Al填料改性PIP-2D SiC_(f)/SiC复合材料力学性能和电磁屏蔽性能

Mechanical and electromagnetic shielding properties of PIP-2D SiC_(f)/SiC composite materials modified with Al filler

以Al粉为活性填料,采用先驱体浸渍裂解法(PIP法)制备二维连续碳化硅纤维增强碳化硅复合材料(2D SiC_(f)/SiC复合材料),采用XRD、SEM和热失重仪分析不同Al粉含量对聚碳硅烷裂解产物的组织成分演变行为,采用力学试验机和矢量网络分析仪研究不同Al粉含量对复合材料的力学及电磁屏蔽性能影响。结果表明:随着Al填料质量分数从0%增加至40%,复合材料弯曲强度先升高后下降,最高可达383 MPa;Al填料的引入使得复合材料复介电常数逐渐升高,电磁屏蔽效能逐渐增加至26 dB,得到了显著的提升,电磁屏蔽效能大幅度提升主要原因是Al填料含量增加引起复合材料复介电常数虚部显著增加。

A two-dimensional continuous silicon carbide fiber reinforced silicon carbide composite material(2D SiC_(f)/SiC composite material)was prepared by precursor impregnation cracking method(PIP method)using Al powder as the active filler.XRD,SEM and thermogravimetry were used to analyze the evolution behavior of the microstructure and composition of polycarbosilane pyrolysis products with various Al powder contents.The effects of various Al powder contents on the mechanical and electromagnetic shielding properties of the composites were studied by mechanical testing machine and vector network analyzer.The results show that as the mass fraction of Al filler increases from 0%to 40%,the bending strength of the composite material first increases and then decreases,and the maximum bending strength can reach 383 MPa.The introduction of aluminum filler leads to a gradual increase in the complex dielectric constant of the composite material,and the electromagnetic shielding efficiency gradually increases to 26 dB,which has been greatly improved.This is mainly due to the significant increase in the imaginary part of the complex dielectric constant caused by the increase in the content of Al filler,resulting in a significant improvement in the absorption and shielding efficiency of the composite material.