Properties and fractography of Si3N4/TiN ceramic joined to steel with active single layer and double layer braze filler alloys Original Research Article

Active metal brazing is a widely used technique for joining of advanced ceramics to metals. Two Ti-activated brazes have been investigated for joining of a Si3N4/TiN ceramic composite to steel. A commercially available braze CB6 (Ag 98.4%, In 1%, Ti 0.6% from Degussa) has been compared with a CuSnTiZr alloy. In addition, the properties of a two-layered brazing filler system with and without WC particle reinforcement have been investigated. In the present study, standard 4-point flexural strength testing of brazed joints is combined with a detailed fractographic study to determine the causes of failure in the different systems. In the best systems, an average bending strength of 466 MPa was achieved when joining ceramic to ceramic and 398 MPa when joining ceramic to metal.