Shape memory alloy characterization

Abstract

The present work aims to establish the repeatability, reproducibility, hysteresis and uncertainty of measurement, of the displacement in thin Ni-Ti alloy wires under constant axial load when electrically heated. An experimental setup was built for carrying out the measurements in air, samples of 1 m length wires with two diameters: 100 and 150 μm were analyzed. The readings were done in a digital length gauge. The arithmetic means of the readings, both in air, had a nonlinear behavior and showed a temperature hysteresis. All results had good repeatability and reproducibility in increasing measurements of displacement. The expanded uncertainties found were the expected for this length wire. The results have shown to be in accordance with other Ni-Ti shape memory alloy literature.