Current Status of Fusion Reactor Structural Materials R&D

Abstract

Japanese activities on fusion structural materials R&D have been well organized under the coordination of university programs and JAERI/NIMS programs more than two decades. Where, two categories of structural materials have been studied, those are; reduced activation ferritic/martensitic steels (RAFs) as reference material and vanadium alloys and SiC/SiC composite materials as advanced materials. The R&D histories of these candidate materials and the present status in Japan are reviewed with the brief explanation of Japanese strategy and current status of fusion reactor engineering R&D.

Microstructure and texture evolution during accumulative roll bonding of aluminium alloy AA5086

“…Much stronger anisotropy in strength has been noted for ARB processed material with the specimen tested along 90• possesses the highest yield strength. [36][37][38][39][40][41] Strength of the specimens tested along 0• or 45• is almost the same. The ductility, on the other hand, varies with testing direction for both starting and ARB processed material.…”

“…This can be attributed to the fine grain size in the ARB processed material. It has been reported that PLC effect in AA5088 alloy weakens on reducing the grain size from 61 to 35 m and disappears altogether on further reduction to 13 m [37]. Instabilities in the post necking region for ARB processed material indicate continuous local fracture of layers before the final fracture could initiate along the last interface.…”

Friction Stir Processing of Particle Reinforced Composite Materials

“…The fusion structural materials should have good mechanical properties at high temperatures, good corrosion resistance with the coolant, be able to accommodate high heat loads, and have low levels of induced radioactivity. Vanadium alloys are under consideration for use in fusion energy systems as structural materials because they offer significant advantages over other iron based alloys in several of the areas mentioned above [ 71 , 72 ]. Extensive research in the past two decades has lead to a basic understanding of the physical, mechanical and metallurgical aspects of vanadium alloys including the effects of radiation.…”

Microstructural evolution analysis of NITE SiC/SiC composite using TEM examination and dual-ion irradiation

“…The NITE SiC/SiC composites were fabricated at Ube Co. Ltd using b-SiC nano-powder (Marketech International Inc., USA). This NITE SiC/SiC composite grade is named Pilot grade-2 [8]. The particle size of b-SiC nano-powder was below 30 nm.…”