Nanolayered CrAlTiN and multilayered CrAlTiN–AlTiN coatings for solid particle erosion protection

• Nanolayered CrAlTiN and multilayered CrAlTiN–AlTiN coatings were fabricated.
• Both coating systems outperform CrN coating in erosion resistance.
• CrAlTiN having smaller bilayer period performs better at 30° than its counterpart.
• The erosion resistance is optimal at a certain layer number for CrAlTiN–AlTiN.

Applying hard coatings on airfoil surfaces is proven to be an effective approach to mitigating erosion damage to engine components. Nanolayered or multilayered coatings, because of their capability of tailoring hardness and toughness through modifications in the chemistry and architecture of layer constituents, have been explored as potential candidates for this specific application. In this study, nanolayered CrAlTiN (CrN/AlTiN) coatings with different modulation periods, along with multilayered CrAlTiN–AlTiN coatings having different number of layers and different thickness of individual layers, were fabricated, characterized and evaluated. All the coatings significantly outperformed the CrN baseline in erosion resistance, and their performance was strongly affected by the bilayer period of the nanolayered coatings or the layer architectural characteristics of multilayered coatings.