2005 Volume 46 Issue 10 Pages 2176-2179
As a high temperature protective layer, platinum–iridium alloys were electroplated on the nickel-base single crystal superalloy TMS-82+ from amidosulfuric acid solutions by the direct current method. It was found that Ir content in the films was always lower than the ratio of concentration ([Ir3+]/([PtCl62−] + [Ir3+])) in the electrolytes, indicating that preferential deposition of Pt occurred in this study. The as-deposited Pt–Ir films formed an fcc single phase structure with a granular surface. When Ir content exceeded 3 at%, Pt–Ir films exhibited the 〈111〉 preferred growth orientation. It was also found that pre-deposition of Ni and Pt promoted the deposition rate and changed composition of overlaying Pt–Ir films.