TiAlTaSiN/TiAlTaSi multilayer coatings for enhancing hot salt corrosion fatigue resistance of TC11 Alloy

This study investigates the effect of TiAlTaSiN/TiAlTaSi multilayer coatings with varying modulation periods on the hot salt corrosion fatigue (HSCF) behavior of TC11 alloy, and discusses the mechanisms by which the coatings enhance resistance to hot salt corrosion (HSC) and fatigue crack initiation. The results indicate that the 4-layer coated samples exhibit the highest resistance to HSC and HSCF among the three modulation period designs. The alternating structure of nanocrystalline ceramic and amorphous metal layers effectively prevents the diffusion of corrosive elements such as Cl and O into the substrate. The HSCF limit of the 4-layer coated sample is improved by 30.5 % compared to the uncoated substrate. Additionally, the multilayer coating's high toughness inhibits surface strain localization and suppresses dislocation slip at the surface, thereby delaying fatigue crack initiation.