Regensburg 2010 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 7: Intermetallic Phases I

MM 7.4: Talk

Monday, March 22, 2010, 11:00–11:15, H5

Low temperature phases in Ni-rich Ni-W and Ni-Re — •Nils Schindzielorz, Katharina Nowak, and Stefan Müller — Universität Erlangen-Nürnberg, Lehrstuhl für Theoretische Physik 2, Staudstr. 7, D-91058 Erlangen

It is known from experiment [1] that the mechanical properties of Ni-based superalloys heavily depend on the individual amount of W and Re in the alloy. To understand this different behaviour a detailed knowledge of the zero Kelvin groundstate diagram would be of great importance. We find, by use of a density functional theory driven cluster expansion performed with the program package UNCLE [2], that the zero Kelvin groundstate diagrams for Ni-Re and Ni-W with all possible structures based on an fcc lattice up to 20 basis atoms differ significantly. While for Ni-Re we find only one groundstate i.e. the D1a structure at 20 at.% Re, for Ni-W there are six stable groundstates with concentrations less than 40 at. % W.
Supported by Deutsche Forschungs-Gemeinschaft.
H.S.Ko et al., J. Mater. Sci. 33 (1998) 3361
D.Lerch et al., Modelling Simul. Mater. Sci. Eng. 17 (2009) 055003 (19pp)