The SiBCN matrix via chemical vapor infiltration (CVI) or/and polymer infiltration pyrolysis (PIP) technologies was orderly introduced to SiC_f/SiC composites to optimize the mechanical property and electromagnetic (EM) shielding effectiveness simultaneously. The BN interface with the thickness of 350 nm was designed to obtain a little stronger interface bonding. The flexural strength of SiC_f/SiC-SiBCN composites reached 545.45±29.59 MPa thanks to the crack deflection between the CVI SiC and CVI SiBCN, as well as CVI SiBCN and PIP SiBCN matrix because of the modulus difference between them. The fracture toughness (K_IC) with the value of 16.02±0.94 MPa·m^1/2 was obtained owing to the extension of crack propagation path. The adverse effect of stronger interface bonding was eliminated by the design of matrix microstructure for SiC_f/SiC-SiBCN composites. The thermal conductivity in the thickness direction was 7.64 W·(m·K)⁻¹ at 1200 °C and the electric resistivity decreased to 1.53×10³ Ω·m. The tunable dielectric property was obtained with the coordination of wave-absorption CVI SiBCN matrix and impedance matching PIP SiBCN matrix, and the total shielding effectiveness (SE_T) attained 30.01 dB. It indicates that the SiC_f/SiC-SiBCN composites have great potential to be applied as structural and functional materials.

SiBCN 基体通过化学气相渗透 (CVI) 或/和聚合物渗透热解 (PIP) 技术有序地引入 SiC _f / SiC 复合材料，以同时优化机械性能和电磁 (EM) 屏蔽效果。设计厚度为 350 nm 的 BN 界面以获得更强的界面键合。由于CVI SiC和CVI SiBCN以及CVI SiBCN和PIP SiBCN基体之间的模量差异，SiC _f /SiC-SiBCN复合材料的弯曲强度达到545.45±29.59 MPa。断裂韧度（K _IC）为16.02±0.94 MPa·m ^1/2由于裂纹扩展路径的扩展而获得。通过设计 SiC _f /SiC-SiBCN 复合材料的基体微观结构，消除了更强界面结合的不利影响。厚度方向的导热系数在1200℃时为7.64 W·(m·K) ^-1，电阻率降低至1.53×10 ³ Ω·m。用波吸收CVI SiBCN矩阵和阻抗匹配PIP SiBCN矩阵的协调中获得的可调谐介电特性，并且总屏蔽效能（SE _Ť）达到30.01分贝。这表明 SiC _f /SiC-SiBCN 复合材料作为结构和功能材料具有巨大的应用潜力。