DENDRITIC GROWTH IN LEAD

Abstract

Dendritic growth of large single crystals of lead is revealed by decanting the remaining liquid at any required stage of the process of solidification. The direction of dendritic growth was determined as a function of crystallographic orientation and direction of solidification. It was found that all the dendritic rows in a single crystal were not quite parallel, owing to a crystal substructure. An explanation is advanced for the presence of the substructure in terms of dendritic growth based on their observed properties. Temperature measurements during solidification showed that the region of the liquid where dendrites were formed was supercooled by several degrees. No supercooling was observed in the portions not showing dendritic growth.