Deformation twinning with zero macroscopic strain in a coarse-grained Ni-Co-based superalloy

Macroscopically zero-strained twin lamellae are observed in a coarse-grained Ni-Co-based superalloy after plastic deformation. The twin lamellae presented as three layers of overlapping stacking faults with zero overall Burgers vector. The atomic stacking sequence in the twin lamellae is consistent with pairs of parallel stacking faults at neighboring or next-neighboring glide planes. The twinning is facilitated by the low stacking fault energy of the superalloy and the lengthening of stacking faults by shear stress from nearby stacking faults. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.