Cu-based shape memory microwires : towards complex structures

Abstract

Shape memory alloys are a distinctive type of material that exhibits the fascinating properties of the shape memory effect and superelasticity. Shape memory properties are characterized by the diffusionless phase transformation between austenite and martensite that can be thermally or stress induced. Cu-based shape memory alloys provide an exciting area of research due to lower costs and higher working temperatures compared to Ni-Ti alloys prevalent in industry today. This work investigates the shape memory properties of oligocrystalline Cu-Al-Ni and Cu- Al-Mn-Ni microwires produced using a melt spinner. The melt spinner yielded continuous wires in quantities useful for the creation of complex structures. The composition of the wires is observed to change throughout processing of alloys and wires. Electropolishing rates were determined for improving surface texture and size constraint.