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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.
MnGa串田 悠彰*; 福田 康太*; 寺井 智之*; 福田 敬*; 掛下 知行*; 大庭 卓也*; 長壁 豊隆; 加倉井 和久; 加藤 健一*
Journal of Physics; Conference Series, 165, p.012054_1 - 012054_4, 2009/06
Neutron diffraction measurements using single crystal and powder synchrotron X-ray diffraction measurements revealed that an intermediate (I-) phase and a martensite (M-) phase in NiMnGa have incommensurate modulated structures. The modulation vectors of the I- and M-phases are nearly equal to 
= 0.341 at 210 K and = 0.427 at 100 K, respectively. Moreover, displacements of Ni, Mn and Ga atoms in both the I- and M-phase are expressed by sinusoidal waves with the same phase and almost the same amplitudes.
MnGa studied by neutron diffraction串田 悠彰*; 福田 康太*; 寺井 智之*; 福田 敬*; 掛下 知行*; 大庭 卓也*; 長壁 豊隆; 加倉井 和久; 加藤 健一*
European Physical Journal; Special Topics, 158(1), p.87 - 92, 2008/05
被引用回数：22 パーセンタイル：72.02(Physics, Multidisciplinary)We have investigated crystal structures of martensite and intermediate phases in stoichiometric NiMnGa. The neutron diffraction profile of the martensite phase measured at 
= 4.2 K exhibits four satellites between [2 0 0] and [0 2 0] refrections at incommensurate positions of [
2 - 0] with = 0.428, 0.863, 1.136 and 1.572. The profile of the intermediate phase measured at = 210 K exhibits two satellites between [2 0 0] and [0 2 0] refrections at incommensurate positions of [ 2 - 0] with = 0.343 and 1.657. Although each satellite of the martensite phase moves toward its nearest fundamental refrection as temperature increases, that of the intermediate phase does not move significantly. On the contrary, the intensity of each satellite decreases significantly in the intermediate phase as temperature increases while not in the martensite phase. A synchrotron X-ray diffraction and a Rietveld analysis of the result reveal that, for both the phases, the displacement of atoms from the parent phase are represented by a sine wave whose propagation vector is parallel to [1 1 0].
MnGa合金単結晶を用いたマルテンサイト相及び中間相の中性子回折串田 悠彰*; 福田 康太*; 寺井 智之*; 福田 敬*; 掛下 知行*; 大庭 卓也*; 長壁 豊隆; 加倉井 和久
no journal, ,
NiMnGa合金のマルテンサイト相(M相)は10層周期構造であると考えられてきたが、粉末中性子回折や粉末X線回折を用いた構造解析から14層周期構造であるとの報告もあり、その長周期構造は未だ明確になっていない。本研究では、M相並びに中間相(I相)の長周期構造を調べることを目的に、単結晶試料に加圧治具を用いてシングルバリアント状態にして中性子回折実験を行った。その結果、M相は10層周期ではなく、14層周期に近い長周期構造であり、I相は6層周期に近い長周期構造を有することを初めて明らかにした。
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。
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.
