Nanosecond pulsed laser shock processing (LSP) techniques, including laser shock peening, laser peen forming, and laser shock imprinting, have been employed for widespread industrial applications. In these processes, the main beneficial characteristic is the laser-induced shockwave with a high pressure (in the order of GPa), which leads to the plastic deformation with an ultrahigh strain rate (10⁵–10⁶/s) on the surface of target materials. Although LSP processes have been extensively studied by experiments, few efforts have been put on elucidating underlying process mechanisms through developing a physics-based process model. In particular, development of a first-principles model is critical for process optimization and novel process design. This work aims at introducing such a theoretical model for a fundamental understanding of process mechanisms in LSP. Emphasis is placed on the laser-matter interaction and plasma dynamics. This model is found to offer capabilities in predicting key parameters including electron and ion temperatures, plasma state variables (temperature, density, and pressure), and the propagation of the laser shockwave. The modeling results were validated by experimental data.

Laser shock peening (LSP) is one of the widely used surface processing technique for tailoring functional behavior of the surfaces. The LSP has been shown to provide enhanced friction, wear, and mechanical properties. However, understanding of LSP treated surfaces involving tribological contacts in electrochemically active environments is limited because the mechanism of wear-corrosion interactions (tribocorrosion) for such surfaces is still unclear. In the present study, the effect of LSP surface processing on wear-corrosion behavior of AZ31B Mg alloy was investigated. A zero resistance ammeter (ZRA) method has been utilized to examine the evolution of open circuit potential during wear-corrosion analysis. The study finds that the LSP processing can decrease the corrosion potential difference between worn and unworn regions of the surface, thereby mitigating the effect of wear-accelerated corrosion during sliding. The effect of wear-accelerated corrosion was evident from the change in average surface roughness (S_a) of the unworn areas. It was found that understanding the change in surface roughness due to wear-corrosion is necessary to investigate the onset and propagation of galvanic corrosion. Based on these results, the study details the mechanism of wear-corrosion interactions during sliding.