Cold spraying: From process fundamentals towards advanced applications

• Review of the scientific and technological progress in cold spray is performed.
• The phenomenon of surface activation by abrasive particle is discussed.
• Particularities of spray nozzle design are discussed.
• Cold spray has a significant potential for deposition of composite coatings.

Cold spraying (CS) is a relatively new material deposition technique based on the phenomenon of high-velocity particle/substrate impact. In this process, the powder is accelerated to supersonic speed in specially developed supersonic nozzles in which air, nitrogen or helium is usually employed as a powder carrier gas. In the absence of melting, oxidation and thermal decomposition of a particle in-flight during CS, the deposited coatings demonstrate low residual stresses and preserve the initial phase composition of the source material, which are important advantages for spraying temperature sensitive powders including nanostructures and nanocomposites. In the present paper the review in the field of development of cold spray technology is performed. Different scientific and technological aspects of CS such as surface activation, nozzle geometry, powder preheating, powder injection, control of spatial resolution of particle flux and proper selection of spraying parameters are discussed.