Determining The Appropriate Time For Usage of Sodium Sesquicarbonate for Cleaning and Extraction of Chloride Ion in Treatment of Historical Bronze Objects by Electrochemical Metho

Bronze artifacts are attacked by the chloride ion that placed in marine environments or buried under the soil, which results in corrosion. Bronze can be treated using two approaches, stabilization and  cleaning corrosion products. The main reason for deterioration of most bronze artifacts is the lack of direct supervision during the treatment. Therefore, there is a need for a scientific approach such as the electrochemical technique. Electrochemical methods for the treatment of large objects such as artillery and anchors as well as combination of leather, wood, textiles which are not completely immersed during treatment, also objects that do not recognize the composition of the ingredients can be used. Because of the direct observation capability of the technique, this method is used for monitoring the effect of sodium sesquicarbonate on treating bronze objects. The potentiostat was used along with the linear sweep voltammetry technique to measure the corrosion potential values and tafel parameters over time. Through comparison of the pH values chloride concentration, solution resistance, and the treatment method itself were evaluated. The results of this study show that Sodium sesquicarbonate extracts the chloride ion and increases the corrosion potential. If the electrolyte solution is saturated with the chloride ion the corrosion potential will approach negative values and the solution needs to be renewed. The treatment is to be conducted only while the corrosion potential is constant or while the chloride ion concentration is decreasing.

Keywords:

Bronze Artifacts , Active Corrosion , Electrochemical Methods , Corrosion Potential , Treatment , - Sodium Sesquicarbonate , اشیا برنزی تاریخی , خوردگی فعال , روش های الکتروشیمیایی , پتانسیل خوردگی , درمان , سسکویی کربنات سدیم ,