Ceramic-metal bonding

A method for making a liquid-diffusion formed, fully dense and substantially defect-free ceramic-metal joint for practical uses at temperatures over about 630.degree. C., comprising:

• providing a ceramic;
• providing a metal;
• selecting a ceramic metallizing composition having a plurality of mixed powdered metallizing ingredients and, when molten, causing reactions between the ingredients and also with the ceramic to form a metallized layer thereon;
• preparing the composition to have gravitationally substantially nonsegregating qualities when applied onto said ceramic;
• coating onto a selected surface of the ceramic a layer of the metallizing composition,
• assembling together the metal and the coated ceramic surface;
• heating the assembled metal and coated ceramic surface to a temperature at which the metallizing composition melts to cause said reactions between the ingredients and with the cermaic thereby achieving ceramic metallization at the selected surface;
• and
• keeping the composition molten for a sufficiently long time to thereby form on the ceramic by liquid diffusion the metallized layer for bonding the ceramic to the metal, said metallized layer being strong, adherent, fully dense, substantially defect-free, and thermomechanically shock resistant and having a controlled interfacial region of substantial thickness whose microstructure is substantially free of voids, inclusions, and microcracks.