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. (C) 1999 Kluwer Academic Publishers.