Laser-assisted cold spraying (LACS) attracts much interest as an advanced surface treatment technology combining cold spray technology with laser. However, the primary role of laser in LACS is inadequately explored. This study aims to investigate the impact of laser on in-flight particles through cleverly designed experiments and multi-physical field simulations, in which the in-flight iron and nickel particles were heated by the laser parallel to the substrates and deposited on the substrates, while the substrates were not heated by the laser. The cross-sectional microstructures, porosity, oxygen content and microhardness of the coatings were characterized to explore the effect of the laser on the in-flight particles. The heating behavior of the in-flight particles with different velocity and laser power were evaluated using multi-physical field simulations. The results indicated that the microstructures and properties of the coatings, including porosity, flattening ratios, oxygen content and microhardness, were not significantly affected by the laser irradiation. The simulations revealed that laser irradiation had negligible impact on the temperature variation of the in-flight particles, due to the short duration time of laser exposure. The investigation contributes to deeper understanding of the mechanism of LACS.

Cold spray, Laser, In-flight particles, Simulation, Heating