Nanotwinned microstructures from low stacking fault energy brass by high-rate severe plastic deformation

High-rate severe plastic deformation by machining is explored in a prototypical low stacking fault energy material, brass, as a route for generating a high density of nanometer-scale twins amidst dislocation structures. This nanotwinned system shows a greatly improved strength compared to the bulk microcrystalline state. The twin densities are found to be retained even after modest thermal agitation, which is also seen to engender a small hardening by annealing effect in the nanotwinned material. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.