Metallic objects are considered among the most significant findings in Cultural Heritage and represent the 'culture of Materials' and the habits of an historical period and of a population. They also preserve traces of time: from the transformation of the ores in metal (by smelting) to the degradation from metal to oxidised compounds (by corrosion processes). Metallography, historically devoted to connect the microstructural features to production processes and to chemical-physical-mechanical properties is a powerful and relatively easy approach to characterise metallic findings. All analytical tools and methods in the hands of a metallographer are improved through experience and practice and provide a large number of information (elemental composition, primary and secondary microstructures, surface treatments, corrosion rate, original ores traces) by the preparation of a fairly small microdestructive sample. A wise and careful use of the metallography allows the balance "object sacrifice/knowledge improvement" to lean on the right side contributing to the hard work of rebuilding humankind history. Beside a description of a research protocol some practical examples concerning archaeological findings are presented in this paper.
tombs of the Necropolis of Chiavari in Italy. A heterogeneous microstructure of the bronze P. PICCARDO was observed, exhibiting a wide range of grain sizes, and a predominant a-phase solid solution containing a/d and a/e eutectoid phases decorated with a high density of inclusions.
M. R. PINASCOT he composition of grain boundary surfaces was determined, using scanning Auger micros-E. STAGNO copy (SAM), on specimens fractured in vacuo. T he extent of tin segregation at the grain M. G. IENCO boundaries was 3-5 times greater than that in the grain interiors. Copper rich sulphides
R. MAGGIoccasionally containing the oligoelements (iron and lead) were identified as the predominant type of inclusions formed at the grain interfaces and within the grains. Analysis of the corrosion patina at the surface of the bronze artefacts was conducted by combining X-ray diVraction, scanning electron microscopy with energy dispersive X-ray analysis, and SAM. T he patina was found to exhibit a multilayered structure and a complex chemical composition forming various crystallographic phases including malachite, cuprite, and copper-tin oxide. Corrosion of the underlying bronze matrix proceeded along the grain boundaries, where the sacrificial corrosion of tin reacting with diVused oxygen and chlorine was identified. T he results of this study have been used to clarify the metallurgy and manufacturing processes of the examined finds, and to evaluate the state of their degradation.
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