Institute of Metals Division - Grain Boundary Migration in High-Purity Lead and Dilute Lead-Tin Alloys

The motion of individual grain boundaries under a constant driving force was investi,qated for zone-refined lead, with and without solute tin additions. The rate of boundary migration was found to depend strongly on tin content and on the orientation relationship between the adjacent grains. The results are compared with the theory of impurity-controlled grain boundary miqration developed by Lucke and Detert. Evidence was found that grain boundaries separating grains which have the Kronberg-U&apos;ilson orientation relationships of 38 and 22 deg about <Ill> and 28 deg about <100>, correspond to boundaries of high mobility. The results are discussed in relation to the formation of annealing textures in metals and the structure of high-angle boundaries. It is generally known that small amounts of impurities in solid solution greatly influence the re-crystallization behavior of metals. For example, the addition of 0.005 at. pct of tellurium to copper,&apos; or 0.005 at. pct of silver to lead,2or 0.01 at. pct of manganese or nickel to aluminum3 greatly decreases the rate of recrystallization of these metals. However, this effect may be the combined result of a decrease in the rates of both nucleation and growth; recrystallization experiments do not separate these two factors. Bolling and winegard4 determined the effects of small quantities of tin, silver, and gold on grain growth in polycrystalline zone-refined lead.