关键词: 铝锂合金, 超塑性, 动态再结晶

Abstract: The superplastic deformation results of Al-l.91Li-l.25Cu-0.46Mg-0.21Zr alloy show that the optimum aging process is 400'C , 8h; cold rolled specimens display higher elongation (5 = 630%) than hot rolled ones do (δ5 = 550%); the optimum condition of superplastic deformation is T=550℃ , εi =3.33 × 10-3s-1 (initial strain rate). It is found out by TEM (transmission electron microscope) observations and grain boundary angle measuring that under the optimum deformation condition, dynamic recovery and dynamic recrystallization are present in the total process of superplastic deformation of Al-l.9Li-l.25Cu-0.46Mg-0.21Zr alloy, which is close to an eguilibrium. Grain boundary angle measuring results also indicate that the superplastic pre-processes of Al-I.91Li-l.25Cu-0.46Mg-0.21Zr alloy affect the grain boundary structure of the alloy. It is pointed out that the superplastic pre-processes of Al-l.91Li-l.25Cu-0.46Mg-0.21Zr alloy (aging process and rolling process) affect the strain-induced-recrystallization at early stage of superplastic deformation and superplastic properties, and dynamic recovery and dynamic recrystallization are one of the important accomodation mechanisms for grain boundary sliding in superplastic deformation.

Key words: Al-Li alloy, superplasticity, dynamic recrystallization.