a method of joining metal and metal , or metal and ceramic parts , wherein a first metal part is selected and then processed to form a bond coat that will effectively bond to a sealing material which in turn bonds to a second metal or ceramic part without degrading under the operating conditions of electrochemical devices . preferred first metal parts include alumina forming alloys from the group consisting of ferritic stainless steels , austinetic stainless steels , and superalloys , and chromia forming alloys formed of ferritic stainless steels . in the case of chromia forming ferritic stainless steels , this bond coat consists of a thin layer of alumina formed on the surface , with a diffusion layer between the first metal part and this thin layer . the bond coat provides a good bonding surface for a sealing layer of glass , braze or combinations thereof , while at the same time the diffusion layer provides a durable bond between the thin alumina layer and the first metal part . in the case of alumina forming alloys , the bond coat consists of cauliflower - like growths of an aluminum oxide nodules embedded in the surface of the alumina forming alloys .