On dislocation formation by vacancy condensation

Abstract

The mechanism of dislocation loop formation by vacancy condensation is examined in a quantitative manner. The critical vacancy supersaturation necessary for the growth of the loops and the climb rate of the dislocations are determined. It is shown that the mechanism proposed for lineage formation based upon loop growth (Frank, 1956 a) is inapplicable. The number of dislocation loops produced by collapsing vacancy discs is calculated as a function of the cooling rate, cooling range and dislocation density existing in the crystal before cooling.