Study The Evaluation Indicators And Methods Of Cleaning Agent Of Bronze Protctive Materials

Bronze as a civilization treasure of the China, is one of the most important part of culture heritage. With times go on, corrosions are occurred on the surface of bronze artifacts. Through different ways to prevent and delay the corrosion is the most important goal of heritage industry. So choose the most suitable materials and technology is one of the problems in heritage conservation. In this paper, a comprehensive evaluation system which combined Analytic Hierarchy Process (AMP) and Delphi method was built to the cleaning agent of bronze protective materials. Based on the evaluation principles of keep the original appearance, effectiveness, reprocessed and environmental friendliness, set up the evaluation methods of the10second level evaluation indicators (color change, if the harmless patina off, if new substances generate, the corrosion rate of the matrix, desalination rate, if the cleaning agent remain, the influence of removing, the effects to the humans and environment, physical properties and chemical properties) which under the five first level evaluation indicators (keep the original, protective effect, side effects and reprocessed, environmental friendliness and performance). Simulated the harmless patina(Cu2O), harmful patina (CuCl and powdery patina) and mixed patinas(Cu2O+powdery patina) on the bronze with different tin content, and cleaning the patina bronze in the cleaning agent of sodium sesquicarbonate, edetate disodium and thiourea-citric acid. Through the comprehensive evaluation system, we give quantitative results of the cleaning agent on the patina bronze. From this study we can provide an important basis for scientific evaluation of the protective materials on bronze, which can promote the reliability, effectiveness and safety application of high-tech and new materials on the heritage culture.