Synergistic Enhancement of Mechanical and Tribological Properties in TiB ₂ /Mo Composites via Core–Shell Structure Mediated Dislocations Migration

ABSTRACT Ceramic reinforcement is crucial for crafting ultrastrong and wear‐resistant metallic components. However, pronounced stress concentration and strain incompatibility at ceramic–metal interfaces often trigger microcrack initiation and ceramic spalling exacerbating friction under sliding conditions. This study presents a heavily reinforced TiB 2 /Mo composite (20 vol% TiB 2 ) that exhibits remarkably reduced friction‐wear and enhanced strength–ductility synergy. Relying on a “borrowing‐dislocations” strategy, the TiB 2 /Mo composite enables ultrahigh strength and excellent wear resistance–lubrication simultaneously, it provides a gigapascal compressive strength of 1987 ± 45 MPa with an engineering strain of about 19.7% and a high hardness of 680 ± 28 HV 5 combining the low friction coefficient of 0.332 and wear rate of 3.38 × 10 −5 mm 3 N −1 m −1 under 30 N (contact stress 3.1 GPa). These outstanding properties stem from the formation of a Mo–Mo 2 B–(Mo, Ti)B 2 dislocation‐slip channel, such a self‐assembled core–shell structure with coherent interfacial bonding facilitates dislocation transfer from the metal matrix into the ceramic phase during deformation. The unique core–shell structure effectively mitigates interfacial stress concentration enabling an exceptional combination of strength and ductility. The significant friction reduction is attributed to the in situ formation of a wear‐induced oxide film, high damage tolerance, and effective load support during repetitive sliding. This study provides new insights to overcome the strength–ductility trade‐off and enhance wear resistance in metal matrix composites via the “borrowing‐dislocations” strategy.