Microstructure and properties of the Si3N4/Si3N4 brazing joint

Si3N4 ceramic was brazed using a filler alloy Of (CUZn)(85)Til(5) alloy, and a Si3N4/Si3N4 joint with a high bonding strength was obtain under a suitable brazing condition. The brazing joint was composed of Cu2TiZn and Cu solution containing Titanium Silicide and Titanium Nitride. With increasing brazing temperature from 1123K to 1323K, the thickness of the reaction layer increased and the amount and size of the reactant increased. The addition of the Zn made the melting point of the filler alloy and the brazing temperature decreased, which improved the flowability and wettablility of the filler alloy. The evaporation of Zn was enhanced with increasing welding temperature. The shear strength of the Si3N4/Si3N4 joint increased with increasing welding temperature. The average shear strength of the joint reached 265 MPa when the welding temperature is 1223K.