In situ neutron diffraction study of strain evolution and load partitioning during elevated temperature tensile test in HIP-Treated electron beam powder bed fusion manufactured Ti-6Al-4V

Pandian, K.*; Neikter, M.*; Ekh, M.*; Harjo, S.; Kawasaki, Takuro; Woracek, R.*; Hansson, T.*; Pederson, R.*

JOM, 77(4), p.1803 - 1815, 2025/04

https://doi.org/10.1007/s11837-025-07128-1

A Lightweight shape-memory alloy with superior temperature-fluctuation resistance

Song, Y.*; Xu, S.*; Sato, Shunsuke*; Lee, I.*; Xu, X.*; Omori, Toshihiro*; Nagasako, Makoto*; Kawasaki, Takuro; Kiyanagi, Ryoji; Harjo, S.; et al.

Nature, 638, p.965 - 971, 2025/02

https://doi.org/10.1038/s41586-024-08583-7

Strain analysis by neutron diffraction on NbSn strands in ITER central solenoid conductors of short and long twist pitch

Suwa, Tomone*; Isono, Takaaki*; Harjo, S.; Kawasaki, Takuro; Aizawa, Kazuya

Superconductor Science and Technology, 38(1), p.015008_1 - 015008_8, 2024/12

https://doi.org/10.1088/1361-6668/ad9417

Deformation behavior of ultrafine-grained TRIP steel observed by neutron diffraction

Harjo, S.; Mao, W.*; Gong, W.; Kawasaki, Takuro

Proceedings of the 7th International Symposium on Steel Science (ISSS 2024), p.205 - 208, 2024/11

https://doi.org/10.2355/isijisss.2024.0_205

Polarized and unpolarized neutron scattering for magnetic materials at the triple-axis spectrometer PONTA in JRR-3

Nakajima, Taro*; Saito, Hiraku*; Kobayashi, Naoki*; Kawasaki, Takuro; Nakamura, Tatsuya; Furukawa, Hazuki*; Asai, Shinichiro*; Masuda, Takatsugu*

Journal of the Physical Society of Japan, 93(9), p.091002_1 - 091002_5, 2024/09

https://doi.org/10.7566/JPSJ.93.091002

Stress evaluation using multi-peaks

Harjo, S.; Gong, W.; Kawasaki, Takuro

Nihon Zairyo Gakkai Dai-58-Kai X Sen Zairyo Kyodo Ni Kansuru Shimpojiumu Koen Rombunshu, p.51 - 54, 2024/07

Microscopic insights of the extraordinary work-hardening due to phase transformation

Ma, Y.*; Naeem, M.*; Zhu, L.*; He, H.*; Sun, X.*; Yang, Z.*; He, F.*; Harjo, S.; Kawasaki, Takuro; Wang, X.-L.*

Acta Materialia, 270, p.119822_1 - 119822_13, 2024/05

https://doi.org/10.1016/j.actamat.2024.119822

Mechanical stability of retained austenite and texture evolution in additively manufactured stainless steel

Chae, H.*; Huang, E.-W.*; Jain, J.*; Lee, D.-H.*; Harjo, S.; Kawasaki, Takuro; Lee, S. Y.*

Metals and Materials International, 30(5), p.1321 - 1330, 2024/05

https://doi.org/10.1007/s12540-023-01575-8

neutron diffraction revealing the achievement of excellent combination of strength and ductility in metastable austenitic steel by grain refinement

Mao, W.; Gong, W.; Harjo, S.; Morooka, Satoshi; Gao, S.*; Kawasaki, Takuro; Tsuji, Nobuhiro*

Journal of Materials Science & Technology, 176, p.69 - 82, 2024/03

https://doi.org/10.1016/j.jmst.2023.07.036

The yield stress of Fe-24Ni-0.3C (wt.%) metastable austenitic steel increased 3.5 times (158 551 MPa) when the average grain size decreased from 35 m (coarse-grained [CG]) to 0.5 m (ultrafine-grained [UFG]), whereas the tensile elongation was kept large (0.87 0.82). neutron diffraction measurements of the CG and UFG Fe-24Ni-0.3C steels were performed during tensile deformation at room temperature to quantitatively elucidate the influence of grain size on the mechanical properties and deformation mechanisms. The initial stages of plastic deformation in the CG and UFG samples were dominated by dislocation slip, with deformation-induced martensitic transformation (DIMT) also occurring in the later stage of deformation. Results show that grain refinement increases the initiation stress of DIMT largely and suppresses the rate of DIMT concerning the strain, which is attributed to the following effects. (i) Grain refinement increased the stabilization of austenite and considerably delayed the initiation of DIMT in the 111//LD (LD: loading direction) austenite grains, which were the most stable grains for DIMT. As a result, most of the 111//LD austenite grains in the UFG specimens failed to transform into martensite. (ii) Grain refinement also suppressed the autocatalytic effect of the martensitic transformation. Nevertheless, the DIMT with the low transformation rate in the UFG specimen was more efficient in increasing the flow stress and more appropriate to maintain uniform deformation than that in the CG specimen during deformation. The above phenomena mutually contributed to the excellent combination of strength and ductility of the UFG metastable austenitic steel.

Microstructure and plasticity evolution during Lders deformation in an Fe-5Mn-0.1C medium-Mn steel

Koyama, Motomichi*; Yamashita, Takayuki*; Morooka, Satoshi; Sawaguchi, Takahiro*; Yang, Z.*; Hojo, Tomohiko*; Kawasaki, Takuro; Harjo, S.

Tetsu To Hagane, 110(3), p.197 - 204, 2024/02

https://doi.org/10.2355/tetsutohagane.TETSU-2023-038