Extended dislocation barriers in tilt boundaries in fcc crystals

Abstract

Extended dislocation barriers at tilt boundaries in fcc crystals are considered. For boundaries with a high degree of lattice coincidence, stable extended dislocation barriers, analogous to those occurring within a single crystal, are shown to exist. Other boundaries can have components equivalent to the high coincidence boundaries. The boundary barriers are shown to be possible nucleation sources for mechanical twins or martensite phase transformations.

Key words:

• Extended dislocations
• Dislocation barriers
• Grain boundaries