Can the high-strain recovery and temperature memory aspects of shape memory alloys make them useful for developing a coupling between the dissimilar materials of high-temperature materials?
DSIAC received a technical inquiry on using shape memory alloys (SMAs) as a joining or coupling intermediate for materials with dissimilar thermal expansion coefficients (CTEs) in extreme thermal gradients. Historically, the integration of high-temperature materials used for leading edges, control surfaces, heat shields, etc., with metallic structural components has been challenging due to the brittle nature of the high temperature materials and their differences in CTE from the more structural components. The inquirer seeks information about using the features of high-strain recovery and temperature memory aspects of SMAs to develop a coupling between these dissimilar materials that might allow controlled displacements and/or mitigated, thermally-induced stress at the integration points. Materials engineering subject matter experts at the Texas Research Institute Austin, Inc. and the University of North Texas performed literature searches using DTIC, open sources, and university libraries to provide a listing of the efforts that have tried to produce these material systems (mostly sponsored by NASA) and identified several options in varying degrees of development and technology readiness levels. The inquirer was also connected to Dr. Marcus Young from the University of North Texas who presented a DSIAC webinar titled “Shape Memory Alloys for DoD Applications.”