Regensburg 2019 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 29: Microstructure and Phase Transformations

MM 29.5: Vortrag

Mittwoch, 3. April 2019, 16:00–16:15, H46

Study on nucleation rates and nucleation parameters of binary alloys — •Manoel da Silva Pinto, Martin Peterlechner, and Gerhard Wilde — Institute of Material Physics, Münster, Germany

Nucleation has an importance in diverse phenomena studied in a broad range of scientific areas. In material science, topics of special interest are, among others, new phase nucleation in alloys, solid-liquid interface energies, glass formability and possible formation of new phases in deep undercooled melts. Yet, only a few data is available on the general behavior of nucleation in alloy melts. With the help of a statistical approach related to survival analyses applied to calorimetric data of deeply undercooled alloys, we measure and analyze the nucleation rates of Au-Ge and Cu-Ge alloys for different compositions. Further parameters can be derived from this data and a comparison with the theoretical predictions from the classical nucleation theory of pure metals can be made. A dimensionless solid-liquid interface energy, the so called Spaepen factor, is determined in order to gather information about the possible nucleating phases. As a quantity depending on the crystallographic structure of the lattice formed during nucleation, the Spaepen factor could be used to describe the most probable nucleating phase and therefore the nucleation behavior in alloy melts.