Coating deposition and adhesion enhancements by laser surface texturing-metallic particles on different classes of substrates in cold spraying process

A nonsystematic study of metallic particle deposition behavior in kinetic spray process for three classes of substrate materials was performed (metallic, polymer, and ceramic). The particle-substrate contact time, temperature, and area upon impact were estimated for different topographies by numerical analysis. The results indicated that the deformation and the resultant bonding were dependent on the contact shape area. Laser surface texturing was used as a surface prior treatment to create specific topographies. The deposition efficiency and the adhesion strength were evaluated and compared with the numerical results. First, metal-metal couples investigated large adiabatic shear instability at the interface causing intimate adhesive bonds. It was maximized for cavities because the interface temperature and contact area were larger at the interface. Besides, the mechanical anchoring was more efficient with laser gripping zones. Then, metal deposition on polymer was a challenge. Particle embedded in the substrate only if the particle kinetic energy was sufficient to penetrate as far as its diameter. Cold spray process needed to be studied. However, concave shape indicated a larger deposition efficiency by minimizing bounces. Also, metallization of ceramic by cold spray demonstrated a problem due to a nondeformation of the substrate. So, particle compressive states were the key for mechanical anchoring, and it was provided by laser surface texturing. Finally, cold spray parameters and surface topography were dependant. A methodology was established with particle states and particle/substrate properties to adapt the surface topography to enhance deposition efficiency and adhesion. The window of deposition was larger for laser-treated surface. Laser surface texturing enabled an adapted surface structuration for many applications.