Whatever it is plasma spraying, (conventional or HVOF) flame spraying or electric arc spraying, in all the cases the principle is the same, only temperatures and velocities of powder particles differs.
Flame spraying is well suitable for manufacturing low melting temperature materials (polymers and certain metals), electric arc spraying is use for manufacturing coatings with electrical conductive materials, and plasma spraying is well suitable for spraying refractory materials like oxides.
The thermal spraying process happen according the following steps:
> The selected material designed as to be the coating is injected in the melting source (flame, plasma or electric arc) under the form of powder or wire,
> The material is thus melted under the form of fine droplets which are propelled with the stream of the melting source to impact with a high velocity onto the substrate to be coated,
> Particles cool down very quickly by giving their calories to the previous deposited layers,
> Bond coat with the substrate is high if it has been properly prepared