Disorientations and Their Role on the Work-Hardening in Stage IV
The eect of deformation-induced disorientations on work-hardening of metals is modelled by dislocation dynamics. By incorporating excess dislocations related to disori- entations, Kocks' dislocation model describing stage III hardening is extended to stage IV. Disorientations evolving from purely statistical reasons still lead to stage III behavior and a saturation of the ow stress, but deterministic contributions to the development of disorienta- tions, as dierences in activated slip systems across boundaries, cause a linear increase of the flow stress at large strains. Such a constant work-hardening rate is characteristic for stage IV.
W. Pantleon "Disorientations and Their Role on the Work-Hardening in Stage IV", Materials Science Forum, Vol. 482, pp. 155-158, 2005