Research on the forming and strengthening mechanism and performance thermal stability of microstructures induced by laser shock imprinting

•Dislocation configuration and grain change and strengthening mechanism caused by LSI.•High temperature stability of the microstructure produced by LSI.•The influence of target thickness on microstructure and forming mechanism.•The microstructure produced by LSI can be used as a hot imprinting mold. Laser shock processing can induce a large number of dislocations in metal crystals by producing ultra-high strain rate deformations. This study investigated the mechanism and process of dislocation strengthening and the various dislocation configurations that play strengthening roles. The materials in this experiment were heat-treated in accord with the annealing strengthening mechanism, and the surface morphology, hardness, surface roughness, and corrosion resistance of the formed microstructure were measured and characterized, the amount of change were within 10%, which proved that the mechanical and physical properties were not degraded. Considering the possibility of using laser shock imprinting (LSI) manufacturing for actual production, the target parameters in the experiment were optimized, and it was found that with an appropriate molding depth ratio, the microstructure could be fully formed without deformation of the back surface. This discovery allowed the formed microstructure to withstand a greater axial load. Then, the changes and stress conditions in the target material during the forming process for targets with different thicknesses were explored. Finally, the prepared microstructures were used in hot embossing experiments, and the microstructures were perfectly transferred to the polymer surface, proving that the microstructures prepared by LSI have the potential to work under high-temperature and high-pressure scenarios.