Microstructuring of steel surfaces via cold spraying with 316L particles for studying the particle-wall collision behavior

The surface morphology can have a significant influence on the contact behavior during particle collisions with surfaces. This work focuses on the design of surfaces to study the dynamic interactions between particles and component surfaces. Within this study two different methods with particle-substrate collisions were used. A cold spray method utilised for surface coating was adapted to generate different nub structures by applying single spherical stainless steel particles (316L) in the size range of 1-8 mu m on stainless steel substrates (316Ti). Euler-Lagrange Computational Fluid Dynamics simulations of the spray process were performed to obtain impact velocities and temperatures of the particles. In cold spray experiments, different nub concentrations on the surface were generated by varying the spraying time. Measurements with Scanning Force Microscopy show a significant increase of the roughness with increasing spraying time. Collisions of polystyrene particles on the produced surfaces were observed by two high-speed cameras. A strong effect of the surface roughness on the coefficient of restitution during the particle collisions were obtained. These results can be used to create surfaces with a certain energy dissipation in future studies.