Capacitor-discharge joining of oxide ceramics

Abstract

A capacitor-discharge joining technique has been used to fabricate alumina-metal-alumina and zirconia-metal-zirconia joints using thin foils of aluminum, titanium, or amorphous AlxNiyYz alloys as interlayers. The technique involves passing a high-energy pulse through a conductive interlayer, so converting the interlayer into a liquid-vapor "energized foil" which wets and bonds the pieces of ceramic being joined. The bond strengths of the joints were measured by shear testing which showed that the highest bond strengths for both alumina and zirconia substrates were obtained when an amorphous AlxNiyYz interlayer was used. An investigation of the interfacial structure of the joints revealed that there is a distinct reaction layer between the ceramic substrate grains and the amorphous AlxNiyYz interlayer.