Thanks Edster.
That is a very informative article.
I note that there is an earlier article by the same authors (Barzagli et al, 2013) in which they examined the characteristics of six tsubas. Here is the Abstract of that article.
In this work we present a systematic study of Japanese sword hand-guards (tsuba) carried out by means of non-invasive techniques using neutrons. Several tsuba from different periods, belonging to the Japanese Section of the Stibbert Museum, were analysed using an innovative approach to characterise the bulk of the samples, coupling two neutron techniques, namely Time of Flight Neutron Diffraction (ToF-ND) and Nuclear Resonance Capture Analysis (NRCA). The measurements were carried out on the same instrument: the INES beam-line at the ISIS spallation pulsed neutron source (UK).
NRCA analysis allows identifying the elements present in the sample gauge volume, while neutron diffraction is exploited to quantify the phase distribution and other microstructural parameters of the metal specimen. The results show that all samples are made of high-quality metal, either steel or copper alloy, with noticeable changes in composition and working techniques, depending on the place and time of manufacturing.
These techniques look very promising non-invasive methods for examining the metallurgy of old swords. Unfortunately, they require state-of-the art technology and analysis that is not widely available at this time.
Ian.
Reference
Barzagli E, Grazzi F, CivitaF, Scherillo A, Pietropaolo A, Festa G, Zoppi M.
Applied Physics A: Materials Science and Processing (2013) 113:1143–1150, DOI 10.1007/s00339-013-7832-y.