Off-axis creep behavior of oxide/oxide Nextel720/AS-0

Oxide/oxide ceramic-matrix composites (CMC) are being demonstrated in engine components that are axisymmetric in shape, and subject to axisymmetric thermo-mechanical loadings. Traditionally, woven CMC materials used in these components are made from 0 deg /90 deg fiber architectures. In many cases, the highest stresses are not always coincident with the orientation of the reinforcing fibers. Tensile and creeps tests at 1100 deg C on a +/-45 deg CMC composed of NextelTM720 fibers and a alumina-silica matrix (AS-0) have been performed. The +/-45 deg orientation has approximately two-thirds the ultimate tensile strength of the 0 deg /90 deg orientation. The creep rupture strength at 100h for the +/-45 deg orientation is approximately one-third that of the 0 deg /90 deg orientation.