On shear coupled migration of low angle grain boundaries

Stress induced migration of symmetric < 110 > tilt grain boundaries with misorientations 6.1 degrees, 10.9 degrees, 14.9 degrees and 19.4 degrees was studied by in situ observations in a scanning electron microscope. The examined boundaries readily moved under an applied stress producing shear strain. The measured coupling factors between normal boundary displacement and produced shear matched geometric predictions. The grain boundary mobility and its temperature dependence were measured and the corresponding migration activation parameters were determined. The obtained values of migration activation enthalpy were in the range between 0.72 and 1.09 eV. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.