Abstract
Aging behavior and structures of an Al-2.26wt%Li alloy were studied by means of hardness and electrical resistivity measurements and transmission electron microscopy. Increases in hardness and electrical resistivity are caused by homogeneous precipitation of spherical δ' phases at aging temperatures below 200° and 150°C, respectively. It is suggested that excess vacancies are almost confined in the δ' phase during aging, because of the aging structure free from dislocation loops. The phase change from δ' to δ is unlikely to occur at 250°C. The "petal-like", precipitation of δ' phase appears in the alloy directly quenched and aged at 200°C.
