The structure and properties of nanocrystalline Ni/Al2O3 layers produced by electrocrystallization
Maria Trzaska, Grzegorz Cieślak
Quarterly No. 4, 2014 pages 203-207
DOI:
keywords: nanocomposites, electrocrystallization, Ni layers, Al2O3 disperse phase
abstract The paper presents the study of nanocrystalline Ni/Al2O3 layers produced by the electrocrystallization method on a copper substrate. Two variants of Ni/Al2O3 layers with different contents (5 and 10 g/dm3) of Al2O3 disperse phase in the nickel plating bath and, for comparison a nickel layer of nanocrystalline structure were tested. The Al2O3 powder and composite layers were characterized using the following research techniques: scanning electron microscopy (SEM), X-ray diffraction (XRD), optical microscopy, microhardness measurements, measurements of surface roughness parameter Ra and electrochemical corrosion resistance studied by the potentiodynamic method. The paper presents results of the studies of the Al2O3 powder, Ni and Ni/Al2O3 structure, and the results of microhardness and corrosion resistance in the environment of 0.5 M NaCl. The produced layers have a nanocrystalline structure, are compact and have uniform thickness. The Al2O3 powder particles embedded in the nickel matrix increase the degree of expansion of the surface layer and hardness of the layer material. There is no increase in the corrosion resistance of the Ni/Al2O3 composite layers compared with the nickel layer in the same test corrosive environment.