Archaeometallurgy of Japanese sword using neutron diffraction

Harjo, S.   ; Oikawa, Kenichi   ; Kawasaki, Takuro   ; Grazzi, F.*; Shinohara, Takenao   ; Tanaka, Manako*

In this study, we used neutron diffraction mapping measurements to elucidate the Japanese sword's microstructure and discuss the manufacturing procedures. Mapping measurements using pulsed neutron diffraction with time-of-flight method were performed on a full-shape and test pieces of Japanese sword. The distributions of residual macroscopic stresses in the width and thickness directions are small. The stress in the longitudinal direction is compressive at the ridge side, turns to quite large tensile at the middle part of width, then drastically decreases to be quite large compressive at the edge side of about -650 MPa.