The dislocation structure in Ni₃, (Al, Ti) above the temperature of the maximum in flow stress

Abstract

The dislocation structure in Ni₃(Al, Ti) deformed at 1073 K, a temperature above that at which the flow stress peaks, illustrates features of planar localized single slip. Deformation proceeds by movement and multiplication of dislocations of the ±a[110](001) slip system. Edge dislocations transform into locked configurations. APB dragging is observed to operate locally but is not regarded to be a rate-controlling process for dislocation motion. Delocalization of the APB on several atomic planes parallel to the fault plane could be the reason for glide plane ‘softening’ and the formation of a planar dislocation structure.