The effect of metal coating on the strength of capacitor-discharge joining of oxide ceramics

Abstract

The Surfaces of alumina and zirconia tiles were sputter coated with various metallic films (Al, Ti, Al+Y and Nb) and were joined by a capacitor-discharge technique using either Al, Ti or Nb as interlayer materials. The strength of the joints were measured using the shear testing method and found that the strenght of the bonds made with sputter-coated zirconia were higher than those joints made without sputtering, whereas weak bonds were obtained for the alumina ceramics. The interfacial structure of these joints were investigated using a range of microscopes. Transmission electron microscope investigations showed that there was a distinct reaction layer containing small particles when the surface of the zirconia sputtered with Ti and joined using an Al interlayer.