HVOF process (high velocity oxygen fuel) uses a high pressure internal combustion system. This technology produces a miniature rocket engine utilizing fuel and oxygen to produce a supersonic gas in excess of 2800 Cº and velocities of 2000 m/sec. The process uses extreme velocities to impregnate a target substrate with tungsten carbide. The process exhibits very high bond strengths and virtually no porosity. HVOF is a high heat process and great care must be taken not to distort thin materials.
While it is necessary to transfer sufficient velocity to the particles to ensure high coating density and bond strength, only enough thermal energy is absorbed by the powder particle to soften the metallic binder and ensure inner-particle adhesion upon impact. The result is a coating with lower residual stress, higher bond strength, reduced oxide content and very high density.