Nanosecond pulsed laser-generated stress effect inducing macro-micro-nano structures and surface topography evolution

Abstract

High-energy short-pulse lasers can induce significant shock waves, and they have been increasingly used in the field of material processing. The authors summarize the effects of pulsed laser-generated stresses on the surface topography of materials, introducing their related applications, and they highlight several unpredicted surface structures of different scales that were formed by laser shocks and reported in recent years. Laser-induced shock waves can lead to severe plastic deformation of material surfaces. The effects that the initial surface state of the material to be processed, the absorption layer, and the shape of the laser spot have on the plastic deformation of the surface are summarized in this paper. The reasons why lasers cause the formation of different sizes of pits on the surface of materials and the shape characteristics of the pits are both described in detail. Additionally, a series of special structures of smaller sizes reported in recent years, such as surface relief and craters, are introduced. This paper has important reference value and guiding significance for researchers to further explore the mechanism of high strain rate dynamic plastic deformation of materials treated by laser shock.