Refine your search:     
Report No.
 - 
Search Results: Records 1-6 displayed on this page of 6
  • 1

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Impacts of friction stir processing on irradiation effects in vacuum-plasma-spray coated tungsten

Ozawa, Kazumi; Tanigawa, Hiroyasu; Morisada, Yoshiaki*; Fujii, Hidetoshi*

Fusion Engineering and Design, 98-99, p.2054 - 2057, 2015/10

 Times Cited Count:1 Percentile:9.79(Nuclear Science & Technology)

Reduced activation ferritic/martensitic steel, as typified by F82H, is a promising candidate for structural material of DEMO fusion reactors. To prevent plasma sputtering, tungsten (W) coating was essentially required. This study aims to examine the irradiation effects on hardness and microstructure of vacuum-plasma-spray coated W-F82H steel, with a special emphasis on the impacts of grain-refining induced by frictional stir processing (FSP). It was revealed that the hardness of the VPS-FSP W after ion-irradiation to 5.4 dpa at 800$$^{circ}$$C were not remarkably changed, where bulk W usually exhibited significant irradiation hardening.

Journal Articles

Modification of vacuum plasma sprayed tungsten coating on reduced activation ferritic/martensitic steels by friction stir processing

Tanigawa, Hiroyasu; Ozawa, Kazumi; Morisada, Yoshiaki*; Noh, S.*; Fujii, Hidetoshi*

Fusion Engineering and Design, 98-99, p.2080 - 2084, 2015/10

 Times Cited Count:10 Percentile:64.82(Nuclear Science & Technology)

The vacuum plasma spray (VPS) technique has been investigated as the most practical method to form Tungsten (W) layer as a plasma facing material in fusion devices. The issues are the thermal conductivity and the strength of VPS-W, i.e., the thermal conductivity of VPS-W were significantly lower than that of the bulk W, and the hardness of VPS-W is much less than that of the bulk W. These are mainly caused by the porous structure of VPS-W. In order to solve these issues, friction stir processing (FPS) was applied on VPS-W in this study. It was suggested that FSP can contribute to significant improvement both in mechanical and thermal properties of VPS-W coating.

Oral presentation

Hardness and microstructure after ion-irradiation of vacuum-plasma-splay coated W-F82H refined by friction stir processing

Ozawa, Kazumi; Tanigawa, Hiroyasu; Morisada, Yoshiaki*; Fujii, Hidetoshi*

no journal, , 

no abstracts in English

Oral presentation

Modification of vacuum plasma sprayed tungsten coating by friction stir processing

Tanigawa, Hiroyasu; Ozawa, Kazumi; Morisada, Yoshiaki*; Fujii, Hidetoshi*; Noh, S.*

no journal, , 

no abstracts in English

Oral presentation

Applicability study of Friction-Stir Process on Cu and its irradiation resistivity

Hamaguchi, Dai; Tanigawa, Hiroyasu; Ozawa, Kazumi; Fujii, Hidetoshi*; Morisada, Yoshiaki*

no journal, , 

Friction-Stir Process were applied to OFCCu in order to evaluate the applicability of the process to mechanically strengthening pure-Cu and possible structural improvement on CuCrZr alloy. In this study, the tool rotational speed was varied from 50 to 500 rpm in order to clarify the effect of rotational speed on the process. The result showed the achievement of very fine grain structure at the rotational speed of 100 and 200 rpm and also the hardness increase to about 1.5 time higher within the stir-zone than that of the base metal at the most. However, the result also revealed that the rapid decrease of the hardness toward a depth direction and relatively shallow stir-zone depth compared to a length of the pin. This can be explained as post-annealing effect due to a good thermal conductivity of a pure-Cu. To avoid the effect, we are considering to introduce compulsory cooling system during the process, which application is more important to a CuCrZr alloy because more rapid cooling and lower thermal diffusion to base metal are required.

Oral presentation

Applicability study of Friction-Stir Process on CuCrZr-alloy

Hamaguchi, Dai; Morisada, Yoshiaki*; Fujii, Hidetoshi*; Tanigawa, Hiroyasu; Ozawa, Kazumi

no journal, , 

Friction-Stir Process (FSP) were applied to OFCCu and ITER-Gr CuCrZr cooling pipe in order to evaluate the applicability of the process to mechanically strengthening pure-Cu and possible structural improvement on CuCrZr alloy. Former study revealed that the achievement of very fine grain structure at certain rotational speed and also the hardness increase to about 1.5 time higher within the stir-zone but also relatively shallow stir-zone depth compared to a length of the pin and rapid void formations. In order to avoid this phenomenon, compulsory cooling with liquid Co$$_{2}$$ during the process was introduced, and the results showed the absence of void formation at relatively lower rational speed of around 300 RPM and also maintaining the effective stir-zone to relatively higher rotational speed compared to non-cooling tests. Similar FSP tests with compulsory cooling were also applied to ITER-Gr CuCrZr cooling pipe for divertor application. The detail will be reported on the presentation.

6 (Records 1-6 displayed on this page)
  • 1