Stress induced martensitic transformations in tension/torsion of CuAlNi single crystal tube

A CuAlNi single crystal tube was loaded in tension while keeping the torsional displacements free. The tube extended and simultaneously twisted during the stress induced martensitic transformation. A cooperative activity of four habit plane/shear direction transformation systems appearing at the same time in different quadrants of the tube wall is considered to rationalize the unusual mechanical behavior. (C) 2003 Published by Elsevier Science Ltd. on behalf of Acta Materialia Inc.