Home > Research > Publications & Outputs > Engineering grain boundary sliding and cavitati...

Associated organisational unit


Text available via DOI:

View graph of relations

Engineering grain boundary sliding and cavitation effects in superplastic alloys employing thermodynamics

Research output: Contribution to Journal/MagazineJournal articlepeer-review

<mark>Journal publication date</mark>1/04/2015
<mark>Journal</mark>Materials Science and Technology (United Kingdom)
Issue number6
Number of pages11
Pages (from-to)677-687
Publication StatusPublished
<mark>Original language</mark>English


Plastic deformation by grain boundary sliding in superplastic alloys is described by a novel thermostatistical approach. The Gibbs free energy for cavity formation at moving grain boundaries is obtained. It equals the competition between the stored energy at the boundaries and the energy dissipated by grain boundary sliding. The latter is approximated by an entropy term induced by moving dislocations to facilitate boundary displacement. Strength loss evolution is estimated from the cavity evolution rate. The theory describes superplastic behaviour of Zn22Al, Zn21Al2Cu and Mg3Al1Zn for various temperatures, strain rates, grain sizes, and specimen geometries. Transition maps are defined for finding the optimal conditions for achieving superplastic behaviour in terms of composition, temperature, geometry and strain rate.