Dislocation Interactions in Olivine Revealed by HR-EBSD

Dislocation interactions mediated by grain boundaries

The dynamics of dislocation assemblies in deforming crystals indicates the emergence of collective phenomena, intermittent fluctuations and strain avalanches. In polycrystalline materials, the understanding of plastic deformation mechanisms depends on grasping the role of grain boundaries on dislocation motion. Here the interaction of dislocations and elastic, lowangle grain boundaries is studi...

Microstructure characterization of ZK60 magnesium alloys using TEM and HR-EBSD.

ZK60 (Mg-Zn-Zr) alloys exhibited a variation in precipitates with aging, and their mechanical properties also changed. Microindentation tests were carried out on two types of ZK60 alloys of solid solution (T4) and peak aging (T6). Microstructure and texture evolution during indentation was investigated using electron backscatter diffraction. Twinning occurred near the indentation marks in most ...

Finite-temperature dislocation interactions

Hydrogen-dislocation Interactions and Intrinsic Dislocation Relaxation in Niobium

The dislocation relaxation between 100 K and 200 K (IkHz) in plastically deformed niobium, formerly named "a-relaxation" is a hydrogen Snoek-Koster relaxation (cold work relaxation). This is shown by experiments on extremely degassed samples, which contained controlled amounts of hydrogen and/or oxygen. The intrinsic, hydrogen-free dislocation relaxation appears between 30 K and 70 K (IkHz), th...

Hydrogen-Vacancy-Dislocation Interactions in α-Fe

Atomistic simulations of the interactions between dislocations, hydrogen atoms, and vacancies are studied to assess the viability of a recently-proposed mechanism for the formation of nanoscale voids in Fe-based steels in the presence of hydrogen. QM/MM calculations confirm EAM simulations showing that individual vacancies on the compressive side of an edge dislocation can be transported with t...