SKM 2023 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 18: Transport in Materials: Metals, Alloys and Oxides

MM 18.2: Vortrag

Dienstag, 28. März 2023, 11:45–12:00, SCH A 118

Composition dependent thermodynamic factor, Manning factor, and impurity diffusion coefficients estimated by a tracer-interdiffusion couple technique — •Esakkiraja Neelamegan¹, Daniel Gaertner¹, Jasper Berndt², Stephan Klemme², Aloke Paul³, Gerhard Wilde¹, and Sergiy V Divinski¹ — ¹Institute of Materials Physics, University of Münster, Münster, Germany — ²Institut für Mineralogie, University of Münster, Münster, Germany — ³Department of Materials Engineering, Indian Institute of Science, Bangalore, India

The thermodynamic driving force for the diffusion was never validated experimentally. The newly proposed augmented tracer-interdiffusion couple method could be adapted to validate the thermodynamic factor. The approach is demonstrated for a model Ni-Fe binary system, especially for the Ni-rich corner. Pure Ni is diffusion-coupled with a Ni-10 at. % Fe diluted alloy at 1000 C for 24h. The interdiffusion coefficients are estimated from the composition profile measured by an Electron Microprobe Analyser. The composition-dependent tracer diffusion coefficients are estimated following the Belova-Murch approach. Diffusion of the Fe55 and Ni63 isotopes under a chemical gradient is followed. The Fe tracer diffusion coefficients are found to be faster than those of Ni in this composition region. Utilizing the Darken-Manning relation, the thermodynamic factor is estimated and compared with that provided by a ThermoCalc software database. As a result, the composition-dependent impurity diffusion coefficients of Co, Cr, and Mn in these alloys are analysed in detail.