実験報告書様式（一般利用課題・成果公開利用）（ ※本報告書は英語で記述してください。ただし、産業利用課題として採択されている方は日本語で記述していただいても結構です。 ）MLF Experimental Report

提出日 Date of Report2016.05.10

課題番号 Project No.

装置責任者 Name of responsible person

課題番号 Project No.2014B0144

Kenichi Oikawa

実験課題名 Title of experiment

装置名 Name of Instrument/（BL No.）

Nondestructive study of traditional Japanese forged iron

BL10

artifacts using pulsed neutron imaging for evaluating

実施日 Date of Experimentcrystallographic texture and microstructure and investigating

02/20/2016～02/27/2016

their manufacturing techniques
実験責任者名 Name of principal investigator
Manako Tanaka
所属 Affiliation
Tokyo University of the Arts
試料、実験方法、利用の結果得られた主なデータ、考察、結論等を、記述して下さい。（適宜、図表添付のこと）
Please report your samples, experimental method and results, discussion and conclusions. Please add figures andtables for better explanation.
1. 試料 Name of sample(s) and chemical formula, or compositions including physical form.
(1) Reproduction sample of Japanese sword, Fe, solid(2) Reproduction sample of Japanese sword, Fe, solid(3) Reproduction sample of Japanese sword, Fe, solid(4) Reproduction sample of Japanese sword, Fe, solid(5) Reproduction sample of Japanese sword, Fe, solid(6) Reproduction sample of Japanese sword, Fe, solid(7) Fragments of Japanese sword, Fe, solid(8) Fragments of Japanese sword, Fe, solid(9) Fragments of Japanese matchlock gun, Fe, solid

2. 実験方法及び結果 （実験がうまくいかなかった場合、その理由を記述してください。）
Experimental method and results.

If you failed to conduct experiment as planned, please describe reasons.

【Experimental method】
The experiment was carried out by the pulsed neutron imaging using the TOF method (Fig.1) atJ-PARC/MLF BL10. We observed the incident neutron TOF spectra and the transmitted neutron TOF
spectra. The distortion of the incident spectrum was clearly observed in the transmitted spectrum due tothe Bragg scattering. A 2D-PSD, µ-PIC(the spatial resolution: 400μm, detection
area: 10cm×10 cm), was used to get thespatial dependent TOF data.
Measurements was performed at room temperature.
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Fig.1. Experimental layout

2. 実験方法及び結果（つづき） Experimental method and results (continued)【Results】
Although there was a trouble at J-PARC and a postponement of the experiment, the experiment itself
was conducted as planned. One of the aim of this experiment is to analyze tamahagane steel samples
manufactured by a contemporary sword smith which show the each manufacturing process of
traditional Japanese sword (reproduction sample of Japanese sword) by pulsed neutron imaging and toevaluate their crystallographic texture and microstructure to clarify the details of the traditional
Japanese sword making techniques nondestructively. We also want to check how detailed information(tracesmarks of the manufacturing process) we can get by pulsed neutron method.
Fig,2-5 show representative results of the Reproduction sample of Japanese swords. As shown inFgi.2, the shape of the Bragg edge, especially the shape of the edge (110) changed in accordance withthe outer steel making process. That implies that the texture of the sample was changed by folding andforge welding. From the position of each edges, (110), (200), and (211), lattice spacing were calculated.
by RITS code (a Rietveld-type analysis code). Fig.3 shows quantitative analytical result of lattice
constant. Lattice constant of Kowari sample shows large variation, however, lattice constant ofShita-gane sample and Agegitae sample become uniform. From the results, it is supposed that surface
oxide (scale) and impurity were eliminated through outer steel making process (by folding and forge
welding. As shown in Fig.4 and Fig.5, change of density, crystalline size, and texture were observed inFig.2 Change of the Bragg edge through outer steel(Kawagane) Fig.3 Quantitative analytical result
making processof lattice constantFig,4 Change of the Bragg edge through forge welding Fig.5 Change of the Bragg edge throughprocess of outer steel(Kawa-gane) and inner steel(Shin-gane)2

hammering and quenching processeach manufacturing process of traditional Japanese sword. We continue to analyze the details of theresults using RITS code, but so far, we confirmed that each steel sample showed a distinctive shape of
Bragg edge which tells information of crystal structure, crystalline size, texture, and density. Thosedifferences in microstructure remarkably reflect their material characteristics and the sword
manufacturing techniques. It is concluded that by using pulsed neutron imaging, we can clarify themetallurgical characteristics and reveal the traditional Japanese sword making techniques
nondestructively. We will continue to analyze the details and plan to use the results of this experiment
as a basic data and extend our study towards a systematic nondestructive measurement of precious
cultural heritage, such as Japanese swords by pulsed neutron.

Acknowledgement
This work was partially supported by ISIJ Research Promotion Grant, a grant from the Iketani Scienceand Technology Foundation, and JSPS KAKENHI Grants No. 26702004 and No. 23226018.

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