Friction Stability and Wear Behavior of Te NW–TiB2/Epoxy Composites

Epoxy thermosets offer excellent dimensional stability and mechanical rigidity, but their inherent brittleness limits their durability in dynamic sliding applications. To overcome this limitation, we synthesized a multi-dimensional hybrid filler composed of one-dimensional Tellurium Nanowires (Te NWs) and Titanium Diboride (TiB2) particles via an in situ hydrothermal method to improve the dry-sliding friction and wear resistance of the epoxy matrix. Neat epoxy and nanocomposites containing 0.25–1.00 wt.% hybrid filler were tested against hardened AISI 8620 steel over a sliding distance of 2000 m at normal loads of 5–10 N and sliding velocities of 1.00–1.75 m/s. Tribological stability and wear behavior were systematically assessed using the mean coefficient of friction (COF), dispersion metrics (standard deviation, coefficient of variation, and interquartile range), percentage mass loss, infrared thermography, and field-emission scanning electron microscopy (FESEM) of the worn surfaces. The hybrid composites showed a nonlinear tribological response to filler loading. The 0.50 wt.% Te NW–TiB2/epoxy composite delivered the best overall performance, particularly under the most demanding conditions (10 N and 1.75 m/s). It achieved the lowest mean COF (0.181 ± 0.027), minimal percentage mass loss (0.12%), a narrow friction distribution (coefficient of variation ≤ 13.61%; interquartile range ≤ 0.027), and a lower maximum surface temperature measured by infrared thermography (54.1 °C, compared with 68.6 °C for neat epoxy). Criterion weights were calculated using the Criteria Importance Through Intercriteria Correlation (CRITIC) method and validated using the entropy method. Across all four multi-criteria decision-making methods, the 0.50 wt.% formulation consistently ranked highest, identifying it as the best-performing hybrid composition within the tested range, with 0.75 wt.% as a close alternative.