Microstructure and mechanisms of cyclic deformation in aluminum single crystals at 77 K: Part II. Edge dislocation dipole heights

Aluminum single crystals were cyclically deformed at 77 K and the dislocation substructure was analyzed. The dipole height in the presaturation microstructure is approximately independent of location, being equal in the dipole bundles (or veins) and within the channels, perhaps suggesting a homogeneous stress distribution. The maximum dipole height suggests a strength approximately equal to the flow stress, while the average dipole height suggests a strength over a factor of 2 higher than the flow stress. The stress to move a dislocation through a dipole bundle is also calculated to be approximately equal to the flow stress.