The enhanced mechanical properties of SiC nanowires/Ba_0.75Sr_0.25Al₂Si₂O₈ ceramics with embedded SiO₂ interface

In this work, low-softening-temperature and low-modulus SiO₂ was introduced as an embedded interface between SiC nanowires (SiCnws) and a Ba_xSr_1−xAl₂Si₂O₈ ceramic matrix to enhance strength and toughness of the ceramic. During the sintering process, molten SiO₂ enhances the flowability of the ceramic powders and modifies the dispersion of SiCnws. The strengthening effect of SiCnws was fully realized, and the flexural strength of the optimized ceramics reached 193±16 MPa, which represents an increase of 52.6%. After the formation of the embedded SiO₂ interface with a low modulus, cracks can deflect along the SiCnws surface, which is consistent with the criterion of He and Hutchinson. This can effectively extend the crack propagation path, and the fracture toughness ( $K_{\mathrm{I}\mathrm{C}}$) is thus improved by 94.0%, reaching 3.1±0.5 MPa·m^1/2.