Abstract
The project aims at exploring powder metallurgy as a route for fabricating complex concentrated alloys (CCAs) with high-temperature martensitic transitions, in particular those mechanically strengthened by ultrafine-grain microstructure. The main ambition is to unravel the complicated interplay between the high density of grain boundaries, chemical and elastic stability of the lattice, and the displacive transitions in such materials, and to evaluate their application potential as high-temperature shape memory alloys (SMAs). This research will utilize characterization techniques ranging from macro-scale mechanical test to 3D atom probe tomography, and exploit the long-term experience of the proposing teams with fine-grained NiTi-based SMAs. While focusing on Cu-Ni-Ti-Zr-Hf based CCAs and the effects of composition variations in them (including both spontaneous segregation and tailored changes in Zr and Hf content), general microstructure-property relationships will be sought, aiming at identifying paths to new, more durable and efficient smart materials for future technologies.