SiC Whisker Content on the Microstructure, Mechanical, and Tribological Behaviors of Hot-Press Sintered SiC-Y2O3 Composite Ceramics

Silicon carbide whiskers (SiC w ) are promising reinforcements for ceramic materials due to their high strength and elastic modulus. In this work, SiC/SiC w -Y 2 O 3 composite ceramics were fabricated by hot-press sintering at 1800 °C and 40 MPa, using 7.5 vol.% Y 2 O 3 and varying SiC w contents (0-15 vol.%). The effects of SiC w on microstructure, mechanical properties, and tribological behavior were systematically studied. The results show that 10 vol.% SiC w yields the best overall performance, with improvements in relative density (97.0%), Vickers hardness (21.6 GPa), fracture toughness (7.7 MPa m 1/2 ), and flexural strength (573.2 MPa). However, excessive SiC w (15 vol.%) led to decreased densification and wear resistance due to whisker agglomeration and increased porosity. The main toughening mechanisms include whisker pull-out, crack deflection, and bridging. These findings suggest that a moderate SiC w content effectively enhances the mechanical and tribological properties of SiC/SiC w -Y 2 O 3 ceramics, providing a feasible strategy for developing advanced structural ceramics.