Dendritic growth of α(Fe,Si) ferrite in annealed Fe₈₀Si₈B₁₂ metallic glass

Generally, experimental study on the dendritic growth has been confined to transparent organic materials. In this experiment, using the fact that, during the crystallization of Fe₈₀Si₈B₁₂ metallic glass, dendritic growth of α(Fe,Si) ferrite occurs, we examined the growth direction, tip morphology, growth process, growth condition and initial secondary arm spacing of α(Fe,Si) dendrite. Experimental results revealed that the dendritic growth direction is <111>, the dendrite tip morphology is a nearly exact paraboloid and the growth rate is controlled by the diffusion of boron into the amorphous matrix. Moreover, the dendritic growth condition of α(Fe,Si) does not satisfy the maximum velocity condition, but the marginal stability condition.