Fabrication and toughening mechanisms of B4C-SiCf ceramics based on TiB2 interface regulation

The interphase is vital for optimizing the mechanical properties of fiber-reinforced B 4 C ceramics. In this study, the TiB 2 interface composed of one or several layers of fine TiB 2 grains was in-situ formed between B 4 C and SiC fibers by introducing Ti 3 SiC 2 -coated SiC f into B 4 C matrix. The TiB 2 interface not only obviously reduced the densification temperature of the B 4 C ceramics, but also enhanced the mechanical properties. The micro-mechanics modeling was performed to investigate the weak interphase and thermal residual stress distribution induced by TiB 2 , where the stress tend to deflect or propagate at the fiber-matrix interface, compared to B₄C-SiC f ceramics. The particle toughening inside the TiB 2 interface layer and stress transfer at the weak interface were identified as the major factors for the improvement of fracture toughness in this system. These results provide valuable guidance for improving the comprehensive performance of B 4 C-SiC f ceramic composites by interface regulation in future investigations.