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 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 〈1 1 2〉 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.