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Okada, Michio*; Tsuda, Yasutaka*; Oka, Kohei*; Kojima, Kazuki*; Di
o, W. A.*; Yoshigoe, Akitaka; Kasai, Hideaki*
Scientific Reports (Internet), 6, p.31101_1 - 31101_8, 2016/08
Times Cited Count：28 Percentile：73.49(Multidisciplinary Sciences)We report results of our experimental and theoretical studies on the oxidation of Cu-Au alloy surfaces, viz., Cu
Au(111), CuAu(111), and AuCu(111), using hyperthermal O
molecular beam (HOMB). We observed strong Au segregation to the top layer of the corresponding clean (111) surfaces. This forms a protective layer that hinders further oxidation into the bulk. The higher the concentration of Au in the protective layer formed, the higher the protective efficacy. As a result, of the three Cu-Au surfaces studied, AuCu(111) is the most stable against dissociative adsorption of O, even with HOMB. We also found that this protective property breaks down for oxidations occurring at temperatures above 300 K.
Oshikawa, Takumi*; Funakoshi, Yoshihiko*; Imaoka, Hiroshi*; Yoshikawa, Kohei*; Maari, Yasutaka*; Iguchi, Masahide; Sakurai, Takeru; Nakahira, Masataka; Koizumi, Norikiyo; Nakajima, Hideo
Proceedings of 19th International Forgemasters Meeting (IFM 2014), p.254 - 259, 2014/09
ITER is a large-scale experiment that aims to demonstrate that it is possible to produce commercial energy from fusion. ITER Toroidal Field Coil Case (hereinafter referred to as "ITER TFCC") is one of the important components of ITER. The ITER TFCC materials are made of high nitrogen austenitic stainless steel and having various configurations. The ITER TFCC material which manufactured by JCFC has a complex configuration with heaver thickness than other materials. It is difficult to form near net shape to delivery configuration by ordinary open die forging method such as upset and stretching, because the ITER TFCC materials manufactured by JCFC have a complex configuration. Therefore ingot weight and lead time of machining increase when ITER TFCC materials are forged by ordinary open die forging method. Moreover, in order to get good attenuation at Ultrasonic examination, it is necessarily to make fine and uniform grain of the material. However, it is impossible to control grain size of austenitic stainless steel by heat treatment. The grain becomes fine and uniform by only forging process with suitable condition. Therefore, JCFC has studied suitable forging method to become near net shape to delivery configuration and also to get fine grain of center of the material. Based on these result, ITER TFCC materials were manufactured. This innovative forging process led to reduce the weight of ingot compared with general forging. And it had good Ultrasonic attenuation. It was confirmed that the results of material test and nondestructive examination satisfied the requirements of Japan domestic agency (hereinafter referred to as "JADA"). Moreover, the test coupons were taken from center of thick part of product and used for various tests. As the result of tests, it was confirmed that results of material test satisfied the requirements of JADA. It is clear that this innovative forging method is very suitable process for manufacturing of ITER TFCC materials.
Au(111)Oka, Kohei*; Tsuda, Yasutaka*; Makino, Takamasa*; Okada, Michio*; Hashinokuchi, Michihiro*; Yoshigoe, Akitaka; Teraoka, Yuden; Kasai, Hideaki*
Physical Chemistry Chemical Physics, 16(36), p.19702 - 19711, 2014/08
Times Cited Count：11 Percentile：40.33(Chemistry, Physical)Au(111) oxidation; Oxygen induced Cu segregation and the protective Au layer profileTsuda, Yasutaka*; Oka, Kohei*; Makino, Takamasa*; Okada, Michio*; Dio, W. A.*; Hashinokuchi, Michihiro*; Yoshigoe, Akitaka; Teraoka, Yuden; Kasai, Hideaki*
Physical Chemistry Chemical Physics, 16(8), p.3815 - 3822, 2014/02
Times Cited Count：14 Percentile：49(Chemistry, Physical)Onishi, Kazunori*; Takahashi, Yoshihiro*; Imaki, Shunsaku*; *; Yoshikawa, Masahito
Proc. of 21st Int. Symp. for Testing and Failure Analysis (ISTFA 95), 0, p.269 - 274, 1995/00
no abstracts in English
-ray radiation*; *; Takahashi, Yoshihiro*; Yoshikawa, Masahito; Onishi, Kazunori*
Denshi Joho Tsushin Gakkai Gijutsu Kenkyu Hokoku, 93(172), p.23 - 27, 1993/07
no abstracts in English
Imaki, Shunsaku*; *; Takahashi, Yoshihiro*; Yoshikawa, Masahito; Onishi, Kazunori*
Heisei-5-Nendo (Dai-37-Kai) Nihon Daigaku Riko Gakubu Gakujutsu Koenkai Koen Rombunshu; Zairyo, Bussei, p.135 - 136, 1993/00
no abstracts in English
Au(111) oxidationTsuda, Yasutaka*; Makino, Takamasa*; Hashinokuchi, Michihiro*; Okada, Michio*; Oka, Kohei*; Dio, W. A.*; Kasai, Hideaki*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
Au(111) surfaceTsuda, Yasutaka*; Oka, Kohei*; Makino, Takamasa*; Lehmuskoski, J.*; Okada, Michio*; Dio, W. A.*; Kasai, Hideaki*; Yoshigoe, Akitaka; Teraoka, Yuden
no journal, ,
no abstracts in English
Okamoto, Yoshihiro; Masuno, Atsunobu*; Owaku, Kohei*; Tsukada, Takeshi*; Kanehira, Norio*
no journal, ,
In the development of vitrification technology for high burnup fuel and MOX fuel, tests using various compositions of raw glass materials were conducted to find the optimum composition. The Si/B ratio and the amount of alkali in the raw glass, and even the loading ratio of waste components were varied. In this study, we summarize the composition dependence obtained by structural analysis of those samples.
