Cyclic oxidation behavior of Pt-modified aluminide coating treated with ultrasonic nanocrystal surface modification (UNSM) on Ni-based superalloy

►The microstructure of Ni-Pt alloy layer was changed to have fine grain size and many defects by UNSM. ►The fine grain size caused the thick coating and the smooth surface during pack cementation. ►UNSM-treated Pt-modified aluminide coating had superior resistance to cyclic oxidation due to the thick coating and the smooth surface.