Frequently Asked Questions
Flame spraying uses heat from combustion of a fuel gas (usually acetylene or propane) with oxygen to melt the coating material, which can be fed into the spraying gun as a powder, wire or rod. The consumable types give rise to the two process variants:
- Powder flame spraying
- Wire or rod flame spraying
In powder flame spraying, powder is fed directly into the flame by a stream of compressed air or inert gas (argon or nitrogen). Alternatively, in some basic systems, powder is drawn into the flame using a venturi effect, which is sustained by the gas flows. It is important that the powder is heated sufficiently as it passes through the flame. The carrier gas feeds powder into the centre of an annular combustion flame where it is heated and accelerated towards the substrate.
In wire (or rod) flame spraying, the wire feed rate and flame settings must be balanced to produce continuous melting of the wire to give a fine particulate spray. The annular compressed air flow atomises and accelerates the particles towards the substrate.
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