High-throughput optimization of the phase stability of complex alloys

Tilmann Hickel, Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany

While the present ab initio guided search for novel materials is often focused on ground state properties, the finite temperature stabilities of the involved phases are commonly not considered and largely unknown. We discuss our recent ab initio based developments to determine accurate free energies and derived properties with a focus on the search for novel hard magnetic materials. In the Ce-Fe-Ti ternary system, for example, the promising phase CeFe11Ti competes – as energy-dispersive X-ray spectroscopy reveals – with various Laves phases. To overcome this limitation we use the ab initio thermodynamics, capturing vibrational, electronic, magnetic and configurational entropy contributions, in order to determine the Helmholtz free energy of all relevant phases. Using this methodology we predict how adding various alloying elements affects partitioning and relative phase stabilities. Based on these insights, we discuss strategies to improve the stability of CeFe11Ti.ogy we predict how adding various alloying elements affects partitioning and relative phase stabilities. Based on these insights, we discuss strategies to improve the stability of CeFe11Ti.

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Session M3: Moday, 25 June 2018

Start: 05:30 p.m.
End: 05:45 p.m.