Modelling periodic structure formation on 100Cr6 steel after irradiation with femtosecond-pulsed laser beams

TL;DR

This study models the formation of periodic surface structures on 100Cr6 steel after femtosecond laser irradiation, combining theoretical simulations with experimental validation to understand the underlying physical mechanisms.

Contribution

It introduces a comprehensive theoretical model that predicts the formation of laser-induced periodic structures on steel surfaces, integrating electron excitation, heat transfer, and hydrodynamics.

Findings

Simulations match experimental periodicity measurements.

Laser wavelength influences the structure periodicity.

Sequential formation of sub-wavelength and supra-wavelength features.

Abstract

We investigate the periodic structure formation upon intense femtosecond pulsed irradiation of chrome steel (100Cr6) for linearly polarised laser beams. The underlying physical mechanism of the laser induced periodic structures is explored, their spatial frequency is calculated and theoretical results are compared with experimental observations. The proposed theoretical model comprises estimations of electron excitation, heat transfer, relaxation processes, and hydrodynamics-related mass transport. Simulations describe the sequential formation of sub-wavelength ripples and supra-wavelength grooves. In addition, the influence of the laser wavelength on the periodicity of the structures is discussed. The proposed theoretical investigation offers a systematic methodology towards laser processing of steel surfaces with important applications.