Palladium Alloy Pinning Wires for Gas Turbine Blade Investment Casting

Turbine blades in aero-engine and land-based power generation gas turbines are complex components manufactured to precise geometric, structural and machanical property tolerances. High pressure turbine blades used in the hottest, most hostile and demanding sections of gas turbines often contain integral cooling channels. The production of such cooling channels has been a significant advance in gas turbine efficiency and emission control. Pinning wires are used during mould preparation and investment casting of the blades for reliable manufacture of the cooling channels. Traditional platinum-based materials and new palladium-refactory alloys for use as pinning wire are discussed here.