Novel Intermediate Temperature Ceramic Composites, Materials and Processing for Siloxane based Basalt Fiber Composites

摘要

SiC composites have been developed by various processing methods, i. e. reaction bonding, CVD/CVI and liquid phase impregnation. This class of composites is handicapped by the high cost of investment and processing, interface coatings and raw materials and therefore only attractive for applications in astronautics and military aviation. Polymer Matrix Composites (PMC) are widely used in lightweight applications. The manufacturing technologies are fully developed and raw materials are cheap. The major drawback and limiting factor of these reinforced polymers is the limited service temperatures. Novel composite materials, bridging the gap between PMC and CMC, are manufactured by the use of polysiloxanes as SiOC matrix precursor. Such competitive free formable composites are capable for service temperatures up to 800°C even in oxidative atmosphere. In order to make the material attractive for series applications, cost effective manufacturing technologies like Resin Transfer Moulding (RTM), filament winding or warm pressing techniques are employed. Beside the improved thermal and chemical resistivity in comparison to reinforced polymers and light metals, a major benefit of SiOC composites is investigated in the field of friction materials. A promising alternative to carbon and synthetic ceramic fibers are mineral based Basalt fibers. These lightweight fibers show high thermochernical stability up to 700°C, are relatively cheap and became recently available in industrial scale.