Abstract

The weak mechanical property and low electromagnetic interference (EMI) shielding effectiveness of short carbon fiber reinforced composites (SCFRCs) hinder their application in the aerospace field. To overcome these drawbacks, magnetic Co@CNT is decorated on the short carbon fiber (SCF) surface by In-situ growth method to enhance the interfacial characterizations of SCFRCs. The results demonstrate that the application of Co@CNT results in a dramatic increase of tensile strength, flexural strength and modulus by 250?%, 160?% and 190?%, respectively, compared to the pure SCF-epoxy (EP) composite. The primary reason can be attributed to the formation of a Co@CNT interfacial region between the short-cut carbon fiber (SCF) filler and the epoxy (EP) matrix in the composites. This interfacial region facilitates efficient stress transfer from the matrix to the surface-modified SCF filler, leading to enhanced mechanical properties of the SCF-EP composites. In addition, Co@CNT-modified SCFRCs obtained EMI shielding effectiveness as high as 59?dB in X-band, which is about 2.3 times that of pristine SCF-EP composite. The excellent EMI shielding effectiveness is ascribed to enhanced dielectric loss and magnetic loss caused by magnetic Co@CNT. Thus, the synergistic effect of magnetic Co and highly conductive CNT resulted in the improvement of mechanical properties and electromagnetic shielding properties. This work offers insights into the preparation of structural–functional integrated SCFRCs.