Microstructure and strength of the material joining austenitic steel and insulating ceramics which is favorite for nuclear fusion reactors

For the purpose of elucidating the possibility of applying the materials joining metals and ceramics to nuclear fusion reactors, the materials joining stainless steel JPCA and insulating ceramics Al2O3 and ZrO2 which are favorite for nuclear fusion reactors were made by solid phase diffusion process, and the strength was measured, at the same time, the factors which determine the strength were clarified by the observation of the internal structures. Based on this, the way of improving materials taking insert materials and formed reaction layers in consideration was shown. Moreover, by the irradiation to the vicinity of the interface of metals and ceramics, the formation of the characteristic dislocation loops was observed. In nuclear fusion reactors, the possibility of use for the first wall, window materials and insulators has been considered for ceramics. They have the merits of high melting point, low radioactivation and low atomic number, and the defects of low heat conductivity, small toughness, high price and difficulty of working. The methods of joining metals and ceramics are discussed. The experimental method and the results are reported. (K.I.)