HVOF

The high-velocity flame spraying (HVOF, derived from High-Velocity Oxygen Fuel) is a thermal coating process for surface treatment.

Principle:

In the high-velocity flame spraying a continuous fuel combustion under high pressure within a water-or air-cooled combustion chamber. As fuels are fuel gases (such as propane, ethylene, propylene, butane, acetylene, hydrogen, liquid fuels (e.g. diesel, kerosene), and used combinations of these. The oxidant is usually oxygen but also air. The high pressure generated in the combustion chamber of the burning fuel-oxygen mixture and the downstream expansion nozzle generates the necessary high speed of the gas jet.

Most powdery (but also as rods and wires) spray materials (particle size 1-150 microns) are axially or radially fed into the combustion chamber in the area of the expansion. Thus the spray particles are accelerated to high speeds, which lead to very dense spray coatings with excellent adhesion properties.

By the controllable heat input energy to the spray material during the spray process, the spray material will be changed metallurgically just slightly.

Applications:          Power plants, aerospace, automotive, paper and engineering industries.