The Reverse Shape Memory Effect in a DO3 type CuZnAl Alloy
이상환Sang Hwan Lee, 박정식Jung Sik Park, 정인상In Sang Chung
Abstract
In order to provide further evidence to support the mechanism of the reverse shape memory effect(RSME) in a Cu-Zn-Al alloy, more detailed investigations have been carried out in DO₃ type CuZnAl alloys which are Cu-24.0Zn-6.1Al and Cu-24.4Zn-5.3Al in composition. The Cu-24.0Zn-6.1Al alloy shows both SME(301∼503K) and RSME(563∼673K) with increasing temperature after bending deformation. The shape change of the sheet occurs spontaneously and the amount of shape change by RSME is much larger than that of SME. The other specimen of the Cu-24.4Zn-5.3Al alloy not. occured the tw-step transformed martensite(α₁`) and the reversible shape memory. Comparing the scanning electron micrographs of the bainite morphology of the two alloys, RSME observed when the directional bainite exits. It should be noted that directional bainite is produced when the two-step transformed martensite(α₁`) exits. It is concluded that the RSME is attributed to the directional bainites produced due to two-step transformed martensite(α₁`).