Deformation kinetics at constant structure during work hardening and steady state deformation of pure aluminium

Stress change tests are performed with pure polycrystalline Al during deformation at constant stress 10 MPa less than or equal to sigma less than or equal to 40 MPa between room temperature and 523 K. The spacings lambda of thermal obstacles derived from the stress change tests decrease as the strain rate epsilon over dot approaches its steady state value. This corresponds to deviations from the Cottrell-Stokes law during deformation at constant epsilon over dot. The decrease in lambda is discussed as a consequence of dynamic recovery. It is shown that it can be explained by small changes in the athermal stress component caused by concurrent dynamic recovery.