Texture in Cu-based shape memory strips obtained by twin roll casting

Strips of Cu-13Al-5Ni-1Ti (wt.%) of about 400 mu m thickness were obtained by twin-roll casting directly from the melt. Temperature-induced transformations under constant tensile load show a larger deformation, associated with the reversible martensitic transformation, for strips annealed at 700 degrees C and 900 degrees C than for the as-cast samples. This effect is partially ascribed to relaxation of internal stresses produced by the rapid solidification, some recovery of short-range disorder and microstructural changes related to Ti-rich X-phase precipitates. On the other hand, the strips show a columnar grain morphology and annealing leads to an increase of texture intensity related with the increase in elongation rate. Columnar grains are mostly aligned with the < 0 4 0 > (R18) // < 100 > (DO3) directions. (c) 2007 Elsevier B.V. All rights reserved.