Corrosion And Conservation Of Cultural Heritage Metallic Artefacts

The conservation of metallic archaeological and historic artefacts is a major challenge whether they are ancient bronzes or relics of our more recent industrial past. Based on the work of Working Party 21 Corrosion of Archaeological and Historical Artefacts within the European Federation of Corrosion (EFC), this important book summarises key recent research on analytical techniques, understanding corrosion processes and preventing the corrosion of cultural heritage metallic artefacts.After an introductory part on some of the key issues in this area, part two reviews the range of analytical techniques for measuring and analysing corrosion processes, including time resolved spectroelectrochemistry, voltammetry and laser induced breakdown spectroscopy. Part three reviews different types of corrosion processes for a range of artefacts, whilst part four discusses on-site monitoring techniques. The final part of the book summaries a range of conservation techniques and strategies to conserve cultural heritage metallic artefacts.Corrosion and conservation of cultural heritage metallic artefacts is an important reference for all those involved in archaeology and conservation, including governments, museums as well as those undertaking research in archaeology and corrosion science. Summarises key research on analytical techniques for measuring and analysing corrosion processes Provides detailed understanding of corrosion processes and corrosion prevention Discusses on-site monitoring techniques

This chapter introduces the techniques used when investigating corrosion layers formed on cultural heritage artefacts. Various multiscale analysis methods, from macroscopic to nanoscopic scales, are presented. Information on the morphology, the elementary composition and the crystalline structure that each method allows for determining the constituents of the corrosion layers is examined, as well as their limits in terms of set-up, spatial and detection resolution. This chapter discusses the characteristics of the scientific tools that can be used to understand corrosion phenomena, by taking into account the major parameters responsible for alteration mechanisms.

This chapter attempts to address monitoring problems from a wider point of view than is usual in the cultural heritage field. It discusses the issues connected to variations of space and time in the measured quantities. Some differently structured systems which can be employed in designing a monitoring infrastructure are discussed and a case study is reported to illustrate the practical application of general guidelines.

This chapter deals with the description of suitable and innovative solutions devoted to preserve metallic artefacts in their original contexts, underwater cultural heritage sites of archaeological and historical interest, as well as with the analysis of the degradation processes of ferrous and non-ferrous artefacts induced by contact with an aggressive environment such as sea water. The chapter also provides an overview of the most common conservation strategies applied to recovered artefacts.

Metallographic investigations may be an essential component in the search for authenticity and fabrication technology. Assessing how an artefact is made may involve metallographic examination, usually entailing the removal of a small sample from the object concerned. Examples of the use of metallography are discussed with reference to copper alloys, high-tin bronzes, Chinese bronze mirrors, copper plaques, iron and steels, and plated or coated metals, such as depletion gilded surfaces or those covered with gold foil or other metals. The different types of features which metallography can reveal concerning ancient metallic structures are briefly discussed with several colour photomicrographs which illustrate the features described in this chapter. The importance of metallography as one component of the scientific tools to aid in the determination of authenticity of ancient metallic artefacts is stressed, and an example given of old electrotypes from the Victoria and Albert Museum. Important literature references are provided to direct the reader to more detailed studies on the subject.

This chapter discusses the importance of using standards in conservation methodology and practice for cultural heritage (CH) metals. The past general trend in the field is the use of metal industry standards. The chapter surveys the relevant scientific publications, and concludes that conservation researchers use a variety of these standards adopted by different organisations. As a result, it can be difficult to compare scientific data for CH metal studies carried out by different laboratories. The chapter discusses the necessity to draft new standards for metals specific for CH by examining how three independent researchers had different findings when testing the same coating. The role of CEN/TC 346 ‘Conservation of Cultural Heritage’ is also discussed.

This chapter reviews the applicability and specific uses of corrosion inhibitors in metal conservation practice. Corrosion inhibitors are one of the different methods used by conservation-restoration professionals to preserve metallic cultural heritage. In the first part, specific requirements and needs for corrosion inhibitors in conservation treatments are reviewed, as well as the different methods for the assessment of their efficiency. The second part of the chapter reviews the different inhibitors used by type of metals: copper and its alloys, iron and its alloys, and other metals (including silver, lead and zinc), from traditional ones to state-of-the-art treatments.