Copper and Nickel Alloys Clad with Platinum and Its Alloys

Cladding base metals with platinum or platinum alloys offers certain technical and economic advantages. In an earlier paper the mechanical properties of the metals to be joined were discussed. In this second paper it is shown that interdiffusion of the two materials being joined together must be considered, and that if the partners have different diffusion coefficients difficulties can result during later production stages. This is especially true if voids form in the diffusion zone due to the Kirkendall effect. This effect is particularly pronounced when copper alloys are used as the base metal, however it can be avoided either by using nickel-rich alloys or by incorporating an electrodeposited intermediate nickel layer of suitable thickness.