Influence of the interaction between nanoparticles and high brilliant laser radiation during μs-pulses on the ablation process of metals

Abstract

A characteristic of the laser ablation process of metals with high brilliant radiation is a significant formation of nanoparticles within the vapour plume. Due to the interaction between the incoming radiation and the particles, the intensity is attenuated at the workpiece. This leads to a decrease of the ablation rate and the related ablation velocity. In order to verify the influence of the interaction between nanoparticles and high brilliant radiation on the ablation process, experimental and theoretical results of the laser ablation process of stainless steel with a single mode fiber laser are presented. For an ablation process with an intensity of 1.9×108W/cm², it is shown that the average particle size is 9nm. Within a further time-dependent analysis of the correlation between particle formation and ablation velocity, the beam of a test laser is directed through the vapour plume and the angle-dependent scattered radiation is detected. The results point out that a decrease of the ablation velocity corresponds with an increasing of the particle density within the ablation plume.