Influence of the annealing temperature of the shape memory alloy actuator on its thermal characteristics

Shape memory alloys (SMA) are used in different areas of engineering and science thanks to their unique properties. They also continue to be an innovative material for the sustainable construction industry. In this study, a commercial helical-type SMA spring actuator was investigated by subjecting it to annealing at various parameters. The thermal shape memory properties were evaluated by means of the DSC method. In most cases, the higher the annealing temperatures for the material were in the range up to 595°C, the lower the transformation temperatures. As the DSC runs showed, a different character of the changes especially in characteristic temperatures, was observed for annealing temperatures above 600°C. The results showed that the different annealing temperatures, and even the method of cooling, provide a wide range of possibilities to control the SMA spring reaction – transformation behaviour and temperatures. Such treatment can be a simple technical procedure used for the preparation of the selected SMA functional properties if required. This means that the same SMA element can be reused without having to source a new one. This may be desirable from the point of view of sustainability.