Effect of Y2O3–MgO Addition on Heterogeneous Precipitation-Thermal Reduction Synthesis and Sintering of Fe–Mo/Si3N4 Powders

Effect of Y2O3–MgO addition on heterogeneous precipitation-thermal reduction synthesis and the sintering of Fe–Mo/Si3N4 powders has been investigated. It was found that the whiskers-like β-Si3N4, good wettability phases on Si3N4 surface, and high toughness Fe phase appeared in Fe–Mo/Si3N4 cermets with Y2O3–MgO additives. The results show that Y2O3–MgO additives can effectively optimize the microstructures of Fe–Mo/Si3N4 cermets, and improve the material mechanical properties. Therefore, it indicated that Y2O3–MgO additives can be used for strengthening of sintered cermets, and the dual function of whiskers self-toughening and different metal-composition toughening can be achieved in Fe–Mo/Si3N4 cermets with Y2O3–MgO additives.