Quantitative Microscopy of β‐Si ₃ N ₄ Ceramics

Abstract

The three‐dimensional grain size distribution in an experimental β‐Si 3 N 4 material has been determined using the hexagonal prism as a model of β‐Si 3 N 4 grain shape. Results from quantitative microscopy of polished and etched sections were compared with computer‐generated two‐dimensional stereological parameters of hexagonal prisms with different aspect ratios in order to determine an average grain shape (i.e., aspect ratio) in the microstructure. Section parameter distributions for the average grain shape were obtained from the computer simulations and used in a three‐dimensional reconstruction of the microstructure. The results showed that this Si 3 N 4 ceramic had the postulated fibrous microstructure and a broad grain size distribution.