Research Progress in Metallic Coatings Prepared with the In - Situ Micro - Forging Assisted Cold Spraying

In - situ densification of the sprayed coating layer was realized by mixing large size shot peening particles into spray powder, which could improve not only the strength of the deposits but also the bonding strength of the deposited coatings with the substrate through the hammering effect of shot peening particles on deposited coatings. In this paper, recent development of the in - situ micro - forging assisted cold spraying technology was summarized. Firstly, the working principle of this technology was briefly introduced, and the influence of parameters such as shot peening volume fraction and particle size was discussed. Secondly, the evolution of the microstructure of the coating was discussed, including its effects on interparticle bonding quality, plastic deformation degree and subsequent heat treatment on the microstructure. Then, the mechanical properties and corrosion protection performance were summarized. Finally, some important issues which needed further investigations were pointed out.