Macroscopic shape change of Cu13Zn15A1 shape memory alloy on successive heating

The shape change of Cu-13Zn-15A1 shape memory alloy on successive heating at a heating rate of 5 degrees C/min has been studied. The behavior of shape change is strongly temperature dependent. As the heating temperature is below 320 degrees C, the stabilization phenomenon of the martensite appears, and the first reverse shape memory effect (FRSME) in the Cu-13Zn-15A1 alloy occurs due to the martensitic nature transformation that involved in the martensite stabilization process. At the temperature between 320 and 400 degrees C, the forward shape memory effect (FSME) can be caused by the reverse transformation of the stabilized martensite. The second reverse shape memory effect (SRSME) in the Cu-13Zn-15A1 alloy occurs when the ribbon is heated to above 450 degrees C and subsequently air-cooled to room temperature, this phenomenon attributes to the growth of an asymmetric martensite phase due to the constraining of a-phases distributed along the boundary of the new-formed martensite variants. (c) 2006 Elsevier B.V. All rights reserved.