Correlation area size of excess dislocations of the same sign as a new mesoscopic characteristic of the dislocation substructure

Abstract The conception of correlation area size (CAS) of excess dislocations of the same sign (EDSS) as a new characteristic of deformation substructure of metals and alloys has been developed. CAS plays important role in elevated temperature creep deformation behavior of metals along with such substructure characteristics as subgrain size and misorientation angle. The main reasons of appearance and some features of CAS of EDSS have been considered. It is shown that CAS can be considered as feature determining the critical grain size. When grain size is less than CAS the creep rate becomes depending on grain size and mechanism changes from high temperature recovery to grain-boundary glide one.