著者

上杉 健太朗 鈴木 芳生

出版者

公益社団法人 日本金属学会

雑誌

まてりあ (ISSN:13402625)

巻号頁・発行日

vol.45, no.6, pp.451-455, 2006-06-20 (Released:2011-08-11)

参考文献数

26

著者

岡本 佳之 高柳 毅 釣谷 浩之 佐山 利彦 上杉 健太朗 星野 真人 長瀬 達則 森 孝男

出版者

公益財団法人 高輝度光科学研究センター

雑誌

SPring-8/SACLA利用研究成果集 (ISSN:21876886)

巻号頁・発行日

vol.3, no.2, pp.497-501, 2015-07-21 (Released:2021-01-15)

参考文献数

3

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SPring-8における放射光光源を利用したX線マイクロCT装置(SP-μCT)を用い、フリップチップのSn-Ag-Cu鉛フリーはんだ接合部を対象として、デジタル画像相関法による、ひずみ分布の非破壊計測の可能性について検証を行った。ひずみ計測の前段階として、変位ベクトルの粗探索を行った結果、Ag3Sn相のような特徴点の周囲では、比較的高い精度で、ひずみ計測を行うことができる見通しが得られた。今後、追加の実験を行うことでマイクロ接合部における新たな信頼性手法の開発が期待できる。

著者

杉山 明 安田 秀幸 柳楽 知也 吉矢 真人 上杉 健太朗 梅谷 啓二 大中 逸雄

出版者

公益社団法人 日本鋳造工学会

雑誌

鋳造工学 = Journal of Japan Foundry Engineering Society (ISSN:13420429)

巻号頁・発行日

vol.83, no.3, pp.131-136, 2011-03-25

参考文献数

11

被引用文献数

1

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It is well known that controlling the graphite shape in cast iron is a critical issue to achieve appropriate properties. It is of interest to know how the microstructure in cast iron evolves during solidification. So far, time-evolution of the microstructure has not been observed in-situ. This paper presents the in-situ observation results of cast iron solidification using X-ray imaging of synchrotron radiation. Transmission X-ray images with a spatial resolution of as small as 5<i>μ</i>m were obtained by an X-ray detector SATICON in an imaging beam line 20B2 at SPring-8. A 10 × 10 × 0.1mm specimen was melted and solidified in a mold made of Al₂O₃ placed in a vacuum chamber. The observation showed that the solidification started with austenite dendrites, after which the eutectic structure was formed. Graphite clusters of about 100<i>μ</i>m in diameter were formed in the remaining liquid surrounded by the eutectic structure at a cooling rate of less than 10K/min. At a cooling rate of 10K/min, the primary dendrite and the eutectic grains moved up and down, respectively, due to the bouncy force.

著者

杉山 明 前川 裕貴 後藤 耕太 山根 功士朗 安田 秀幸 吉矢 真人 柳楽 知也 牛込 智章 佐藤 彰洋 梅谷 啓二 上杉 健太朗

出版者

公益社団法人 日本鋳造工学会

雑誌

鋳造工学 全国講演大会講演概要集 第161回全国講演大会講演概要集 (ISSN:18805388)

巻号頁・発行日

pp.13, 2012 (Released:2017-03-01)

著者

吉中 奎貴 中村 孝 髙久 和明 塩澤 大輝 中井 善一 上杉 健太朗

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.856, pp.17-00104-17-00104, 2017 (Released:2017-12-25)

参考文献数

23

被引用文献数

2

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The initiation and growth of internal small fatigue cracks with around ten or several dozen μm in Ti-6Al-4V were nondestructively examined by using synchrotron radiation μCT at the large synchrotron radiation facility SPring-8. Lots of grain-sized internal cracks were observed roughly evenly in the observation volume in the specimen; in contrast, only one surface crack was detected. The initiation lives of the internal cracks were widely different for each crack and had no significant correlation with the crack initiation site nor the initial crack size. The internal cracks propagated microstructure-sensitively with several crack deflections, and the growth rates were very small, less than 10-10 m/cycle. The crack growth rates just after facet formations showed large variability and had no apparent relationship with the crack initiation life nor the initial crack size. This variability can likely be attributed to microstructural inhomogeneities around the crack initiation facets. The estimated facet formation rate indicated that most facets formed rapidly compared with the following internal crack growth rate.

著者

戸田 裕之 山本 信 小林 正和 小林 俊郎 Qian Lihe 上杉 健太朗

出版者

社団法人日本材料学会

雑誌

学術講演会講演論文集

巻号頁・発行日

vol.56, pp.85-86, 2007-05-18

著者

つち山 明 上杉 健太朗 中野 司

出版者

Tokyo Geographical Society

雑誌

地學雜誌 (ISSN:0022135X)

巻号頁・発行日

vol.109, no.6, pp.845-858, 2000-12-01

被引用文献数

6 6

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X-ray computerized tomography (CT) is a non-destructive method by which crosssectional images of rocks and minerals are obtained using X-ray attenuation. Threedimensional structures of samples can also be obtained by constructing a number of successive images. This review discusses high-resolution X-ray CT machines including an industrial machine in commercial use and that developed by our group at SPring-8, which is the largest synchrotron radiation facility in Japan. Spatial resolution of CT images, which is determined by X-ray detectors and X-ray beam size, is practically limited by sample size due to the limited numbers of X-ray detectors. A resolution of about 1 μm was realized at SPring-8. This resolution is the lower limit for imaging with simple optics. The contrast of an X-ray CT image is expressed as a two-dimensional distribution of CT values, which related to the X-ray linear attenuation coefficient (LAC), , μ. CT values of standard minerals were measured to compare with their values of μ. As μ is a function of X-ray photon energies, beamhardening occurs when we use polychromatic beams. Thus, we cannot compare CT and μ values directly with the industrial scanner, which aplies a polychromatic X-ray beam. If the CT and μ values are normalized by a standard mineral having similar size as samples for the photon energy or the accelerating voltage of an X-ray tube, both values agree well as long asμis less than about 2.5 × μ of Fo<SUB>92</SUB> olivine. We can compare CT and μ values directly in the SPring-8 machine, where monochromatic X-ray beams are available. In this case, normalized CT and μ values agree well in various materials havinga large μ at least including metallic iron. However, absolute CT values are slightly smaller than μ by about 10%, which is probably due to scattered X-ray beams, although the exact reason is not known at present. The high-resolution X-ray method was applied to three-dimensional structures of chondrules, which are characteristic constituents of primitive meteorites, named chondrites. It is known from external shapes and internal textures, which are related to distributions of voids and platy olivine crystals, that chondrules spin at high revolutions of about 50-500 rps during their formation in the primordial solar nebula. This greatly constrains the formation mechanism of chondrules.