中文摘要：

以1420铝锂合金作为实验材料，通过改变应变速率来探求最佳的超塑性变形条件，即延伸率大幅度提高和获得变形均匀的细小微观组织。研究发现当温度为480℃，应变速率为3×10-4 s -1时可以获得最佳超塑性变形状态，此时延伸率δ＝550％，流变应力σ＝1．9 MPa。同时通过金相分析以及 TEM 微观组织观察发现，在此条件下的组织等轴性好同时晶粒分布细小均匀，出现了细小的再结晶亚晶粒，有助于超塑性变形的进行。

英文摘要：

1420Al-Li alloy was used to explore the best deformation results including high elongation, uniform, and fine-grain structure by changing deformation temperature and strain rate.The results showed that, on the condition of deflection temperature T =480 ℃ and strain rate .ε =3 ×10 -4 s -1 , 1420 Al-Li alloy showed good superplasticity, of which the maximum elongation δ =550% and the minimum flow stress σ=1.9 MPa.Furthermore, the grain micro-structure was isometric and fine after superplastic deformation through metallurgical analysis and TEM microstructure observation.Besides, the re-crystallization grains appeared which could promote the super-plastic deformation process during the deformation.