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high temperature shape memory alloy, Ni–30Pt–50Ti (at.%), with an M near 600 °C, was isothermally oxidized in air for 100 h over the temperature range of 500–900 °C. Nearly parabolic kinetics were observed in log–log and parabolic plots, with no indication of initial fast transient oxidation. On average the rates were about a factor of 4 lower than values measured here for a binary Ni–49Ti commercial SMA. The overall behavior could be best described by the Arrhenius relationships:The activation energy was consistent with literature values for TiO scale growth measured for elemental Ti and some NiTi alloys, at ~210–260 kJ/mol. However, a number of other studies produced activation energies in the range of 135–150 kJ/mol. This divergence may be related to various complex scale layers and depletion zones, however, no specific correlation can be identified at present. [ABSTRACT FROM AUTHOR]

In this paper are presented the design and experimental results of using a shape memory alloy (SMA) wire as an actuator for position control of a composite beam. The composite beam is honeycomb structured, having wires of SMA embedded in one of its face sheets for the purposes of active actuation. Nickel-titanium SMA wires were chosen as actuating elements due to their high recovery stress (>700 MPa) and tolerance to high strain (up to 8%). A simple proportional and derivative controller plus a feed-forward current is designed and implemented for controlling the tip position of the composite beam. Experiments have demonstrated the effectiveness of the SMA wire as an actuator for active position control of a composite beam. [ABSTRACT FROM AUTHOR]