Achieving near-theoretical strength and high elasticity in micrometer scale TiB₂ ceramics

Achieving near-theoretical strength and elastic limits in crystalline solids remains challenging, yet defect sensitivity typically restricts such behavior to nanometer scale specimens. Here we report experimental evidence of near-theoretical strength and large elastic tensile strains in micrometer scale TiB₂ ceramics, produced in situ by eutectic solidification in steel. In situ bending of crystallographically oriented cantilevers, fixed end beams and C-shaped structures, combined with specimen specific finite element analysis, reveals tensile side stresses of tens of gigapascals and elastic strains up to 9%. Direct microscale tension shows that a large gauge volume exceeding 4 μm³ sustains nearly uniform tensile stress of ~13 GPa without fracture before grip edge failure, providing a conservative lower bound tensile benchmark, while micropillar compression confirms high stress bearing capability. These results establish eutectic solidification as a scalable pathway to suppress strength limiting defects over micrometer scale volumes, extending near-theoretical ceramic strength beyond the nanoscale and enabling robust microarchitected components.