Effect of cavitation and spallation on ribbon morphology of Fe73.5Si13.5B9Cu1Nb3 alloy in planar flow melt spinning process

Abstract

An experimental and analytical study concerns the effect of cavitation and spallation during the puddle solidification in planar flow melt spinning rapid solidification process. An instantaneous change in solidification temperature, dynamic variation in pressure distribution, density and motion of the liquid puddle leads to defect formation on ribbon surface. The initiation of nucleation and kinetic crystal growth at weak zone where pressure is relatively low may leads to inception of cavitation in the puddle province. The liquid puddle behaves like elastic membrane due imbalanced force between the liquid and entrapped air molecules caused to irregular contact on wheel substrate. Spallation of cavitate nuclei causes to grow equiaxed cellular shapes at boundary layer of the liquid puddle which leads formation of micro dimple on ribbon surface. The shear bands are affected to nucleus in the puddle due to dynamic fluctuation at the weak zones, which controls the solidification process of puddle.