Microstructural modifications and high-temperature oxidation resistance of arc ion plated NiCoCrAlYSiHf coating via high-current pulsed electron beam

A NiCoCrAlYSiHf coating prepared via arc ion plating was irradiated using a high-current pulsed electron beam (HCPEB) technique. The self-quenching and polishing effect induced by HCPEB treatment normalized the defects, re-melted the surface, refined the grains, introduced the dislocations, and changed the elemental distributions. After oxidation for 200 h, severe spalling of the oxide scale and internal oxidation occurred in the original coating. The restructuring of the remelted layer contributed to a very stable, continuous, slow-growing, and uniform alpha-Al2O3 scale during the entire oxidation stage. HCPEB technique is an effective way to dramatically improve the service life of an MCrAlYX-type coating.