What Does Metal Spraying Mean?
Metal spraying is a process for covering a surface with a metallic coating using a spray of molten particles. Numerous variations of the technique exist, including:
- Flame spraying
- Wire arc spraying
- Plasma spraying
- Detonation spraying
- High velocity oxy-fuel coating spraying (HVOF)
- High velocity air fuel (HVAF)
- Warm spraying
- Cold spraying
These processes can also be labeled with a more general term, thermal spraying. However, the general term includes coatings created with not just metallic materials, but also oxides and ceramics.
Metal spraying works by first subjecting the source material to a high degree of heat to achieve a molten state. The molten material is then atomized into small particles and sprayed outwards onto a surface. The molten particles do not heat the surface because the heat of a particle is proportional to its size. On contact, the particle flattens out and adheres to the surface as it hardens.
Most applications of metal spraying are found in the anti-corrosion and engineering markets. Coatings are used in these industries to add finishing coatings, anti-corrosion layers and thermal barriers, and to add wear resistance. Both flame spraying and arc spraying techniques are used to add these protective coatings.