Experimental investigation of phase transformations in steel using X-ray and neutron diffraction

Tomota, Yo*; Harjo, S.; Xu, P. G.; Morooka, Satoshi; Gong, W.; Wang, Y.*

Metals, 15(6), p.610_1 - 610_19, 2025/05

https://doi.org/10.3390/met15060610

Crystal structures of ReO under hydrostatic pressure; A Combined neutron, X-ray, Raman, and first-principles calculation study

Efthimiopoulos, I.*; Klotz, S.*; Kunc, K.*; Baptiste, B.*; Chauvigne, P.*; Hattori, Takanori

Physical Review B, 111(13), p.134103_1 - 134103_13, 2025/04

https://doi.org/10.1103/PhysRevB.111.134103

We present a comprehensive study of the high pressure behaviour of ReO using X-ray and neutron diffraction, Raman scattering and first-principles calculations to 15 GPa. We show that the ambient pressure structure converts at 0.7 GPa in a continuous phase transition directly to a cubic phase with space group and rhombohedral structures in this pressure range are an artifact due to an alteration of the sample by high-flux synchrotron X-ray radiation. The structural pressure dependence of the O samples are presented. The data shed light onto the unusual transition and densification mechanism due to progressive tilting of essentially rigid ReO octahedra.

Deformation mechanism of a strong and ductile maraging steel investigated using X-ray synchrotron diffraction

Li, H.*; Liu, Y.*; Zhao, W.*; Liu, B.*; Tominaga, Aki; Shobu, Takahisa; Wei, D.*

International Journal of Plasticity, 165, p.103612_1 - 103612_20, 2023/06

https://doi.org/10.1016/j.ijplas.2023.103612

In order to clarify the strength properties of Co-free maraging steel, tensile experiment using high energy synchrotron X-ray diffraction was performed. Diffraction profiles from the martensitic and austenitic phases were obtained, and their strength and width were observed to vary as loading. Analysis of the diffraction profiles showed that the content of martensite in the as-aged material decreased slowly at low stress levels and decreased rapidly at high stress levels. On the other hand, the austenite phase in the as-solution materials was significantly transformed the martensite phase as the stress increased. It was clarified to be responsible for their respective strength properties.

Structure of the {U} polyoxo cluster UOCl(MeO) (x = 2.3, MeO = methoxide)

Fichter, S.*; Radoske, T.*; Ikeda, Atsushi

Acta Crystallographica Section E; Crystallographic Communications (Internet), 77(8), p.847 - 852, 2021/08

https://doi.org/10.1107/S2056989021007623

Thermal behavior, structure, dynamic properties of aqueous glycine solutions confined in mesoporous silica MCM-41 investigated by X-ray diffraction and quasi-elastic neutron scattering

Yoshida, Koji*; Inoue, Takuya*; Torigoe, Motokatsu*; Yamada, Takeshi*; Shibata, Kaoru; Yamaguchi, Toshio*

Journal of Chemical Physics, 149(12), p.124502_1 - 124502_10, 2018/09

https://doi.org/10.1063/1.5039892

Differential scanning calorimetry, X-ray diffraction, and quasi-elastic neutron scattering (QENS) measurements of aqueous glycine solutions confined in mesoporous silica (MCM-41) were performed at different glycine concentrations, pH, and loading ratio (= mass of glycine solution / mass of dry MCM-41) in the temperature range from 305 to 180 K to discuss the confinement effect on the thermal behavior, the structure, and the dynamic properties of the solutions.

observation of dislocation evolution in ferritic and austenitic stainless steels under tensile deformation by using neutron diffraction

Sato, Shigeo*; Kuroda, Asumi*; Sato, Kozue*; Kumagai, Masayoshi*; Harjo, S.; Tomota, Yo*; Saito, Yoichi*; Todoroki, Hidekazu*; Onuki, Yusuke*; Suzuki, Shigeru*

Tetsu To Hagane, 104(4), p.201 - 207, 2018/00

https://doi.org/10.2355/tetsutohagane.TETSU-2017-082

Effect of thermo-mechanical treatments on nano-structure of 9Cr-ODS steel

Oka, Hiroshi; Tanno, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Uwaba, Tomoyuki; Kaito, Takeji; Onuma, Masato*

Nuclear Materials and Energy (Internet), 9, p.346 - 352, 2016/12

https://doi.org/10.1016/j.nme.2016.10.007

Hydrostatic compression behavior and high-pressure stabilized -phase in -based titanium aluminide intermetallics

Liss, K.-D.*; Funakoshi, Kenichi*; Dippenaar, R. J.*; Higo, Yuji*; Shiro, Ayumi*; Reid, M.*; Suzuki, Hiroshi; Shobu, Takahisa; Akita, Koichi

Metals, 6(7), p.165_1 - 165_22, 2016/07

https://doi.org/10.3390/met6070165

Titanium aluminides find application in modern light-weight, high-temperature turbines, such as aircraft engines, but suffer from poor plasticity during manufacturing and processing. Huge forging presses enable materials processing in the 10 GPa range and hence, it is necessary to investigate the phase-diagrams of candidate materials under these extreme conditions. Here we report on an in-situ synchrotron X-ray diffraction study in a large-volume-press of a modern ( + ) two-phase material, Ti-45Al-7.5Nb-0.25C, under pressures up to 9.6 GPa and temperatures up to 1686 K. At room temperature, the volume response to pressure is accommodated by the transformation rather than volumetric strain, expressed by apparently high bulk moduli of both constituent phases. Crystallographic aspects, specifically lattice strain and atomic order are discussed in detail. It is interesting to note that this transformation takes place despite an increase in atomic volume, which is due to the high ordering energy of . Upon heating under high pressure, both the eutectoid and -solvus transition temperatures are elevated, and a third, cubic -phase is stabilized above 1350 K. Earlier research has shown that this -phase is very ductile during plastic deformation, essential in near-conventional forging processes. Here, we were able to identify an ideal processing window for near-conventional forging, while the presence of the detrimental -phase is not present under operating conditions. Novel processing routes can be defined from these findings.

Large ferroquadrupole moment induced in the octupole-ordered CeLaB revealed by high-resolution X-ray diffraction

Inami, Toshiya; Michimura, Shinji*; Hayashi, Yuya*; Matsumura, Takeshi*; Sera, Masafumi*; Iga, Fumitoshi*

Physical Review B, 90(4), p.041108_1 - 041108_5, 2014/07

https://doi.org/10.1103/PhysRevB.90.041108

We carried out a high-resolution X-ray diffraction experiment on CeLaB. This compound exhibits antiferro-octupole order (AFO) below = 1.4 K, and it is theoretically suggested that ferroquadrupole moments and a resultant rhombohedral deformation are induced in the AFO phase. We observe the splitting of Bragg reflections below and find that the unit cell is rhombohedral with the elongated [111] axis. We also precisely evaluate the magnitude of the induced quadrupole moments from the obtained shear strain and find that the quadrupole moments are not reduced in the AFO phase.

Investigations of relativistic laser plasma from micron-sized Ar clusters

Fukuda, Yuji; Yamakawa, Koichi

Progress in Ultrafast Intense Laser Science II, p.231 - 251, 2007/00

To better understand a fundamental aspect of the laser cluster interaction, we have carried out systematic investigations of X-ray radiation properties of high-density and high-temperature cluster plasma, created by the action of superintense laser irradiation. The interrelationship between the X-ray radiation properties and ion kinetic energies has been for the first time examined by the simultaneous measurements of X-ray radiation spectra and ion energy spectra. Time scale and mechanism of X-ray emission process have been discussed based on a time-dependent plasma kinetics model. Moreover, in order to demonstrate the practical capability of X-rays thus produced, the pulse X-ray diffraction has been examined from Si crystal with this source.