PVA Assisted Electroless Ni-P Coating of Carbon Fibers

Ex-PAN carbon fibers are considered as vital reinforcements in production of aluminum based cast composites due to their unique characteristics. In the present study, the effect of polyvinyl alcohol (PVA) addition, as a low cost alternative surfactant, to an acidic Ni-P electroless bath on the coatability of ex-PAN carbon fibers was investigated. Scanning electron microscopy (SEM) results showed that with PVA addition, fine Ni-P particles were uniformly deposited on carbon fibers. The surface finish of the coated layer significantly improved when the PVA concentration reached 0.5 gL(-1). The most favorable conditions for the electroless coating process in terms of uniformity and integrity of the coatings were obtained at a bath of pH 5. The energy dispersive X-ray analysis (EDS) confirmed that the phosphorous content of the Ni-P deposit was about 5 wt% for PVA addition of 0.5 gL(-1).