Interstitial alloying can improve the mechanical properties of high-entropy alloys (HEAs). In some cases, the interstitial-alloying impact is very different from those in conventional alloys. We investigate the effect of interstitial alloying in the CrMnFeCoNi HEA, particularly focusing on the solution energies and the impact on the stacking fault energy, based on first-principles calculations. Our results clarity, e.g., that the interstitial solution energy in HEAs is no longer a single value but shows a substantial distribution due to the dependence on local chemical environments.
Local lattice distortion is one of the core effects in complex concentrated alloys (CCAs). It has been expected that the strength CCAs can be improved by inducing larger local lattice distortions. In collaboration with experimentalists, we demonstrated that VCoNi has larger local lattice distortions and indeed has much better strength than the prototypical CrCoNi CCA has.
In order to explore the possibility of using high entropy alloys (HEAs) for functional applications such as magnetic refrigeration it is necessary to have an in-depth understanding of their magnetic properties. The main goal of this project is to understand and improve the magnetic properties (e.g., saturation magnetization, Curie temperature etc.) in different medium and HEAs.
Magnetic properties of magnetocaloric materials is of utmost importance for their functional applications. In this project, we study the magnetic properties of different materials with the final goal to discover new magnetocaloric materials more suited for practical applications.
A high degree of configurational entropy is a key underlying assumption of many high entropy alloys (HEAs). However, for the vast majority of HEAs very little is known about the degree of short-range chemical order as well as potential decomposition. Due to slow diffusivity, characteristic for e.g. refractory HEAs, chemical ordering is hardly ever approached under typical experimental conditions but could potentially influence creep properties long-term applications. In this project we study the phase stability and short-range order of selected refractory HEAs computationally.