HVAF and HVOF have been merged into a single system HVAF/HVOF that offers the highest spray rates in the industry in either mode. The HVAF/HVOF system produces economically high-quality coatings with easy to use, reliable equipment. The HVAF system sprays tungsten carbide coatings, according to HVOF specifications, with a 5 times faster spray rate and at half the cost. Deposit coatings in compliance with SAE AMS 2447, 2448 or proprietary standards. HVAF/HVOF coatings will meet all existing HVOF specifications. Our Convertible HVAF/HVOF system can be used in an existing HVOF or plasma spray booth and sprays superior HVAF or HVOF coatings by choice.Hybrid Convertible HVAF-HVOF Thermal Spraying EquipmentOur Convertible HVAF / HVOF system can be used in an existing HVOF or plasma spray booth.HVAF/HVOF equipment includes:
- HVAF/HVOF Spray Torch
- Control console equipped with a PLC and an industrial mobile computer
- Powder feeder
- Gas vaporizer
- Optional grit feeder for HVAF grit blasting
HVAF – High-Velocity Air Fuel Process DescriptionHVAF is a process for the deposition of high-quality coatings of metals, alloys, cemented carbides and borides onto metallic surfaces. The coating material in the form of pre-alloyed or composite powder is fed into a HVAF thermal spray system. The torch combusts compressed air and fuel gas (propane, propylene, natural gas, etc.) generating a high-velocity jet of combustion products. Being heated and accelerated in the jet, the spray powder impacts a workpiece (substrate) to form a coating.The quality and efficiency of the systems family are due to the relatively low combustion temperature of the air-fuel mixture combined with the axial injection of the feedstock through the long combustion chamber where the low gas velocity provides sufficient time for the powder particles to gradually heat. The materials’ acceleration occurs in the nozzle that has a large diameter. The large diameter of the nozzle is needed to pass through the volume of nitrogen present in the combustion air. It also assures that the nozzle walls do not interact with the particles, allowing the use of a nozzle that is as long as is needed for feedstock acceleration, typically from 800 to over 1,000 m/s. The Ceramic Catalytic Insert is used in the combustion chamber to provide a wide range of stable combustion parameters.Precise temperature control of the spray material near the melting point and high impact velocities are the distinguishing characteristics of the HVAF coating deposition process.HVAF Coating QualityThe combustion temperature in air-fuel mixtures is typically 1,000°C lower than in oxygen-fuel combustion. This lower temperature is ideal for the gradual heating of the feedstock particles of metals and cemented carbides to or slightly above the metals’ melting temperature. The initial oxygen content in the combustion gas mixture is 5-fold lower in the HVAF process compared to any HVOF process. Both factors prevent the oxidation of metals and the decomposition of carbides and their dissolution into the metal binder. These factors allow the retention of the original ductility of the powder feedstock material in the applied coating, even when the hardness of the cemented carbide coating exceeds 1600 HV300.The HVAF and HVOF FamiliesThere are three families of HVAF and HVOF systems:
- Multi-purpose HVAF AK – versatile systems to spray metal, carbide and alloyed powders coatings all possible ways: outer and internal diameters, manual, on-site
- Convertible HVOF + HVAF – systems to spray superior HVAF or HVOF coatings by choice
- Specialized HVAF S – highly focused systems to spray particular metals in the most efficient way
Benefits:
- Industrial IP67-rated Tablet + PLC Controller
- Unlimited data logging – one system fits all torches
- Variety of powder feeders and gas vaporizers
- Custom-made systems and torches by request
Hybrid High-Velocity Thermal Spraying Equipment ChoiceOur Convertible HVAF / HVOF system can be used in an existing HVOF or plasma spray booth.
media/convertible-hvaf-hvof-thermal-spraying-equipment-med.jpg
(image address)
media/hvaf-configuration.jpg
(image address)
media/convertible-hvaf-hvof-thermal-spraying-equipment-lg.jpg
(image address)
Uses:High quality coatings of metallic alloys, cemented carbides and other composite powders
Pros:High Spray rates. Dense, low porosity coatings at minimum thickness with very low Ra roughness.
Used with: HVOF / HVAF Spray Guns
HVOF / HVAF Auxiliary Equipment
