Seminars and Events

Single-crystal nickel-based superalloys developed by numerical multi-criterion optimization techniques based on thermodynamic calculations

Date/Time: 17.09.2014. 2:55 p.m.
Place: Ruhr-Universität Bochum, Bochum, Germany

Ralf Rettig, Lehrstuhl Werkstoffkunde und Technologie der Metalle, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen

A method for finding the optimum alloy compositions considering a large number of property requirements and constraints by systematic exploration of large composition spaces is proposed. This Computational Alloy Development can greatly enhance traditional trial-and-error testing. It is based on a numerical multi-criterion global optimization algorithm (Sequential Quadratic Programming), which delivers the exact optimum considering all constraints. The CALPHAD-method is used to provide the thermodynamic equilibrium properties of the alloys and the creep strength of the alloys is predicted based on a qualitative numerical model considering the solid solution strengthening of the matrix by the elements Re, Mo and W and the optimum morphology and fraction of the γ' phase. The alculated alloy properties are provided via very fast Kriging surrogate models. The capability of the optimization is experimentally verified with two new single crystal compositions.

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