Thermal spray is a process which is used to restore or improve a solid surface. This industrial coating process is commonly used for applying coatings to mechanical parts and even medical implants. The technique involves applying a heated or melted coating of anywhere between 20 microns to several millimetres thick to resist corrosion, abrasion and heat, and can also be used to improve electroconductivity.
Processes
The choice of process depends largely on the materials that are needed, which in turn, depend on the results desired.
For example, High-Velocity Air Fuel (HVAF) thermal spray involves the combustion of propane in a stream of compressed air. It provides a uniform coating and is a great chrome plating alternative. It’s good for high-wear parts that require smooth surfaces and protects surfaces from cavitation and resistance to corrosion.
Flame spray uses either wire or powder materials. It melts them in the combustion stream and then sprays them onto the part.
Arc spray coating is a technique that involves heating and melting two metal wires of different types to create a tailored alloy coating. This is then sprayed with compressed air onto the surface, enhancing or repairing shafts, enhancing electroconductivity or creating non-slip coating solutions.
Thermal plasma spray, provided by specialists such as poeton.co.uk/advanced-treatments/apticote-800-thermal-plasma-spray/, combines flame and arc spray technologies. It can be used to apply ceramic coatings and is also good for use in high-temperature environments.
The spray and fuse coating process uses a slightly different technique. It sprays the powdered material onto the part and then follows up with an acetylene torch, melting the powder and bonding it to the surface.
Thermal spray and the environment
According to a report published on Springer Link, thermal spraying can be instrumental in reducing the carbon footprint of primary metal industries. Through the strengthening and repair of parts, it reduces their consumption of energy and raw materials.
In addition, by coating wind turbines to protect them against harsh environments, thermal plasma spray has been directly used in green energy production.
