Platinum plating for turbine blades: technology development and process improvement

Abstract

Traditionally turbine blades in both aircraft and power turbines are plated with a platinum deposit to enhance significantly their service life. Such platinum deposits are typically 5 μm in thickness and are subsequently put through a pack diffusion process to form a platinum alumina composite deposit, with physical properties that are superior to platinum itself. Technology involving either platinum 'P' salt or platinum 'Q' salt is commonly used as plating electrolytes. In many of these formulations plating will involve the use of ammonia and often elevated temperatures, together with lengthy plating times, to give the desired deposit qualities. This paper describes innovative process development that gives benefits in process cycle time and also addresses environmental concerns by eliminating ammonia from the system.