Internal stress and thermally activated dislocation motion in an AZ63 magnesium alloy

Magnesium alloy AZ63 was deformed at temperatures between room temperature and 300 °C. Stress relaxation tests were performed in order to reveal the physical base of the deformation process/-es. Internal and effective components of the applied stress have been estimated. Very high values of the internal stress estimated at room temperature decrease rapidly with increasing deformation temperature. The apparent activation volume decreases with increasing effective stress. Estimated values of the activation volume as well as the activation enthalpy indicate that the main thermally activated process is connected with the rapid decrease of the internal stress.

► Analysis of the stress relaxation tests.
► Determination of the stress components – internal stress and effective stress.
► Identification of the main thermally activated process occuring during the plastic deformation of a AZ63 magnesium alloy at elevated temperatures.