High-Velocity Oxy-Fuel Coating Technique

The principles of High-Velocity Oxy-Fuel Coating (HVOF): A mixture of gaseous or liquid fuel and oxygen is fed into a combustion chamber, where they are ignited and combusted continuously. The resultant hot gas at a pressure close to 1 MPa emanates through a converging–diverging nozzle and travels through a straight section. The jet velocity at the exit of the barrel (1500~2000  m/s) exceeds the speed of sound. The stream of hot gas and powder is directed towards the surface to be coated. The powder partially melts in the stream, and deposits upon the substrate.

• The resulting coating has low porosity (<1%, <0.5% for special coating)
• Higher bonding strength
• Ideal hardness
• Coating surface has better resistance to impact
• Larger thickness of coating than plasma or chemical plating
• Improves the fatigue life of the coated parts
• Exceptional resistance to wear and corrosion
• Better surface finish