Investigation on Properties of Shape Memory Alloy Wire of Cu-Al-Be Doped with Zirconium

Abstract

Abstract: In this paper, the effect of wire drawing on the microstructures, mechanical properties, and shape memory effect of compositions Cu<inf>87.85</inf>-Al<inf>11.70</inf>-Be<inf>0.45</inf> (CAB) and Cu<inf>87.73</inf>-Al<inf>11.70</inf>-Be<inf>0.45</inf>-Zr<inf>0.12</inf> (CABZ) has been experimentally investigated. The wires with a diameter of 1.33 mm are manufactured from the casted round bars through the rolling and drawing (secondary) process. Investigations are performed on microstructure and phase for both as-cast and wire-drawn SMAs. Further, wire-drawn SMAs are investigated for phase transformation temperatures, hardness, ductility, and shape memory effect. The results show that the average grain size decreased with 73.06% by adding Zr to the CAB alloy. Further, the grain size of CABZ alloy wire decreased with 67.38% in the longitudinal direction and 67.07% in the transverse direction as compared to CAB alloy wire after the secondary process. Improvement of the grain structure in CABZ alloy wire resulted in an enhancement in the hardness of 13.86% in longitudinal and 12.43% in the transverse direction, and tensile strength of 134.58% and ductility of 177.06%. The phase transformation temperatures reduced by the addition of Zr, and better shape recovery is observed in CABZ alloy wire. Graphic Abstract: [Figure not available: see fulltext.] © 2020, ASM International.