Effects of Quenching Temperatures on Microstructure, Phase Transformation Characteristics and Shape Memory Behaviors of CuAlTa and CuAlTaNb HTSMAs.

Three different quenching processes were applied to CuAlTa and CuAlTaNb high-temperature shape memory alloys (HTSMAs). The phase components, microstructural properties, PTTs, shape recovery behaviors, and grain sizes of the alloys were examined; moreover, XRD, SEM–EDX, DSC analyses, and bend test measurements were accomplished for the HTSMAs. It was found that the quenching conditions applied to the samples changed the phase peak intensities. From the microstructural investigations, it was determined that the precipitate phase present in the alloy samples, declined with decreasing the quenching temperature. Thermal analyses showed that both Nb doping and quenching temperature could change phase transformation temperatures up to about 36 °C. Bend test measurements showed that the shape memory effect was improved by contributing Nb addition and quenching in lower temperatures. It was seen that the changes in the alloys were related to the grain size. [ABSTRACT FROM AUTHOR]