Rolling textures in nanoscale Cu/Nb multilayers

Rolling textures in nanoscale multilayered thin films are found to differ markedly from textures observed in bulk materials. Multilayered thin films consisting of alternating Cu and Nb layers with columnar grains were produced by magnetron sputtering, with individual layer thickness ranging from 4 mum to 75 nm and Cu/Nb interfaces locally satisfying the Kurdjumov-Sachs (K-S) orientation relations. After rolling to 80% effective strain, samples with a larger initial layer thickness develop a bulk rolling texture while those with a smaller initial layer thickness display co-rotation of Cu and Nb columnar grains about the interface normal, in order to preserve the K-S orientation relations. The resulting K-S texture has <001>Nb parallel to and <110>Cu approximately 5degrees from the rolling direction. A crystal plasticity model based on the Principle of Minimum Shear captures the K-S texture approximately and suggests that Nb drags Cu along in the rotation process. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.