The relationship between mechanical properties and dislocation substructure in aluminium after deformation at different strain rates has been studied. It was established that increase in strain rate increases flow stress and decreases the cell size of the dislocation substructure. From measurements of the misorientation angle between subgrains it was possible to determine the dislocation density and to present it as a function of the strain rate (at constant strain). It was also found that the flow stress is related to the cell size by the Hall–Petch equation, and that the proportionality factor k in this equation is independent of the misorientation angle.
