Regensburg 2013 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 63: Computational Materials Modelling - Phase Stability IV

MM 63.2: Talk

Thursday, March 14, 2013, 17:30–17:45, H24

Real-time observation of Ostwald ripening by synchrotron tomography — •Thomas Werz¹, Michael Heinze², Lukas Helfen³, Mario Scheel⁴, Stefan Odenbach², and Carl E. Krill III¹ — ¹Institute of Micro and Nanomaterials, Ulm University, Germany — ²Institute of Fluid Mechanics, TU Dresden, Germany — ³ESRF ID19, Grenoble, France — ⁴ESRF ID15A, Grenoble, France

Synchrotron tomography is an ideal tool for the time-resolved, three-dimensional observation of coarsening phenomena like Ostwald ripening. In contrast to classical grain growth, in which grain boundaries migrate in a single-phase material, Ostwald ripening entails particle growth and shrinkage in the presence of at least two phases, and the evolution of the microstructure depends sensitively on the volume fraction of the coarsening phase, V_V. In the present study we focus on capturing the coarsening behavior at such high values of V_V that the system might manifest signs of a transition between Ostwald ripening and grain growth (V_V = 1). For this purpose, we designed a sample furnace that is compatible with the optical constraints of x-ray tomography, enabling precise control over V_V in a two-phase AlCu alloy by adjusting the temperature. After applying various image processing and segmentation steps to the reconstructed tomographic data, we extract both local and global features of the microstructure and follow their evolution with time.