Microstructure and performance optimization of B4C–TiB2 composites via pre-calcination and hot-pressing

B 4 C–TiB 2 composites with an excellent combination of mechanical properties were consolidated at 1900 ℃ via a combined route of pre‑calcination and hot‑pressing. The effect of TiO 2 content (10 30 wt%) on boron carbide and sintering behavior was investigated. Increasing TiB 2 content accelerated densification, while the concomitant formation of non‑stoichiometric B x C with lattice distortion further enhanced the sintering activity. The pre‑calcination effectively reduced the formation of by‑products and suppressed particle agglomeration prior to sintering. The composite with 26 wt% TiB 2 achieved the best combination of properties: flexural strength of 774 ± 42 MPa, Vickers hardness of 35.1 ± 1.8 GPa, and fracture toughness of 3.17 ± 0.11 MPa·m 1/2 (SEVNB), representing a 58.5% improvement over monolithic B 4 C. Quantitative AFM analysis revealed increasing fracture roughness with TiB 2 content, corroborating enhanced crack‑propagation resistance.