Der Einfluss der Orientierungsbeziehungen benachbarter Korner auf die Wirksamkeit von Korn- und Phasengrenzen als Versetzungshindernisse

Analyzing the influence of orientation relationships between neighbouring grains on the yield stress of polycrystalline materials requires measuring of orientations of as many individual grains as possible. Using electron diffraction techniques in TEM orientation relationship measurements were performed in single- and dual-phase brasses. These data were treated with statistical methods. The orientation space with the coordinates φ₁, Φ, φ₂ (Euler angles) and its symmetry relations are of great importance when comparing measured distributions of orientation relationships. A simple model is introduced which evaluates a parameter λ from measured distributions of orientation relationships considering the respective orientations between the glide systems in adjacent grains. λ can be interpreted as a measure for the efficiency of boundaries as dislocation obstacles. In spite of the rather rough assumptions of the model its results are in surprisingly good agreement with those from tensile tests.