Interfacial Coatings for SiC Fiber-Reinforced Titanium Matrix Composites

Continuous silicon carbide (SiC) fiber-reinforced ordered titanium intermetallic alloy (Ti3Al) matrix composites are enabling materials for next-generation turbojet compressor and hypervelocity vehicle airframe applications. They possess unique combinations of several attractive properties such as high specific strength, high specific stiffness, and excellent fatigue and creep resistance. However, several key issues challenge the fabrication and application of these composites, led by their complex interfacial Phenomena. In this Phase I Program, Ultramet Proposes to deposit single-layer, graded, and duplex interlayers of refractory metals and/or ceramics by chemical vapor deposition (CVD) to eliminate interfacial reactions, eliminate the weak carbon layer on commercially available SiC fibers, and ease thermal stress at the fiber/matrix interface, Ultramet will collaborate with other experts to coat fibers, fabricate and characterize the composites, and screen the material systems Proposed for the interlayers.