INTERMETALLIC-MATRIX COMPOSITES - A REVIEW

With properties lying between those of metals and ceramics, intermetal lic compounds are particularly attractive for high temperature structu ral applications. Considerable progress has been made in improving the ductility of these rather brittle materials, especially with the tita nium aluminides Ti3Al (alpha-2) and TiAl (gamma). But monolithic inter metallic compounds are unlikely to have the right combination of ambie nt temperature ductility and high temperature strength for the most de manding aeroengine applications. Further progress depends on the devel opment of engineered composite materials, which exploit the combined p otential of ceramics, intermetallics and metals to give a desirable ba lance of properties. This paper reviews developments in intermetallic matrix composites (IMCs), concentrating on the last four years and dra wing examples from the three most widely researched matrix systems: ti tanium aluminides, nickel aluminides and molybdenum disilicide.