Basic Principles of Operations

Typical Coating Properties

The HVOF unit uses an oxygen-fuel mixture consisting of propylene, propane, or hydrogen, depending on users coating requirements to produce the highest quality coating available today. Fuel gases are mixed in a proprietary siphon system in the front portion of the HVOF gun. The thoroughly mixed gases are ejected from the nozzle and ignited externally to the gun. Ignited gases form a circular flame configuration which surrounds the powdered material as it flow through the gun. Combustion temperature is between 5000F to 6000F depending on fuel. The circular flame shapes the powder stream to provide uniform heating, melting, and acceleration (See Diagram). Pre-selected oxygen, fuel and air values are specified for each material to optimize dwell time in the flame.

The key success of HVOF is the extremely High Kinetic Energy that is being produced and transferred between the HVOF unit and the substrate using space-age rocket propulsion technology. Typical velocities approach 5000 fps to over 7200 fps depending on which hardware is selected.With both thermal and kinetic energy, the high velocity particles are practically embedded into the substrate to form a superior coating with the following characteristics:

High Density The coatings produced though HVOF develop very high densities because of the high kinetic energy associated with this process.

High Bond Strengths (in excess of 12,000 psi)

Zero Porosity ( with no interconnecting porosity )

Metal Working Capabilities

Essentially Stress Free

Greater Hardness

Greater Thickness

Low Thermal Input ( substrate temperature less than 300 degrees F which insures original mechanical properties and with No Stress Relieving Required)

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