Time dependent ablation and liquid ejection processes during the laser drilling of metals

Numerical modeling and characterization of the laser–matter interaction during high-power continuous wave laser perforation of thin metal plates

“…While typical laser applications such as, for instance, cutting and welding are carried out with focus radii in the submillimeter range, [1][2][3][4][5] this work investigates laser effects in a different regime with significantly larger beam radii in the millimeter and centimeter range and at intensities between 0.1 and 100 kW/cm 2 . This parameter range is representative for applications where high-power lasers are used as an effector over long distances, as, e.g., in security research.…”

Modeling of keyhole dynamics and analysis of energy absorption efficiency based on Fresnel law during deep-penetration laser spot welding

“…Howere, the method is limited because the equipment is expensive and complex. Solana et al [6][7][8] modeled a mathematical model to calculate the keyhole geometry during the laser drilling of metals. Some researchers [9][10][11] adopted body heat source in the laser beam welding simulation, the power density distribution of keyhole didnot meet the fact.…”

The ejection angle of molten aluminum induced by millisecond pulsed laser

“…The mechanisms of the interaction between pulsed laser and metal target are different, when the parameters of pulsed laser or the thermal properties of material changes. For example, vaporization or sublimation [3] is the major mechanism when irradiated by nanosecond pulsed laser, while ejection [4] of molten liquid becomes the major mechanism when irradiated by millisecond pulsed laser. Yilbas et al [5] built a creep model of steel target on the boundary of phase change when the pulsed laser duration is 24 ns.…”

“…Based on the Fresnel principle of absorption in a real-time multiple reflection of keyhole model, Cho et al [10] calculated the shape of molten pool after the liquid flowed induced by millisecond pulsed laser. Solana et al [4] collected the liquid from ejection via a glass slide and concluded that molten liquid's momentum was obtained from vapor pressure in evaporation when the surface tension declined meantime. Collins et al [11] assumed the area of evaporation on metal target, then the temporal evolution of temperature on surface and the depth of molten pool were obtained by iterative computation numerically.…”