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Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Kawai, Jun*; Yabuta, Naohiro*; Furuya, Shunsuke*; Sugiyama, Naoki*
JNC TJ1400 2005-021, 350 Pages, 1998/02
Kawai, Jun*; Yabuta, Naohiro*; Furuya, Shunsuke*; Aoki, Norikatsu*
JNC TJ1400 2005-024, 139 Pages, 1995/03
Wakai, Eiichi; Noto, Hiroyuki*; Shibayama, Tamaki*; Nakagawa, Yuki*; Ishida, Taku*; Makimura, Shunsuke*; Wakui, Takashi; Furuya, Kazuyuki*; Ando, Masami*
no journal, ,
In the fields of energy, nuclear power, high-energy accelerator target systems, nuclear fusion, and biology, radiation causes degradation of materials and equipment, and thus it is expected to create new materials with high durability and superior functionality. In this study, for Fe-, Ti-, and W-based high-entropy alloys (HEA) composed of low activation elements (Ni and Co free), Fe-based alloys were prepared by radio frequency melting, Ti-based alloys by cold crucible levitation melting, and W-based alloys by arc melting using metal powders. These materials were tested by X-ray diffraction, microstructural observation, hardness measurement, magnetic measurement, electrical resistivity measurement, scanning transmission electron microscope STEM (or TEM, SEM) and energy dispersive X-ray spectroscopy, ultrasonic measurement, and hot isostatic pressing (HIP) method. These HEAs were found to be much harder than normal alloys, and in Fe-based HEAs, the magnetic properties and related microstructural analysis showed that they have interesting characteristics such as micro magnetic domain structures. In particular, for Fe- and W-based HEAs, the changes in crystal structure, orientation, and internal microstructure caused by HIP treatment and the accompanying effects of high temperature and pressure have been found to have a significant effect on magnetic properties and material strength properties.
Wakai, Eiichi; Shibayama, Tamaki*; Noto, Hiroyuki*; Furuya, Kazuyuki*; Iwamoto, Yosuke; Wakui, Takashi; Makimura, Shunsuke*; Ishida, Taku*; Ando, Masami*; Sato, Koichi*; et al.
no journal, ,
In fields such as nuclear power and high-energy accelerator target systems, radiation causes degradation of materials and equipment, so materials with high durability and excellent functionality are expected to be created. High-entropy alloys (HEA) are expected to have high irradiation resistance and often have high strength and good ductility. In recent years, research and development is underway worldwide for various applications. In this study, Fe- and Ti-based and W-based HEAs composed of low activation elements (free of Ni and Co) were fabricated. These materials were subjected to X-ray diffraction, microstructural observation, hardness, magnetism, electrical resistance, STEM (or TEM, SEM) and EDS, ultrasonic measurements, and hot isostatic pressing (HIP). Ion irradiation, pulsed laser irradiation, and pulsed electron beam irradiation were also performed on some of the samples to investigate their response characteristics. These HEAs were much harder than normal alloys, and the magnetic properties and related microstructural analysis of Fe-based HEAs revealed that they have interesting properties such as micro magnetic domain structures. In particular, for Fe- and W-based HEAs, the changes in crystal structure, orientation, and internal microstructure induced by HIP treatment and the accompanying effects of high temperature and pressure had a significant effect on magnetic properties and material strength properties. Furthermore, the irradiation response properties of Fe-based HEAs have been characterized.
Wakai, Eiichi; Noto, Hiroyuki*; Makimura, Shunsuke*; Ishida, Taku*; Furuya, Kazuyuki*; Shibayama, Tamaki*
no journal, ,
Recently, high-entropy alloys have been vigorously researched and developed by research institutes around the world because of their higher strength and ductility than conventional materials due to their atomic mixing ratio and composition. In this study, titanium-based high-entropy alloys (HEAs), TiVCrZrTa, TiVZrTaAl, and TiVCrZrW, were melted by the cold crucible surface melting method and subjected to homogenization heat treatment at 1200
C for 5 hours. Mechanical property tests and properties of these HEAs were investigated, and it was found that the TiVCrZrTa HEAs have relatively better hot-rollability and hot-forgeability than other titanium-based HEAs. The Vickers hardness of these titanium-based HEAs was also found to be considerably higher than that of normal titanium alloys.
-phase based titanium alloysWakai, Eiichi; Ishida, Taku*; Kano, Sho*; Shibayama, Tamaki*; Sato, Koichi*; Noto, Hiroyuki*; Makimura, Shunsuke*; Furuya, Kazuyuki*; Yabuuchi, Atsushi*; Yoshiie, Toshimasa*; et al.
no journal, ,
Titanium materials have been applied to beam window materials and beam dumps in large accelerator systems because of their low specific gravity, high corrosion resistance, strength, and other advantages. As the beam power becomes higher, further improvement of irradiation resistance is required. We have investigated further the properties of titanium alloys based on the -phase, and it was found that Ti-15-3-3-3 alloys have excellent irradiation resistance when subjected to ion irradiation. In order to investigate the cause of this, microstructures and point defects in this and related materials were evaluated by TEM, positron lifetime measurement, electrical resistivity, and stress-induced changes, among others. In addition, we have recently begun to develop a prototype of a titanium-based high-entropy alloy based on -titanium, which is attracting worldwide attention and is being developed, and have also begun to evaluate the emotional properties of this alloy. We have examined the various properties of this material and found that it has considerably higher strength than conventional iron- and titanium-based materials.
Wakai, Eiichi; Noto, Hiroyuki*; Shibayama, Tamaki*; Iwamoto, Yosuke; Ishida, Taku*; Sato, Koichi*; Yabuuchi, Atsushi*; Yoshiie, Toshimasa*; Takahashi, Toshiharu*; Kobayashi, Yasuhiro*; et al.
no journal, ,
In recent years, it has been reported that high-entropy alloys (HEA) have high strength but good ductility, and they are being researched and developed by cutting-edge research institutions around the world with the aim of finding various applications in progress. In this study, we considered several Fe-based, W-based, and Ti-based HEAs, excluding Co and Ni elements, in order to aim for use in high radiation fields and considering low-activation properties. These materials mainly have a bcc crystal structure and were fabricated using a melting method and their material properties were evaluated. As a result, it was found that Fe-based HEA has properties that exceed the hardness of pure W and has excellent irradiation resistance. In addition, a Ti-based HEA that can be subjected to high-temperature forging and high-temperature rolling has been found, and evaluation of the optimal heat treatment temperature is progressing. The hardness of W-based HEA increased through Hot Isostatic Pressing (HIP) treatment, and it was found to have the world's highest hardness among HEA materials.
