Related resources
Full-text held externally
Search for item elsewhere
University researcher(s)
Academic department(s)
Microstructure and Texture Evolution during Annealing a Cryo-SPD Processed Al-Alloy with a Nano-Scale Lamellar HAB Grain Structure
G. H. Zahid, Y. Huang and P.B. Prangnell
Acta Mater. 2009;57:3509-3521.
Access to files
Abstract
The grain structure and texture evolution during annealing a Al-0.13%Mg submicron grained alloy, deformed by plane strain compression (PSC) at cryogenic temperatures, has been investigated by TEM and EBSD. After deformation the alloy contained a lamellar grain structure with a high angle grain boundary (HAGB) spacing of 190 nm and area fraction of ~ 80%. On annealing the grain structure coarsened and transformed from lamellar to equiaxed. Remarkably, the fraction of low angle grain boundaries (LAGBs) progressively increased during annealing, to ~ 50% above 300 ??C, leading to instability and discontinuous recrystallisation, at higher temperatures. This resulted in a ???bimodal grain structure??? comprised of bands of coarser grains and fine subgrains, arising as a result of the increase in proportion of lower mobility LAGBs. The surprisingly large increase in LAGB fraction on annealing is shown to be related to orientation impingement, originating from the strong texture present after PSC in liquid nitrogen