Creep processes in pure aluminium processed by equal-channel angular pressing

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 410; pp. 408 - 412
• Main Authors: Sklenicka, V., Dvorak, J., Kral, P., Stonawska, Z., Svoboda, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.11.2005
• Subjects: Aluminium; Creep; Equal-channel angular pressing (ECAP); Grain boundary sliding; Ultrafine grained material; Equal-channel angular pressing (ECAP); Grain boundary sliding; Aluminium; Creep; Ultrafine grained material
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2005.08.099

It is suggested that creep of pure aluminium processed by equal-channel angular pressing (ECAP) occurs by diffusion-controlled movement of intragranular dislocations and by grain boundary sliding. The contribution of grain boundary sliding is increasingly higher with increasing number of ECAP passes. The coexistence of a dislocation process and grain boundary sliding may explain the observed decrease of the creep resistance with increasing number of ECAP passes. This is because high-angle boundaries are necessary in order to achieve grain boundary sliding. Therefore, an increase in the fraction of high-angle boundaries with increasing number of ECAP passes will essentially lead to increasing contribution of grain boundary sliding to the total creep strain, as it was observed experimentally.