Volume 19, Issue 1 (January 1991)
Deformation of Aluminum Alloy under Cyclic Creep Loadings
Cyclic creep tests were conducted on an aluminum alloy at 160 and 200°C. Measured results indicated that mechanical load cycling with long dwell periods can produce significant creep acceleration. Such creep acceleration not only resulted in the increasing of minimum strain rate at subsequent loading cycles, but also reduced the creep rupture life of the material. Microstructure examinations by TEM and SEM were carried out to study microstructural damages under monotonic and cyclic loadings. Results indicated that remobilization of dislocation and damage enhancement during stress cycling were chiefly responsible for creep acceleration.