An integral ring gear and torque arm for a wind turbine gearbox and method of manufacturing same includes forming the ring gear and the associated gear housing as a single part using the same material, e.g., using a casting process. Further, the ring gear defines an inner circumferential surface having a plurality of gear teeth. Thus, the method also includes applying a coating material to the gear teeth of the ring gear via an additive manufacturing process, such as cold spraying, so as to increase a hardness of gear teeth.

An integral ring gear and torque arm for a wind turbine gearbox and method of manufacturing same includes forming the ring gear and the associated gear housing as a single part using the same material, e.g., using a casting process. Further, the ring gear defines an inner circumferential surface having a plurality of gear teeth. Thus, the method also includes applying a coating material to the gear teeth of the ring gear via an additive manufacturing process, such as cold spraying, so as to increase a hardness of gear teeth.

Fracture-resistant and self-lubricating wear surfaces are provided. In an implementation, a machine surface that is subject to wear is coated with or is constructed of a metallic nanostructure to resist the wear and to provide fracture-resistant hardness, built-in lubrication, and thermal conductivity for heat-sinking friction. The metallic nanostructured surface may be used, for example, on a face seal, bushing, bearing, thrust member, or hydraulic flow passage of an electric submersible pump. In an implementation, the metallic nanostructured surface is a nanocrystalline alloy including nanograin twins of a body-centered cubic (BCC), face-centered cubic (FCC), or hexagonal closest packed (HCP) metal. The nanostructured alloy may include atoms of copper, silver, gold, iron, nickel, palladium, platinum, rhodium, beryllium, magnesium, titanium, zirconium, or cobalt, and may provide more hardness and lubricity than diamond-like carbon coatings or carbides.