Chemical heterogeneity-induced plasticity in Ti–Fe–Bi ultrafine eutectic alloys

•The colony of ultrafine structure was encapsulated by immiscible Bi upon solidification.•This chemical heterogeneity has a strong effect to dissipate the localization of the stress.•The ultrafine eutectic alloy with the chemical heterogeneity presented plasticity up to 8.5%.

Chemical heterogeneity in Ti–Fe ultrafine eutectic structure has been introduced by addition of Bi without structural heterogeneities such as length-scale, volume fraction and morphology of lamellar and colony structures. The detailed microstructural investigation clearly reveals that the Bi was highly saturated at the colony boundary of the ultrafine eutectic alloys. The chemical heterogeneity introduced by the additional Bi in the present investigation effectively dissipates the localization of the stress thus improving the plasticity up to 8.5% without compromising the strength of 2100 MPa.