High temperature oxidation behavior of NiCoCrAlFeY high entropy bond coating fabricated by high-speed laser cladding

The low-diluted NiCoCrAlFeY high entropy bond coating is prepared by high-speed laser cladding (HSLC). Investigation shows it exhibits excellent high temperature oxidation resistance and slow TGO (thermally growth oxides) growth rate, for a protective α-Al2O3 layer fast covering its surface. Meanwhile, the bulk-like structure by HSLC process suppress the internal oxidation effectively. The severe lattice distortion of high entropy composition makes high diffusion energy and low diffusion coefficient for Al, leading the Al slowly consumed in the coating. Results confirm the bond coating deposited by HSLC possess a tremendous potential application at elevated temperature.