Effect of ageing in the two-phase region in a Cu–Zn–Al shape memory alloy

A plateau in the biased displacement versus temperature curves was observed for Cu–Zn–Al based shape memory alloys (SMAs) which were aged at the two-phase region for a long time. This corresponds to the plateau in the reversely transformed quantities of martensite versus temperature curves, which has been confirmed by the in-situ X-ray diffraction study. These plateaus are caused by the stabilized martensite which is aged at the two-phase region and undergoes structural changes.