Regensburg 2022 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MM: Fachverband Metall- und Materialphysik

MM 9: Non-equilibrium Phenomena in Materials Induced by Electrical and Magnetic Fields 2

MM 9.2: Vortrag

Montag, 5. September 2022, 17:45–18:00, H45

Understanding DC-induced abnormal grain growth in FeC-thin films — •Thomas Brede, Michel Kuhfuss, Reiner Kirchheim, and Cynthia Volkert — Institut für Materialphysik, Universität Göttingen, Deutschland

The field of processing materials with magnetic or electric fields and currents in steadily growing, since it opens the door to more efficient ways of material treatment and former not achievable material modifications. In this scope, it was shown recently, that high DC electric current densities up to 4 MA/cm² can be used at elevated temperatures of 550^∘C to produce elongated ferrite grains with high aspect ratios in an otherwise nanocrystalline iron-carbon thin film. To understand the underlying mechanism we will present experiments in a wide range of process parameters. The samples were characterized by SEM and EBSD in different stages of the experiment. The results shown allow a detailed description of the underlying mechanism of the evolution of the abnormal grown structures. In addition they reveal a threshold linked to the electromigration-induced C-flux, below which no changes occur. A purely kinetic model will be presented to describe the observed behaviour and allow the prediction of similar effects at different process parameters and material systems.