Thermo-structural Shape Memory Effect Characterization of Novel CuAlCoMg HTSMA with Ternary Co and Quaternary Mg Addititions

Abstract

The second largest world-wide commercial functional materials group in smart materials class is the shape memory alloys (SMAs). Among SMAs, Cu-based SMAs thanks to their good shape memory effect properties, capable of high transformation temperatures, cost-effective and relative simplicity of production/processing and achievable desired properties by tuning their alloying compositions by additions are described as the closest alternative to the superior NiTi SMAs. In this work, the novel quaternary CuAlCoMg high temperature shape memory alloy (HTSMA) by the additions of minor amount of Co as the ternary and trace amount of Mg as the quaternary additive alloying elements was fabricated by arc melting method. The martensitic transformation temperatures and other properties of the alloy were characterized by carrying out several thermal and structural measurements of DTA and XRD analysis and the magnetization status of the alloy was also investigated by measuring with a vibrating sample magnetometer (VSM). The DTA results showed that the alloy is a high temperature shape memory alloy (HTSMA) exhibiting reverse martensitic transformations in a temperature range between 208.95°C and 394.32°C. The VSM test showed that the alloy shows a diamagnetic behavior with a weak ferromagnetic coersivity. The XRD result revealed the diffraction peaks observed at room temperature indicating the martensite phases existing in the alloy, formed by the end of quenching the alloy. The produced alloy can be useful in HTSMA research and applications.