Abstract: Intermetallic phases and microstructures of a rapidly solidified Al94Ti4C2(at%)alloy have been investigated. The DC casting microstructure comprises α Al, sheet like Al 3Ti and 0 3~1μm sized Ti 5C 4 particles appearing in the form of particle clusters. In the rapidly solidified alloy ribbons, the Ti 5C 4 phase disintegrates as fine particles of 20~40nm size, accumulating at and becoming trapped along the α Al grain boundaries, while Al 3Ti is replaced by an ordered LI 2 crystal structure (a 0≈0 404nm)metastable phase(~Al 4Ti),which is distributed in the α Al grains and retains a coherent lattice relationship with α Al matrix. Moreover, the formation mechanism of the intermetallic phase is discussed.

Key words: solidification, aluminum alloy phase, microstructure