Rate-controlling processes during creep of super-purity aluminium

Abstract
The response to a sudden reduction in applied stress during creep of single and polycrystalline aluminium has been compared with the behaviour recorded in conventional creep tests carried out in tension and compression. In addition, studies have been made of the dislocation arrangements and the surface deformation patterns developed during creep. The results obtained are compatible with a recovery model for creep based on diffusion-controlled growth and rearrangement of the three-dimensional dislocation network present within subgrains. These recovery processes lead to the development of link lengths in the network which are sufficiently long to act as dislocation sources, allowing slip to occur.