Joining of Si3N4/Si3N4 with CuNiTiB paste brazing filler metals and interfacial reactions of the joints

The joining of Si₃N₄/Si₃N₄ was carried out using CuNiTiB paste brazing filler metals. The maximum room-temperature three-point bend strength of the joints is 338.8 MPa. The cross-section microstructures of the joints and the element area distribution were examined by scanning electron microscope (SEM) equipped with wave dispersive X-ray spectroscopy (WDS). The phases appeared on the fracture surfaces of the joints were determined by means of X-ray diffraction analysis (XRDA) method. A model is established of the interfacial reactions between Si₃N₄ and the CuNiTiB brazing filler metals. With this model, the relationship between the joint strength and the interfacial reactions is discussed.