Variant selection of dynamically nucleated twins at triple junctions in a copper tricrystal

The preferential nucleation of grains at triple junctions (TJs) during high temperature deformation was investigated systematically using a copper tricrystal. Their relationships to the parent grain were also determined. All the new grains were twin-related to the matrix and were formed by means of grain boundary migration (GBM). Selection of the twinning plane depended sensitively on the direction of GBM and on the geometry of the grain boundaries composing the TJ. It did not seem to be affected by slip plane activity or by the Schmid factor of the parent grain.