Challenges in Alloying of NiTi - New Approaches for Low-Hysteresis and High-Temperature SMAs

Abstract Despite the evident existence of market demand and great efforts in alloy development and processing, non-binary NiTi alloys struggle to exploit their full potential and to satisfy the high expectations from industry. Two exemplary fields of research are low-hysteresis (LH-SMA) and high temperature shape memory alloys (HT-SMA), in which many alloy solutions with promising results were proposed in the last decades, but almost none was commercialized on an industrially relevant scale. The reasons for the limited success might be manifold: Material inherent challenges like creating workable, reliable and performing alloys, cost of setting-up a stable process, trust in new technology, communication between material designer and potential end-user, lack of material provider and further drawbacks obstacle the way to commercialization. Evidentially, existing LH-SMA and HT-SMA solutions suffer a lack of trust from industries to achieve commercial success. Therefore, besides developing material solutions, new ways need to be found to achieve and demonstrate the full potential of the most promising alloys and systems. The here presented research work consists of an assessment of the main obstacles in designing and preparing high-performing ternary and quaternary alloys. The scope is to answer what could be the ideal low hysteresis and high temperature shape memory alloys for industrial commercialization, what are the potentials and limits of commonly used theories and models in material design? What could be suitable demonstrators, experiments and prototypes of simple configurations from a technical point of view in order to convince potential end-users of such novel materials, how could they to be prepared and benchmarked? To be more persuasive, the demonstrator should constitute of an application relevant shape and could be prepared by non-conventional processes if it supports the full exploitation of the material advantages.