Researchers in Kassel Uncover New Secrets of Metallic Shape-Memory Alloys
Researchers of the Department of Metallic Materials have succeeded in uncovering new deformation mechanisms in shape-memory alloys. As part of a comprehensive study involving researchers from TU Bergakademie Freiberg, LMU Munich, the neutron research facility at the Rutherford Appleton Laboratory in Oxford, and the Czech Academy of Sciences in Prague, far-reaching findings were obtained, which have now been published in “Nature Communications”. The findings will enable the future development of new and long-term stable shape-memory alloys, e.g. sustainable solutions in the construction industry.
Shape-memory alloysare a class of smart materials characterized by unique properties, such as the ability to “remember” a previously imprinted shape. “Shape memory alloyshave so far been used primarily in biomedicine, including as vascular supports, known as stents. If we succeed in developing systems that can also be used in other fields of application, they will become established in many other high-tech applications. I’m thinking, for example, of applications in construction, where these materials can ensure greater safety and durability,” says Prof. Thomas Niendorf, head of the Metallic Materials Division at the Institute of Materials Engineering at the University of Kassel. Dr. Christian Lauhoff, the study’s first author and the driving scientific force behind the experimental investigations at the University of Kassel, adds: “Such a scientific success was only possible through collaboration between leading national and international research groups. In our study, we not only had the opportunity to examine the sample materials as a whole using neutron diffraction; central to our work were the capabilities of acoustic emission as well as in-depth model-based analyses of the underlying martensitic transformation. This allowed us to simultaneously see, hear, and interpret what was happening in the material at that very moment. Only in this way were we able to uncover and explain the new mechanism.”
The collaboration between the participating groups in the field of shape memory alloys is rooted in a long-standing tradition. The Kassel group specializes in the mechanical and functional evaluation of shape memory alloys, while the Freiberg research group is a global leader in acoustic emission for the analysis of these alloys. The partners in Munich and Oxford, in turn, contribute expertise in neutron diffraction, while the colleagues in Prague are internationally recognized in the fields of modeling and martensite theory. This collaboration has been funded by the German Research Foundation (DFG). There are plans to continue these activities in the future, including within the framework of a Research Group. The findings now obtained provide an excellent foundation for this.
The publication with the title “On the origin of acoustic emission in the stress-induced martensite regime of shape memory alloys” is freely accessible at the following link: https://doi.org/10.1038/s41467-026-73946-9