Effect of Sintering Parameters on the Microstructure and Mechanical Properties of (TiB ₂ –SiC)/B ₄ C Composite Ceramics

ABSTRACT In the present investigation, (TiB 2 –SiC)/B 4 C composite ceramics were successfully prepared through an in situ reaction strategy utilizing SPS, where precisely synthesized controlled additions of 25 wt.% TiSi 2 and carbon powders functioned as effective sintering aids. The processing parameters, specifically sintering temperature (1450°C, 1550°C, 1650°C, and 1750°C) and applied pressure (0, 50, and 80 MPa), were systematically varied under short‐duration holding conditions to elucidate their effects on phase evolution, microstructural development, and resultant mechanical properties. The findings indicate that both sintering temperature and pressure significantly govern the densification kinetics and mechanical response of the composite system. The optimum mechanical properties were attained under specific sintering conditions of 1650°C and 80 MPa, where the composite demonstrated exceptional mechanical characteristics with a Vickers hardness of 33.92 GPa, flexural strength of 546.02 MPa, and fracture toughness of 6.75 MPa·m 1/2 . The enhancement in comprehensive performance is principally ascribed to a reduction in residual porosity, refined grain microstructure, a combination of intergranular and transgranular fracture modes, and synergistic strengthening mechanisms facilitated by the in situ‐formed second phases.