1420铝锂合金超塑性行为

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3×10-4s-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=1.9MPa。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。

Superplastic behavior of 1420Al-Li alloy

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 =3×10-4s-1, 1420 Al-Li alloy showed good superplasticity, of which the maximum elongation δ=550％ and the minimum flow stress σ=1.9MPa. Furthermore, the grain microstructure 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.