Rapid crystal growth kinetics of tungsten dendrites under electrostatic levitation state

Abstract

The rapid crystal growth kinetics of tungsten dendrites within extremely refractory W60Re40 liquid alloy was examined under electrostatic levitation state. Tungsten dendrite growth through two solidification modes was revealed through modulating the active nucleation and spontaneous nucleation within the liquid undercooling range between 145 and 470 K, leading to the displacement of normal peritectic transition by metastable isomorphous solidification. The tungsten dendrites kept the priority growth direction of 〈100〉 and their growth velocity versus undercooling showed a power law function. The liquid alloy would solidify through normal peritectic transition if assisted with active nucleation from bottom Mo electrode.