SYNTHESIS AND CHARACTERIZATION OF Si3N4@Al(OH)3–Y(OH)3 CORE-SHELL COMPOSITE PARTIC3LES

Silicon nitride (Si3N4) has attracted substantial interest because of its extreme chemical and physical properties, but the sintering densification of Si3N4 is difficult, and it is easily oxidized in the high-temperature air to impact high-temperature strength, which restricts its applied range. In order to decrease the oxidization and improve the strength of Si3N4 at high temperature, the surface of Si3N4 is coated with Al(OH)3 and Y(OH)3 to synthesis Si3N4@Al(OH)3–Y(OH)3 core-shell composite particles. Through TEM, XRD, and BET analysis, when pH is about 9, Si3N4@Al(OH)3–Y(OH)3 core-shell composite particles are successfully synthesized by co-precipitation methods. Coating layer is about 200 nm, which is compaction and conformability. Dispersion of coated Si3N4 with Al(OH)3 and Y(OH)3 particles are very good. Synthesis of Si3N4@Al(OH)3–Y(OH)3 core-shell composite powder will lay the foundation for preparing high-performance YAG/Si3N4 multiphase ceramic materials.