Ultrashort single-pulse laser ablation of stainless steel, aluminium, copper and its dependence on the pulse duration

Abstract

In this work, we investigate single-pulse laser ablation of bulk stainless steel (AISI304), aluminium (Al) and copper (Cu) and its dependence on the pulse duration. We measured the reflectivity, ablation thresholds and volumes under the variation of pulse duration and fluence. The known drop of efficiency with increasing pulse duration is confirmed for single-pulse ablation in all three metals. We attribute the efficiency drop to a weakened photomechanically driven ablation process and a stronger contribution of photothermal phase explosion. The highest energetic efficiency and precision is achieved for pulse durations below the mechanical expansion time of 3-5 ps, where the stress confinement condition is fulfilled.

Investigation of Ablation Efficiency of Stainless Steel Using Pulsed Lasers in Burst Mode

“…[ 12 ] In this approach, the ablation threshold can be calculated out of the crater diameter that is produced from single‐pulse experiments when the laser spot has a Gaussian spatial distribution. [ 13 ] This value is a good indicator on how much energy is needed for ablating the respective material and can be partially correlated to optical abortion as well as heat diffusion. [ 14 ] Thus, these experiments attain to determine correlations between the ablation threshold with the thermal properties of the investigated materials as well as the pulse duration.…”

Research on the mechanism of particle deposit effects and process optimization of nanosecond pulsed laser truing and dressing of materials

“…The removal threshold I th of laser power density of bronze bond was calculated, and the approximate range of laser power density I p can be determined preliminarily. The threshold I th for laser power density removal of bronze bond can be determined by formula calculation, as shown below : [25][26][27][28]…”

High-quality percussion drilling with ultrashort laser pulses

“…The material-specific and laser-specific parameters used for the calculation are listed in Table 1. According to [18], the ablation threshold Φ th corresponds to the single-pulse ablation threshold of iron [29] and AISI 304 [30], so that Φ abs,th = A • Φ th = 0.128 J/cm 2 . The effective penetration was set to a value of 35 nm [31].…”

“…Material-specific parameters for iron and laser-specific parameters used for the model calculation a[35], b[29,30], c[31] …”