Theoretical and experimental study of surface texturing with laser machining

To explore the forming process and mechanism of the surface texture of laser micropits, this paper presents the thermal model of laser machining based on the Neumann boundary conditions and an investigation on the effects of various parameters on the processing. The surface profile and quality of the formed micropits were analyzed using NanoFocus 3D equipment through a design of experiment (DOE). The results showed that more intense melting and splashing occurred with higher power density and narrower pulse widths. Moreover, the compressive stress is an important indicator of the damage effects, and the circumferential thermal stress is the primary factor influencing the diameter expansion. During the process of laser machining, not only did oxides such as CuO and ZnO generate, the energy distribution also tended to decrease gradually from region #1 to region #3 based on an energy dispersive spectrometer (EDS) analysis. The factors significantly affecting the surface quality of the micropit surface texture are the energy and pulse width. The relationship between taper angle and energy is appropriately linear. Research on the formation process and mechanism of the surface texture of laser micropits provides important guidance for precision machining.