High-Velocity Oxygen Fuel

The Hypersonic HVOF works by mixing fuel and oxygen, which is fed into a combustion chamber and ignited in a controlled manner. The resulting gas has extremely high temperature and pressure (up to 3,000°C) , which is ejected through a nozzle at supersonic speeds.

The powder is then injected into a specific position in the high-velocity gas flow, and partially melts, forming the so-called “melt” (agglomeration of melted or semi-melted particles). The hot gas stream and semi-molten powder are then directed against the surface to be coated. The resulting dense coating has low porosity (<1%), high adhesion (>10,000psi) and low amounts of oxides, providing many benefits such as corrosion and wear resistance. Layers up to 300 µm thick are usually applied.

This process is the only one that produces layers based on carbides and borides. In the case of extremely hard layers, metallic compounds and aggregates are formed by alloying metals such as nickel, cobalt and nickel-chromium alloys.