HVOF is a technique used to apply a metallic or composite metal/ceramic coating. It is based on the use of a gas flow with high temperature (over 2000°C) and high speed (over 2000m/s) to project molten particles on a target surface. The system is composed by a spray-gun, containing a combustion chamber and expansion nozzles responsible for the combustion reaction and acceleration of the gas flow, that is mounted on a robot that moves the gun along the target component at precise distance and speed. These are enclosed in a soundproof spraying booth, with some ancillary devices that provide process gases, electric power, cooling air and water, and feedstock powder.