Fabrication and characterization of nanocrystalline nickel with a grain size gradient by direct current electrodeposition

Abstract

Two series of nanocrystalline nickel samples with a grain size gradient and symmetric structure were successfully prepared by direct current electrodeposition under the guidance of deposition kinetics. The microstructures of as-deposited samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and microhardness measurements. Comprehensive and quantitative analysis of the grain size indicated that the microstructure gradient was composed of nanograins varying from 20-100nm. Electronic microcosmic observation and microhardness analysis revealed that the samples with a grain size gradient had good structural homogeneity and symmetry.