Recrystallization of as-solidified highly-undercooled Fe40Ni40B20 eutectic alloy: In situ formation of duplex structure

Non-equilibrium effects (e.g. strain energy) are stored upon highly undercooled solidification of Fe40Ni40- B20 eutectic alloy. Only for sufficiently high undercooling (e.g. 200 K), recrystallization, with the strain energy as the driving force, can occur upon annealing the as-solidified structure, thus forming a duplex structure consisting of as-recrystallized single-phase layer (outer) and as-solidified two-phase anomalous eutectic bulk (inner). As compared to the samples subjected to lower undercoolings, the mechanical properties of the samples with the duplex structure are improved substantially.