Formation of icosahedral phase in an Al93Fe3Cr2Ti2 bulk alloy

The microstructural investigation of a suction-cast Al93Fe3Cr2Ti2 bulk alloy reveals that an icosahedral phase forms together with monoclinic Al13(Fe,Cr)4 and tetragonal Al3Ti in an α-Al matrix. The icosahedral phase is often surrounded by Al3Ti particles indicating that the formation of the icosahedral phase strongly competes with the Al3Ti phase. Chemical analysis reveals that Ti has a strong influence to stabilize the Al3Ti phase. In contrast, both Cr and Fe are effective to stabilize the icosahedral phase.