The article deals with tribological evaluation of DLC coating. This coating is deposited on a material which, due to its mechanical properties, is suitable for components of weapons and military equipment. The results of the Department of Engineering of the Faculty of Military Technology of the University of Defense in Brno in the field of plasma nitriding are used in this work. Plasma nitriding technology has been found to have a positive effect on the performance of components operating under extreme conditions. One of the significant surface changes is the increase in surface hardness. Further increases wear resistance and corrosion resistance. By setting the parameters of plasma nitriding technology appropriately, fatigue life can be increased.Deposition of the DLC coating by PVD technology on a tempered or plasma nitrided surface results in qualitative changes on the surface of the component. Evaluation of tribological properties such as coefficient of friction or wear coefficient can be verified by adjusting surface treatment technologies to specific applications, eg in armaments production.The paper presents the results of tribological properties of the surface of the DLC coating deposited on substrate of the heat-treated steel 42CrMo4. The comparison was done with the deposition of a DLC coating on the surface substrate of a steel 42CrMo4 that has been plasma nitrided, like a duplex system. Tribological properties such as friction coefficient and wear coefficient were measured by a Tribolab UMT-3 equipment. Tribological tests such as Scratch test and Ball on Disc were performed on this device.

Hard anodized layers were produced by two different manufacturers on the same type of aluminium alloy on a vacuum pump part of complex shape. The sulphuric acid/water solution was used to produce alumina layers, which were subsequently sealed in demineralized water. A comparative analysis based on metallographic methodology, with the aim to control the stability of alumina formation process and to identify its defects, was performed by means of light and scanning electron microscopy, surface profilometry and microhardness measurements. To determine the thickness of alumina layers, the image analysis was also used.

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Alkaline blackening is one of the most popular surface treatment technology of components with the requirement for higher surface corrosion resistance, increased hardness, and the decorative appearance.This contribution deals with the appearance of surface defects on carburized steel components after the process of alkaline blackening, which appeared to be red shiny stains on an otherwise black matte surface of the component. The occurrence of defects on surface was observed several days after the alkaline blackening process. By means of metallographic methods, direct connection between surface defects and the microstructure of the material was found.Contribution further deals with the influence of microstructure and technological parameters on the quality of the final surface layer of the components.