材料期刊网

The microstructure of hot-rolled AEREX350 alloy under various heat treatments was investigated by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is found that with increasing temperature, η phase precipitated firstly at grain boundaries in parallel at 800℃ and then began precipitating within grains at about 980℃. The η phase precipitating at grain boundaries played a role on preventing the migration of grain boundaries, and that precipitating within grains would develop as Widmanstätten structure with further increasing temperature. Both η phase dissolved at the temperature between 1085℃ and 1095℃, resulting in grain growth promptly due to release of pinning effect on grain boundaries. γ′ phase precipitated during the process of air cooling after hot-roll, and dissolved at temperature between 1010℃ and 1020℃.