Ancient metal artifacts production technologies revealed through neutron imaging and neutron diffraction.

The history of metallurgy represented for several centuries the history of the main technological features reached by civilizations. Among metal objects production, artistic artifacts and weapons represent the most interesting objects in archaeometallurgy and historical metallurgy because they were manufactured, over the ages, using the highest quality materials and the most advanced technology and skill. The compositional and microstructural characterization of these artifacts can hence allow us to learn about the technological skills reached by different civilizations. The use of non-invasive techniques allows for the study of museum objects in excellent conservation conditions, thus giving a clear view of their characteristics. Neutron imaging and neutron diffraction are, to the author's knowledge, among the best methods to quantify phase composition and microstructure, study morphology, identifying non-metallic inclusions, cracks and defects. Thanks to the use of advanced techniques such as energy selective imaging, the microstructural features and the distribution of the different phases in metal complex artifacts can be determined, so gaining important information about composition and manufacturing treatments (both thermal and mechanical). Following this path, we have performed a number of experiments using neutron imaging and neutron diffraction to reveal the characteristics of many artifacts from different civilizations, of which the production procedures are not yet fully clear. The results obtained and presented in this contribution allow us to identify unique features that can shed new light on the manufacturing methods, thus increasing the level of our knowledge about the technological skills of such civilizations.