Effect Of Modified And Arranged Carbon Fibers On Electromagnetic Properties

Carbon fiber has excellent properties, such as low density, high strength,high thermal conductivity and excellent high temperature mechanical performance. There are good prospects for application in the field of high temperature stealth. Three sets of experiment including electroless nickel, silica sol/wcnt modified carbon fiber, arranged carbon fiber were designed. The factors affecting the morphology of electroless nickel and silica sol/wcnt modified carbon fiber were investigated respectively. Electromagnetic properties of electroless nickel, silica sol/wcnt modified carbon fiber, arranged carbon fiber were briefly discussed.Under different electroplating conditions,there will be two different morphologies of nickel particles:one is the initial nickel particles; a needle-like particles catalytic growed on the initial particles. With the current changes, the mode of nickel layer growth changes, When the current is0.1A,the nickel particles growas Frank-van der Merwe (FM) mode, the current of0.2A,nickel particles grow as Volmler-Weber (VW) mode. Nickel particles as isolated particles, can improve the absorbing properties of carbon fiber,or it will reduce the absorbing properties of carbon fiberThe silica sol concentration reducing, continuity of the coating is depraved. carbon nanotubes joined lead to SiO2reunion, and improve the real part of dielectric constant of the carbon fiber.The UD plate and short carbon fiber have a strong reflection of electromagnetic waves but electromagnetic interference can reduce the reflectivity. The short carbon fiber content is beneficial for reducing the refiectivity.The electromagnetic interference plays an important roie in improving the absorbing properties of the materials, for sample with vertical-arrangement UD plate,absorption of-16dB,and the-5dB effective bandwidth of7GHz.