High Angle Grain Boundary Mobilities in a High Purity Single-Phase Al-0.1 wt% Mn Alloy
The migration rates (V) of “random” high angle grain boundaries (HAGB) during annealing of a cold deformed (e=1.3) high purity Al-0.1wt% Mn alloy were determined using a combination of in-situ annealing and EBSD in the SEM at temperatures between 200 and 330°C. The SEM heating stage used for these experiments is described and results on the local recrystallization kinetics of the Al-Mn alloy are presented. For this, the local stored energies (P) were determined by subgrain size and misorientation analyses to give the boundary mobilities (M) through the standard V = M.P equation. The solute drag “force” was analysed with the atomistic model of Lücke and Stüwe (1971) for a “loaded” boundary and used to estimate the diffusion rates in the above temperature range. The activation energies for boundary migration were found to be consistent with those of solute atoms moving behind the grain boundary, i.e. intermediate between the values for bulk and boundary diffusion of Mn.
B. Bacroix, J.H. Driver, R. Le Gall, Cl. Maurice, R. Penelle, H. Réglé and L. Tabourot
A. Lens et al., "High Angle Grain Boundary Mobilities in a High Purity Single-Phase Al-0.1 wt% Mn Alloy", Materials Science Forum, Vols. 467-470, pp. 771-776, 2004