Al-Cu合金における初期析出物の生成および成長
1974 年 38 巻 6 号 p. 545-552
詳細
1974 年 38 巻 6 号 p. 545-552
The precipitation process during aging at 150°C in Al-4 wt%Cu alloy was investigated by measuring the changes of hardness, electrical resistivity and X-ray Laue photographs. To elucidate the growth process of pre-percipitates, the structures of G.P. zones and θ″-phase were examined by means of high-resolution electron microscopy including the lattice image technique.
In electron micrographs, G.P. zones were observed as single black lines and θ″-phases were observed as pairs of black lines aligned in parallel with a distance of about 6 or 8 Å.
The positions of lattice fringe in (200) lattice images were measured precisely to determine the coherent strain around the precipitates. Consequently, an asymmetric strain field was found to exist around the G.P. zones and θ″-phase. The existence of such asymmetric strain field may suggest that there exists an unknown transient stage of growth in the process from G.P. zones to θ″-phase.
