QUANTITATIVE-ANALYSIS OF DISLOCATIONS IN RELATION WITH THE MARTENSITIC-TRANSFORMATION IN CU-ZN-AL ALLOYS

A quantitative evaluation of the dislocation energies in relation with the beta --> 18R martensitic transformation in Cu-Zn-Al alloys has be en performed. Dislocations produced by macroscopic deformation of the parent or martensitic phase have been considered. The crystallographic changes of the dislocations upon transformation have been established and the anisotropic theory of dislocations has been used to calculate their energy when embedded in beta or martensite. Good agreement was found between the calculated separation of the partials and the corres ponding line orientations for the minimum energy and the experimental results from transmission electron microscopy observations.