The Research on the Features of Aluminum Coating Layer and Bath in the Process of Molten Salt Plating Aluminum
|School||Dalian Jiaotong University|
|Keywords||Anodized aluminum Bath composition Coating thickness Current efficiency Surface morphology|
In this study, three yuan AlCl3-NaCl-KCl molten salt system on Q235 steel substrate obtained by plating a certain thickness of the aluminum layer . In experiments using optical microscopy, scanning electron microscopy, analytical balance , atomic absorption spectrophotometer, such as testing equipment, study the plating bath process element content of different current densities and processing time under the conditions of the surface morphology of the aluminum layer , coating thickness , the coating deposition rate and current efficiency were studied. The results showed that: the use of time as the bath , potassium ions and sodium ions have a small increase , and the aluminum and chlorine content is gradually decreased , by analyzing the electroplating process Al2Cl7- ion concentration , AlCl4- ion aluminum concentration and the relationship between the deposition rate obtained A1C13-NaC1-KC1 three yuan low temperature molten salt system which anodized aluminum cathode deposition kinetics empirical formula : formula shows that , in this study acidic molten salt Al2Cl7- ion controlling the concentration of the plating process proceeds . And , whether in the low current density , or at high current densities, the current efficiency of the electroplating process is decreasing with time of the extension , with the plating thickness of the plating layer showed an increasing trend in the extension of time . Coating the surface morphology and the size of the current density , but whether it is at a low current density , or at high current densities , Q235 steel, aluminum layer is formed on the surface by a small aluminum particles on the surface of the continuous nucleation , grow and form. At low current density, the aluminum particles grow up to be carried out by the step mechanism .