Estimation of three-dimensional grain size distribution from microstructural serial sections

Particle/grain size distribution is an important attribute of microstructures. However, direct estimation of three-dimensional particle/grain size distribution has never been performed in opaque material microstructures due to lack of a suitable serial sectioning technique. In this contribution, application of a montage-based efficient serial sectioning technique is presented for direct unbiased estimation of three-dimensional grain size distribution. The technique is used for estimation of three-dimensional grain size distribution of tungsten grains in a liquid phase-sintered (LPS) microstructure. It is shown that the montage-based serial sectioning technique is very efficient. It yields 25–100 times larger high-resolution three-dimensional serially sectioned volume as compared to that obtained from the same number of serial sections. The larger reconstructed microstructural volume provides sufficient number of particles/grains for a reliable estimation of detailed size distribution.