Which method is NOT a type of thermal spray application?

Dip coating is not considered a type of thermal spray application because it involves a fundamentally different process. In dip coating, a substrate is submerged in a liquid coating material, which then adheres to the surface as it is withdrawn. This method relies on the physical properties of the liquid and often involves a curing phase to achieve the final coating characteristics.

In contrast, thermal spray applications, such as flame spraying, plasma spraying, and arc spraying, involve melting a feed material and projecting it onto a substrate at high velocities. These methods utilize heat to transform solid materials into a molten or semi-molten state and rely on kinetic energy to deposit the coating onto the surface, forming a solid layer as it cools. Each of these thermal spray techniques has specific applications and advantages in surface enhancement, restoration, or protection against corrosion and wear, which differ significantly from the dip coating process.