There are various types of thermal spray coating processes, each of which offers different key benefits, such as speed, cost, or density. We take a look at three of the most common types of thermal sprays: arc, thermal, and plasma.
Arc Spray
In arc spray, an electric arc is used as the heat source, with two conductive wires as the feedstock. The arc is formed between them, causing the ends to melt. Gas is then used, at high pressure, to atomise the melted metal and project it onto the surface being treated. The process is relatively low in cost and faster than other processes.
Flame Spray
This is one of the oldest types of thermal spray processes and is favoured for its versatility. In this method, a combustion flame is produced from a fuel gas, such as oxygenated propane, into which the feedstock, either wire or powder, is fed. The flame melts the feedstock, and compressed gas is used to propel the molten feedstock onto the surface.
Plasma Spray
This method uses a plasma jet to both melt and propel the feedstock. The plasma is created with gases such as argon or nitrogen and has extremely high temperatures. It’s often used for specialised coatings and creates a very dense surface. This type of thermal spray is available from specialist providers such as https://www.poeton.co.uk/surface-treatments/thermal-metal-sprays/.
If you’re not sure what thermal spray process is best for your needs, speak to a coating specialist who will be able to advise whether arc, flame, or plasma spray coating is the right choice.