HVOF-spraying
In the HVOF (High Velocity Oxygen Fuel) process, powder is injected axially into a chamber, in which a gas flame is constantly burning under high pressure. The exhaust gas leaves the chamber through an expansion nozzle, as a consequence of which it generates a high velocity gas flow (600m/s). The powder particles are heated in this gas flow (3,000°C) and are moved by the kinetic energy to the surface of the work piece. This is how they form a dense coating with a very good adhesive strength.
Through the mild heat transfer to the powder particles and the work piece, there is no metallurgic change of both the sprayed material and the base material.
Advantages of HVOF
- High density
- Very good adhesion
Typical materials
- Wolfram carbide
- Cromium carbide