POSTER, DAYS OF CORROSION AND MATERIALS PROTECTION (8 ed.), LNEG
- I. Tissot,a,b, M.A. Barreirosc, M. Lemosb, M. Tissotb. 2022. Looking into historical cracks analysing repaired silver objects by electron microscopy, in Days of Corrosion and Materials Protection (8th ed.), National Laboratory of Energy and Geology (LNEG), 24 Nov, Lisboa.
Days of Corrosion and Materials Protection (8th ed.)
aLIBPhys, NOVA University of Lisbon bArcheofactu cNational Laboratory of Energy and Geology
In search of the shining silver
Objects made of silver alloys are frequent in museums and private collections. The preservation of these objects involves the definition of conservation methodologies that include maintenance plans and costs. This requires knowledge of the corrosion and alteration processes of silver. The alteration of silver objects by atmospheric corrosion is a research topic widely addressed in the literature, including the corrosion mechanisms and intervention. Less attention has been paid to the influence of past restoration procedures on the objects’ current state of conservation and future conservation actions of these objects. Aiming to improve conservation methodologies of historical silver objects, we illustrate, in this work, how scanning electron microscopy (SEM) can contribute to the assessment of silver alloy historical objects’ state of conservation.
Scanning electron microscopy (SEM) - A tool for silver objects’ conservation
SEM is a technique with many advantages for the study of historical silver objects. It is non-invasive (depending in object dimensions), with high resolution, extensive depth-of-field, and wide range of magnification. An additional advantage is that elemental microanalysis can also be performed with an energy dispersive spectrometer (EDS) coupled to the SEM equipment. The study was carried out by using a SEM-EDS Philips XL 30 FEG model operated at acceleration voltages ranging from 10 to 15 kV. The Thermo Scientific EDS system is equipped with a UltraDry silicon drift X-ray detector, and the X-ray spectra were collected in point analysis for 50 s acquisition time.
