Bimetallic copper-aluminium tube by severe plastic deformation

A new process of joining tubes from different materials to a bimetallic tube based on a combination of large shear and high hydrostatic pressure is proposed. It results in improved mechanical locking of surface asperities, along with enhanced diffusivity owing to the ultrafine-grained microstructure produced. This is augmented by a temperature increase due to heat release associated with mechanical work. Electron microscopy characterization of the interface and the adjacent regions supports the hypothesis of enhanced interdiffusion. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.