Diffusion under periodic-supersaturation conditions during cyclic heat treatment

Conclusions The materials in which a tendency toward pore formation is observed during cyclic heat treatment are supersaturated with impurities at the low temperature of the cycle. The maximum supersaturation occurs in regions in which there is a high diffusion coefficient, particularly along grain boundaries. The impurities precipitated in these regions serve as crystallization centers for impurity diffusion from other regions. The pore formation can be thought of as the expansion of such regions and the enrichment of these regions with impurities and vacancies.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 126–128, November, 1970.