Recrystallization of Zone-Refined Lead

Abstract

THE decrease in recrystallization temperature with increasing purity of a metal is well known. This general phenomenon has been observed in the past few years especially in high-purity aluminium obtained by zone-refining; moreover, in France it has been demonstrated that recrystallization will occur at remarkably low temperatures. The work of Dimitrov and Albert^1,2, is representative of the recent papers on this subject; they have shown that following 97 per cent deformation at low temperatures, the recrystallization of aluminium was complete after 200 hr. at −52° C., and at least initiated after 100 hr. at −79° C. These low-temperature investigations are significant because it seems that no current theory readily explains the processes involved. Then in conjunction with other experiments on zone-refined aluminium involving recrystallization and other phenomena, they show the marked effect of small amounts of impurity.