Zhang Mingjun, Ma Zhijun, Pan Xueqin, Li Yun, Zhang Nanlong, Xue Jiaxiang, Yang Jianfeng, Wang Bo
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
China Nuclear Power Technology Research Institute Co., Ltd., Shenzhen 518026, China.
Materials (Basel). 2025 Jan 2;18(1):157. doi: 10.3390/ma18010157.
Silicon carbide-based titanium silicon carbide (SiC-TiSiC) composites with low free alloy content and varying TiSiC contents are fabricated by two-step reactive melt infiltration (RMI) thorough complete reactions between carbon and TiSi alloy in SiC-C preforms obtained. The densities of SiC-C preform are tailored by the carbon morphology and volumetric shrinkage of slurry during the gel-casting process, and pure composites with variable TiSiC volume contents are successfully fabricated with different carbon contents of the preforms. Due to the increased TiSiC content in the obtained composites, both electrical conductivity and electromagnetic interference (EMI) shielding effectiveness improved progressively, while skin depth exhibited decreased consistently. The improvement in the EMI shielding effectiveness of the composite is due to the free electrons being bound to move in the conductive network formed by the TiSiC phase, converting electrical energy into thermal energy and reducing the energy of electromagnetic waves. Notably, at a TiSiC content of 31 vol.%, the EMI shielding effectiveness of the SiC-TiSiC composites in the X-band reached an impressive 62.1 dB, confirming that SiC-TiSiC composites can be treated as high-performance EMI shielding materials with extensive application prospects.
通过两步反应熔体浸渗（RMI）法，利用碳与TiSi合金在所得SiC-C预制体中进行完全反应，制备出具有低游离合金含量和不同TiSiC含量的碳化硅基碳化钛硅（SiC-TiSiC）复合材料。SiC-C预制体的密度通过凝胶注模过程中碳的形态和浆料的体积收缩来调整，并且通过预制体中不同的碳含量成功制备出具有可变TiSiC体积含量的纯复合材料。由于所得复合材料中TiSiC含量增加，电导率和电磁干扰（EMI）屏蔽效能均逐渐提高，而趋肤深度则持续降低。复合材料EMI屏蔽效能的提高是由于自由电子在由TiSiC相形成的导电网络中受限移动，将电能转化为热能并降低了电磁波的能量。值得注意的是，当TiSiC含量为31体积%时，SiC-TiSiC复合材料在X波段的EMI屏蔽效能达到了令人瞩目的62.1 dB，证实了SiC-TiSiC复合材料可被视为具有广泛应用前景的高性能EMI屏蔽材料。
