In this high velocity process with continuous combustion a mixture of fuel and oxygen is brought to combustion under high pressure, creating gas velocities of 1500 to 2000 m/sec. A spraying powder is injected into this mixture and transported at high speed to the workpiece.
H.V.O.F. stands for High Velocity Oxygen Fuel. This spraying process results in a microscopic weld layer between workpiece and spraying powder. The spray gun must be air or water-cooled.
Other than by continuous combustion, this process can also be brought about by explosive combustion. Here a mixture of oxygen and acetylene is ignited electrically at a determined frequency. The spraying powder is heated and accelerated in an explosion wave and accelerated to a speed of around 900 m/sec. During the explosion the temperature of the gas rises to about 3000°C. Paraffin oil can also be used as fuel.
Fields of application:
- Components susceptible to wear: abrasive, adhesive, erosion, fretting and cavitation effect
- Chemical resistance
- Protection from oxidation and galvanic corrosion
- Atmospheric and heat corrosion protection
- Thermal and electrical insulation