— Electro-spark deposition (ESD) has been already recognized as an economically effective surface coating method. It requires a simple and low-cost equipment to run a process. Furthermore,...

Laser-induced periodic surface structures (LIPSS) enable advanced surface functionalization with broad applications in various fields such as micro- and nanoelectronics, medicine, microbiology, tribology, anti-icing systems, and more. This study demonstrates the possibility of achieving anisotropy in the tribological behavior of C45-grade steel structured by nanosecond laser radiation using the LIPSS method. The lateral surface of the steel roller was irradiated with a pulsed Nd:YAG laser at an optimum intensity I = 870 MW/cm² for the formation of LIPSS. Two sets of samples were formed with LIPSS that were perpendicular and parallel to the roller’s rotational motion direction. The Raman intensity maps revealed that the LIPSS structure consisted of periodically arranged oxides at the top of hills. At the same time, the valleys of the LIPSS structures were almost not oxidized. These results correlated well with scanning electron microscopy energy dispersive X-ray spectroscopy mapping and atomic force microscopy measurements. A comparison of Raman and X-ray photoelectron spectroscopy spectra revealed that both the magnetite phase and traces of the hematite phase were present on the surface of the samples. Tribological tests were performed in two cycles with periodic changes in the normal clamping force and sliding speed. It was found that the LIPSS structures which were formed perpendicularly to the sliding direction on the roller had a significantly greater impact on the friction processes. Structures oriented perpendicular to the direction of motion had a positive influence on reducing the energy consumption of a friction process as well as increasing the wear resistance compared to LIPSS formed parallel to the direction of motion or ones having a non-texturized surface. Laser texturing to produce LIPSS perpendicular to the direction of motion could be recommended for friction pairs operating under low-load conditions.

This work presents the results of tribological tests of Mo and combined coatings TiAlC formed using electrospark alloying (ESA) technology and additionally processed using thermochemical electrolyte anodic heating (TEAH). ESA makes it possible to form 15–20 µm thick coatings on the friction surface, characterized by a high hardness and wear resistance. Tribological studies were performed by testing the block-on-roll friction pair under 300 N and 600 N loads. The duration of the tests was 180 km of friction path, and the constant rotation rate of the disk was 600 rpm. It was observed that the friction torque during the 300 N loading tests was stable for all samples and throughout the entire testing period, whereas at 600 N loading, the pair with the Mo coating had a decreasing trend, and the pair with the TiAlC coating, friction torque slightly increased. For a reference sample without the coating trend of friction torque became drastically unstable. At both loads (300 N and 600 N), the friction pair with the reference sample had the highest cumulative wear, and the pair with the Mo coating had the lowest. At both loads, the cumulative wear of the friction pair with Mo coating is about 2 times lower than the TiAlC, and ≥1.8 times lower than the control (not coated) version. This study shows that at lower loads, the friction pair formed by the TiAlC coating and steel C45 is more matched than the friction pair with Mo coating.