The France-Switzerland cross-border territory has been marked by a succession of contacts and interactions on both sides of the current border that began in prehistoric times and whose archaeological, historical, artistic, architectural and industrial heritage bears witness to. The desire to preserve this cultural heritage is at the heart of this project.
The objective of the MetalPAT-Interreg project is to develop a low-cost computer application (MiCorr) to assist conservation professionals in the efficient, quick and non-invasive diagnosis of heritage metals.
This diagnosis is currently based on the visual observation of the forms of corrosion developed on the metals and on the knowledge and/or experience of each expert. The latter is not immune to an error of appreciation that may lead to inappropriate intervention. The only current alternative to consolidate the diagnosis is to resort to physico-chemical analyses to assess the extent of corrosion in the materials' core and its development on a microscopic scale. However, they are invasive and costly.
In order to carry out this project, cross-border expertise in the field of macroscopic description of forms of corrosion, of detailed study of microstructures and corrosion mechanisms, and of computer management will have to be pooled.
A MiCorr user, observing an altered metal object
with the naked eye and/or under binocular (step 1, fig. 1) schematizes the
observed corrosion structures from the most external strata to the residual metal (step 2, Fig. 1). From MiCorr search engines based on the digital
reconstruction of corrosion structure strata and/or keywords characterizing the
object under consideration (step 3, fig. 1), matchings can be made with the
corrosion forms in the system database (step 4, fig. 1). More information is provided under the About tab.
Fig. 1: The steps involved in using the MiCorr expert system.
The research unit of Haute Ecole
Arc Conservation-restauration (HE-Arc CR) in Neuchâtel, Switzerland, began several years ago to collect
and homogenize metallographic analysis data on Swiss historical and
archaeological artefacts in order to constitute a first reference database for
heritage professionals confronted with the question of diagnosing the conservation condition of metals found on Swiss territory. A catalogue of corrosion models documented
according to a standardised observation and analysis procedure was compiled. As this database did not allow professionals to simply establish
correspondences between the objects newly studied and the corrosion models collected,
HE-Arc CR collaborated with the Management division of Haute Ecole Arc (HEG
Arc) in Neuchâtel in order to automate the correlation of data. A feasibility study was thus carried out and led to the creation of the MiCorr expert system.
The CNRS (Centre National de Recherche Scientifique) Laboratory Metallurgies and
Cultures (LMC-IRAMAT) of the University of Technology of Belfort-Montbéliard
(UTBM) and its advanced characterization platform, the Laboratory Archéomatériaux
et Prévision de l’Altération (LAPA-NIMBE) of the Alternative Energies and Atomic Energy Commission
(CEA) located on the Saclay plateau in Ile de France, have developed a
methodology for the detailed investigation of corrosion forms, particularly
those developed on ancient materials. This methodology is based on the use of
multi-technical characterization protocols to describe the corrosion forms
developed over the long term and from nano to macroscale, creating then a link with the observations made by HE-Arc CR and the group of end-users.
End-users are essential to the development of MiCorr thanks to an iterative approach, where the different functions of the application will be tested in-situ. Their feedback should make it possible to validate the functions judged to be effective and/or to modify the others in order to improve the relevance and effectiveness of the application. Furthermore, they will contribute to the enrichment of the database.
*: Section d'Archéologie et Paléontologie (SAP)
**: Unité Patrimoine du Service des affaires culturelles du canton de Vaud (SERAC)
***: together with Musée des Beaux-Arts et d'Archéologie
****: together with Musée de la montre de Villers le Lac
The MetalPAT project is supported by the European cross-border cooperation programme Interreg France-Switzerland 2014-2020 and has received a European Regional Development Fund (ERDF) grant of 186,599€.
The project is also supported by the following Swiss cantons: Bern, Jura, Neuchâtel, Valais and Vaud.
The Communauté du Savoir has also contributed to the implementation of the search tools, more particularly the identification of metals through their visual observation. The end-users involved in this work were: Stiftung HAM, Musée International d'Horlogerie de la Chaux-de-Fonds, Musée Historique Lausanne, Musée d'Ethnographie de Genève, Musée du Temps de Besançon, Musée des Beaux-Arts et d'Archéologie de Besançon and Musée d'Horlogerie de Morteau. Other external partners joined this work: Musée Rural Jurassien des Genevez, Musée de Pontarlier, Centre de Conservation et d'Etude des Musées of Lons-le-Saunier and Musée national de l'automobile de Mulhouse.