Aligned monotectic growth in unidirectionally solidified Zn-Bi alloys

Abstract

The solidification morphology of the Zn-Bi monotectic alloy is studied through directional solidifcation processing. It is shown that the aligned growth depends on the crystallography of the solid-liquid interface. The best alignment of the monotectic liquid phase (L 2) occurs when the growth direction is [0001]Zn followed by that of [101¯ 0]Zn. Aligned growth could not be observed in other growth directions. A parametric approach is adopted, which incorporates the mechanical stability of the three phases at the growing interface and Derby and Favier’s criterion for monotectic growth, derived from Jackson and Hunt theory of coupled growth, to identify the possible window of growth conditions and phase spacings where aligned growth is possible.