ENERGY-DISSIPATION EFFICIENCY IN ALUMINUM DEPENDENT ON MONOTONIC FLOWCURVES AND DYNAMIC RECOVERY

In the hot working of Al, the flow curves are usually monotonic, reach ing saturation at a lower strain epsilon(s) and stress sigma(s) as tem perature rises and strain rate declines, Microstructural examination c onfirms that the dislocation density rises to a steady-state level thr ough formation of an equiaxed subgrain substructure with constant dime nsion that is larger for lower stress. The energy dissipation efficien cy estimated by dynamic materials modeling for flow curves of the abov e type is the result of dynamic recovery, not of dynamic recrystalliza tion, which is characterized by flow curves with a peak and marked sof tening to a steady-state regime.