Jing Yang

M. Todorova, and J. Neugebauer

Max-Planck-Insitut für Eisenforschung GmbH, D-40237 Düsseldorf, Germany
 

Constructing surface phase diagrams with pyiron workflow: application on Mg alloy

Defect phases formed at alloy surfaces and interfaces govern their chemical and mechanical behavior. Constructing phase diagrams from ab initio modeling provides valuable information for understanding the microscopic mechanisms of surface and interface processes. In this work, we aim to build surface phase diagrams to study the aqueous corrosion of magnesium alloyed with Al and Ca, an important structural material for the automotive and aerospace industries.

We develop a pyiron-based workflow that combines DFT simulation with cluster expansion, and subsequently construct the surface phase diagram in the chemical potential space. We show that such an approach allows for fast and accurate survey of surface phases on a large grid, and is capable of simulating order-disorder transition on the surface. The workflow can also be easily transferred to other alloying systems, providing a general tool for studying alloy surfaces.