Characterization and High‐Temperature Mechanical Behavior of an Oxide/Oxide Composite

An oxide/oxide ceramic fiber‐matrix composite (CMC) has been extensively characterized for high‐temperature aerospace structural applications. This CMC is called GEN‐IV™, and it has a porous and cracked aluminosilicate matrix reinforced by 3M Nextel 610™ alumina fibers woven in a balanced eight harness weave (8HSW). This CMC has been specifically designed without an interphase between the fiber and matrix, and it relies on the porous matrix for flaw tolerance. Stress‐strain response is nearly linear to failure and without a well‐defined proportional limit in tension and compression. In‐plane shear and interlaminar strength increases with increasing temperature. The 1000°C fatigue limit in air at 105 cycles is 160 MPa, and the residual tensile strength of run‐out specimens is not affected by the fatigue loading. The creep‐rupture resistance above 1000°C is relatively poor, but it can be improved with a more‐creep‐resistant fiber.