Titanium carbonitride coatings are widely used to improve the wear resistance of surfaces. The results of tribological investigations of TiC, TiN, and TiCN coatings deposited on an AISI 304 steel substrate by the magnetron sputtering method were presented. The research aimed to describe the wear processes of the coatings during friction in an emergency situation, i.e. with a lack of lubrication and concentration of pressure in a small contact area. Tribological tests were performed on a ball-on-disk tribotester in reciprocating motion under technically dry friction conditions. The Hertz pressure in the contact area was ph = 2500-2700 MPa. Additionally, scratch tests and microscopic observations of the surfaces of the samples were performed after tribological tests to describe the wear process of the coatings. The results showed cracking, and coatings detachment from the substrate occur during friction. Deformation wear was observed as bulges in the material at the edge of the friction path. The deformation occurred primarily in the substrate material despite friction occurring on the surface of the coating. The best coating in terms of tribological properties was the TiN coating, which showed the highest resistance to wear in an emergency situation and the friction coefficient in the final stage of the test (above 90 cycles of movement) was only slightly higher than the values recorded for the other coatings. The TiN coating had high hardness, showed good adhesion to the substrate, and was not cracked, protecting it from damage.

The modified technology for strengthening the surface layer of low-carbon steel for machine components by electroplasma processing is proposed. This technology is to be used as an alternative carburizing method with subsequent hardening. The developed technology of strengthening by the proposed method is based on the author’s invention. The parameters of this process are given, resulting in a thickness of the reinforced surface layer of 1000 µm to 1700 µm. An increase in microhardness of 1.5 to 2 times (compared to the initial state) was observed. With hardening, chemical modification of the material’s surface layer occurs. The microstructure of the treated surface of the steel samples is characterised by a dark modified surface layer: a fine needle-like structure of martensitic origin under the dark layer transforms into an initial perlite-ferritic structure. The advantage of strengthening based on the electrolytic plasma processing consists of low energy consumption at high hardening speeds and the possibility of local processing of surface areas, especially large parts of complex shapes. In addition, the proposed surface treatment method using electrolytic plasma processing (EPP) not only achieves a smooth surface but also improves the service qualities of the components, specifically wear resistance.

The paper presents tribological tests of selected materials used as liners in a composite hydraulic cylinder. Three coating materials were used for the analysis: Sika F180 polyurethane, Huntsman Araldite LY1564 with Aradur 3487 amine hardener and Bezlona 1111 Super Metal. In addition, uncoated carbon epoxy laminate (CFRP) samples were used as reference material. The instantaneous course of the friction force, its maximum and average value, were the analysed parameters. Ball-on-disk tests were performed on a specialised tester that allows, among other things, to control the operating conditions (clamping force, operating temperature, speed, friction path) and measurement of the instantaneous value of the friction force. After these tests, the friction paths were observed using a Leica DCM8 contactless profilometer with an EPI 20x lens. The amount of energy dissipated due to friction was also determined. The conducted tests and comparative analyses allowed to conclude that the F180 material is the most desirable in terms of tribological properties.

The use of thermoplastic elastomers (TPE) in 3D printing technology enables the use of this technology to produce prototype seals with an unusual shape or design solution. Tribological tests were carried out on a pin-on-disc test stand. The influence of contact pressure and sliding velocity on the friction coefficient of the TPE-steel friction pair under mixed lubrication conditions was analyzed. Based on the obtained tribological test results, it was found that the coefficient of friction of the thermoplastic TPE elastomer on steel in the presence of hydraulic oil (mixed lubrication) at a sliding velocity below 1 m/s does not exceed μ = 0.25. The obtained friction coefficient values are comparable to the results for other elastomeric materials used for technical seals. It was found that the influence of contact pressure on the value of the friction coefficient in the tested friction pairs is varied and depends, for example, on the sliding velocity. It was recommended to carry out research on the assessment of durability (wear intensity) and structure (porosity) of the material in elements manufactured using 3D printing to obtain full knowledge of the possibility of using these materials in the area of technical aircraft seals.