ДОСЛІДЖЕННЯ ПРОТИЗНОСНИХ ВЛАСТИВОСТЕЙ АВІАЦІЙНОГО КЕРОСИНУ F-35 В УМОВАХ ТЕРТЯ КОВЗАННЯ

The aim is to investigate the wear process of a model sliding contact assembly in the environment of a conventional aviation fuel for comparative analysis with fuel mixtures containing experimental bio-additives and to assess their ability to form protective films that reduce friction force and wear intensity. Methodology: Five repeated four-stage sliding tests were conducted on the NAU-01 complex using the AСК-01 tribometer at axial load 100 N and sliding speed 0.3 m/s. Specimens were ShKh15 steel (HRC 58–63) finished to Ra ≈ 0.02 μm. Measured parameters included profilometric linear wear, gravimetric mass loss (analytical balance resolution 0.0001 g), worn volume computed from segment geometry, and wear-track morphology by SEM. Results: Mean total linear wear was 24.89 μm; maximum mean worn volume ≈ 0.053 mm³. Gravimetric losses were 0.0001–0.0002 g for counter-samples and 0.0003–0.0012 g for flat specimens, indicating limited sensitivity of mass measurements. Bulk contact temperature rose to 36.8 °C. SEM showed mixed adhesive–abrasive mechanisms, micro-adhesion, plastic deformation and secondary tribofilm formation. Measurement uncertainties: linear ≤5%; volumetric ≤7%; gravimetric relative errors may exceed 50% at low wear. Conclusions: The four-stage protocol on NAU-01 yields reproducible, sensitive tribological indicators suitable as a reference baseline for evaluating bio-additives. Profilometry and volumetric assessments are recommended as primary metrics for fine differentiation; gravimetric data should be interpreted cautiously. Complementary EDS and XRD analyses are recommended to identify chemical and phase composition of wear products and tribofilms. The obtained reference data may be used to compare effects of experimental bio-additives under identical conditions and to guide selection of promising formulations for engine-scale testing. This article was prepared as part of a grant project of the National Research Fund of Ukraine, “Experimental and analytical foundations of the reliability of dual-use aviation equipment through the improvement of aviation fuel technology in accordance with ASTM and NATO standards” (project No. 0124U004599).