Selected Applications of Aeropropulsion Actuation and Shape Control Devices Using HTSMAs

Recent research has contributed to the relatively rapid development of high-temperature shape memory alloys (HTSMAs), materials that combine useful work output with transition temperatures well in excess of the range of typical binary NiTi SMAs. This article describes recent demonstration applications of HTSMAs in devices representative of mechanisms useful for a variety of aeropropulsion applications requiring high transition temperatures. Work to date has chiefly featured application of Pt-doped NiTi alloys in wire form, although some data on the use of Hf-doped alloys has also been generated. The results presented describe benchtop and wind tunnel experiments of demonstration devices employing HTSMA wire actuators. The test results validate operation at 573+ K (300+ °C) and document the force and strain capability of the new alloys. Ongoing and projected work in pertinent areas is also described.