Effect of high temperature oxidation on mechanical and electromagnetic interference shielding effectiveness of Ti3SiC2 modified SiCf/BN/SiBCN composites.

SiC f /BN/SiBCN composites were prepared through the technique of polymer infiltration pyrolysis (PIP). To enhance the electromagnetic interference (EMI) shielding effectiveness (SE), 20 wt% of Ti 3 SiC 2 was incorporated into the composites. The study investigated the influence of different oxidation temperatures (1300 °C, 1400 °C, and 1500 °C) on both the mechanical properties and EMI SE of the composites. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were utilized to analyze the phase and microstructure of the composites, while characterizing their mechanical properties and EMI SE. The outcomes revealed a decline in the mechanical properties of the composites following high temperature oxidation, with the formation of SiO 2 and TiO 2 as the main oxidation products. Notably, an oxide layer formed on the material's surface at 1400 °C acted as a barrier to oxygen diffusion, facilitating self-healing of pores and cracks and thereby enhancing material protection. Moreover, the material oxidized at 1400 °C demonstrated a remarkable synergy between impedance matching and electromagnetic loss, resulting in the optimum EMI SE. The EMI SE of this material was 6.35% higher than the total shielding effectiveness at room temperature and effectively shielded 99.88% of electromagnetic waves. [ABSTRACT FROM AUTHOR]