Synergistic effects of bioinspired surface structures and matrix modification on friction reduction in SiMoOC ceramics

Stable low friction in ceramic components requires optimized surface structures and suitable lubricating components. Fish scale inspired Elops, Bichir, and Shark structures were fabricated on SiOC ceramics by DLP 3D printing, and Mo was introduced to obtain SiMoOC ceramics containing finely dispersed Mo containing nanophases, with Mo₃Si as the most plausible assignment. The bioinspired structures reduced friction by about 50% compared with untextured SiOC through wear debris trapping and contact stress redistribution. Mo incorporation further improved tribological performance by increasing matrix hardness, promoting free carbon ordering, and forming MoO₃ containing lubricating products during sliding. Elops and Bichir reduced friction by 16.7–31.6% under low to medium loads and by about 20% under high loads, while Shark showed limited improvement. Bichir SiMoOC exhibited sustained friction performance during 1 h sliding against Al₂O₃, GCr15, and Si₃N₄, with counterface dependent variations. These results demonstrate a strategy for low friction ceramic components.