Martensite destabilization in Au7Cu5Al4 shape-memory alloy
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Date
2011-03
Authors
Bhatia, VK
Kealley, CS
Prior, MJ
Cortie, MB
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Aging-induced changes in the austenite peak (Aρ) temperature of Au7Cu5Al4 shape-memory alloy are investigated. Whereas heat treating the parent phase at temperatures >140°C or aging the martensite for long times at room temperature both stabilized the Aρ to ~80°C, low-temperature excursions into the parent phase caused the subsequent Aρ to drop to ~60°C and the transformation hysteresis to decrease. The evidence indicates that this destabilization of the martensite is caused by time-dependent relaxation of elastic constraint due to parent-phase lath migration during the preceding low-temperature austenitizing treatment. This mechanism of aging is different from that of the better-known symmetry-conforming short-range order phenomenon. © 2011, Elsevier Ltd.
Description
Keywords
Aging, X-ray diffraction, Neutron diffraction, Shape memory effect, Gold alloys, Martensite
Citation
Bhatia, V. K., Kealley, C. S., Prior, M. J., & Cortie, M. B. (2011). Martensite destabilization in Au7Cu5Al4 shape-memory alloy. Acta Materialia, 59(5), 2193-2200. doi:10.1016/j.actamat.2010.12.021