Abstract: Cyclic creep tests of Al-Mg alloy have been conducted at a wide range of stress and temperature.When Mg content is beyond 0.45%, the strain bursts can be observed in the cyclic creep curves.There exists a critical stress for the occur- rence of the strain burst,which increases with an in- crease of Mg content and is almost 60% of the ul- timate tensile stress.The occurrence of strain burst is proposed to be controlled by the easiness of the cross-slip of dislocations.For Al-Mg alloy,the dynamic strain aging plays an important role in the strain bursts.

Key words: cyclic creep, Al-Mg alloy, strain burst, cross-slip