Analysis of Parameters of Laser-Induced Periodic Microstructures (LIPSS) on the Surface of Stainless Steel Using Autocorrelation Functions

Abstract

In modern mechanical engineering, the control of surface quality of components, which directly affects their operational characteristics, is becoming increasingly important. One of the key aspects is the analysis of surface microstructure, particularly its periodicity, as it determines properties such as wear resistance and corrosion resistance. Laser processing is one of the promising technologies that allows the formation of regular microstructures, such as LIPSS (Laser-Induced Periodic Surface Structures). Despite extensive research, the mechanism of LIPSS formation remains not fully understood, and the results often show variable periodicity and orientation. To accurately analyze these structures, mathematical and statistical methods, such as two-dimensional autocorrelation analysis (ACF) and fast Fourier transform (FFT), are required. This study proposes a methodology for evaluating the periodicity of microstructures obtained during laser treatment of metallic samples, using digital video microscopy. The application of two-dimensional autocorrelation and spectral analysis within the Gwyddion environment ensures reproducible and objective assessment of microstructures, while demonstrating the effectiveness of ACF for surface topography analysis. The obtained data show the presence of pronounced periodicity in the studied microstructure and confirm the complexity of the LIPSS formation mechanisms, contributing to accurate quantitative analysis and adaptive control of laser modification processes.