Pressureless sintering of silicon nitride with magnesia and ceria

An investigation of the pressureless sintering of Si3N4 with MgO–CeO2 revealed that MgO–CeO2 is a much more effective sintering aid for silicon nitride than either MgO or CeO2 alone. The concentration of MgO–CeO2 and the MgO/CeO2 weight ratio have a strong influence on the densification behavior and mechanical properties of the sintered materials. The pressureless sintered silicon nitride with MgO–CeO2 achieved a relative density of 98.5% and a bending strength of 948 MPa.