Phase selection during solidification of undercooled Ti–Fe, Ti–Fe–O and Ti–Fe–Si–O melts—Influence of oxygen and silicon

The alloy system Ti–Fe(–O, –Si) shows a great variety of stable and metastable solid phases including structurally complex phases such as quasicrystals and approximant phases. In this work the change in phase selection during solidification as a function of composition on going from the binary Ti72.3 Fe27.7 over the ternary Ti69.4 Fe26.6 O4.0 to the quaternary Ti65.4 Fe25.0 Si5.7 O3.9 alloy (numbers indicate at.%) is investigated. The liquid samples are processed and analyzed in situ using a combination of the electromagnetic levitation technique and energy-dispersive diffraction of synchrotron radiation. This allows us to directly determine the crystal structures of the solid phases formed during solidification.