Laser surface texturing optimization for metallic repair coating deposited by cold spraying

Particle impact behavior on raw and textured substrates in kinetic spray process was studied by numerical modeling and experimental approaches. Textured surfaces were produced by ns-laser surface texturing. Topography played a key role for window of deposition and adhesion bond strength through kinetic spraying. Structured surfaces increased deposition efficiency and adhesion bond strength. A finite element analysis hence were made to evaluate the residual stresses and strains relative to particle size and speed for different impacted shape to optimize surface topography for cold spraying. Concave shape exhibited significant interface temperature rates and particle-substrate strains compared to raw or rough surfaces. Particle-substrate contact-time, contact temperature and contact area upon impact were estimated and adhesion-rebound energy were evaluated to obtain window of deposition. Particle compressive states promoted direct embedment and anchoring mechanisms in cavities. However, no-adapted morphology can form near-interface defaults. The proposed window of deposition was correlated with deposition efficiency for the first pass of cold spraying. Thus, laser surface texturing appeared to be optimized for the initial deposition efficiency and adhesion bond strength depending on materials.