A high-index (Sigma = 51b) coincidence-site lattice (CSL) grain boundary of an Al-4wt% Mg alloy was investigated by high-resolution electron microscopy. The sample was prepared from a polycrystalline tensile specimen strained to 3%. Since the grain boundary is an incidental high-index CSL boundary, its structure and property resemble in many aspects those of a general grain boundary of a deformed polycrystalline material. The boundary was observed to be divided into symmetric and asymmetric sections. Periodic boundary structures were evident in both segments. Grain-boundary migration due to irradiation or heating was observed in situ as a result of ledge motion along the boundary. This observation supports Gleiter's model that the grain-boundary migration occurs by step mechanisms.
No takes yet. Share an insight, caveat, or question.
Shichao Song (1999) studied this question.