This project addressed the challenge of improving the efficiency and sustainability of technologies that still rely on combustion processes, such as power generation and aviation. To enable higher operating temperatures and lower emissions, complex multi-phase alloys are developed that can also perform under cryogenic conditions, for instance in hydrogen or LNG storage systems. Understanding how deformation and load are distributed among their constituent phases is critical for optimizing their mechanical performance.
Using state-of-the-art in situ neutron diffraction over a broad temperature range (–253 to 730 °C), the research investigated how internal stresses evolve during deformation in Ni-based superalloys and eutectic high-entropy alloys. The studies revealed that particle size and phase interactions strongly influence load partitioning, and that plastic deformation of the strengthening phase can occur even at cryogenic temperatures—an unexpected discovery. At elevated temperatures, a reversal of phase roles was observed, with the softer phase at low temperature becoming the reinforcing phase.
These findings provide valuable insight into microscopic deformation mechanisms and phase behavior in complex alloys, enabling the development of more accurate multi-scale models and the design of next-generation materials that enhance performance and sustainability in demanding energy and transportation applications.