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.