Grain Nucleation and Growth During Phase Transformations
S. E. Offerman,12*
N. H. van Dijk,1
J. Sietsma,2
S. Grigull,3
E. M. Lauridsen,4
L. Margulies,34
H. F. Poulsen,4
M. Th. Rekveldt,1
S. van der Zwaag2
The mechanical properties of polycrystalline materials are largely
determined by the kinetics of the phase transformations during the
production process. Progress in x-ray diffraction instrumentation at
synchrotron sources has created an opportunity to study the transformation kinetics at the level of individual grains. Our measurements show that the activation energy for grain nucleation is at
least two orders of magnitude smaller than that predicted by
thermodynamic models. The observed growth curves of the newly formed
grains confirm the parabolic growth model but also show three
fundamentally different types of growth. Insight into the grain
nucleation and growth mechanisms during phase transformations contributes to the development of materials with optimal mechanical properties.
1 Interfaculty Reactor Institute, Delft
University of Technology, Mekelweg 15, 2629 JB Delft, Netherlands.
2 Department of Materials Science, Delft University
of Technology, Rotterdamseweg 137, 2628 AL Delft, Netherlands.
3 European Synchrotron Radiation Facility, BP 220, 38043 Grenoble Cedex, France.
4 Center for
Fundamental Research: Metal Structures in 4D, Materials Research
Department, Risø National Laboratory, 4000 Roskilde, Denmark.
*
To whom correspondence should be addressed. E-mail:
Offerman{at}IRI.TUDelft.nl
