The Preparation, Characterization, and Influence of Multiple Electroless Nickel-Phosphorus (Ni-P) Composite Coatings on Poplar Veneer

Nickel-Phosphorus (Ni-P) composite coatings were prepared on a poplar veneer surface via a simple electroless nickel (Ni) approach. The substrate deformation, flatness, crystalline structure, and wear resistance of the NiP composite coatings were investigated. The deformation degree of the substrate decreased as the number of deposition steps was increased. The flatness and wear resistance of the composite coatings were enhanced with the increase in the number of depositions. The full width, at half of the maximum values of Ni X-ray diffraction (XRD), of peaks in the composite coatings were broadened and strengthened with an increment of the number of depositions in the coatings. The XRD patterns revealed that the Ni that had been deposited on poplar veneer had a crystallite size structure between 42 and 88 Å. The composite structure was characterized with scanning electron microscopy (SEM) images. The uniformity of the particles in the composite coatings could be improved with the increase in the number of depositions. The wear resistance of ideal coatings with a homogeneous thickness was measured via the rolling wear testing machine (RWTM), and the wear resistance of the coatings was increased by 200% compared with that of coatings obtained via a single deposition.