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及川 健一; Harjo, S.; Pham, A. H.*; 川崎 卓郎; 森戸 茂一*; 鬼柳 善明*; 篠原 武尚; 甲斐 哲也; 大庭 卓也*; 伊藤 正和*
JPS Conference Proceedings (Internet), 33, p.011062_1 - 011062_6, 2021/03
The metallurgy of historic melee weapons is one of the most interesting topics in archaeometallurgy. In particular, Japanese swords are paid great admiration in the world as the honor of classical technology and of the art. There have been many reports in the past that tried to elucidate this Japanese sword's microstructure and/or manufacturing process scientifically. In this study, we tried to use neutron diffraction as the non-destructive testing method. TOF neutron diffraction experiment was performed at TAKUMI of J-PARC. The gauge volume for the mapping was limited to 2 
2 2 mm. Data sets for the normal and transverse direction and the normal and axial direction were obtained for the four pieces of sliced Japanese sword. All diffraction data were analyzed by the Rietveld refinement program to obtain lattice constants, phase volume fractions, preferred orientation, the crystallite size and the microstrain from the line-broadening. Detailed analysis results will be presented.
及川 健一; 鬼柳 善明*; 佐藤 博隆*; 大前 良磨*; Pham, A.*; 渡辺 賢一*; 松本 吉弘*; 篠原 武尚; 甲斐 哲也; Harjo, S.; et al.
Materials Research Proceedings, Vol.15, p.207 - 213, 2020/02
Japanese swords are very attractive not only as a work of art but also a metallurgical point of view. Since Japanese vintage swords became valuable, it is indispensable to establish non-destructive analysis method to identify some peculiar characteristics. Bragg edge imaging gives real-space distributions of bulk information in a crystalline material as well as neutron tomography. In this work, we investigated crystallographic information of a Japanese sword made by Sukemasa in Izumi province in the first quarter of the 16th century. The experiments have been performed at RADEN at J-PARC. The Sukemasa sword was measured with a counting-type 2D detector and with a CCD camera. We are now analyzing the measured 2D-transmission spectra using RITS code to obtain spatial distribution of the crystallite size, the texture variation, the d110 shift and its broadening. Complementary data analysis using white beam tomography is also on going. Detailed analysis results will be presented.
Zhang, S.; 森戸 茂一*; 小溝 裕一*
no journal, ,
Development of lath martensite structure in low carbon high alloy steel was in-situ observed using high temperature laser scanning confocal microscopy. The crystallography of the martensite structure was analyzed using electron backscatter diffraction patterns. It was observed that martensite transformation starts from the prior austenite grain boundary. Then, transformation proceeds along the growth direction of martensite block formed initially in the prior austenite grain. Finally, transformation takes place in the neighbors of transformed martensite block.
及川 健一; Harjo, S.; 鬼柳 善明*; 川崎 卓郎; 森戸 茂一*; 伊藤 正和*; 大庭 卓也*; Pham, A.*; 篠原 武尚; 甲斐 哲也
no journal, ,
日本刀のミクロ組織は主に、刃側は高い硬度のマルテンサイトであり、背面側は比較的低い硬度のフェライトであることが知られている。ミクロ組織のタイプは、同じような位置でも刀ごとに異なり、製造方法の違いによるものと考えられている。今回、30年以上前に光学顕微鏡分析およびXRDを用いて研究された4種の日本刀試料片を用い、中性子回折実験を行った。顕微鏡分析から相分率分布は評価されず、またX線回折は定性的にのみ利用され、格子定数、相分率、構成相の転位密度は評価されなかった。そこで我々は、MLFのTAKUMIを用い、マッピング測定を3つの直交する方向に実施した。マッピング測定におけるゲージボリュームは、2mm角とした。Z-Rietveldを用いた解析により、試料毎に可能な相(フェライト, マルテンサイト, セメンタイトなど)の格子定数、相分率、選択配向のマッピングを行った。当日はこれら解析結果の概略を紹介し、過去の報告と比較を行う。
Harjo, S.; 及川 健一; Pham, A.*; 森戸 茂一*; 川崎 卓郎
no journal, ,
本研究では、日本刀の微細構造を定量的に解明するため、中性子回折法を用いた非破壊での測定を行った。本研究では4種類の日本刀(政光, 忠廣, 忠重及び國光)から切り出した試験片を用いた。中性子回折の実験マッピング測定はJ-PARCの匠にて実施し、刀を立てて222mm
ゲージ体積で棟から刃に亘って行なった。得られた回折パターンをMAUDのRietveld法によって構成相の結晶構造, 格子定数, 体積率等, 結晶子サイズ等を求めた。発表では本研究の詳細及び結果を報告し、中性子回折の適用可能性について議論する。
Harjo, S.; 及川 健一; 川崎 卓郎; Grazzi, F.*; 篠原 武尚; 田中 眞奈子*; Pham, A.*; 森戸 茂一*; 鬼柳 善明*; 伊藤 正和*
no journal, ,
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 obtained diffraction patterns are analyzed by the Rietveld refinement and a line profile analysis. The constituent phases in the area closer to the back of the blade (ridge) are found to be ferrite and cementite, composing pearlite, while the area close to the edge is composed by martensite and austenite. The distributions of constituent phases are well explained with the distributions of dislocation density and crystallite size.
及川 健一; 鬼柳 善明*; 佐藤 博隆*; Pham, A.*; 渡辺 賢一*; 松本 吉弘*; 篠原 武尚; 甲斐 哲也; Harjo, S.; 大沼 正人*; et al.
no journal, ,
Japanese swords are paid great admiration in the world as the honor of classical technology and of the art. There have been many reports in the past that tried to elucidate this Japanese sword's microstructure or manufacturing process scientifically. These reports were mainly done by destructive testing methods, such as the microscopic and chemical analyses on the cross sections of swords after mechanical cutting and polishing. Neutron tomography and neutron diffraction are commonly used as a non-destructive investigating method to see inside of the object and evaluate its microstructure. In J-PARC, Bragg edge imaging, a 2D mapping method based on analysis of thousands of position-dependent transmission spectrum data, is actively used to elucidate the crystallographic structure of Japanese swords. Recent research project works by the authors using J-PARC instruments will be introduced.
