Fabrication, Phase Transformation and Microstructure Analysis of CuAlGaV Shape Memory Alloy with a Low Conduction Electron/Atom Ratio

Abstract

Cu-based shape memory alloys (SMAs) are functional materials that exhibit shape memory effect and superelasticity due to their reversible martensitic transformation. They have attracted considerable attention for their potential applications in various fields, such as biomedical, aerospace, and automotive industries. However, there are still many challenges to overcome in order to optimize their properties and performance. In this study, we fabricated a Cu-based SMA with a new composition of CuAlGaV and investigated its phase transformation and microstructure. The alloy was prepared by using the arc melting method and then annealed at 900°C for 1 hour and cooled rapidly by quenching. The e/a ratio of the alloy was calculated as 1.33, which indicated that the alloy would most probably have a dominant β1' type and α' type of martensite phases formed by the quenching. This prediction was confirmed by the XRD analysis of the alloy, which showed that the alloy had a main peak of β1'(0018) type martensite phase and two smaller peaks of β1'(320) and α'(3R) type martensite phases. The DSC analysis revealed that the alloy exhibited a high temperature phase transformation and had a martensite stabilization, which are influenced by the alloy composition, processing, and thermal history. These results showed what thermal and structural shape memory properties the fabricated CuAlGaV alloy with low Al content exhibited.