Wire Flame Spray Gun is a thermal spraying process that uses an oxy-fuel gas flame as a source of heat for melting the coating substance. Compressed gas is sometimes used for atomizing and propelling the material to the workpiece. After melting the melted metals are then atomized with compressed air to create a spray stream that applies the coating on the surface being sprayed. A Wire flame Spray gun is a uses for spraying both iron & non-iron material. Major applications are restoring worn-out components, conductivity, and anti-corrosion coating.
The wire is fed into the front torch of flame spray through the air-driven turbine. Fuel gas like acetylene, LPG, Propane & oxygen is properly and safely mix in the siphon plug head assembly which provides a combustible heat source.
The spraying material in the wire form is fed continuously into a fuel gas-oxygen flame where it is melted by the heat of that combustion. And, Compressed air surrounds the flame and atomizes the molten tip of the wire. This speeds up the spray of molten particles towards the prepared work-piece surface. Wire flame spray is the flame best process coating. It allows for the application of aluminum, zinc, and zinc/aluminum alloy coatings using the flame spraying method.
A schematic of a typical flame spray system depicts a typical Powder flame spray gun. The wire flame spray gun consists of a drive unit with a motor and drives rollers for feeding the wire and a gas head with valves, gas nozzle, and air cap that control air of the flame and atomization. Comparison with arc spraying, wire flame spraying is slower and more costly because of the high cost of the oxygen-fuel gas mixture compared with the cost of electricity. Flame spray systems are field-portable and it may be used to apply the quality type of coatings for corrosion protection.
Process Advantages:
- Low capital investment
- Simple to operate
- Wire form cheaper than powder
- Deposit efficiency very high
- Probably still best for implementing pure molybdenum coatings for wear resistance.
- The preheating facility built-in, unlike arc spraying
- Possible to use the system in areas without electricity supply.
Process Disadvantages:
- Limited to spraying materials supplied in wire or rod form.
- Not capable of the low oxide, high density, and high strength coatings of plasma and HVOF.
