Enhanced interfacial properties of PBO fiber via electroless nickel plating

Conventional electroless nickel plating was utilized to enhance the interfacial properties of PBO fibers. Moreover, the possible interfacial shear strength (IFSS) enhancing reasons were investigated. The elemental composition, crystal structure and cross-sectional morphology of nickel-plated PBO fiber were characterized by energy dispersive spectrometer (EDS), X-ray diffractometer (XRD) and transmission electron microscopy (TEM), respectively. Ultrasonic exposure tests implied that the nickel coating exhibited high adhesive durability. Scanning electron microscopy (SEM) was employed to characterize the surface morphology of PBO fibers and the de-bonding surface morphology of PBO fiber composites. Atomic force microscopy (AFM) results showed that the surface morphology of nickel-plated PBO fiber was undulating, and its surface roughness (R_a) increased obviously. Single fiber pull-out tests showed that the IFSS increased from 40.4 to 56MPa. Meanwhile, the nickel-plated PBO fiber maintained satisfactory tensile strength. Hygrothermal aging tests revealed that the nickel-plated PBO fiber had excellent hygrothermal aging resistance properties. Heat treatment results showed that IFSS was decreased with the increase of temperature.