Bulk ultra-fine eutectic structure in Ti–Fe–base alloys

An ultra-fine eutectic structure has been obtained in the Ti70.5Fe29.5 binary alloy by slow cooling from the melt through arc melting and cold crucible rod casting. The addition of 3.85 at.% Sn to the binary Ti–Fe alloy induces a change of the morphology of the eutectic and increases the volume fraction of the FeTi (Pm3m) phase. A significant improvement of the plastic deformability of the ternary alloy has been observed under uniaxial compressive loading resulting in 16% strain to failure compared to 3.4% for binary Ti70.5Fe29.5. The morphology of the eutectic colonies, their refinement and supersaturation of the β-Ti phase are crucial factors for improving the ductility of the ultra-fine eutectic alloys.