Regensburg 2013 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 31: Computational Materials Modelling - Diffusion & Kinetics II

MM 31.1: Talk

Wednesday, March 13, 2013, 10:15–10:30, H24

AKMC simulations of solid-solid phase transformations in molybdenum — •Ari Harjunmaa, Jutta Rogal, and Ralf Drautz — ICAMS -- Ruhr University Bochum, 44789 Bochum, Germany

Molybdenum is a refractory metal used as an alloying element to improve the properties of high-performance materials such as Ni-base superalloys. A common problem in these materials is the formation of topologically close-packed (TCP) phases, which deprive the bulk matrix of the alloying elements and cause the material to become brittle. It is therefore of utmost importance to understand the atomistic processes at work in solid-solid phase transitions leading to the formation of TCP phases. We begin this task by investigating interfaces between the TCP A15 and the cubic BCC phases in molybdenum. We use adaptive kinetic Monte Carlo simulations to discover atomistic processes at the interfaces and to model the time evolution of the systems in question. We also investigate the energetics and stability of the interface structures, and we evaluate the reliability of the employed interatomic potentials by comparing results obtained from density functional theory to those from bond-order and empirical potential simulations.