Time-of-flight neutron diffraction: a new analytical technique for conservation?

Historical metallurgy is an important aspect of archaeometry, and the study of the process of steel making is of great interest in this field. In order to achieve a high level of material characterization by traditional analytical methods, a destructive approach is usually necessary. This article reports the first systematic use of a neutron-based, non-destructive method that enables resolution of the complex microstructure of a metallic object while retaining full authenticity and artefact integrity. Historical Japanese swords represent some of the best examples of historical metalwork and are, therefore, one of the most rewarding classes of artefacts to study in order to elucidate the evolution of metallurgy. With the aim of characterizing the materials and forging methods used, we analysed two Japanese long swords from the Pitt Rivers Museum, using time-of-flight neutron diffraction (ToF-ND). The results showed that ToF-ND is a very promising method of analysis and investigation for ancient metals.