Thermal cycling at constant stress for thin films over a wide temperature range: Design and fabrication of a specific device for the study of microactuators.

The characterization of the mechanical behavior of shape memory thin film alloys is essential for their application as microactuators. Depending on the particular application, different elements have been considered for the fabrication of ternary NiTi-based alloys in order to shift the martensitic transformation toward a lower or a higher temperature range. This work presents the design and implementation of a specific device to perform thermal cycles at constant stress on film-like samples over a wide temperature range, between -130 and 300 °C. The uniaxial stress application, the elongations and contractions measurements associated with the martensitic transformations, and the cooling and heating methods are detailed in the present work. The fabrication and operation features of this relatively low cost device facilitate and promote the study of shape memory thin films.

Stage for texture measurements above room temperature in a Philips X'Pert Pro MPD diffractometer.

A special stage for texture measurements above room temperature was designed with the proper size and weight to be fitted onto the Eulerean cradle of the Philips X'Pert Pro MPD diffractometer. With such device, flat samples of 2x2 cm(2) area can be analyzed at a nearly constant temperature with variations below +/-4 degrees C in the range between ambient temperature and 200 degrees C.