Scope

Scope

The ADIS2018 workshop is number eight in a series of international scientific seminars on the topic “Ab initio Description of Iron and Steels (ADIS)” which started in 2006. The aim of the workshop is to create a platform for leading experts in metals research to discuss and exchange recent scientific developments, methods, and results in the field of thermodynamics, kinetics and structural defects, aiming in particular on the impact of magnetism on these properties. It is inspired by the fact that any design strategy for iron-based alloys and steels requires a combined multi-disciplinary effort. A wide array of approaches and algorithms needs to be developed, implemented and evaluated with respect to predictive power.

To best fit these needs, the ADIS workshops are characterized by Gordon style, tutorial-like one hour talks, intensive discussions and, last but not least, the inspiring cooperationpromoting atmosphere of Ringberg castle. Although the ab initio description of iron and steel remains the main goal, each of these events has its own focus on a specific topic: The series started 2006 on “Status and future challenges”. The focus of following workshops was for example on “Thermodynamics and Kinetics” or “Magnetism”, but also “Mechanical properties” have been a topic before. All of them were mainly devoted to the discussion of recently developed ab initio based methods, which allow one to answer key questions in the respective field. To ensure the multidisciplinary approach, selected presentations that report about alternative methods or experimental investigations are also desired.

Scientific Content

The workshop will encompass

1. accurate theoretical as well as experimental methods that are able to capture phenomena on the electronic and atomic level and
2. efficient coarse-graining methodologies to access target physical properties and to perform the screening of materials compositions.

For the former, ab initio methods such as density functional theory have for many materials classes already proven to be a highly successful tool. For Fe-based alloys, however, a critical bottleneck is the role that magnetic ordering, excitations and transitions have on thermodynamic, defect and kinetic properties. This is immediately evident for magnetocaloric, soft- or hard-magnetic materials. In addition, also phenomena like the resistance to radiation damage caused by the chemical decomposition in Fe-Cr, the grain-boundary embrittlement in ferritic Fe-Mn, the high strength of austenitic Fe-Mn, and the relative stability/ordering of α and γ phases in Fe-Co cannot be fully understood without properly accounting for magnetic effects.

We therefore intend to concentrate on the following topics:

• Recent progress in ab initio methods to treat magnetism in perfect as well as defective (with point/extended defects) multi-component systems. Examples are spin-space averaging techniques and approaches beyond the standard collinear approximation.
• Recent method developments to bridge between (i) highly accurate electronic calculations and (ii) large-scale atomistic thermodynamic and kinetic simulations, which allow one to take the impact of magnetism on defect properties, diffusion and microstructural evolution into account. Examples are potentials based on machine-learning, lattice-based effective interaction models (EIMs) and magnetic tight-binding (TB) models.
• Dedicated experiments in bulk alloys and along intergranular / interphase boundaries, since they are essential for verifying the robustness of the theoretical predictions. Examples are electron diffraction experiments with magnetic resolution, nuclear magnetic resonance and diffusion experiments.
• Current attempts to improve thermodynamic and diffusion databases and tools for magnetic materials. Examples are high-throughput working environments and established tools like DICTRA.

In addition, intriguing methodological developments that are promising but still waiting for being applied to magnetism, will also be discussed.