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Ramadhan, R. S.*; Glaser, D.*; 祖山 均*; Kockelmann, W.*; 篠原 武尚; Pirling, T.*; Fitzpatrick, M. E.*; Tremsin, A. S.*
Acta Materialia, 239, p.118259_1 - 118259_12, 2022/10
被引用回数：3 パーセンタイル：45.58(Materials Science, Multidisciplinary)Mechanical surface treatment technologies such as laser peening and cavitation peening require detailed characterization, including residual stress analysis, to optimize their processing parameters. Recent developments at neutron facilities allow non-destructive 2-dimensional residual strain mapping through Bragg edge imaging. The present work highlights the application of Bragg edge neutron imaging for the study of mechanical surface treatments, through determination of lattice spacing distributions by energy-resolved radiography. Through three different examples, the unique capabilities of the method are demonstrated, particularly for providing near surface residual strain maps within samples with complex geometries with relatively high spatial resolution. By providing a comparison with X-ray diffraction and neutron diffraction results, the present work emphasizes the potential of Bragg edge neutron imaging as a tool for surface treatment research.
Busi, M.*; Polatidis, E.*; Malamud, F.*; Kockelmann, W.*; Morgano, M.*; Kaestner, A.*; Tremsin, A.*; Kalentics, N.*; Log
, R.*; Leinenbach, C.*; et al.
Physical Review Materials (Internet), 6(5), p.053602_1 - 053602_8, 2022/05
被引用回数：7 パーセンタイル：71.37(Materials Science, Multidisciplinary)In this work we perform a neutron Bragg edge tomography of stainless steel 316L additive manufacturing samples, one as built via standard laser powder bed fusion, and one using the novel three-dimensional (3D) laser shock peening technique. First, we consider conventional attenuation tomography of the two samples by integrating the signal for neutron wavelengths beyond the last Bragg edge, to analyze the bulk density properties of the material. Second, we obtain strain maps for each of the tomography projections by tracking the wavelength of the strongest Bragg edge corresponding to the {111} lattice plane family. It is found that not only the volume of the sample where the shock peening treatment was carried out yields a higher bulk density, but also a deep and remarkable compressive strain region.
Zhang, S. Y.*; Godfrey, E.*; Kockelmann, W.*; Paradowska, A.*; Bull, M. J.*; Korsunsky, A. M.*; Abbey, B.*; 徐 平光; 友田 陽*; Liljedahl, D.*; et al.
Materials Today, 12(7-8), p.78 - 84, 2009/07
被引用回数：19 パーセンタイル：51.2(Materials Science, Multidisciplinary)中性子回折は格子面間隔の精密評価に基づいて結晶材料内部の弾性歪みを直接測定できる。無材料除去のままで実際部品の内部組織や変形因子の変化などを非破壊測定的に評価するため、この技術は現代工程材料の設計や古代器物の材料考古学などの分野に特に有効である。本文はISIS核破砕型パルス中性子源に備えたEngin-X中性子回折装置における多数代表性試験研究にめぐって、中性子回折技術は材料科学の深入解明から産業への実際利用まで有効な基礎実験手法であることを示した。
徐 平光; 伊藤 崇芳*; Harjo, S.; 秋田 貢一; 相澤 一也; Vogel, S. C.*; Kockelmann, W.*
no journal, ,
Neutron diffraction may easily obtain the bulk information of various materials from the ex-situ/in-situ stress/strain change, the crystallographic structure evolution to the crystallographic preferred orientation rotation because of high penetrability of neutron beams. Though two angle dispersive diffractometers have been upgraded at JAEA for bulk texture evaluation of coarse-grained materials, structure-anisotropic materials, low symmetric materials as well as various metallic materials, the measurement speed is slow which makes it difficult to carry out in situ texture measurements. In order to improve measurement efficiency and increase the accessibility for general users, the time-of-flight neutron diffraction bulk texture evaluation technique is being developed urgently. Here, our bulk texture measurement research and development activities on TAKUMI will be introduced, including our recent experiment results using overseas time-of-flight neutron diffraction facilities.
