Reciprocating Tribological Response of Basalt/Carbon Hybrid FiberReinforced Composites under Hertzian Contact

<span class="fontstyle0">Hybridizing basalt with carbon is a route to tailor tribological performance of polymer laminates.<br>This study quantified how the surface ply governs friction and wear under Hertzian reciprocating contact.<br>Epoxy laminates with 0/90 woven carbon and basalt were vacuum infused in four eight-ply sequences: 8B,<br>8C, 2B4C2B, and 2C4B2C. Tests at 30 N, 2 Hz, and 50 m recorded friction and 3D topography of wear<br>tracks. Responses separated by the outer lamina. Carbon-skinned 2C4B2C gave the lowest friction,<br>sustaining 0.06–0.07 and the smallest footprint, 653 μm wide and 7 μm deep. All-carbon 8C remained<br>similarly low, drifting to 0.08–0.09 with 649 μm and 8 μm. Basalt-skinned 8B rose toward 0.45–0.50 and<br>produced the largest groove, 1602 μm wide and 128 μm deep, while 2B4C2B transitioned mid-distance to<br>0.48–0.52 with 1180 μm and 76 μm. Topographies corroborated these trends, showing shallow polishing<br>for carbon skins but deep valleys and spallation for basalt skins. Higher stiffness and thermal conductivity<br>of carbon stabilize a lubricious film and limit matrix softening and third-body formation. Carbon as the<br>outer lamina minimizes frictional heating and material loss; basalt is better reserved for sub-surface roles<br>when contact stability is critical. These findings guide hybrid design for aerospace tribo-contacts.</span> <br style="font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; font-variant-emoji: normal; line-height: normal; text-align: -webkit-auto; text-size-adjust: auto;">