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Coating with Plasma Spray Gun

Coating with Plasma Spray Gun

Date posted: March 14, 2016 // Coating

Coating is a common industrial process that may be undertaken for a wide variety of reasons. Its purpose, for instance, may be to render surfaces more resistant to wear, to limit the risk of corrosion, to provide shielding from electromagnetic and radio frequency interference, for use as a dielectric coating on semi-conductors, or perhaps simply to provide a barrier against heat transfer. As the means to apply these surface treatments, the plasma spray gun is widely regarded as the most versatile option currently available and may be use on any material that is considered to be sprayable.

The principle utilised by these devices involves the production of an arc between a pair of electrodes that are surrounded by a gas mixture that, at sufficiently high temperatures, is able to generate plasma. Most commonly, the mixture used will be argon with hydrogen or argon with helium. The arc may reach a temperature of around 20 000°C and, as it continues to get hotter, the plasma expands rapidly and is then accelerated via a shaped nozzle to speeds of up to twice that of sound. The powdered coating is introduced through a separate inlet and mixes with the outgoing stream from the plasma spray gun, thus bonding it with heat and pressure to the surface to be treated.

The surfacing materials in common use vary quite widely, as do the applications in which this type of treatment is now employed. Typical spray materials range from polymers with relatively low melting points such as nylon, to refractory metals such as tungsten and tantalum, and ceramic oxides, all of which have very high melting points. Because of the versatility of this technique, it has been adopted by a wide range of industries. Typically, various forms of coating are to be found on electronic components, on automotive and aircraft parts, on farm implements and on a great many of the items that we make use of on a daily basis.

Among the more crucial uses for the plasma spray gun is the treatment of the components of jet engines. Here, a mix of yttrium and zirconium provide the essential protection against the extremely high temperatures that are generated by the burning jet fuel and exhaust gasses. Other cases in which these surface treatments are vital include the screening of medical diagnostic equipment that might otherwise be affected by background interference.

The importance of coating technology in the modern world is well established, so the need for a reliable source of the necessary equipment is a given. In South Africa, Labotec Industrial Technologies is equally well-established both as a supplier of the equipment and consumable used in various coating processes, and as among the best at what we do. We are able to provide high-quality nozzles and electrodes, as well as molybdenum wire for use in your plasma spray gun assembly. In addition, we carry an extensive range of coating solutions, including tungsten, tantalum, niobium, titanium and ceramics for use in Physical Vapour Deposition (PVD) procedures.

If you have an application for one or more of these specialised surface treatments, and want to be sure of the most efficient and cost-effective solution, then be sure to give us a call at LIT Africa.