MODIFICATION OF THE FIBER-MATRIX INTERFACE IN ALUMINIDE-BASED INTERMETALLIC-MATRIX COMPOSITES

The success of continuous fiber-reinforced intermetallic-matrix composites, including those based on aluminides, depends on developing an optimized fiber/matrix interface. This paper addresses different issues related to the modification of the fiber/matrix interface in intermetallic-matrix composites. The interface issues discussed here include interfacial reaction barriers, interfacial layer to reduce the effect of coefficient of thermal expansion mismatch between the fiber and the matrix, and interfacial layers to improve fiber/matrix bonding. Various concepts are demonstrated with examples drawn from some of the systems of current interest. The examples include interfacial reaction barriers for the NiAl/Nb2Be17 composite system, interface layer to accommodate fiber/matrix CTE mismatch in Ti3Al/SiC system, and interface layer to improve fiber/matrix bonding in NiAl/Al2O3 composite.