Thanks to the impressive developments within the DFT (Density Functional Theory) based methods, numerical solvers and computational power during the last few decades, modern materials research receives increasing support from first-principles materials modeling. Such approach gives fundamental understanding, offers efficient pre-screening against various degrees of freedom and provides information where experimental assessments are not feasible. Today the ab initio theory-aided materials assay finds its way in almost all areas of advanced materials design and characterization.
Due to the complexity of the problem, for a long time DFT modeling was practically missing within the exciting field of multicomponent alloys such as stainless steels. Starting from the early 2000s, we made a series of attempts to fill this gap and extend the scope of ab initio modeling to high-technology alloys. In my seminar, I will overview the pioneering applications of alloy theory in the case of steels, and point out the main known and hidden challenges associated with such efforts. Our recent progress in predicting the mechanical properties from first-principles theory will be demonstrated for paramagnetic Fe and austenitic stainless steels. Special emphasis will be placed on plastic deformation and intrinsic energy barriers. So far the intrinsic energy barriers were accessible only by theory. I will briefly discuss an experimental technique suitable to determine the intrinsic energy barriers. Finally, I will expound the possibility of metastable twinning in some special multicomponent alloys.