Mechanical properties of cold sprayed titanium and nickel based coatings

Abstract

In the last 10 years, cold spray coating technology is finding large attention in the scientific world. Its main characteristics are safeness, innovation, versatility and high efficiency if compared with traditional similar technologies such as plasma spray, high velocity oxygen fuel, arc wire or powder flame [P. Cavaliere: ‘Cold Spray coating technology for metallic components repairing’, in ‘Through-life engineering services: motivation theory and practice’, (ed. L. Redding and R. Roy), 175-184, doi: 10.1007/978-3-319-12111-6_11; 2015, Springer International Publishing]. Very fine particles are accelerated and then sprayed on a substrate in a condition very far from material melting. The unique mechanical properties experienced by the sprayed material are due to the severe plastic deformation acting during particle impact. No limits are experienced by the material quantity sprayed on the substrate; in this way, bulk coatings capable of repairing and restoring can also be produced. The technology is applied in the aerospace, automobile and chemical industries. The results presented in the literature in the last years show cold spray appearing very promising in the production of nanostructured composites with enhanced microstructural and mechanical properties. In the present paper, the microstructural and mechanical behaviours of Ti and Ni based nanocomposite coatings produced via cold spray are presented. The results are analysed as a function of spray velocity, and they are compared to those belonging to pure base materials.