Processing and properties of 3D woven SiC/SiC composites with hybrid matrix

3D woven SiC/SiC composites with SylramicTM-iBN SiC fibers have been fabricated by first partially infiltrating 3D woven fiber preforms with SiC by chemical vapor infiltration (CVI) and then by polymer infiltration and pyrolysis (PIP) of SiC-yielding polymer. The influence of fiber architecture on damage evolution and failure mechanisms during tensile loading, in-plane tensile properties, transverse thermal conductivity, and interlaminar tensile strength of the composites has been investigated. Wherever possible, the data are compared with those of 2D woven melt infiltrated (MI), CVI, and (CVI+PIP) hybrid SiC/SiC composites. The composites exhibit 300-hr creep durability at 1482 degrees C in air at stresses up to 138 MPa and show potential for elevated-temperature applications. Further improvements in composite properties are possible by optimizing composite constituents and fiber architecture.