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This paper investigates the impact of laser infrared radiation on the surface modification of DLC coatings. The authors found that the texture created on the surface of the coating resulted in improved surface properties (smaller coefficient of friction). They also observed that certain laser fluency, waveform, frequency, and laser head scanning speed led to creating a relevant depth of the groove without completely removing a thin coating (about 4 µm) coating. The texture applied to the surface can be beneficial under certain conditions, for example, when coated parts work under lubricated conditions. The textured surface shows a microreservoir effect in which the debris particles accumulate to some extent in the created grooves. The study provides insight into the potential use of laser surface modification as a method for improving the properties of DLC coatings, which are widely used in various industrial applications. Research is relevant to scientists and engineers working in the fields of materials science, surface engineering, and industrial manufacturing. [ABSTRACT FROM AUTHOR]

This paper discusses the effect of selected parameters of laser welding on the mechanical properties of welds. Two parameters were analysed: the welding speed and the laser power. The properties of the material in the fusion zone and the heat affected zone were determined by performing static tensile tests, hardness tests and microscopic analysis. The welding was carried out using a TRUMPF Lasercell 1005 CO2 laser (wavelength λ=10.6 µm). The specimens were 0.8 mm in thickness and they were made of DC04 steel. The static tensile tests were conducted by means of a LabTest 5.20SP1 universal testing machine designed to determine the tensile and compressive strengths. The material hardness was measured with a NEXUS 4304 Vickers hardness tester. The microscopic analysis was performed with a Joel JSM-5400 scanning electron microscope. The results indicate that welds produced at different welding parameters have similar mechanical properties. [ABSTRACT FROM AUTHOR]

The aim of the study was to determine the influence of the laser processing on the properties of electro-spark coatings. The properties were assessed by analyzing the coating microstructure, X-ray radiation, microhardness, corrosion resistance, porosity and tribological tests. In addition, the paper presents the results of measurements and analysis of electrical pulse during ESD. The tests were carried out on WC-Cu coating (the anode) obtained by electro spark deposition over carbon steel C45 (the cathode) and molten with a laser beam. The coatings were deposited by means of the EIL-8A and they were laser treated with the Nd:YAG. The tests show that the laser-treated electro-spark deposited WC-Cu coatings are characterized by lower hardness and friction force, higher seizure resistance, roughness. The laser treatment process causes the homogenization of the chemical composition, the structure refinement and the healing of microcracks and pores of the electro-spark deposited coatings. Laser treated electro-spark deposited coatings are likely to be applied in sliding friction pairs and as protective coatings. [ABSTRACT FROM AUTHOR]