ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Polyhedron analysis for structure identification in atomistic simulations

Date: 12.03.2012
Place: TMS Annual Meeting and Exhibition, Orlando, USA

Thomas Schablitzki
Jutta Rogal
Ralf Drautz

The formation of topologically close‐packed (TCP) phases in metal alloys can significantly influence the macroscopic materials properties. These complex phases are of particular interest in special purpose materials such as high‐temperature superalloys or modern high‐strength steels. The atomic structure of complex phases is described by an ordered arrangement of coordination polyhedra around inequivalent lattice sites. To identify the corresponding TCP phases during atomistic simulations we have developed a polyhedron analysis. Within our analysis we create fingerprints of the arrangement of coordination polyhedra around each atom which enables us to locally determine the actual crystral structure. Of particular importance in trying to understand the formation and growth of TCP‐phases on an atomistic level are processes taking place at the interface between the complex phase and the alloy matrix. Here, we employ an adaptive kinetic Monte Carlo approach together with our polyhedron analysis to investigate concerted atomic rearrangements at the interface.

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