Al-Mn-Mg-B合金におけるβ相の析出挙動に及ぼすB添加の影響

抄録

In order to investigate the effect of boron on the precipitation behavior of β phase in Al-Mn-Mg-B alloy used as a material for cask baskets, 1.00×10⁴ hours aging treatment was carried out focusing on the temperature history in the cask as in the previous report, and the Time-temperature-precipitation diagram and Supersaturation-diffusion length-precipitation diagram were evaluated using the change tendency of the specific resistance obtained. In the Al-Mn-Mg-B alloy, although grain refinement by AlB₂ was confirmed, the effect of boron addition on the precipitation rate of β phase was hardly recognized. That is to say, it was confirmed that the grain boundary and the interface between B compound and matrix phase hardly contributed as nucleation sites of β phase. In conclusion, it is considered that the reduction of the solid solution Mg content in the Al-Mn-Mg-B alloy does not occur even after 60 years if the Mg content is 1.0 mass% as in the Al-Mn-Mg alloy.