SOL-ENHANCED Au–Ni–TiO₂ ELECTROPLATED COATINGS

Abstract

A sol-enhanced gold ( Au ) — nickel ( Ni ) — titanium dioxide ( TiO 2 ) composite coating technique has been developed at the University of Auckland. The aim of the present study is to achieve quality control and thickness homogeneity of the coatings in order to scale up this process to the workshop level. Multi-coating samples were prepared in the same electroplating unit with same processing parameters. The thickness variation and influence of titanium dioxide ( TiO 2 ) sol content on the thickness have been studied. The consumption of Au and Ti ions in the electrolytes during the electroplating process was measured by inductively coupled plasma-mass spectrometry (ICP–MS) method. The cross-section microstructures of coatings were studied by field emission scanning electron microscope (FESEM) with an energy dispersive spectroscopy (EDS) system. An optimized processing method has been put forward for the industry process to produce coatings with uniform thickness and good quality.