4. Thermal spray thick films

4.1 Principle

Thermal spraying consists in melting particles injected in solid form or formed from wires, strings or rods, the ends of which are melted and then atomized, before being crushed first onto the substrate, then onto the deposit under construction [2]. The particles are crushed in the form of lamellae, which solidify in a few microseconds or tens of microseconds, depending on their impact speed, which is largely determined by the process used, and whose stacking will form the deposit. The actual contact between solidified lamella and substrate or lamella and lamella varies according to the spraying conditions. Naturally, the higher the percentage of surfaces in contact, the better the thermomechanical properties of the deposits. It is also possible to spray partially melted...