Microstructure characteristics of Fe-Mo/Si 3N 4 cermet during sintering

Fe-Mo/Si 3 N 4 composite powder was synthesized by heterogeneous precipitation-thermal reduction process and then consolidated to Fe-Mo/Si 3 N 4 cermet via hot press. Microstructure and phase transition of the powder and its sintered body were characterized by SEM, TEM, EDS and XRD. In reduction processes, particles with nanometer Fe-Mo nitride, and Si and Mo which adhere to the surface of Si 3N 4 are formed by the reaction between Fe 2 (M oO 4) 3 and Si 3N 4, and Mo particles coated with Fe thin layers are formed by decomposition of Fe 2 (M oO 4) 3 in the powders. In the hot process, Si, Fe, Fe-Mo alloys with low melting points are in liquid phase.Fe flows to the surface of Si 3N 4 to generate Fe-Mo nitride. Si flows to the surface of Mo particles to form Mo 5Si 3. © 2012 American Scientific Publishers All rights reserved.