US Patent 7998593 Process for coating silver indium alloy metallic seal

A process for the manufacture of a metallic seal comprising applying a first intermediate layer to a base metal, applying a second intermediate layer overlying the first intermediate layer, applying a first coating layer comprising silver overlying the second intermediate layer, applying a second coating layer comprising indium overlying the first coating layer, baking the base metal with applied intermediate and coating layers at a temperature to diffuse the coating layers to form a silver indium alloy coating layer. A seal comprising a substrate having a metal surface, a first intermediate layer overlying the base metal, a second intermediate layer overlying the first intermediate layer, an alloy coating layer overlying the second intermediate layer, wherein the alloy coating layer comprises a silver indium alloy.