Mechanical Properties of Silicon Nitride

The room temperature mechanical properties of reaction bonded and hot‐pressed silicon nitride are reviewed with respect to the microstructure of the material. It is shown that the strength of these compounds is predominantly controlled by microstructural features. These are the volume fraction of porosity and the pore size distribution for reaction bonded Si 3 N 4 , and the volume fraction of elongated transformed β grains and their grain size for hot‐pressed Si 3 N 4 .