[Table of Contents]

Plasma and Fusion Research

Volume 9, 3405069 (2014)

Regular Articles

Effect of Heat Cycling on Microstructure and Thermal Property of Boron Carbide Sintered Bulk as a Shielding Material for Fusion Blanket
Yoshimitsu HISHINUMA, Megumi AKOSHIMA1), Yuichiro YAMASHITA1), Teruya TANAKA, Akio SAGARA and Takeo MUROGA
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
1)
National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba 305-8563, Japan
(Received 10 December 2013 / Accepted 5 March 2014 / Published 10 June 2014)

Abstract

In the Force Free Helical Reactor (FFHR) design activity in NIFS, metallic carbides and hydrides are considered as candidate shielding materials for the fusion blankets. These materials are expected to have some advantages on neutronic and thermo-physical properties. In order to promote the blanket design, it is necessary to clarify thermal properties of the candidate materials. We studied microstructure and thermal property of boron carbide (B4C), which is one of the promising candidates shielding materials, including the effect of heat cycling. By the laser-flash method, thermal diffusivity, which is one of the properties necessary for evaluating thermal conductivity, was measured precisely for B4C samples. The thermal diffusivity of B4C around 200 ° C decreased to 1/3 (5 × 10−6 m2 S−1) compared with that at room temperature. The sintering density of B4C bulk was decreased slightly by the thermal cycling. It was suggested that the B4C bulk has high thermal stability and soundness of microstructure during the life-time of blanket system.

Keywords

shielding material, boron carbide, thermo-physical property, laser-flash method, thermal cycling

DOI: 10.1585/pfr.9.3405069

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This paper may be cited as follows:

Yoshimitsu HISHINUMA, Megumi AKOSHIMA, Yuichiro YAMASHITA, Teruya TANAKA, Akio SAGARA and Takeo MUROGA, Plasma Fusion Res. 9, 3405069 (2014).