Production of TiNi amorphous/nanocrystalline wires with high strength and elastic modulus by severe cold drawing

The microstructure and properties of Ti-50.9 mol.% Ni wires after severe cold drawing were studied. X-ray diffractometry, transmission electron microscopy and electrical resistivity measurements revealed that the amorphous phase was dominant in the as drawn wires. Young's modulus depended strongly on the drawing reduction. The amorphous/nanocrystalline wires after 70% reduction exhibit high tensile strength (> 2 GPa), a high Young's modulus (71 GPa) and a large pseudoelastic recovery strain (similar to 3%). The recovery strain was further improved to 5.8% by aging at 573 K. (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.