WHAT IS COLDSPRAY?
Cold Spray (CS) is one of the technologies included in the thermal spraying family. Still, unlike the other methods, the energy for material build-up is the sprayed powder’s kinetic energy.
CS is one of the many names used to describe the process, categorised as a kinetic spraying process, which involves consolidating coating on the surface of a component by exposing the substrate to a stream of small particles (5÷50 µm) accelerated by a supersonic gas jet (300÷1200 m/s).
The coating-forming powder particles are introduced into the gas stream, accelerating them as they expand in the divergent part of a DeLaval-type nozzle. A characteristic feature of the CS process is that the temperature of the gas stream is much lower than the melting point of the coating material, hence the material is applied in a solid state. After leaving the nozzle and impacting the substrate, the solid particles undergo plastic deformation and form a combination of permanent metallurgical and mechanical bonding to the substrate.
