The process is basically the spraying of molten metal onto a surface to provide a coating. Material in wire form is melted in a flame (Oxy-Acetylene flame most common) & atomised using compressed air to form a fine spray. When the spray contacts the prepared surface material, the fine molten dropletsw rapidly solidify forming a coating.
Characteristics of Wire Flame Spray
Material Form
Wire
Heat Source
Oxy-Fuel Combustion
Flame Temperature (°C)
3000
Gas Velocity (m/sec)
< 300
Porosity (%)
10 to 15
Coating Adhesion (MPa)
14 to 21
Advantages:
Simple to operate
Wire form cheaper than powder
Very high deposit efficiency
It has a portable system and can be used in areas without electricity
Possibly still best for applying pure Molybdenum coatings
Disadvantages:
Limited to spraying material supplied in wire or rod form
Coatings have higher porosity and lower bond strength
Not capable of spraying low oxide, high density & high strength coatings
