Ultrafast growth kinetics of titanium dendrites investigated by electrostatic levitation experiments and molecular dynamics simulations

An ultrafast crystal growth velocity of 122 m/s for β–Ti dendrites was achieved at a liquid undercooling of 352 K (0.18T_m) by electrostatic levitation technique. In contrast, most refractory metals attained slower dendrite growth velocities but displayed similar power laws with liquid undercooling. A combined analysis by current dendrite growth theory with molecular dynamics simulation indicates that liquid thermal diffusion rather than solid-liquid (S/L) interface kinetics is still the dominant factor to control dendrite growth. Besides, the atomic-scale thickness of the S/L interface layer may determine the dendrite growth velocity difference for various refractory metals.