Effect of transition layer on the quality of non-cyanide electrodeposited gold film on tungsten helix

A transition layer was applied to improve the quality of gold films electrodeposited on tungsten helix. The morphology and the component of deposits were evaluated by means of scanning electron microscope (SEM) and Energy Dispersive Spectrometer (EDS), respectively. The results indicate that the thickness of the transition layer affects the quality of gold films. The transition layer is thin, which leads to a low covering power of gold films. To the contrary, Au-Cu alloy with high copper content formed due to diffusion will be melted at high temperature. As a result, peeling and spalling occur on the gold films. The appropriate thickness of transition layer would be deposited at 10 s.