Flame spraying, flame spraying process, flame spray coating, Flame spraying guns for thermal spraying, Gujarat, India

Flame Spraying

Process :

Flame spraying is a thermal spraying process that uses an oxy-fuel gas flame as a source of heat for melting the coating material. Compressed air is usually used for atomizing and propelling the material to the work piece. There are two variations: one uses metal in wire form and the other uses materials in powder form. The method of flame spraying which uses powder is sometimes known as powder flame spraying. The method of flame spraying using wire is known as metalizing or wire flame spraying.

In both versions, the material is fed through a gun and nozzle and melted in the oxygen fuel gas flame. Atomizing, if required, is done by an air jet which propels the atomized particles to the work piece. When wire is used for surfacing material, it is fed into the nozzle by an air-driven wire feeder and is melted in the gas flame. When powdered materials are used, they may be fed by gravity from a hopper which is a part of the gun. In another system, the powders are picked up by the oxygen fuel gas mixture, carried through the gun where they are melted, and propelled to the surface of the work piece by the flame.

Figure shows the flame spray process using wire. The version that uses wires can spray metals that can be prepared in a wire form. The variation that uses powder has the ability to feed various materials. These include normal metal alloys, oxidation-resistant metals and alloys, and ceramics. It provides sprayed surfaces of many different characteristics.

Flame Spraying
Figure : Schematic view of Flame Spray process gun.