Fibre-reinforced intermetallic compounds by physical vapour deposition

This paper describes work on SiC fibre-reinforced γ-Tial and MoSi2 intermetallic matrix composites (IMCs). Electron beam evaporation and vapour mixing were used to matrix-coat SiC fibre with a thick layer of intermetallic compound, and these coated fibres were successfully fabricated into IMCs. Intermetallic compounds have attractive properties for high-temperature structural applications and have been the subject of much research effort in the last 10 years. Progress has been made in improving the ductility of these rather brittle materials, particularly with the titanium aluminides Ti3Al and TiAl, by alloying and thermomechanical processing. However, it is unlikely that monolithic intermetallics will have the right combination of ambient temperature ductility and high-temperature strength to allow widespread commercial application. Further progress depends on the development of engineered materials which exploit the combined potential of ceramics, intermetallics and metals to give an attractive balance of properties.