Facilitating structural strengthening and electromagnetic wave absorption functionalization of dual-phase SiC ceramics via MBNS-dominated multiphase reinforcement strategy

Multilayer boron nitride nanosheets (BNNSs) are promising two-dimensional structure‒function enhancers due to their structural and mechanical similarity to multilayer graphene (MLG). However, challenges in scalable synthesis/preparation techniques and effective interfacial integration approaches for BNNSs have limited their application in ceramic-matrix composites. Herein, we report the cost-effective, large-scale production of high-quality MBNSs via three-roll milling and their incorporation into a dual-phase SiC matrix through a tailored interfacial modification strategy. These MBNS-dominated microstructures activated multiple synergistic toughening mechanisms, yielding an ~95% increase in flexural strength and an ~50% enhancement in fracture toughness. Additionally, the composite exhibited excellent electromagnetic absorption performance, achieving a minimum reflection loss (RL_min) of −52.59 dB at 1.22 mm and a maximum effective absorption bandwidth (EAB_max) of full Ku-band coverage (5.6 GHz) at 1.09 mm thickness. This work presents a scalable strategy for the fabrication of high-performance, structurally and functionally integrated composites, offering significant potential for advanced structural and electromagnetic applications.