Deformation~ Features Of AZ31 Mg--Alloy In Initial Period Of High Temperature Creep
AZ31镁合金蠕变初期的变形特征

By means of the measurement of the creep curve and the observation of TEM, an investigation has been made into the deformation feature and microstructure evolution of AZ31 Mg--alloy in the initial creep at elevated temperature. The results show that the deformation feature during creep produced in the primary stage is that a great deal of $\langle a\rangle$ dislocation is activated on basal and non--basal planes, and $\langle a+c\rangle$ dislocation slips on pyramidal planes. $\langle a\rangle$ dislocation generated during creep may cross--slip from one of non--basal plane to another non--basal planes. As creep goes on, the dynamic recovery (DRV) may occur, and the dislocations are concentrated to form the dislocation cells or walls. Another feature observed during creep is that twinning occurs as an important deformation mechanism, leading to improvement of the alloy ductility.