Abstract The accurate prediction of residual stress for as-quenched Al-Cu-Mg alloy requires profound knowledge on the materials' constitutive behavior. In present work, the flow stress of as-quenched Al-Cu-Mg alloy is modelled using a dislocation density based model which considers the influences of precipitation, solid solution and forest dislocation. The radii and volume fractions of precipitates at different cooling rates and temperatures are predicted by a multi-class precipitation kinetics model. Parameters of the constitutive model are obtained by calibration using isothermal tensile tests. The model predictions are in good agreement with experimental data in terms of the flow stress and volume fraction evolution. The results show that volume fraction of precipitates decreases with the increasing temperature and cooling rate, in contrast to the increasing trend for radius of precipitates. The quench-induced precipitates have an influence only on the magnitudes of flow stress at low temperatures. However, for the large precipitates, the dislocation loops, i.e. geometrically necessary dislocations (GND's), can influence both the strain hardening rates and magnitudes of flow stress.

中文翻译：

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考虑淬火诱发析出物的Al-Cu-Mg合金淬火时位错密度模型

摘要 准确预测淬火态Al-Cu-Mg合金的残余应力需要深入了解材料的本构行为。在目前的工作中，使用基于位错密度的模型对淬火态 Al-Cu-Mg 合金的流动应力进行建模，该模型考虑了沉淀、固溶和森林位错的影响。不同冷却速率和温度下沉淀物的半径和体积分数由多级沉淀动力学模型预测。本构模型的参数是通过使用等温拉伸试验进行校准而获得的。在流动应力和体积分数演变方面，模型预测与实验数据非常一致。结果表明，随着温度和冷却速度的增加，析出物的体积分数降低，与沉淀半径的增加趋势相反。淬火诱发的析出物仅对低温下的流动应力大小有影响。然而，对于大的析出物，位错环，即几何上必要的位错 (GND's)，会影响应变硬化速率和流变应力的大小。