Structural Characterization of Ancient Japanese Swords from MAAS Using Neutron Strain Scanning Measurements

The current paper presents a forensic study that aims to characterize non-invasively the laminated structure of a set of Samurai's swords, part of the East Asian Collection of the Museum of Applied Arts and Sciences (MAAS) in Sydney, via strain scanning measurements. Neutron residual stress analyses were undertaken on samples of well-known origin, time period and authorship to create a reference database on the main lamination methods developed by Japanese swordsmiths. The benchmark data were cross-matched with results obtained from a mumei (no-signature) blade in order to attribute its manufacturing tradition based on qualitative and quantitative data rather than stylistic criteria. Maps of two stress components and do-values in the transverse cross-section of each sword were determined as a result of the neutron diffraction experiment with sub-millimeter spatial resolution. Since these two material characteristics are induced by the manufacturing process, analysis and comparison of the results allows drawing conclusions about variability or similarity of the actual production techniques of the Japanese swords.