Optimization study on hardness of gold film through supercritical electroplating process by response surface methodology
Chemical Industry and Chemical Engineering Quarterly
Article Highlights • The nanometer size gold film was developed by supercritical electroplating • The hardness of deposited gold film can be for industrial application of soft and hard gold • A theoretical approach was examined by statistical experimental method Abstract A non-cyanide gold bath has been used to deposit gold film on a brass substrate through electroplating process using supercritical carbon dioxide emulsion. The hardness of the deposited gold film was considered as a response
... ed as a response variable to optimize the process parameters of electroplating operation by statistical experimental methods. Effects of current density, pressure temperature, and chemical composition of the solution were investigated to select the optimal operation factors. Scanning electron microscopy and micro--hardness testing were applied to determine the characteristics of the metallic film. The screening of significant variables was examined by a 2 5-1 fractional factorial design with V resolution method. The experimental results showed that the significant variables affecting the deposition of gold film were current density, pressure and temperature. Based on Box-Behnken design and response surface methodology (RSM), a regression model was built by fitting the experimental results with a polynomial equation. The optimal operating variable conditions can be searched at a specified hardness for industrial hard and soft gold application ranged from 83.8 to 157.7 HV.