Abstract
Grain boundaries intersecting a free surface migrate during annealing or creep, becoming nearly perpendicular to the specimen surface. This effect was studied by sectioning perpendicular to the free surface and measuring the angles made with the surface by grain-boundary traces on the section. On such a section, the distribution of angles is sinusoidal with a mean of 57° when the free surface is “as-cut”. After heating, the distribution of angles is sigmoidal with the exclusion of angles below ∼ 60° and a mean which rapidly approaches 80° as the time of annealing is extended. Other consequences of this rearrangement are described. Measurements were made on two grades of magnesium, and on β- and β/γ-brass.
Get full access to this article
View all access options for this article.