Selection of Overlays for Single Crystal Shrouded Turbine Blades
Solar Turbines Incorporated (Solar) is investigating innovative turbine designs that will allow higher electrical efficiency and output power. Liburdi Engineering Limited (Liburdi) and Solar have evaluated the application of a powder metallurgy process based upon the Liburdi Powder Metallurgy (LPM™) repair process. The technique applies a chrome carbide and nickel-chrome alloy composite hardfacing onto a turbine blade’s Z-notches. Processing techniques (such as material form, alloy-hardface ratio optimization, binder ratio and heat treatment cycles) were investigated (some of the details developed at Liburdi are proprietary). Metallurgical, mechanical and short-term oxidation properties of the composite have been studied and defined by Solar. The LPM process was found to be feasible and practical to be applied on CMSX-4 single-cystal Z-notches of shrouded blades.