Abstrakt
Stress relaxation tests have been used in order to determine parameters of a possible thermally activated process in AZ31 magnesium alloy. The samples were deformed at a constant initial strain rate of 6.7x10(-5) s(-1) various temperatures between room temperature and 300 degrees C.
Stress relaxation, i.e. a decrease in the stress with time, was measured at various stress levels and at various temperatures. An analysis of the stress relaxation curves enabled to estimate the internal stress as a function of the strain and the test temperature.
It has been shown that the activation volume is a function of the effective stress independently of the deformation temperature.