FABRICATION AND CHARACTERIZATION OF NOVEL Fe–Ni ALLOY COATED CARBON FIBERS FOR HIGH-PERFORMANCE SHIELDING MATERIALS

Novel Fe–Ni alloy coated carbon fibers (Fe–Ni–CFs) were prepared via two-step electrodeposition with an initial synthesis of Fe coatings on the activated carbon fibers and followed by the co-deposition of Fe and Ni. The effect of annealing treatment on structure and properties of Fe–Ni–CFs was studied through SEM, TEM, XRD and VSM. The results indicated that the Fe–Ni alloy coatings with the thickness of only 0.25 um are highly wrapped on the surface of carbon fibers. The un-annealed coatings showed high saturation magnetization values with 52 dB from 300–1200 MHz, which mainly due to Fe content (18.4 wt.%) of the coatings meets the requirements of high magnetic perm-alloy. The surface quality, crystallinity and conductivity of the Fe–Ni–CFs were obviously improved despite of the reduction of the saturation magnetization resulted from the bigger grains after annealing. Based on the above aspects, annealing at 400∘C was preferred for the Fe–Ni–CFs to obtain good comprehensive performance. Importantly, the Fe–Ni–CFs filled ABS resin composites showed better Electromagnetic Interference shielding effectiveness than the CFs reinforced ABS composites.