Mechanical and oxidation resistance of remanufactured NiCoCrAlYTa coating deposited via arc ion plating

NiCoCrAlYTa coating of the Ni-based superalloy substrate was processed using a feasible remanufacturing method. The coating was deposited using arc ion plating (AIP) and removed by a complex treatment of immersion-etching in hydrochloric acid solution and wet sandblasting. The conventional and remanufactured coatings were homogenized in vacuum at 1080 °C for 4 h and then oxidized isothermally in the air at 1050 °C for 200 h. The constituent phases and the microstructure were characterized using powder X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Additionally, the mechanical performance of the coated specimens was evaluated via tensile testing at room temperature and stress rupture testing at 982 °C/220 MPa. The complex treatment is found to effectively remove the NiCoCrAlYTa coating without causing damage to the substrate. The re-coated specimens had a tensile yield strength greater than 985 MPa at room temperature, a rupture life of 45 h at 982/220 MPa, and an oxidation rate constant K_p of 3.16 × 10^–12 g²cm⁻⁴ s⁻¹ at 1050 °C, which were nearly identical to those of the conventionally coated specimens.