Effect of Powder Type and Composition on Structure and Mechanical Properties of Cu + Al2O3 Coatings Prepared by using Low-Pressure Cold Spray Process

Powder type and composition have a very important role in the production of metallic and metallic-ceramic coatings by using the low-pressure cold spray process. Furthermore, structure and mechanical properties of Cu and Cu + Al2O3 coatings are strongly influenced by powder characteristics of Cu particles. The aim of this study was to evaluate the effect of different particle types of Cu powder and different compositions of added Al2O3 particles on the microstructure, fracture behavior, denseness, and mechanical properties, i.e., hardness and bond strength. Spherical and dendritic Cu particles were tested together with 0, 10, 30, and 50 vol.% Al2O3 additions. Coating denseness and particle deformation level increased with the hard particle addition. Furthermore, hardness and bond strength increased with increasing Al2O3 fractions. In the comparison between different powder types, spherical Cu particles led to the denser and less oxide-contenting coating structure due to the highly deformed particles.