INFLUENCE OF Cu AND Zn RESIDUES FROM WIRE ELECTRO-DISCHARGE MACHINING ON TBC DURABILITY

摘要

Thermal barrier coatings (TBC) are deposited on superalloys in gas turbines to prolong component life. Electro-discharge machining (EDM) provides a convenient way of machining superalloys prior to coating deposition. Wire-EDM may leave residues from the wire material on the cut surface. A study was performed to investigate if brass residues from the EDM wire affected TBC oxidation behavior and spallation life. Isothermal oxidation at 1050°C and thermal cycling at 1100°C were performed on plasma sprayed TBCs on two different EDM cut substrates. No decrease in TBC life was detected due to the brass residues on the cut surfaces.