Surface energy and structure of crystal boundaries in metals

Abstract

The variation of boundary energy y R in lead with the difference of orientation θ was determined using the methods previously described for tin. It was found that the energy decreases progressively as the difference of orientation decreases below about 16°. The curve relating energy with difference of orientation extrapolates to zero energy at zero angle. These results agree qualitatively with those of tin and offer further strong support for the ‘ transitional lattice ’ theory of the crystal boundary. Straight-line plots of log θ against γ R / θ were obtained for lead and tin. These results are closely consistent with Shockley and Read’s theoretical predictions based on a dislocation model of the transition boundary.