GRAIN GROWTH IN POLYCRYSTALLINE ICE

Literature is not available on the grain growth in polycrystalline ice. The present paper deals with such grain growth in pure ice and ice doped with sodium chloride. The technique consists in measuring grain size distributions as a function of time and deriving the numberaverage equivalent “diameter”, considering the grains as spheres. The functional relationship between the average diameter and time of growth is, for pure and doped ice, of the same form as that found for metals. Arrhenius plots show that the energy of activation is higher for doped ice than for pure ice. The results are discussed in terms of interfacial free energy as being ultimately responsible for grain growth. On a molecular scale, processes take place, which lead to diffusion of units consisting of a number of water molecules across the boundaries. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim