Structure characterization of Ni/Al_2O_3 composite coatings prepared by electrodeposition

摘要

In the present study, the electrodeposition of composites consisted of metal matrix (nickel) and inert particles (hard nano-sized Al_2O_3 oxide) has been carried out in a Watt's type bath of pH 4, at room temperature in a system with the steel rotating disk electrode. The influence of dispersed Al_2O_3 powder on structure characteristics (morphology, phase composition, texture, residual stresses) of Ni/Al_2O_3 coatings has been investigated. The crystallographic texture of Ni and Ni/Al_2O_3 coatings deposited on the steel substrates was analyzed by XRD technique based on the back-reflection pole figures. The "sin~2Ψ" X-ray diffraction method was used to determine the residual stress as a function of X-ray penetration depth. The influence of Al_2O_3 particles on the value of the Ni coating microhardness was also analyzed.