MICROSTRUCTURE AND DEFORMATION RESISTANCE IN ROLLING OF ALUMINIUM FOIL

摘要

Transmission electron microscopic observations of technically pure Al (AA 1050) show that the grain structure approaches a steady state during foil rolling due to dynamic recovery and geometric dynamic recrystallization. It is characterized by pancake shaped subgrains of 0.45 μm thickness and an aspect ratio of 0.5 in flat grain layers of 1 μm thickness. As a result of microstructural evolution the tensile strength of the foils remains approximately constant with increasing rolling strain. The evolution of deformation resistance and microstruc-ture can be simulated with a simple model using the dislocation density as single microstructural parameter.