Figure (a) TEM micrographs of the Al-Ti-Fe-Cr RS P/M alloy annealed at 573 K for 1000 h. SAED patterns taken from (b) icosahedral, (c) both icosahedral and α-Al, and (d) α-Al phases. Diffraction spots are indexed by an fcc Al crystal.
Inhibition of Al grain coarsening by quasicrystalline icosahedral phase in the rapidly solidified powder metallurgy Al-Fe-Ti-Cr alloy:
The quasicrystalline icosahedral phase prevents Al matrix grain coarsening in the rapidly solidified powder metallurgy Al92.5Fe2.5Ti2.5Cr2.5 (at.%) alloy due to a thermally stable crystallographic orientation relationship
between the icosahedral and Al phases. The 2-fold axis of the icosahedral
phase is along the <112> axis of face centered cubic Al; this orientation
relationship was observed in alloys annealed at 573 K for 1000 h. A highly
dispersed intergranular icosahedral phase located on the Al matrix significantly
enhances the heat resistance of the alloys.
