Mechanical properties of polymer composite antifriction materials based on polyesteresterketone and babbitts in tensile and compression tests at temperatures above 80°C

The article presents the results of tensile and compressive tests of modern antifriction materials for highly loaded friction units at temperatures ranging from 80 to 180°C, aimed at evaluating their applicability in sliding bearings operating under elevated temperature conditions. The tests were conducted in accordance with methods regulated by GOST standards. A comparative assessment was performed of the mechanical properties of polymer-based antifriction materials (PCM) based on polyetheretherketone and babbitt alloys grades B83 and B16 (GOST 1320–74, ISO 4383–91), as well as the TEGOSTAR 738 alloy analogue. The test results revealed fundamentally different strength mechanisms in PCMs and babbitts, as well as differences in their behavior with increasing temperature. PFMs demonstrate significantly higher values of tensile strength, compressive strength, and yield strength compared to babbitt alloys. Babbitts exhibit pronounced plastic behavior already at 80°C, with a distinct yield stage; however, their strength sharply decreases above 100°C, approaching the yield limit, which limits their load-bearing capacity under heated conditions. Although babbitts’ plasticity helps absorb impact loads, it also contributes to frequent failures of babbitt-layered bearings. At temperatures above 120°C, babbitts undergo significant thermal degradation caused by softening of eutectic structures and microstructural deterioration, while reinforced PCMs maintain stable mechanical properties due to the heat resistance of the polymer matrix and effective load distribution through the reinforcing phase. The possibility of tuning PCM properties by selecting matrices, fillers, and additives was noted, opening prospects for adapting materials to specific operating conditions. The combination of lower plastic deformability and high strength gives PCMs better shape retention and stability during failure, while their high thermal stability allows their use over a wider temperature range compared to babbitts. It was confirmed that the imported babbitt TEGOSTAR 738 does not possess significant advantages over domestic grades such as B83, making imported materials economically unjustified. Meanwhile, PCMs outperform babbitts in strength and thermal resistance, enabling an increase in bearing operating temperatures above 200°C while maintaining performance. This opens prospects for using PCMs in modern rotary systems with high reliability requirements. The results confirm the superior mechanical characteristics of PCMs available on the Russian market and the prospects for their application in highly loaded sliding bearings. Further research is recommended to expand testing, including tribological properties and a wider range of materials. The findings can be used by designers and engineering personnel to broaden the range of bearing materials in the design and modernization of highly loaded friction units of rotary equipment to meet modern demands for load capacity, temperature regime, and reliability.