The High-Temperature Deformation Mechanism in Al–Mg Alloys and the Internal Stress

Abstract

Mean internal stresses measured by the dip test in high-temperature deformation of Al–Mg alloys have been known to be very high compared with those estimated from the assumption of the equidistant distribution of parallel dislocations.
In order to examine the validity of the dip test, stress relaxation and rapid strain rate change tests are performed in Al-5.7 at% Mg, and the high internal stresses are confirmed.
Density and configuration of dislocations in the steady-state deformation are estimated theoretically based on the solute atmosphere dragging mechanism, and the mean internal stress is calculated from the configuration. It is concluded that the high internal stress is due to forest dislocations existing in high density.