The Effect of Dispersoids and Processing Variables on Grain Refinement of Aluminium Alloys Deformed by ECAE
The effect of fine, non-shearable, dispersoids on the grain refinement of aluminium alloys, severely deformed by ECAE, has been studied using a model Al-0.2%Sc alloy, during deformation by Routes A and BC (+90degrees rotation) using a 120°, or 90°, die. The microstructure in the dispersoid-containing alloy was compared to a single-phase alloy using high resolution EBSD analysis. With Route A the presence of fine dispersoids was found to significantly retard the development of new high-angle grain boundaries and the formation of a fine grain structure, by homogenising slip and inhibiting microshear bands. This difference was greatly enhanced, using Route BC. Similar results were obtained with the two die angles, but with Route A refinement tended to be slightly less effective when using the 90° die.
Witold Lojkowski and John R. Blizzard
M. Berta and P. B. Prangnell, "The Effect of Dispersoids and Processing Variables on Grain Refinement of Aluminium Alloys Deformed by ECAE", Solid State Phenomena, Vol. 114, pp. 151-158, 2006