Superelastic memory effect in Ti74Nb26 shape memory alloy

Ti74Nb26 shape memory alloy, superelastically loaded to increasingly larger tensile strains, exhibits superelastic memory. This behavior is closely related to superelastic cycling history, and its origin is attributed to a relative difference in martensite stability caused by the internal stress field created, possibly by point defect mechanisms, from partial superelastic cycles. In addition, superelastic memory appears to be reversible, as its effect gradually diminishes when specimen is allowed to rest under stress-free conditions in between superelastic cycles at room temperature. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.