Proposta de monitorização da corrosão das esculturas de Gonçalo Jardim

The objective of this investigation is to propose a non-invasive monitoring methodology to control the corrosion advance of a carbon steel alloy of three sculptures by contemporary artist Gonçalo Jardim over a year. For this purpose, the materials constituting the alloy, the corrosion products in the patina and the atmospheric conditions that prevail in the place where the works are exposed – Évora – were identified. This research required an interdisciplinary approach between the area of art history, physics, chemistry, conservation and restoration and computational programming, and was supported by specialists from each of these areas. To characterize the corrosion products, chemical and mineralogical characterization tests were performed (optical microscopy, reflection optical microscopy, scanning electron microscopy with X-ray spectrometry by energy dispersion and X-ray diffraction). The classification of atmospheric corrosivity was done according to the methodologies applied in the Portuguese project Mapa Nacional de Corrosão Atmosférica (MNCA), developed by the Instituto Nacional de Engenharia e Tecnologia Industrial (INETI). The diagnostic of the degradation state of the art works was obtained through correlation between the results obtained with the patina corrosion products and the values of the hygrometric parameters of the surrounding atmosphere. Considering the location of the sculptures, the corrosion products that make up the patina and the artist’s intention, a conservation proposal was made based on non-invasive monitoring of the art works through the digital image processing (DIP) method, to evaluate the evolution of the corrosion morphology of the art works in the long term, in order to document them and to analyse whether corrosion is maintained or increased over time and, in the latter case, in what proportio