Recent Developments in High Temperature Shape Memory Alloys
Among these, NiTiPd and NiTiPt alloys were extensively studied in the recent past. However, as a consequence of the increasing need for relatively inexpensive, lightweight and high performance engineering materials, the trend has moved to the design, processing and characterization of cheaper alternatives such as NiTiHf and NiTiZr SMAs. Initial studies carried out on the Ni-rich compositions of NiTiHf and NiTiZr systems, showed that they can provide promising shape memory response while still maintaining relatively high transformation temperatures. Since, the maximum performance of these systems has not been revealed yet, more research is necessary to understand the industrial potential of such materials, in particular performance criteria such as fatigue resistance.
We will present the current state-of-the-art on HTSMAs for their utility as solid state actuators. Different alloy systems will be compared for their actuation stresses, strains, work outputs, efficiencies, and fatigue responses while also discussing current materials challenges and opportunities in various applications.