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Laser surface texturing (LST) is one of the methods for obtaining surfaces with specific properties. In this paper the influence of initial surface state of sliding bearing steel on laser texturing of this material was studied. Initial surface with roughness = 0.13 µm was used for providing shifted laser surface texturing (sLST) by ultrashort laser pulses. On initial “rough” surface laser formation of above-surface-growth (ASG) structures was found. Morphology and chemical composition of the ASG structures were analysed by SEM with EDX spectrometer in comparison with initial surface. Two ways of regression of ASG structures were investigated - fine mechanical repolishing of surface for = 0.01 µm and optimisation of laser processing parameters. It was found that the most suitable method of ASG structures regression is optimisation of laser processing parameters in comparison with mechanical repolishing. Regression of ASG structures formation by optimisation of laser processing parameters was provided by application higher laser fluence. Temperature field distribution for different laser processing parameters is determined from semi-planar thermal model. Heat accumulation effect is evaluated for both - sLST by simple pulses and burst mode. Advantages and disadvantages of presented methods for regression of ASG structures formation were discussed with theoretical background. Presented results improve understanding of physical principles of ASG structures formation and the ways for their regression.
Keywords: Shifted laser surface texturing, optimisation, above-surface-growth, semi-planar model, heat accumulation© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.