Microstructural and mechanical characterization of the Si_3N_4/Si_3N_4 joint brazed using Au-Ni-V filler alloys

摘要

In this study, two Au-Ni-V filler metals were used to braze Si_3N_4 ceramic in the form of foils. The effects of brazing temperature and V content in the filler alloy on microstructure and bonding strength of the joint were studied. The results reveal that a VN reaction layer with a thickness about 4 (mu m was formed at the interface between Si_3N_4 substrate and filler alloy. With increasing brazing temperature or V content the thickness of VN reaction layer increased. A maximum joint bending strength of 242 MPa was achieved when the joint was brazed at the temperature of 1423 K for 30 min using Au58.7Ni36.5 V4.8 filler alloy. The bonding mechanism was discussed with reference to the discovered phases and brazing parameters.