Macroscopic shape change of Cul3Znl5Al shape memory alloy on successive heating

摘要

The shape change of Cu-13Zn-15Al shape memory alloy on successive heating at a heating rate of 5 deg C/min has been studied. The behavior of sgape change is strongly temperature dependent. As the heating temperature is below 320 deg C, the stabilization phenomenon of the martensite appears, and the first reverse shape memory effect (FRSME) in the Cu-13Zn-15Al alloy occurs due to the martensitic nature transformation that involved in the martensite stabilization process. At the temperature between 320 and 400 deg 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-15Al alloy occurs when the ribbon is heated to above 450 deg C and subsequently air-cooled to room temperature, this phenomenon attributes to the growth of an asymmetric martensite phase due to the constraining of alpha-phases distributed along the boundary of the new-formed martensite variants.