Phase constitution and microstructure of the NbTiVZr refractory high-entropy alloy solidified upon different processing

Time- and temperature-resolved phase formation in the equiatomic NbTiVZr refractory high-entropy alloy has been studied situ using high-energy synchrotron X-ray diffraction high-speed video imaging during non-equilibrium solidification. Phase is shown to be dependent on solidification conditions. When melt undercooled over 80 K it crystallizes as a bcc single-phase solid solution despite solute partitioning between dendrites interdendritic regions. sample for some time kept semisolid state, two additional phases form The crystal growth velocity alloy, estimated from videos, shows pronounced sluggish kinetics.