Microstructure and enhanced mechanical/tribological properties of SiC-WC composites prepared via a PDC-SPS route

Silicon carbide (SiC) is a key structural ceramic renowned for its excellent comprehensive properties. However, its inherent brittleness often limits its service lifetime and reliability in high-wear applications. To address this issue, the present work combined the polymer-derived ceramic (PDC) route with spark plasma sintering (SPS), aiming to achieve additive-free densification of SiC-WC composites. Composite powders were prepared from liquid polycarbosilane (PCS) and nano-sized WC, and the resulting ceramics were systematically characterized. With increasing WC content, the composites exhibited synergistic improvements in hardness, fracture toughness, and tribological properties. The sample containing 50 wt% WC (SW-50) achieved a balanced set of properties, including a Vickers hardness of 22.7 ± 0.81 GPa, a fracture toughness of 6.0 ± 0.26 MPa m 1/2 , and a wear rate of 8.5 × 10 −7 mm 3 N −1 m −1 . These values represented improvements of approximately 11%, 46%, and 78%, respectively, relative to the WC-free sample (SW-0). All these findings demonstrates that the PDC-SPS process holds promising for achieving synergistic improvements in composite ceramics via microstructural regulation. This work provides a new and practical strategy for fabricating high-performance SiC-WC composites without sintering additives.