Single crystals of high-purity Al-0.05% Si single-phase alloy, with an orientation of {110}<001>, were deformed by channel-die plane-strain compression at room temperature or 350C. The specimens were annealed at temperatures of between 250 and 400C, and detailed measurements were made of the extensive sub-grain growth which occurred in the crystals. It was found that the sub-grain growth tended to be discontinuous; thus showing that sub-grain growth was quite different to normal grain growth. The mean misorientation between sub-grains decreased during annealing, and this had a marked effect upon the kinetics of sub-grain growth. The mobilities of low-angle boundaries (2.6 to 5.6º), at temperatures of between 250 and 400C, were deduced from the sub-grain growth kinetics and the activation energies for migration were found to be consistent with control by the lattice-diffusion of solute. The boundary mobilities were found to increase rapidly with increasing misorientation.

Subgrain Growth and Low Angle Boundary Mobility in Aluminium Crystals of Orientation {110}<001>. Y.Huang, F.J.Humphreys: Acta Materialia, 2000, 48[8], 2017-30