Effects of passivation on the properties of Ni-P alloy coating deposited on CFs reinforced PEEK

Electroless Ni-P alloy coating was deposited on carbon fibers (CFs) reinforced polyether ether ketone (PEEK), and a transparent passive film was formed on it. Effects of passivation on the oxidation behavior and electromagnetic interference shielding effectiveness (EMI SE) of Ni-P alloy coatings were investigated. The phase structure of the Ni-P coating was investigated by X-ray diffractometry (XRD). Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) showed that dense and uniform nodules presented in the coating, and chromate (VI) passive film formed onto Ni-P alloy coating. Electrochemical tests showed that passivation improved the corrosion resistance and delayed the oxidation of the Ni-P alloy coating. The EMI SE test proved that the passivation enhanced EMI SE greatly because passive film effectively restrained the oxidation of the Ni-P alloy coating. All the data proved that the passivated Ni-P alloy coating to be potential shielding material under oxidation environment.