High Velocity Oxygen Fuel (HVOF) - High Velocity Acetylene Fuel (HVAF) is a process to apply very dense, strongly adhered coatings. A fuel (commonly kerosene or hydrogen) is mixed with oxygen and ignited in combustion chamber. The combustion gases are accelerated through a nozzle. Powder is introduced into the gas stream where it softens and gathers speed before coating onto the sprayed surface. HVOF/HVAF coatings are commonly used as a hard chrome replacement process and produce very dense, hard wearing coatings.
Heat Source: Fuel (liquid or gas) and oxygen flame
Material: Powder (metal)
Transfer: Via the flame
Process: The fuel is mixed with oxygen and ignited. The combustion gases pass through a converging/diverging nozzle and accelerate to around 1,500m/sec. The powder is injected into the accelerated flame where it softens and gathers speed. The high impact speed of the particles produces a highly adherent, dense coating structure.