The Importance of Corrosion Protection of Metal-Containing Historical Artifacts and Common Methods Used for Preservation

Abstract

Metal objects were used for various purposes like in the production, decoration, and painting of metallic coins, kitchenwares, and as structural components from ancient ages to the present. Metal extraction and processing ability became one of the important factors to determine the development level of society. For this reason, repairing and protecting the ancient artifacts buried underground or in an aqueous environment that recovered from the archaeological excavations and historical sites is extremely important to protect the history and cultural heritage of society. Historical artifacts are very fragile against environmental factors after their removal from the dig sites and thus rapid intervention procedures are required. Furthermore, historical artifacts exhibited without an application of a protective coating can easily corrode at an increased rate against atmospheric conditions over time. Therefore, developing new approaches for the preservation of metallic objects of cultural heritage has significant importance. It is necessary to know the type of metal to be processed as the coating to be developed for protection will be determined according to the type of metal. Primarily, metal surfaces must be cleansed from the corroded layer followed by developing and applying a structure able to isolate the metal from the environment in order to prevent corrosion. Various materials such as waxes, oils and greases, polymers, glasses and glassy enamels, metallic, and organic coatings have been used to develop corrosion-resistant coatings. Soluble corrosion inhibitors have also been used, which can promote the spontaneous formation of a protective barrier film on surfaces. The structures to be used in the protection of the ancient artifacts must have specific features:• must not cause a change in color and has to preserve authenticity in visual appearance,• easy to apply,• low cost,• reversibility in some cases, i.e. easy to remove from the surface,• environmentally friendly, non-toxic. In this review, the methods commonly used for the protection of archaeological artifacts are examined and their advantages and disadvantages are stated.