Stereological approach to geometry of grains in nano-crystals
K.J.Kurzydlowski,
Department of Materials Science and Engineering, Warsaw University of
Technology, 02-507 Warszawa, Woloska 141
Nano-polycrystalline materials exhibit distinctly different mechanical
and physical properties. These specific properties to large extent are
related to the high density of the grain boundaries in nano-sized
crystalline aggregates. A proper quantification of this effect
requires precise description of the size and shape of nano-grains in
nano-polycrystals. Such a description can be obtained by modern
methods of stereology and computer aided image analysis. The paper
shows how these methods can be applied to estimate the mean volume of
grains and the density of the grain boundaries. Grain size homogeneity
can also be measured and the variation in the grains elongation.
Examples are given how these parameters can further be used to reveal
changes taking place during processing of nano-grained materials and
to model their plastic deformation.
Key words
Nano-crystals, grain size and shape, image analysis, stereology
|