ABSTRACT The microstructure of an Al-Cu-Li alloy sheet is characterised in the solution treated, underaged, and peak aged tempers. Its mechanical response under uniaxial tension is measured at , , and along , , and to the rolling direction. The anisotropic stress-strain curves are interpreted using a polycrystal plasticity model, which implements three hardening modes suggested by the microstructure, viz., matrix hardening, hardening due to isotropic precipitates, and hardening due to anisotropic precipitates. Phenomenological activation theory based analysis of the work hardening suggests that the physical mechanism underlying work hardening due to anisotropic precipitates remains constant over the temperature range studied, while the mechanism underlying matrix hardening varies strongly with temperature.

中文翻译：

---

Al-Cu-Li合金塑性和断裂的温度依赖性

摘要 Al-Cu-Li 合金板的显微组织具有固溶处理、欠时效和峰值时效回火的特征。其在单轴拉伸下的机械响应在 、 、 和沿 、 、 和轧制方向测量。使用多晶塑性模型解释各向异性应力-应变曲线，该模型实现了微观结构建议的三种硬化模式，即基体硬化、各向同性析出物引起的硬化和各向异性析出物引起的硬化。基于现象学激活理论的加工硬化分析表明，各向异性析出物引起加工硬化的物理机制在所研究的温度范围内保持不变，而基体硬化的机制随温度变化很大。