Optimisation of ENDLESS Metal tools - phase 1

July 31, 2024

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At the beginning of January 2024, Edward Michelet, a materials science engineer from industry, joined the research team at the Haute Ecole Ar Conservation-restoration in Neuchâtel, Switzerland for seven months to help optimise the ENDLESS Metal tools and familiarise himself with the qualitative analysis of heritage metals.

After getting to grips with the tools, Edward made a number of contributions:

- Contributing to enriching the MiCorr database, and more specifically that of the ‘By visual inspection’ search engine;

- Contributing to the optimisation of Pleco. The glassy carbon electrode used as a reference electrode does not have a stable potential. It is also fragile and expensive, so the idea was to replace it with a graphite lead. Our work has focused on several brands and the different leads available. This promising but preliminary work needs to be followed up by trials on objects.

- Helping to expand the Discovery Mat database. The application currently has only two databases: those for copper-based (125) and aluminium-based (110) alloys. In order to broaden the scope of the tool, measurements have been carried out on modern grey metals that are not very prone to corrosion and can be confused: nickel, platinum, cobalt, titanium, magnesium, tantalum, tin, lead, etc. In addition, the effect of the alloying element lead in brass was re-examined and confirmed that it affects the plots in a KNO3 medium and that the Pb/Zn ratio plays an important role in the potential values and the presence or absence of fluctuations. So if there is any doubt as to whether a brass contains lead, plots in KNO3 can be used to make assumptions about the Pb/Zn ratio within the materials.