Characterization of porous silicon nitride ceramics using bentonite as binder and sintering additive

The effect of bentonite addition on extrusion behavior, open porosity, microstructure, and mechanical properties was investigated. The results showed that paste with an appropriate amount of bentonite had a good extrusion behavior. The resultant microstructures consisted of rod-like silicon nitride grains and some intergranular amorphous phase. Furthermore, superior mechanical properties were obtained. Using cheap but effective bentonite as inorganic binder as well as sintering aid is a promising eco-friendly preparation route for cost-effective porous silicon nitride ceramics.