Supercritical carbon dioxide assisted co-electrodeposition of nickel-titanium dioxide composite film and the dispersity

Abstract This work reports effects of supercritical carbon dioxide (SC-CO2) on the dispersion of TiO2 in Ni-TiO2 composite films prepared by SC-CO2 assisted co-electrodeposition. Pure Ni and Ni-TiO2 composite films prepared by the conventional electrodeposition method are prepared as comparisons. The average grain size of the Ni matrix is compared from the X-ray diffraction results, and grain refinement is observed in the composite film prepared by the SC-CO2 assisted co-electrodeposition. The incorporation amount of TiO2 and the dispersity in the composite film are determined from results obtained in energy dispersive X-ray mapping analysis, and the TiO2 content reaches 5.47 wt% and the dispersity of TiO2 becomes more uniform in the composite film by the SC-CO2 assisted co-electrodeposition. The dispersity is quantified through a convolution process. Vickers hardness of the composite film reaches 1167 Vickers Pyramid Number (HV0.1/15) because of the fine Ni grains, high TiO2 content and uniform TiO2 distribution.