Tailored Properties Of Wound All-Oxide Ceramic Matrix Composites

Kurzfassung

All-oxide ceramic composites with a porous matrix and continuous fibres are ideally suited for use in applications demanding long-term high-temperature stability in oxidizing atmosphere. WHIPOX®, (Wound Highly Porous Oxide CMCs) developed at German Aerospace Center (DLR) belongs to this class of ceramics. Current R&D work is focussed on a tailored reinforcement of the material to ensure economic use of the expensive fibers. Thus, local fiber content and fiber orientation will be designed depending on the expected load and strain. For that, the winding process used for WHIPOX CMCs is superior to any fiber fabric infiltration technique: It will be shown that variations of the winding pattern and of particle size and viscosity of the matrix slurry allow an adjustment of the fiber content in a considerable wide range (~8 - 45 vol.%). The resulting micro- and mesostructure of the composite and its related mechanical properties will be discussed in detail.