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利用圆柱样品轴对称等温压缩实验研究了2091Al-Li合金高温塑性变形组织特征,分析了合金在变形过程中的组织变化规律。试验应变速率和温度范围分别为10-3~10.0s-1和300~500℃。结果表明,2091合金在高温塑性变形时主要形成亚晶组织。随变形温度升高和应变速率降低,亚晶尺寸增大,亚晶界处的位错排列更为简单和完整。变形时的软化机制主要为动态回复,动态再结晶只在较高的温度和较低的应变速率情况下才出现。仅发生动态回复时形成的平均亚晶尺寸和变形条件之间满足HallPetch关系。
Axial-symmetric isothermal compression experiments of cylindrical samples were used to study the microstructures of 2091Al-Li alloy at high temperature. The microstructures of 2091Al-Li alloy during deformation were analyzed. The test strain rate and temperature range were 10-3 ~ 10.0s-1 and 300 ~ 500 ℃, respectively. The results show that 2091 alloy mainly forms subgrain at the high temperature plastic deformation. As the deformation temperature increases and the strain rate decreases, the size of the subgrains increases, and the dislocation arrangement at the subgrain boundaries is simple and complete. The softening mechanism during deformation is mainly dynamic response, dynamic recrystallization occurs only at higher temperatures and lower strain rates. The HallPetch relationship is satisfied between the average subgrain size and the deformation conditions that occur only when a dynamic response occurs.