Defects in aluminum quenched from the liquid state

Abstract

High purity aluminum was quenched from the liquid state and specimens were examined by transmission electron microscopy. Very high densities of defects in the form of perfect loops, imperfect loops and small black spots were observed. The vacancy concentration, as deduced from the number and size of defects in foils quenched from various temperatures, increased with increasing temperature at a much slower rate in the liquid than in the solid. Both the vacancy formation energy and the entropy factor appeared to be considerably reduced above the melting point. Also, a discontinuity in the vacancy concentration was found at the melting point.