carbon interlayer and a CVD SiC matrix. Since the fibers and matrix had been examined by the identical experimental technique, direc t comparisons of the creep of the composite and of the constituents were pe rformed. The creep of uncracked microcomposites was successfully modeled us ing a simple rule of mixtures algorithm. When matrix cracks were present, t he microcomposites were modeled using a series composite consisting of inta ct microcomposite, exposed fiber at the matrix crack, and the debonded regi on in between. Trends for behavior with respect to the various mechanical a nd structural parameters that control creep are presented. (C) 1999 Elsevie r Science Ltd. All rights reserved.