US Patent 10364823 Airfoil blade

A fan blade of a gas turbine engine is disclosed which is composed of an airfoil having a leading edge and a trailing edge, and a root with a platform and a blade fixing for engaging a fan hub. The fan blade is composed of a core substrate selected from the group consisting of composites and polymers, and an entirety of the airfoil and the root of the fan blade has a nanocrystalline metal outer layer thereon which forms an outer surface fully enveloping the fan blade. The nanocrystalline metal layer formed of a nanocrystalline metal coating has an average grain size of between 10 nm and 500 nm, and the nanocrystalline metal outer layer forms a structural element of the fan blade.