Shape memory effect and pseudoelasticity in Cu nanowires

Abstract

We report the discovery of a novel pseudoelastic behavior in single-crystalline Cu nanowires through atomistic simulations. Under tensile loading and unloading, the nanowires are capable of recovering elongations up to 51%, well beyond the typical recoverable strains of 5-8% for most bulk shape memory alloys (SMAs). This phenomenon is associated with a reversible crystallographic lattice reorientation driven by the high surface-stress-induced internal stresses due to high surface-to-volume ratios at the nanoscale. The temperature-dependence of this behavior leads to a shape memory effect (SME). This behavior is well-defined for wires between 1.76 and 3.39 nm in size over the temperature range of 100-900 K. © 2007 Springer.