Metallographic characterization of a NiTiCu shape memory alloy

Shape memory alloys (SMA) are well-known as smart materials with increasing applications in many fields. A lot of research work has been carried out on many different systems, but only Cu-Zn-Al and Ni-Ti alloys are widely used. A new heat engine for irrigation purposes driven by wires of 50 at% Ti, 44 at% Ni, 6 at% Cu, is under development at the Fachhochschule Konstanz. To study wire behaviour, a collaborative research work has been established with the University of Seville. Metallographic characterization of SMA is an important way to evaluate material properties, but there is a great lack of information concerning metallographic preparation and etching procedures for the NiTiCu system. In this work we describe a reliable procedure for revealing the microstructure of Nitinol wires.