Quantitative Description of Si3N4 Microstructures

A new characterization technique for the quantification of spatial
parameters of silicon nitride grains is presented.
After some theory about the potential attempts to recover stereoscopic
parameters from metallographic micrographs, a method is discussed,
which transforms the distributions of size and shape parameters of
grain sections measured in the micrograph into the distributions of
spatial size and shape of the grains. It is based on algorithms of
stereology and is valid for regular hexagonal prisms with random size
and shape. Nevertheless the theoretical solution can be adapted to
various shape assumptions such as different types of prisms and
polyhedrons.
Conclusions for the mechanical properties demand particular attention
to the statistics of the rare large and elongated grains. Some attempts
to handle this problem are discussed.