Pulse Electrolysis for the Production of Hard Ni/ZrO2 Composite Coatings
Composite electrodeposition technology is one of the methods used to fabricate metal matrix composite coating materials. One of the most challenging issues concerns the addition of homogeneously suspending oxide powders, such as TiO2 and ZrO2 in the electrolyte, in order to result in the uniform dispersion of the oxide powders in the metal matrix . Moreover, the application of a current periodically varied by time during electrodeposition, i.e. pulse current (p.c.) instead of the commonly used direct current (d.c.) has been concluded that leads to the preparation of surfaces with well-defined properties . It is also well known that composite electrodeposits of Ni/metal oxides have remarkable mechanical and anticorrosion properties . In this work nickel matrix composite electrocoatings including ZrO2 micron–sized particles were produced from an additive free Watts type bath under strong agitation conditions applying d.c. and p.c. regime. The synergetic action of the pulse application, the incorporation of the particles into the nickel matrix and the applied hydrodynamic conditions on the crystalline development, the morphological characteristics, the microhardness and the roughness of the composite electrocoatings, were studied.
Andreas Öchsner, Graeme E. Murch and João M.P.Q. Delgado
M.M. Dardavila and C. Kollia, "Pulse Electrolysis for the Production of Hard Ni/ZrO2 Composite Coatings", Defect and Diffusion Forum, Vols. 312-315, pp. 235-239, 2011