Interfacial structure between TiN sintered ceramics with and without an Fe-containing grain boundary phase and Ag–Cu eutectic brazing filler material

Abstract

To focus on the interfacial reaction between the Ag–Cu alloy layer and TiN in active metal brazing, the Ag–Cu brazed interfacial structures between Cu and two types of TiN sintered ceramics fabricated by different methods were examined. No grain boundary phase components consisting of the Ni-containing Fe phase or Mo2C were detected on the TiN grain surfaces of the TiN liquid-phase sintered ceramic bonding surfaces before brazing. The brazed specimens were heated at 850 °C for 0.5 h. No Cu/TiN solid-phase sintered ceramic bonding was obtained. The Ag–Cu alloy layer was bonded onto the TiN grains in the TiN liquid-phase sintered ceramic through an Fe- and Ni-containing segregation layer. This segregation layer was formed by an interfacial reaction between the TiN grains and the Ni-containing Fe in the TiN liquid-phase sintered ceramic dissolved in the Ag–Cu liquid phase.