ELECTRODEPOSITION OF CuZn ALLOYS FROM THE NON-CYANIDE ALKALINE BATHS

Effect of copper sulfate on CuZn alloys electroplating from non-cyanide baths are investigated by different electrochemical methods. Cyclic voltammetry and current transient measurements are used to characterize the CuZn alloys electroplating system in order to analyze the nucleation and growth mechanism. The reduction of Cu and CuZn alloy on sheet iron substrates shows an instantaneous nucleation process. However, the reduction of Zn on sheet iron substrates shows a progressive nucleation process. The structure and surface morphology of CuZn alloys are analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The morphology of CuZn alloys obtained with 50 g L-1 copper sulfate presents a smooth and compact deposit and the size of crystal particle is uniform.

Evaluation of the Current Modulation Effect on the Cathodic Efficacy during Copper Electroplating in Alkaline Medium

The main aim of this paper is to study copper ions electroplating, evaluating the cathodic current efficacy, from cyanide ion free alkaline baths, stabilized by different complexant agents for the Cu2+ions. The cathodic current efficacy was assessed through quartz microbalance measurements, employing different current modulations. Results revealed that the pulsed current application has great influence on the cathodic current efficacy during electroplating in the baths under study.

EFFECT OF ULTRASONIC ON COPPER ELECTROPLATING FROM THE NON-CYANIDE ALKALINE BATHS

Effects of the different ultrasonic powers on copper electrodeposition from non-cyanide alkaline baths by using pyrophosphate as complexing agent were investigated by different electrochemical methods. Cyclic voltammetry and current transient measurements were used to characterize the nucleation and growth mechanism. It is very obvious that the reduction potential moves to more positive one as the ultrasonic power increases. The quartz crystal microbalance (QCM) and chronoamperometric method were used to study the relationship between the mass change and the deposition time. It was found that the current efficiency of electrolyte under 0, 60, 80 and 100 W is 91.95%, 92.14%, 89.25% and 96.11%, respectively measured by QCM measurements. The surface morphology of the electrodeposited Cu films is analyzed by scanning electron microscopy (SEM). The morphology of copper films electrodeposited under the power of 60 W and 80 W presents a compact surface and the grains are fine and uniform.