The reactive route to ceramic joining: Fabrication, interfacial chemistry and joint properties

Successful techniques for joining ceramics often involve and rely on reactions at ceramic/metal interfaces for achieving strong and stable bonds. in fact, interfacial reactions can affect every stage of the formation of a joint from the onset of bonding through the development of equilibrated microstructure to the optimization of the mechanical properties. This is demonstrated by work on the reactive bonding of Si3N4 using established and developing joining routes. The systems evaluated were brazing with V-active filler metals, diffusion bonding with FeCr alloy interlayers and partial transient liquid phase bonding with Pd/CuTi multilayer interlayers. The reactions that occur at the ceramic/metal interfaces of these systems, how they can be controlled and the ways in which the performance of the Si3N4 joints are affected are discussed. (C) 1998 Acta Metallurgica Inc.