Particle tracking during Ostwald ripening using time-resolved laboratory X-ray microtomography

Journal Article · Tue Apr 01 00:00:00 EDT 2014 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2014.01.022· OSTI ID:22340354

Baumann, M. ^[1]; Wolfram, U. ^[2]; Krill, C. E. ^[1]

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1. Ulm University, Institute of Micro and Nanomaterials, Albert-Einstein-Allee 47, 89081 (Germany)
2. Ulm University, Institute of Orthopaedic Research and Biomechanics, Helmholtzstrasse 14, 89081 (Germany)

Laboratory X-ray microtomography is investigated as a method for obtaining time-resolved images of microstructural coarsening of the semisolid state of Al–5 wt.% Cu samples during Ostwald ripening. Owing to the 3D imaging capability of tomography, this technique uniquely provides access to the growth rates of individual particles, thereby not only allowing a statistical characterization of coarsening—as has long been possible by conventional metallography—but also enabling quantification of the influence of local environment on particle boundary migration. The latter information is crucial to understanding growth kinetics during Ostwald ripening at high volume fractions of the coarsening phase. Automated image processing and segmentation routines were developed to close gaps in the network of particle boundaries and to track individual particles from one annealing step to the next. The particle tracking success rate places an upper bound of only a few percent on the likelihood of segmentation errors for any given particle. The accuracy of particle size trajectories extracted from the time-resolved tomographic reconstructions is correspondingly high. Statistically averaged coarsening data and individual particle growth rates are in excellent agreement with the results of prior experimental studies and with computer simulations of Ostwald ripening. - Highlights: • Ostwald ripening in Al–5 wt.% Cu measured by laboratory X-ray microtomography • Time-resolved measurement of individual particle growth • Automated segmentation routines developed to close gaps in particle boundary network • Particle growth/shrinkage rates deviate from LSW model prediction.

• OSTI ID: 22340354
• Journal Information: Materials Characterization, Vol. 90; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACCURACY
ANNEALING
COMPUTERIZED SIMULATION
IMAGE PROCESSING
MICROSTRUCTURE
PARTICLE SIZE
PARTICLE TRACKS
PARTICLES
SHRINKAGE
X RADIATION