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Dr. Dmitri Kopeliovich
Thermal spraying is a method of deposition of a metal atomized at high temperature and delivered to the substrate surface in a high velocity gas stream.
There are following thermal spraying methods:
Flame spraying involves a combustion heat of the mixture of a fuel gas (propane or acetylene) with Oxygen.
The coating material in form either powder or wire is fed to the spraying gun where it is melted, atomized by the compressed air and ejected to the substrate.
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Arc spraying method utilizes a heat of a DC arc struck between two consumable wires made of the coating material.
The wires melt in the arc region and the molten material is atomized and accelerated by compressed air.
Metals, alloys, metal matrix composites and cermets may be deposited by this high productive method.
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Plasma spraying uses a DC arc struck between two non-consumable electrodes for ionization of an inert gas delivered to the arc region.
Ionized gas (plasma) heats, melts and accelerates the coating material fed to the plasma torch in form of powder.
Ceramic and refractory metals coating of high quality are manufactured by the plasma spraying method.
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High Velocity Oxyfuel Spraying (HVOS) is similar to the flame spraying method, but differs from it by using high pressure fuel gas and oxygen, burning of which produces a flame of supersonic velocity.
Refractory metals and ceramic coatings are produced by high velocity oxyfuel spraying method.
Thermal spraying methods are extensively used for applying corrosion and wear resistant coatings in automotive and aerospace industries, power generation equipment and electronic industry.
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